TY - JOUR TI - Flood resilience loci SUBMERGENCE 1 and ANAEROBIC GERMINATION 1 interact in seedlings established underwater AU - Alam, Rejbana AU - Hummel, Maureen AU - Yeung, Elaine AU - Locke, Anna M. AU - Ignacio, John Carlos I. AU - Baltazar, Miriam D. AU - Jia, Zhenyu AU - Ismail, Abdelbagi M. AU - Septiningsih, Endang M. AU - Bailey‐Serres, Julia T2 - Plant Direct AB - Abstract Crops with resilience to multiple climatic stresses are essential for increased yield stability. Here, we evaluate the interaction between two loci associated with flooding survival in rice ( Oryza sativa L.). ANAEROBIC GERMINATION 1 ( AG1 ), encoding TREHALOSE 6‐PHOSPHATE PHOSPHATASE 7 ( TPP7 ), promotes mobilization of endosperm reserves to enhance the elongation of a hollow coleoptile in seeds that are seeded directly into shallow paddies. SUBMERGENCE 1 ( SUB1 ), encoding the ethylene‐responsive transcription factor SUB1A‐1 , confers tolerance to complete submergence by dampening carbohydrate catabolism, to enhance recovery upon desubmergence. Interactions between AG1/TPP7 and SUB1/SUB1A‐1 were investigated under three flooding scenarios using four near‐isogenic lines by surveying growth and survival. Pyramiding of the two loci does not negatively affect anaerobic germination or vegetative‐stage submergence tolerance. However, the pyramided AG1 SUB1 genotype displays reduced survival when seeds are planted underwater and maintained under submergence for 16 d. To better understand the roles of TPP7 and SUB1A‐1 and their interaction, temporal changes in carbohydrates and shoot transcriptomes were monitored in the four genotypes varying at the two loci at four developmental timeponts, from day 2 after seeding through day 14 of complete submergence. TPP7 enhances early coleoptile elongation, whereas SUB1A‐1 promotes precocious photoautotrophy and then restricts underwater elongation. By contrast, pyramiding of the AG1 and SUB1 slows elongation growth, the transition to photoautotrophy, and survival. mRNA‐sequencing highlights time‐dependent and genotype‐specific regulation of mRNAs associated with DNA repair, cell cycle, chromatin modification, plastid biogenesis, carbohydrate catabolism and transport, elongation growth, and other processes. These results suggest that interactions between AG1/TPP7 and SUB1/SUB1A‐1 could impact seedling establishment if paddy depth is not effectively managed after direct seeding. DA - 2020/7// PY - 2020/7// DO - 10.1002/pld3.240 VL - 4 IS - 7 J2 - Plant Direct LA - en OP - SN - 2475-4455 2475-4455 UR - http://dx.doi.org/10.1002/pld3.240 DB - Crossref ER - TY - ER - TY - JOUR TI - Increased nitrogen fixation and remobilization may increase seed protein without a yield penalty in a soybean introgression line AU - Locke, Anna M. AU - Ramirez, Martha E. T2 - Journal of Crop Improvement AB - Development of soybean [Glycine max (L.) Merr.] varieties with high seed protein concentration are hindered by a negative correlation between seed protein and yield. “Benning HP,” a genotype that breaks this tradeoff, contains an introgressed high-protein allele. Field and growth chamber experiments were conducted to identify N flux(es) that enable Benning HP’s increased seed protein without a yield penalty. When the N source was completely controlled, Benning HP could fix more N than its recurrent parent, but this depended on the rhizobium strain and plant developmental stage. In the field, Benning HP remobilized N from its leaves at a higher rate than its recurrent parent during seed fill in only one of the years studied. These results demonstrate that Benning HP has higher potential N fixation and N remobilization from vegetative tissue compared to its lower protein parent, but the expression of those traits may depend on environment and sink control. DA - 2020/10/28/ PY - 2020/10/28/ DO - 10.1080/15427528.2020.1835771 VL - 35 IS - 4 SP - 486-507 J2 - Journal of Crop Improvement LA - en OP - SN - 1542-7528 1542-7536 UR - http://dx.doi.org/10.1080/15427528.2020.1835771 DB - Crossref ER - TY - JOUR TI - The Impact of Water Loss by Evaporation and Calcite Precipitation on the Sodium Adsorption Ratio (SAR) and an Alternative Method of Estimating the SAR of Irrigation Drainage Water AU - Zhou, Qiyu AU - Bleam, William AU - Soldat, Douglas T2 - [] AB - Soil water loss by evaporation influences the sodium adsorption ratio (SAR) of irrigation drainage water. Evaporation concentrates sodium and magnesium but calcite precipitation has a more complicated effect on soluble calcium and alkalinity. Here we propose a revised sodicity hazard assessment that quantifies the impact of evaporative water loss and calcite precipitation on drainage water SAR. This paper shows sodicity hazard is determined by the initial composition of irrigation water as originally suggested by previous researchers, and provide a simple, accurate way to identify the potential sodicity hazard of any irrigation water. In particular, the initial equivalent concentration of alkalinity and calcium determine the salinization pathway followed during evaporation. If the irrigation water alkalinity exceeds soluble calcium expressed as equivalent concentrations, drainage water SAR approaches an upper limit determined by the initial relative concentration of sodium and magnesium. If irrigation water alkalinity is less than soluble calcium, drainage water SAR approaches a lower limit determined by the initial calcium, magnesium and sodium. In both cases the SAR is scaled by the square root of the concentration factor &radic;Fc quantifying soil water loss. To assess the impact of evaporation and calcite precipitation on the SAR and test the accuracy of the new sodicity hazard assessment, we evaluated data from previously published lysimeter studies. We plotted water composition boundaries for each source water, comparing these boundaries to the drainage water composition recorded in the lysimeter studies. As salinity increased by evaporation, each drainage water followed a distinct salinization path. DA - 2020/10/9/ PY - 2020/10/9/ DO - 10.20944/preprints202010.0187.v1 VL - 10 UR - http://dx.doi.org/10.20944/preprints202010.0187.v1 ER - TY - JOUR TI - Agronomic efficiency of organomineral fertilizer in sequential grain crops in southern Brazil AU - Mumbach, Gilmar L. AU - Gatiboni, Luciano C. AU - Bona, Fabiano D. AU - Schmitt, Djalma E. AU - Corrêa, Juliano C. AU - Gabriel, Camila A. AU - Dall'Orsoletta, Daniel J. AU - Iochims, Daniel A. T2 - Agronomy Journal AB - Abstract The use of organomineral fertilizers in agriculture instead of mineral fertilizers is a way to add organic compounds to the soil, potentially improving its properties and crop production. Our objective was to evaluate the agronomic efficiency of an organomineral fertilizer manufactured from poultry litter and mineral fertilizers. The experiment was carried out in a Humic Cambisol in the subtropical region of Brazil, with high organic matter content, low phosphorus content, and very high potassium content. The study consisted of six treatments: mineral fertilizer (monoammonium phosphate, KCl, and urea), at rates of 100 and 150% of the technical recommendation; organic fertilizer (poultry litter), at 100% rate; organomineral fertilizer (poultry litter + monoammonium phosphate), at rates of 100 and 150%; and control treatment (without fertilization). Between 2015 and 2017, common bean ( Phaseolus vulgaris ), wheat ( Triticum aestivum L.), and corn ( Zea mays L.) were sequentially cultivated. Before performing the experiment and at the end of the fourth crop, chemical properties of the soil were analyzed in the 0‐ to 10‐ and 10‐ to 20‐cm layers. The use of fertilizers increased crop yield, but there was no difference between the three fertilizer sources or between the 100 and 150% rates of the technical recommendation. Chemical properties of the soil were altered in a similar manner with fertilization, regardless of the fertilizer source used. According to the results, the organomineral fertilizer can replace mineral fertilizers with equivalent performance. DA - 2020/7// PY - 2020/7// DO - 10.1002/agj2.20238 UR - https://doi.org/10.1002/agj2.20238 ER - TY - JOUR TI - Ten Years of the Maize Nested Association Mapping Population: Impact, Limitations, and Future Directions AU - Gage, Joseph L. AU - Monier, Brandon AU - Giri, Anju AU - Buckler, Edward S. T2 - The Plant Cell AB - Abstract It has been just over a decade since the release of the maize (Zea mays) Nested Association Mapping (NAM) population. The NAM population has been and continues to be an invaluable resource for the maize genetics community and has yielded insights into the genetic architecture of complex traits. The parental lines have become some of the most well-characterized maize germplasm, and their de novo assemblies were recently made publicly available. As we enter an exciting new stage in maize genomics, this retrospective will summarize the design and intentions behind the NAM population; its application, the discoveries it has enabled, and its influence in other systems; and use the past decade of hindsight to consider whether and how it will remain useful in a new age of genomics. DA - 2020/7// PY - 2020/7// DO - 10.1105/tpc.19.00951 VL - 32 IS - 7 SP - 2083-2093 UR - http://dx.doi.org/10.1105/tpc.19.00951 ER - TY - JOUR TI - A Maize Practical Haplotype Graph Leverages Diverse NAM Assemblies AU - Franco, Jose A. Valdes AU - Gage, Joseph L. AU - Bradbury, Peter J. AU - Johnson, Lynn C. AU - Miller, Zachary R. AU - Buckler, Edward S. AU - Romay, M. Cinta T2 - [] AB - Abstract As a result of millions of years of transposon activity, multiple rounds of ancient polyploidization, and large populations that preserve diversity, maize has an extremely structurally diverse genome, evidenced by high-quality genome assemblies that capture substantial levels of both tropical and temperate diversity. We generated a pangenome representation (the Practical Haplotype Graph, PHG) of these assemblies in a database, representing the pangenome haplotype diversity and providing an initial estimate of structural diversity. We leveraged the pangenome to accurately impute haplotypes and genotypes of taxa using various kinds of sequence data, ranging from WGS to extremely-low coverage GBS. We imputed the genotypes of the recombinant inbred lines of the NAM population with over 99% mean accuracy, while unrelated germplasm attained a mean imputation accuracy of 92 or 95% when using GBS or WGS data, respectively. Most of the imputation errors occur in haplotypes within European or tropical germplasm, which have yet to be represented in the maize PHG database. Also, the PHG stores the imputation data in a 30,000-fold more space-efficient manner than a standard genotype file, which is a key improvement when dealing with large scale data. DA - 2020/8/31/ PY - 2020/8/31/ DO - 10.1101/2020.08.31.268425 VL - 8 UR - http://dx.doi.org/10.1101/2020.08.31.268425 ER - TY - JOUR TI - Genetic variation for plant growth traits in a common wheat population is dominated by known variants and novel QTL AU - DeWitt, Noah AU - Guedira, Mohammed AU - Lauer, Edwin AU - Murphy, J. Paul AU - Marshall, David AU - Mergoum, Mohamed AU - Johnson, Jerry AU - Holland, James B. AU - Brown-Guedira, Gina AB - Abstract Genetic variation in growth over the course of the season is a major source of grain yield variation in wheat, and for this reason variants controlling heading date and plant height are among the best-characterized in wheat genetics. While the major variants for these traits have been cloned, the importance of these variants in contributing to genetic variation for plant growth over time is not fully understood. Here we develop a biparental population segregating for major variants for both plant height and flowering time to characterize the genetic architecture of the traits and identify additional novel QTL. We find that additive genetic variation for both traits is almost entirely associated with major and moderate-effect QTL, including four novel heading date QTL and four novel plant height QTL. FT2 and Vrn-A3 are proposed as candidate genes underlying QTL on chromosomes 3A and 7A, while Rht8 is mapped to chromosome 2D. These mapped QTL also underlie genetic variation in a longitudinal analysis of plant growth over time. The oligogenic architecture of these traits is further demonstrated by the superior trait prediction accuracy of QTL-based prediction models compared to polygenic genomic selection models. In a population constructed from two modern wheat cultivars adapted to the southeast U.S., almost all additive genetic variation in plant growth traits is associated with known major variants or novel moderate-effect QTL. Major transgressive segregation was observed in this population despite the similar plant height and heading date characters of the parental lines. This segregation is being driven primarily by a small number of mapped QTL, instead of by many small-effect, undetected QTL. As most breeding populations in the southeast U.S. segregate for known QTL for these traits, genetic variation in plant height and heading date in these populations likely emerges from similar combinations of major and moderate effect QTL. We can make more accurate and cost-effective prediction models by targeted genotyping of key SNPs. DA - 2020/12/16/ PY - 2020/12/16/ DO - 10.1101/2020.12.16.422696 UR - https://doi.org/10.1101/2020.12.16.422696 ER - TY - JOUR TI - The Yield Responses to Crop Bioremediation Practices on Haplustept and Fluvaquent Saline-Sodic Soils AU - Gunes, Adem AU - Turan, Metin AU - Sahin, Ustun AU - Sahin, Fikrettin AU - Gulluce, Medine AU - Müdahir, Özgül AU - Ors, Selda AU - Ozlu, Ekrem T2 - Communications in Soil Science and Plant Analysis AB - Crop production in salty-sodic soils causes poor crop growth due to ion imbalance, water stress, low hormonal and enzymatic balances. The use of rhizobacteria promoting plant growth in saline and sanitary areas (PGPR) is an economical and environmentally friendly approach that increases and eliminates the tolerance of plants to salt. Field experiments were conducted to determine the response of barley, maize and sorghum crop yields to the application of the bacteria (Halobacillus sp), which was preliminarily experimented by a greenhouse study, on two big soil groups (Haplustept and Fluvaquent). The experiment was established with four different treatments; T0 (control-no application), T1 (the gypsum application), T2 (the PGPR application), and T3 (the gypsum + PGPR application) on the high saline and sodic soils in a semi-arid region. The observations of the present study indicate positive impacts of PGPR applications on crop yield and soil productivity. The gypsum + PGPR treatment was the most effective treatment obtaining higher yields owing to significant improvement in the plant photosynthetic activity, chlorophyll content, stomatal conductance, enzymes, hormones, amino and organic acids, and crop-soil productivity. The seed inoculation with the Halobacillus sp bacteria cultures help in alleviation of stress and enhance crop productivity under the short-term gypsum application on Haplustept and Fluvaquent saline-sodic soils. DA - 2020/11/26/ PY - 2020/11/26/ DO - 10.1080/00103624.2020.1836196 VL - 51 IS - 21 SP - 2639–2657 SN - 0010-3624 1532-2416 UR - http://dx.doi.org/10.1080/00103624.2020.1836196 KW - PGPR KW - photosynthetic activity KW - stomatal conductance KW - amino acids KW - saline soil ER - TY - JOUR TI - Crop rotational diversity impacts soil physical and hydrological properties under long-term no- and conventional-till soils T2 - Soil Research AB - Diversification of crop species and minimum mechanical soil disturbance are the interlinked principles of conservation agriculture that are beneficial in improving soil physical and hydrological properties, and hence crop productivity. The present study was conducted to assess the long-term impacts of crop rotational diversity and tillage on soil water infiltration (qs), soil water retention (SWR), pore size distribution (PSD), bulk density (ρb) and soil penetration resistance (SPR). The study was established in 1991 at Beresford, South Dakota, and included three crop rotation systems (2-year, maize (Zea mays L.)–soybean (Glycine max L.); 3-year, maize–soybean–wheat (Triticum aestivum L.); and 4-year, maize–soybean–wheat–oat (Avena sativa L.)) and two tillage systems (NT, no-tillage; and CT, conventional tillage). Soil samples were collected only under maize and soybean phases of the crop rotations. Our results showed that NT with 4-year rotation had the lowest ρb under maize and soybean phases (1.21 and 1.19 g cm–3 respectively) compared with the CT system. Similarly, NT with 4-year rotation decreased SPR by 20% compared to CT with 4-year rotation in the soybean phase. Soils managed under NT with 4-year rotation in the soybean phase retained 27, 28, 28, 32, 33, 31 and 26% more water compared with CT and 4-year system at 0–7.5 cm depth at 0, –0.4, –1.0, –2.5, –5.0, –10 and –30 kPa matric potentials respectively. A similar trend was observed for qs under the same treatments, in which it was 31% higher under NT than under CT, both with 4-year rotation. Data from this study showed that diversified crop rotation under NT enhanced soil physical and hydrological properties compared with CT with less diverse systems (e.g. maize–soybean). DA - 2020/// PY - 2020/// DO - 10.1071/sr18192 UR - http://dx.doi.org/10.1071/sr18192 KW - chisel plow KW - diverse crop rotations KW - maize-soybean rotation KW - soil bulk density KW - soil penetration resistance KW - soil water retention KW - water infiltration rate ER - TY - JOUR TI - Available ammonium and nitrate levels of highland soil orders in Turkey at different freeze-thaw cycles AU - Gunes, A. AU - Ata, S. AU - Ozgul, M. AU - Turan, M. AU - Ozlu, E. AU - Dizman, M. T2 - Fresenius Environmental Bulletin DA - 2020/// PY - 2020/// VL - 29 IS - 1 SP - 51-61 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-85092703805&partnerID=MN8TOARS ER - TY - JOUR TI - Role of freeze-thaw cycles in available Fe levels of some highland soil orders AU - Ata, S. AU - Gunes, A. AU - Ozgul, M. AU - Turan, M. AU - Yildirim, E. AU - Mokhtari, N.E.P. AU - Ozlu, E. T2 - Fresenius Environmental Bulletin DA - 2020/// PY - 2020/// VL - 29 IS - 1 SP - 62-69 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-85092733191&partnerID=MN8TOARS ER - TY - JOUR TI - Heavy Metals and Photosynthesis: Recent Developments T2 - Photosynthesis, Productivity, and Environmental Stress AB - Heavy metals are among the main pollutants affecting plant photosynthesis. A broad literature screening reveals that heavy metals impair, in a type- and dose-dependent manner, many aspects related to the photosynthetic apparatus. This chapter explores how stomatal and mesophyll conductances, chloroplasts, photosynthetic pigments, photosystems I and II, photosynthetic enzymes, and the antioxidant defense mechanism are negatively affected by heavy metals. It also describes how hyperaccumulator plants cope with potential disturbances in photosynthesis upon heavy metal stress. DA - 2020/// PY - 2020/// DO - 10.1002/9781119501800.CH7 UR - https://publons.com/wos-op/publon/46060143/ ER - TY - JOUR TI - The interplay between irrigation and fruiting on branch growth and mortality, gas exchange, and water relations of coffee trees T2 - Tree Physiology AB - Abstract The overall coordination between gas exchanges and plant hydraulics may be affected by soil water availability and source-to-sink relationships. Here we evaluated how branch growth and mortality, leaf gas exchange and metabolism are affected in coffee (Coffea arabica L.) trees by drought and fruiting. Field-grown plants were irrigated or not, and maintained with full or no fruit load. Under mild water deficit, irrigation per se did not significantly impact growth but markedly reduced branch mortality in fruiting trees, despite similar leaf assimilate pools and water status. Fruiting increased net photosynthetic rate in parallel with an enhanced stomatal conductance, particularly in irrigated plants. Mesophyll conductance and maximum RuBisCO carboxylation rate remained unchanged across treatments. The increased stomatal conductance in fruiting trees over nonfruiting ones was unrelated to internal CO2 concentration, foliar abscisic acid (ABA) levels or differential ABA sensitivity. However, stomatal conductance was associated with higher stomatal density, lower stomatal sensitivity to vapor pressure deficit, and higher leaf hydraulic conductance and capacitance. Increased leaf transpiration rate in fruiting trees was supported by coordinated alterations in plant hydraulics, which explained the maintenance of plant water status. Finally, by preventing branch mortality, irrigation can mitigate biennial production fluctuations and improve the sustainability of coffee plantations. DA - 2020/9/2/ PY - 2020/9/2/ DO - 10.1093/treephys/tpaa116 UR - http://dx.doi.org/10.1093/treephys/tpaa116 KW - abscisic acid KW - branch mortality KW - Coffea arabica KW - photosynthesis KW - plant hydraulics KW - stomatal behavior KW - vapor pressure deficit ER - TY - JOUR TI - Leaf hydraulic properties are decoupled from leaf area across coffee species T2 - Trees DA - 2020/5/11/ PY - 2020/5/11/ DO - 10.1007/s00468-020-01983-y UR - http://dx.doi.org/10.1007/s00468-020-01983-y KW - Coffea KW - Leaf hydraulic conductance KW - Hydraulic vulnerability KW - Vein density KW - Xylem structure ER - TY - JOUR TI - Abscisic Acid Biosynthesis and Signaling in Plants: Key Targets to Improve Water Use Efficiency and Drought Tolerance AU - Cardoso, Amanda A. AU - Gori, Antonella AU - Da-Silva, Cristiane Jovelina AU - Brunetti, Cecilia T2 - Applied Sciences AB - The observation of a much-improved fitness of wild-type plants over abscisic acid (ABA)-deficient mutants during drought has led researchers from all over to world to perform experiments aiming at a better understanding of how this hormone modulates the physiology of plants under water-limited conditions. More recently, several promising approaches manipulating ABA biosynthesis and signaling have been explored to improve water use efficiency and confer drought tolerance to major crop species. Here, we review recent progress made in the last decade on (i) ABA biosynthesis, (ii) the roles of ABA on plant-water relations and on primary and secondary metabolisms during drought, and (iii) the regulation of ABA levels and perception to improve water use efficiency and drought tolerance in crop species. DA - 2020/9// PY - 2020/9// DO - 10.3390/app10186322 UR - https://www.mdpi.com/2076-3417/10/18/6322 KW - ABA receptors KW - ABA receptor antagonists KW - plant metabolism KW - plant-water relations KW - stomatal closure KW - water deficit KW - xylem embolism ER - TY - JOUR TI - Osmotic adjustment and hormonal regulation of stomatal responses to vapour pressure deficit in sunflower T2 - AoB Plants AB - Abstract Dynamic variation of the stomatal pore in response to changes in leaf–air vapour pressure difference (VPD) constitutes a critical regulation of daytime gas exchange. The stomatal response to VPD has been associated with both foliage abscisic acid (ABA) and leaf water potential (Ψ l); however, causation remains a matter of debate. Here, we seek to separate hydraulic and hormonal control of stomatal aperture by manipulating the osmotic potential of sunflower leaves. In addition, we test whether stomatal responses to VPD in an ABA-deficient mutant (w-1) of sunflower are similar to the wild type. Stomatal apertures during VPD transitions were closely linked with foliage ABA levels in sunflower plants with contrasting osmotic potentials. In addition, we observed that the inability to synthesize ABA at high VPD in w-1 plants was associated with no dynamic or steady-state stomatal response to VPD. These results for sunflower are consistent with a hormonal, ABA-mediated stomatal responses to VPD rather than a hydraulic-driven stomatal response to VPD. DA - 2020/// PY - 2020/// DO - 10.1093/AOBPLA/PLAA025 UR - https://publons.com/wos-op/publon/31689867/ KW - Abscisic acid KW - leaf osmotical potential KW - leaf turgor loss point KW - stomatal closure KW - vapour pressure deficit KW - wilty mutant ER - TY - JOUR TI - New developments in understanding plant water transport under drought stress T2 - New Phytologist AB - The Fourth Xylem International Meeting (XIM4) brought together over 100 plant scientists to discuss a wide range of topics related to embolism resistance and efficiency of long-distance water transport through plants, and their implications for cultivated and natural systems. The diversity of methods, plant species, and physiological processes discussed in the context of water stress at the meeting highlighted a need to integrate spatial and temporal data about plant functioning, specifically in regard to climate-change-related challenges. Structural traits, such as pit characteristics and conduit diameter, have been traditionally associated with xylem safety and efficiency. Furthering our understanding of these relationships, it was shown that the hydration of pit membranes, their chemical composition, and three-dimensional structure play a key role in the resistance to air-seeding and embolism spread (J. Werner, Ulm University, Germany; Zhang et al., 2020). Resolving conduit network characteristics, such as conduit grouping and intra-organ anatomical trait correlations like those between pit membrane porosity and conduit diameter, was also shown to be important in upscaling xylem anatomy to drought-induced embolism resistance (Mrad et al., 2018). Though conduit diameter remains the easiest anatomical trait to measure, the lack of more comprehensive knowledge on the inter and intraspecific scaling of conduit size and pit traits prevents a more robust understanding of the link between conduit diameter and drought induced (F. Lens, Leiden University, the Netherlands) or freeze-induced embolism resistance (A. Lintunen, University of Helsinki, Finland). The development of noninvasive techniques (e.g. optical vulnerability and synchrotron-based X-ray microtomography) has enabled the study of hydraulics in soft organs, creating a breakthrough in plant vascular research, as demonstrated by the many studies presenting the application of such methods at XIM4. By using noninvasive methods, for instance, a high number of investigations highlighted intraspecific variation in xylem resistance in the stems (C. Lemaire, Université Clermont Auvergne, France; L. Lamarque, University of Bordeaux, France) and leaves (A. Cardoso, Purdue University, West Lafayette, IN, USA; Hochberg et al., 2017) of woody species, both in time (seasonally) and in space (on different locations of the plant). Large intraspecific variation in xylem resistance has also been shown to result in heterogeneous mortality across the canopy in a tree species exposed to drought, with considerable impacts on plant photosynthesis even after rehydration (Cardoso, et al., 2020a). On the contrary, little intraspecific plasticity of functional and anatomical xylem traits was reported for different species across wide aridity gradients when samples were taken at a fixed distance from the apex (E. Robert, CREAF, Barcelona, Spain). Such contrasting results indicate the need to consider known axial trends of anatomical traits when selecting the site on a branch/stem axis for physiological experiments to avoid potential bias in the interpretation of results (Lechthaler et al., 2019). The use of more rigorous sampling protocols and the new, noninvasive methods will likely lead to further insights into the phenotypic plasticity of xylem's anatomical and functional traits that plants may develop as a response to future climate changes. A number of XIM4 contributions emphasized that, in order to build a holistic picture of the hydraulic processes controlling plant responses to drought, hydraulics at the extremities of the water transport system (i.e. soil–roots and leaves–atmosphere) must be further investigated. The presence of biochemical barriers at both root–soil and leaf–atmosphere interfaces (suberized cell walls of exo and endodermis in roots and extracellular biopolymers of the leaf cuticle, respectively) likely play a key role in water transport efficiency and safety, as they reduce the free diffusion of water and nutrients (Schreiber, 2010). Moreover, declines in soil hydraulic conductivity and root hydraulic conductance during moderate drought have been shown to be linked to the disconnection between roots and the rhizosphere (Rodriguez-Dominguez & Brodribb, 2020), with consequent limitations to leaf transpiration (A. Carminati, University of Bayreuth, Germany). At the other extremity of the hydraulic path, increasing vapor pressure deficit in the atmosphere is long known to be tightly associated with leaf water losses through stomata (McAdam & Brodribb, 2015) and the leaf cuticle (L-M. Billon, Université Clermont Auvergne, France). A better integration of the hydraulics at the extremities in the modeling of plant–water relations will increase our ability to understand plant behavior in the context of water stress. Hydraulic failure due to xylem embolism is recognized as a major trigger of tree mortality under drought (Choat et al., 2018). Plant species display different mechanisms to avoid air-seeding and subsequent hydraulic failure. Declines in stomatal conductance were shown to preserve leaf and stem xylem from embolism in a herbaceous grass (D. Corso, University of Tasmania, Australia) and in woody angiosperms (Creek et al., 2019), as well as in a pair of lycophyte species (S. McAdam, Purdue University, West Lafayette, IN, USA), suggesting an evolutionary trait coordination across land plants (Cardoso, et al., 2020b). Indeed, a trait-based model showed that the time of plant desiccation was longer with wider differences between the water potential at 50% loss in stem hydraulic conductance and stomatal closure (Blackman et al., 2019). Nevertheless, water loss through the cuticle (gmin) was shown to continue well beyond the point of stomatal closure, potentially leading to further increases in xylem tension during prolonged droughts (Duursma et al., 2018). Owing to the importance of leaf water loss to the whole-plant water status, lowering gmin was proposed as an important mechanism preventing the development of excessively low water potentials during drought (L-M. Billon). Additionally, reversible collapse of minor veins in leaves has also been suggested to effectively buffer embolism in major veins in red oak leaves (N. Holbrook, Harvard University, Cambridge, MA, USA; Zhang et al., 2016). It has long been debated whether plants can refill embolized conduits with water, or if embolized conduits are permanently lost. Through the direct observation of embolism via noninvasive methods, refilling under tension has been shown to be an artefact. However, xylem refilling upon rewatering remains uncertain. Lack of refilling upon rewatering in intact plants was found in leaves of a herbaceous grass (Johnson et al., 2018) and stems of two woody species (L. Lamarque, University of Bordeaux, France; R. Rehschuh, Karlsruhe Institute of Technology, Germany), and it has been suggested to occur in silver birch (Y. Salmon, University of Helsinki, Finland). This suggests that xylem refilling upon rewatering may be possible in some species and plant organs but not in others. The formation of new xylem every year plays a key role in plant responses to environmental cues, as a central process in stress acclimation (E. Ziaco, University of Nevada, Reno, USA; G. Battipaglia, University of Campania, Caserta, Italy) and recovery (J. Gričar, Slovenian Forestry Institute, Ljubljana, Slovenia). Growing areas of research on cambial activity and retrospective dendro-anatomy (i.e. the study of time series of wood anatomical traits) are expanding the time resolution of our analyses of xylem physiology, extending our understanding of how intra and interannual environmental variability affects the xylem hydraulic functioning. Alongside hydraulic failure, carbon (C) starvation is an important factor contributing to plant damage during drought, and a combination of these processes has been proposed to result in a cascade of events that ultimately lead to plant mortality (N.G. McDowell, Pacific Northwest National Laboratory, Richland, WA, USA). The association between hydraulic failure and C starvation may be due to the role of carbohydrate supply for preventing and repairing xylem embolism, as well as the role of carbohydrates in regrowth following drought relief and osmotic regulation (McDowell et al., 2019). The interplay of C and water dynamics is a novel frontier for plant physiologists, and novel techniques such as Raman spectroscopy (enabling the measurement of sucrose at the cellular level; J. Gersony, Harvard University, Cambridge, MA, USA) could help us better understand phenomena like drought-induced tree mortality. The plant hydraulic community is aware of climate change threats – see the manifesto signed by all conference participants in Cochard et al. (2019). Our ability to predict, and therefore mitigate, the negative effects of climate change in plants from both cultivated and natural systems relies on a deep and comprehensive knowledge of the plant hydraulic system as a whole. A better understanding of plant water relations is also critical for predicting the contribution of forest ecosystems to the global C and water cycles by implementing the information of plant hydraulics into climate models. To achieve this, several gaps in our understanding of basic plant functioning still need to be filled. Whereas most experimental plant hydraulic studies have been performed using potted plants under controlled environments, it is clear from XIM4 that our current understanding would benefit from experiments on plants in their natural environment. Such experiments would allow us to access the whole soil–plant–atmosphere continuum and the interaction between the different components of this continuum during drought. Robust studies in the field are also important in improving our ability to scale-up plant processes from the individual to the ecosystem level. Significant recent progress has been made in developing new technologies to assess drought damage, understanding the traits associated with drought resistance and building a more holistic picture of plant resistance to drought. However, a number of important questions surrounding plant hydraulics have been highlighted at XIM4, such as the role of carbohydrate metabolism in drought physiology, the existence and importance of post-drought refilling, the intraspecific variation in plant hydraulic traits, and the interaction of different components of the soil–plant–atmosphere continuum. New tools and methodologies presented at XIM4 provide us with the opportunity to address some of these critical knowledge gaps to improve our understanding of plant biology with implications for industry and broader society in the face of global climate change. We thank the participants of XIM4 for their scientific contributions to the meeting. Participation of KMJ, JTG, AM, CL and AFB in XIM4 was supported by Federation of European Societies of Plant Biology. Participation of L-MB, YW, AG, AAC and LF-d-U was supported by the New Phytologist Trust. AAC wrote the report draft based on the contributions of all authors. DA - 2020/// PY - 2020/// DO - 10.1111/NPH.16663 UR - https://publons.com/wos-op/publon/33073430/ KW - drought KW - embolism KW - functional traits KW - hydraulic conductance KW - stomata KW - xylem ER - TY - JOUR TI - Osmotic adjustment and hormonal regulation of stomatal responses to vapor pressure deficit in sunflower T2 - AoB Plants AB - Abstract Dynamic variation of the stomatal pore in response to changes in leaf–air vapour pressure difference (VPD) constitutes a critical regulation of daytime gas exchange. The stomatal response to VPD has been associated with both foliage abscisic acid (ABA) and leaf water potential (Ψ l); however, causation remains a matter of debate. Here, we seek to separate hydraulic and hormonal control of stomatal aperture by manipulating the osmotic potential of sunflower leaves. In addition, we test whether stomatal responses to VPD in an ABA-deficient mutant (w-1) of sunflower are similar to the wild type. Stomatal apertures during VPD transitions were closely linked with foliage ABA levels in sunflower plants with contrasting osmotic potentials. In addition, we observed that the inability to synthesize ABA at high VPD in w-1 plants was associated with no dynamic or steady-state stomatal response to VPD. These results for sunflower are consistent with a hormonal, ABA-mediated stomatal responses to VPD rather than a hydraulic-driven stomatal response to VPD. DA - 2020/6/19/ PY - 2020/6/19/ DO - https://doi.org/10.1093/aobpla/plaa025 ER - TY - JOUR TI - Drought-tolerant coffee plants display increased tolerance to waterlogging and post-waterlogging reoxygenation AU - Toral-Juárez, Marco A. AU - Avila, Rodrigo T. AU - Cardoso, Amanda A. AU - Brito, Fred A.L. AU - Machado, Kleiton L.G. AU - Almeida, Wellington L. AU - Souza, Raylla P.B. AU - Martins, Samuel C.V. AU - DaMatta, Fábio M. T2 - Environmental and Experimental Botany AB - Soil waterlogging negatively impacts plants due to reduced oxygen availability in the rhizosphere. Here we selected two Coffea canephora clones with contrasting tolerance to drought and oxidative stress to test whether they would also exhibit contrasting tolerance to waterlogging and post-waterlogging reoxygenation. Plants were exposed to six days of waterlogging followed by 40 days of reoxygenation. During waterlogging, both clones exhibited lower leaf gas exchange rate, electron transport rate and photochemical quenching as well as increased non-photochemical quenching; overall, these changes were stronger in the drought tolerant (DT) clones over the drought sentitive (DS) ones. Photosynthetic limitations were essentially linked to diffusional constraints regardless of clone. In both clones, declines in stomatal conductance were not associated with foliar ABA or ethylene levels, however stomatal conductance correlated with the plant hydraulic conductance. After reoxygenation, DT plants mostly recovered leaf function and plant mortality was less than 10%. Conversely, DS plants displayed very low water potentials after reoxygenation, which was accompanied by photosynthetic and membrane damage and 40% plant mortality. Our findings confirmed that the DT clone is less impaired by soil waterlogging and reoxygenation than the DS one. The differences between clones were more evident during the reoxygenation than during waterlogging, likely due to the drought experienced by the DS but not DT plants. Collectively, this information leads us to a common path to find new coffee genotypes with increased tolerance to both drought and waterlogging aiming at increased coffee sustainability under an ongoing climate changing scenario. DA - 2020/11// PY - 2020/11// DO - 10.1016/j.envexpbot.2020.104311 VL - 11 SP - 104311 UR - http://dx.doi.org/10.1016/j.envexpbot.2020.104311 KW - Chlorophyll fluorescence KW - Hypoxia KW - Leaf gas exchange KW - Leaf damage KW - Photosynthesis KW - Plant mortality ER - TY - JOUR TI - Coffee plants respond to drought and elevated [CO2] through changes in stomatal function, plant hydraulic conductance, and aquaporin expression T2 - Environmental and Experimental Botany AB - Rising air CO2 concentration ([CO2]) is believed to mitigate the negative impacts of global climate changes such as increased air temperatures and drought events on plant growth and survival. Nonetheless, how elevated [CO2] affects the way coffee (Coffea arabica L.) plants sense and respond to drought remains a critical unknown. In this study, potted coffee plants were cultivated under two air [CO2] (ca. 400 ppm or 700 ppm) in open top chambers under greenhouse conditions. After a 5-month exposure to [CO2] treatments, plants were submitted to a progressive, controlled soil water deficit down to 20 % soil field capacity. Under well-watered (100 % field capacity) conditions, 700-plants displayed lower whole-plant transpiration rates (T) than their 400-counterparts. Changes in T were unrelated to stomatal conductances at the leaf scale (as well as stomatal morphology) or foliar ABA levels, but they were rather associated with faster stomata closure rates upon rapid increases in vapor pressure deficit in the 700-plants. During drought, 700-plants were able to maintain higher water potentials and plant hydraulic conductances for longer in parallel to higher T than their 400-counterparts. Under elevated [CO2], the faster stomatal closure rates (irrigated conditions) or the maintenance of plant hydraulic conductances (drought conditions) were associated with higher (3 to 40-fold) transcript abundance of most aquaporin genes. Altogether, our results suggest that elevated [CO2] has marked implications on how coffee plants respond to soil water deficit, ultimately permitting 700-plants to have improved fitness under drought when compared to 400-plants. DA - 2020/9// PY - 2020/9// DO - 10.1016/j.envexpbot.2020.104148 UR - http://dx.doi.org/10.1016/j.envexpbot.2020.104148 KW - Aquaporin KW - Coffea arabica KW - Elevated [CO2] KW - Hydraulic conductance KW - Stomatal response KW - Whole-plant transpiration ER - TY - JOUR TI - Xylem Embolism Resistance Determines Leaf Mortality during Drought in Persea americana T2 - Plant Physiology AB - The driver of leaf mortality during drought stress is a critical unknown. We used the commercially important tree Persea americana, in which there is a large variation in the degree of drought-induced leaf death across the canopy, to test whether embolism formation in the xylem during drought drives this leaf mortality. A large range in the number of embolized vessels in the petioles of leaves was observed across the canopy of plants that had experienced drought. Despite considerable variation between leaves, the amount of embolized vessels in the xylem of the petiole strongly correlated with area of drought-induced tissue death in individual leaves. Consistent with this finding was a large interleaf variability in xylem resistance to embolism, with a 1.45 MPa variation in the water potential at which 50% of the xylem in the leaf midrib embolized across leaves. Our results implicate xylem embolism as a driver of leaf mortality during drought. Moreover, we propose that heterogeneity in drought-induced leaf mortality across a canopy is caused by high interleaf variability in xylem resistance to embolism, which may act as a buffer against complete canopy death during prolonged drought in P. americana. DA - 2020/// PY - 2020/// DO - 10.1104/PP.19.00585 UR - https://publons.com/wos-op/publon/27738638/ ER - TY - JOUR TI - Starch accumulation does not lead to feedback photosynthetic downregulation in girdled coffee branches under varying source-to-sink ratios T2 - Trees DA - 2020/// PY - 2020/// DO - 10.1007/S00468-019-01893-8 UR - https://publons.com/publon/21671015/ KW - Coffea arabica KW - Carbon metabolism KW - Nitrogen metabolism KW - Photorespiration KW - Photosynthesis KW - Respiration ER - TY - JOUR TI - Drought‐induced lacuna formation in the stem causes hydraulic conductance to decline before xylem embolism in Selaginella T2 - New Phytologist AB - Summary Lycophytes are the earliest diverging extant lineage of vascular plants, sister to all other vascular plants. Given that most species are adapted to ever‐wet environments, it has been hypothesized that lycophytes, and by extension the common ancestor of all vascular plants, have few adaptations to drought. We investigated the responses to drought of key fitness‐related traits such as stomatal regulation, shoot hydraulic conductance ( K shoot ) and stem xylem embolism resistance in Selaginella haematodes and S. pulcherrima , both native to tropical understory. During drought stomata in both species were found to close before declines in K shoot , with a 50% loss of K shoot occurring at −1.7 and −2.5 MPa in S. haematodes and S. pulcherrima , respectively. Direct observational methods revealed that the xylem of both species was resistant to embolism formation, with 50% of embolized xylem area occurring at −3.0 and −4.6 MPa in S. haematodes and S. pulcherrima , respectively. X‐ray microcomputed tomography images of stems revealed that the decline in K shoot occurred with the formation of an air‐filled lacuna, disconnecting the central vascular cylinder from the cortex. We propose that embolism‐resistant xylem and large capacitance, provided by collapsing inner cortical cells, is essential for Selaginella survival during water deficit. DA - 2020/5/9/ PY - 2020/5/9/ DO - 10.1111/nph.16649 UR - http://dx.doi.org/10.1111/nph.16649 KW - ABA KW - embolism KW - evolution KW - hydraulic conductance KW - lycophyte KW - stomatal conductance KW - stomatal evolution ER - TY - JOUR TI - Computational identification of receptor-like kinases “RLK” and receptor-like proteins “RLP” in legumes AU - Restrepo-Montoya, Daniel AU - Brueggeman, Robert AU - McClean, Phillip E. AU - Osorno, Juan M. T2 - BMC Genomics AB - Abstract Background In plants, the plasma membrane is enclosed by the cell wall and anchors RLK and RLP proteins, which play a fundamental role in perception of developmental and environmental cues and are crucial in plant development and immunity. These plasma membrane receptors belong to large gene/protein families that are not easily classified computationally. This detailed analysis of these plasma membrane proteins brings a new source of information to the legume genetic, physiology and breeding research communities. Results A computational approach to identify and classify RLK and RLP proteins is presented. The strategy was evaluated using experimentally-validated RLK and RLP proteins and was determined to have a sensitivity of over 0.85, a specificity of 1.00, and a Matthews correlation coefficient of 0.91. The computational approach can be used to develop a detailed catalog of plasma membrane receptors (by type and domains) in several legume/crop species. The exclusive domains identified in legumes for RLKs are WaaY, APH Pkinase_C, LRR_2, and EGF, and for RLP are L-lectin LPRY and PAN_4. The RLK-nonRD and RLCK subclasses are also discovered by the methodology. In both classes, less than 20% of the total RLK predicted for each species belong to this class. Among the 10-species evaluated ~ 40% of the proteins in the kinome are RLKs. The exclusive legume domain combinations identified are B-Lectin/PR5K domains in G. max , M. truncatula , V. angularis , and V. unguiculata and a three-domain combination B-lectin/S-locus/WAK in C. cajan , M. truncatula , P. vulgaris , V. angularis . and V. unguiculata . Conclusions The analysis suggests that about 2% of the proteins of each genome belong to the RLK family and less than 1% belong to RLP family. Domain diversity combinations are greater for RLKs compared with the RLP proteins and LRR domains, and the dual domain combination LRR/Malectin were the most frequent domain for both groups of plasma membrane receptors among legume and non-legume species. Legumes exclusively show Pkinase extracellular domains, and atypical domain combinations in RLK and RLP compared with the non-legumes evaluated. The computational logic approach is statistically well supported and can be used with the proteomes of other plant species. DA - 2020/7/3/ PY - 2020/7/3/ DO - 10.1186/s12864-020-06844-z VL - 21 IS - 1 UR - http://dx.doi.org/10.1186/s12864-020-06844-z KW - Dicots KW - Model plants KW - Resistance genes KW - proteins KW - Legumes KW - Plasma membrane receptors ER - TY - CONF TI - Tying nutrient and metal leaching losses to infiltration rates in compost-soil blends AU - Kranz, C.N. AU - Rivers, E. AU - Heitman, J.L. AU - McLaughlin, R.A. T2 - Graduate Student Research Symposium C2 - 2020/// CY - Raleigh, NC DA - 2020/// PY - 2020/// ER - TY - CONF TI - Amending roadside with compost post-construction to improve soil hydraulic properties AU - Kranz, C.N. T2 - Department of Crop and Soil Sciences Seminar C2 - 2020/// CY - (Virtual) DA - 2020/// PY - 2020/// ER - TY - CONF TI - Compost amendment rate and level of compaction alter pore size distribution and soil hydraulic properties in three different textured soils AU - Kranz, C.N. AU - Heitman, J.L. AU - McLaughlin, R.A. T2 - Soil Science Society of North Carolina Annual Meeting C2 - 2020/// CY - Raleigh, NC DA - 2020/// PY - 2020/// ER - TY - CONF TI - Compost and Compaction Effects on Soil Hydraulic Properties AU - Kranz, C.N. AU - Heitman, J.L. AU - McLaughlin, R.A. T2 - International Erosion Control Association Annual Conference C2 - 2020/// CY - Raleigh, NC DA - 2020/// PY - 2020/// ER - TY - CONF TI - Using compost post-construction to improve soil hydraulic properties and manage nutrient export AU - Kranz, C.N. AU - Rivers, E. AU - Heitman, J.L. AU - McLaughlin, R.A. T2 - North Carolina Department of Transportation Summit C2 - 2020/// CY - (Virtual) DA - 2020/// PY - 2020/// ER - TY - CONF TI - Nutrient and metal leaching losses verses retention in compost-soil blends AU - Kranz, C.N. AU - Rivers, E. AU - Heitman, J.L. AU - McLaughlin, R.A. T2 - ASA-CSSA-SSSA Annual meeting C2 - 2020/// CY - (Virtual) DA - 2020/// PY - 2020/// ER - TY - JOUR TI - Using Pixel-Based Microscope Images to Generate 3D Reconstructions of Frozen and Thawed Plant Tissue AU - Livingston, David P., III AU - Tuong, Tan D. T2 - PLANT COLD ACCLIMATION, 2 EDITION AB - Histological analysis of frozen and thawed plants has been conducted for many years but the observation of individual sections only provides a two-dimensional representation of a three-dimensional phenomenon. Currently available optical sectioning techniques for viewing internal structures in three dimensions are either low in resolution or the instrument cannot penetrate deep enough into the tissue to visualize the whole plant. Methods using higher resolution equipment are expensive and often require time-consuming training. In addition, conventional stains cannot be used for optical sectioning techniques. We present a relatively simple and less expensive technique using pixel-based (JPEG) images of conventionally stained histological sections of an Arabidopsis thaliana plant. The technique uses commercially available software to generate a 3D representation of internal structures. DA - 2020/// PY - 2020/// DO - 10.1007/978-1-0716-0660-5_10 VL - 2156 SP - 119-139 SN - 1940-6029 KW - Histology KW - Paraffin KW - Pixel-based images KW - Adobe After Effects KW - MRI KW - CT KW - Confocal microscopy ER - TY - JOUR TI - Differences in proteome response to cold acclimation in Zoysia japonica cultivars with different levels of freeze tolerance AU - Brown, Jessica M. AU - Yu, Xingwang AU - Holloway, H. McCamy P. AU - DaCosta, Michelle AU - Bernstein, Rachael P. AU - Lu, Jefferson AU - Tuong, Tan D. AU - Patton, Aaron J. AU - Dunne, Jeffrey C. AU - Arellano, Consuelo AU - Livingston, David P. AU - Milla-Lewis, Susana R. T2 - CROP SCIENCE AB - Abstract Zoysiagrasses ( Zoysia spp.) are warm‐season turfgrasses primarily grown in the southern and transition zones of the United States. An understanding of the physiological and proteomic changes that zoysiagrasses undergo during cold acclimation may shed light on phenotypic traits and proteins useful in selection of freeze‐tolerant genotypes. We investigated the relationship between cold acclimation, protein expression, and freeze tolerance in cold acclimated (CA) and nonacclimated (NA) plants of Zoysia japonica Steud. cultivars Meyer (freeze‐tolerant) and Victoria (freeze‐susceptible). Meristematic tissues from the grass crowns were harvested for proteomic analysis. Freeze testing indicated that cold acclimation accounted for a 1.9‐fold increase in plant survival than nonacclimation treatment. Overall, proteomic analysis identified 62 protein spots differentially accumulated in abundance under cold acclimation. Nine and 22 unique protein spots were identified for Meyer and Victoria, respectively, with increased abundance or decreased abundance. In addition, 23 shared protein spots were found among the two cultivars in response to cold acclimation. Function classification revealed that these proteins were involved primarily in transcription, signal transduction and stress defense, carbohydrate and energy metabolism, and protein and amino acid metabolism. Several proteins of interest for their association with cold acclimation were identified. Further investigation of these proteins and their functional categories may contribute to increase our understanding of the differences in freezing tolerance among zoysiagrass germplasm. DA - 2020/// PY - 2020/// DO - 10.1002/csc2.20225 VL - 60 IS - 5 SP - 2744-2756 SN - 1435-0653 ER - TY - JOUR TI - Impacts of corn stover removal on carbon dioxide and nitrous oxide emissions AU - Drury, C. F. AU - Woodley, Alex AU - Reynolds, W. D. AU - Yang, X. M. AU - Phillips, L. A. AU - Rehmann, L. AU - Calder, W. T2 - SOIL SCIENCE SOCIETY OF AMERICA JOURNAL AB - Abstract Harvesting corn ( Zea mays L.) stover for production of biofuels, industrial sugars, bioproducts, and livestock bedding is increasing rapidly, but little is known of the impacts of stover removal on soil‐borne greenhouse gas (GHG) emissions. This study evaluated the impacts of removing surface corn stover (0, 25, 50, 75, 100 wt. % removal) on carbon dioxide (CO 2 ) and nitrous oxide (N 2 O) emissions from a sandy loam soil cropped to monoculture corn using conventional moldboard plow tillage (CT) and no‐tillage (NT). Stover removal systematically decreased CO 2 emissions from CT, whereas stover removal had little effect on CO 2 emissions from NT. In particular, the CT 0% stover removal treatment produced 47% greater CO 2 emissions (5.75 Mg CO 2 –C ha −1 ) than the CT 100% removal (3.91 Mg CO 2 –C ha −1 ) treatment. Stover removal increased N 2 O emissions from both tillage treatments, producing up to a 75% increase under CT (2.79 kg N ha −1 at 0% removal; 4.87 kg N ha −1 at 100% removal) and up to a 95% increase under NT (1.75 kg N ha −1 at 0% removal; 3.41 kg N ha −1 at 100% removal). Cumulative nitrate exposure increased in comparable patterns to N 2 O emissions when stover residues were removed. There was a trade‐off in GHG emissions resulting from stover removal under CT, whereby increasing stover removal reduced CO 2 emissions but increased N 2 O emissions. In contrast, stover removal did not affect CO 2 emissions under NT but it increased N 2 O emissions especially at the 100% removal rates. DA - 2020/// PY - 2020/// DO - 10.1002/saj2.20104 ER - TY - JOUR TI - Early high-moisture wheat harvest improves double-crop system: II. Soybean growth and yield AU - Parvej, Md Rasel AU - Holshouser, David L. AU - Kratochvil, Robert J. AU - Whaley, Cory M. AU - Dunphy, E. James AU - Roth, Gregory W. AU - Fae, Giovani S. T2 - CROP SCIENCE AB - Abstract Double cropping soybean [ Glycine max (L.) Merr.] after winter wheat ( Triticum aestivum L.) increases total food production without additional land. However, double‐crop soybean usually yields less than full‐season soybean, mainly due to late planting. We evaluated double‐crop soybean growth and yield as affected by early planting immediately after high‐moisture wheat harvest across 20 site‐years in five Mid‐Atlantic states during 2015–2017. At each site, six soybean cultivars from relative maturity group (rMG) 3.1–5.9 were planted at three to five dates in a 4‐ to 14‐d interval. Soybean growth, measured by normalized difference vegetation index (NDVI) across the growing season, was affected only by planting date. Although NDVI peaked near the R5 stage, it took 9–27 more days to reach the peak NDVI (0.84–0.98) for early‐planted soybean than for late‐planted soybean. Relative yield declined with planting dates, which explained 41–81% of the relative yield variability. The yield loss from delayed planting was greater in the north (33–80%; Pennsylvania, Maryland, and Delaware) than in the south (20–27%; Virginia, North Carolina) due to longer delay in planting and shorter growing season in the north. Soybean NDVI from the R1–R6 stages was associated with yield, with the strongest association ( R 2 = .55–.57) at the R2 and R3 stages. The area under the NDVI curve (AUNDVIC) was also strongly associated ( R 2 = .77) with relative yield, indicating an excellent tool for explaining double‐crop soybean yield loss due to poor growth. High‐moisture wheat harvest facilitated soybean planting 4–21 d earlier, which increased growth and yield. DA - 2020/// PY - 2020/// DO - 10.1002/csc2.20174 VL - 60 IS - 5 SP - 2650-2666 SN - 1435-0653 ER - TY - JOUR TI - Early high-moisture wheat harvest improves double-crop system: I. Wheat yield and quality AU - Parvej, Md Rasel AU - Holshouser, David L. AU - Kratochvil, Robert J. AU - Whaley, Cory M. AU - Dunphy, E. James AU - Roth, Gregory W. AU - Fae, Giovani S. T2 - CROP SCIENCE AB - Abstract Double cropping winter wheat ( Triticum aestivum L.) and soybean [ Glycine max (L.) Merr.] increases total food production without additional land. However, yield and/or quality of both crops often suffer if wheat harvest is delayed beyond maturity. We evaluated the impact of high‐moisture wheat harvest on wheat yield and quality and soybean planting time across eighteen site‐years in five Mid‐Atlantic states during 2015 to 2017. Wheat was harvested three to five times beginning at 150 to 200 g kg −1 moisture at 4 to 14 d intervals. High‐moisture wheat harvest facilitated 4 to 21 d earlier soybean planting. Grain moisture generally decreased with harvest date, but temperature and rainfall varied moisture content. Wheat test weight declined linearly 2.91 to 4.87 kg m −3 d −1 delay in harvest. Wheat relative yield was not affected by delayed harvest in Pennsylvania but declined linearly 2.6% per day delay in harvest after 4 July in Maryland, 0.55% after 30 June in Delaware, 3.1% after 19 June in Virginia, and 0.42% after 4 June in North Carolina. Test weight was positively associated with relative yield and explained 37 to 82% of relative yield variability. Critical days for desirable test weight were similar to the critical harvesting days for maximum yield, indicating that test weight is an excellent predictor of optimum harvesting day. Delayed harvest decreased grain falling number but increased softness equivalent. Overall, high‐moisture wheat harvest improved wheat yield and quality by reducing test weight loss and would allow earlier soybean planting to maximize growth and yield. DA - 2020/// PY - 2020/// DO - 10.1002/csc2.20172 VL - 60 IS - 5 SP - 2633-2649 SN - 1435-0653 ER - TY - JOUR TI - Identifying interest, risks, and impressions of organic peanut production: A survey of conventional farmers in the Virginia-Carolina region AU - Kaufman, Amanda A. AU - Jordan, David L. AU - Reberg-Horton, Chris AU - Dean, Lisa L. AU - Shew, Barbara B. AU - Brandenburg, Rick L. AU - Anco, Dan AU - Mehl, Hillary AU - Taylor, Sally AU - Balota, Maria AU - Goodell, L. Suzanne AU - Allen, Jonathan T2 - CROP FORAGE & TURFGRASS MANAGEMENT AB - Crop, Forage & Turfgrass ManagementVolume 6, Issue 1 e20042 CROP MANAGEMENT—BRIEFS Identifying interest, risks, and impressions of organic peanut production: A survey of conventional farmers in the Virginia–Carolina region Amanda A. Kaufman, Amanda A. Kaufman Department of Food, Bioprocessing, and Nutrition Sciences, North Carolina State University, Box 7624, Raleigh, NC, 27695 USASearch for more papers by this authorDavid L. Jordan, Corresponding Author David L. Jordan david_jordan@ncsu.edu orcid.org/0000-0003-4786-2727 Department of Crop and Soil Sciences, North Carolina State University, Box 7620, Raleigh, NC, 27695 USA Correspondence Department of Crop and Soil Sciences, North Carolina State University, Box 7620, Raleigh, NC 27695 Email: david_jordan@ncsu.eduSearch for more papers by this authorChris Reberg-Horton, Chris Reberg-Horton Department of Crop and Soil Sciences, North Carolina State University, Box 7620, Raleigh, NC, 27695 USASearch for more papers by this authorLisa L. Dean, Lisa L. Dean Market Quality and Handling Research Unit, ARS, SEA, USDA, Raleigh, NC, 27695 USASearch for more papers by this authorBarbara B. Shew, Barbara B. Shew Department of Entomology and Plant Pathology, North Carolina State University, Box 7613, Raleigh, NC, 27695 USASearch for more papers by this authorRick L. Brandenburg, Rick L. Brandenburg Department of Entomology and Plant Pathology, North Carolina State University, Box 7613, Raleigh, NC, 27695 USASearch for more papers by this authorDan Anco, Dan Anco Edisto Research and Extension Center, Clemson University, 64 Research Road, Blackville, SC, 29817 USASearch for more papers by this authorHillary Mehl, Hillary Mehl Tidewater Agricultural Research and Extension Center, 6321 Holland Road, Suffolk, VA, 23437 USASearch for more papers by this authorSally Taylor, Sally Taylor Tidewater Agricultural Research and Extension Center, 6321 Holland Road, Suffolk, VA, 23437 USASearch for more papers by this authorMaria Balota, Maria Balota orcid.org/0000-0003-4626-0193 Tidewater Agricultural Research and Extension Center, 6321 Holland Road, Suffolk, VA, 23437 USASearch for more papers by this authorL. Suzanne Goodell, L. Suzanne Goodell Department of Food, Bioprocessing, and Nutrition Sciences, North Carolina State University, Box 7624, Raleigh, NC, 27695 USASearch for more papers by this authorJonathan Allen, Jonathan Allen Department of Food, Bioprocessing, and Nutrition Sciences, North Carolina State University, Box 7624, Raleigh, NC, 27695 USASearch for more papers by this author Amanda A. Kaufman, Amanda A. Kaufman Department of Food, Bioprocessing, and Nutrition Sciences, North Carolina State University, Box 7624, Raleigh, NC, 27695 USASearch for more papers by this authorDavid L. Jordan, Corresponding Author David L. Jordan david_jordan@ncsu.edu orcid.org/0000-0003-4786-2727 Department of Crop and Soil Sciences, North Carolina State University, Box 7620, Raleigh, NC, 27695 USA Correspondence Department of Crop and Soil Sciences, North Carolina State University, Box 7620, Raleigh, NC 27695 Email: david_jordan@ncsu.eduSearch for more papers by this authorChris Reberg-Horton, Chris Reberg-Horton Department of Crop and Soil Sciences, North Carolina State University, Box 7620, Raleigh, NC, 27695 USASearch for more papers by this authorLisa L. Dean, Lisa L. Dean Market Quality and Handling Research Unit, ARS, SEA, USDA, Raleigh, NC, 27695 USASearch for more papers by this authorBarbara B. Shew, Barbara B. Shew Department of Entomology and Plant Pathology, North Carolina State University, Box 7613, Raleigh, NC, 27695 USASearch for more papers by this authorRick L. Brandenburg, Rick L. Brandenburg Department of Entomology and Plant Pathology, North Carolina State University, Box 7613, Raleigh, NC, 27695 USASearch for more papers by this authorDan Anco, Dan Anco Edisto Research and Extension Center, Clemson University, 64 Research Road, Blackville, SC, 29817 USASearch for more papers by this authorHillary Mehl, Hillary Mehl Tidewater Agricultural Research and Extension Center, 6321 Holland Road, Suffolk, VA, 23437 USASearch for more papers by this authorSally Taylor, Sally Taylor Tidewater Agricultural Research and Extension Center, 6321 Holland Road, Suffolk, VA, 23437 USASearch for more papers by this authorMaria Balota, Maria Balota orcid.org/0000-0003-4626-0193 Tidewater Agricultural Research and Extension Center, 6321 Holland Road, Suffolk, VA, 23437 USASearch for more papers by this authorL. Suzanne Goodell, L. Suzanne Goodell Department of Food, Bioprocessing, and Nutrition Sciences, North Carolina State University, Box 7624, Raleigh, NC, 27695 USASearch for more papers by this authorJonathan Allen, Jonathan Allen Department of Food, Bioprocessing, and Nutrition Sciences, North Carolina State University, Box 7624, Raleigh, NC, 27695 USASearch for more papers by this author First published: 14 June 2020 https://doi.org/10.1002/cft2.20042Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat Volume6, Issue12020e20042 RelatedInformation DA - 2020/// PY - 2020/// DO - 10.1002/cft2.20042 VL - 6 IS - 1 SP - SN - 2374-3832 ER - TY - JOUR TI - Efficacy of chlorantraniliprole on southern corn rootworm in peanut AU - Royals, Brian AU - Brandenburg, Rick AU - Hare, Andrew AU - Jordan, David AU - Taylor, Sally AU - Malone, Sean T2 - CROP FORAGE & TURFGRASS MANAGEMENT AB - The authors report no conflicts of interest. DA - 2020/// PY - 2020/// DO - 10.1002/cft2.20045 VL - 6 IS - 1 SP - SN - 2374-3832 ER - TY - JOUR TI - Peanut and soybean response to cropping systems including corn, cotton, and grain sorghum AU - Jordan, David AU - Hare, Andrew AU - Johnson, Dewayne AU - Alston, Joel AU - Alston, Trevor AU - Ambrose, Derek AU - Callis, David AU - Corbett, Tommy AU - Hoggard, Riley AU - Stevens, Brian AU - Wilkins, Reginald AU - Shew, Barbara AU - Brandenburg, Rick T2 - CROP FORAGE & TURFGRASS MANAGEMENT AB - The authors declare no conflict of interest. DA - 2020/// PY - 2020/// DO - 10.1002/cft2.20041 VL - 6 IS - 1 SP - SN - 2374-3832 ER - TY - JOUR TI - Potential economic value for peanut by increasing soil pH in North Carolina AU - Jordan, David AU - Hardy, David AU - Barnes, Steve AU - Corbett, Tommy T2 - CROP FORAGE & TURFGRASS MANAGEMENT AB - The authors declare no conflict of interest. DA - 2020/// PY - 2020/// DO - 10.1002/cft2.20012 VL - 6 IS - 1 SP - SN - 2374-3832 ER - TY - JOUR TI - "Cycling of amino-nitrogen and other nutrients between shoots and roots in cereals-A possible mechanism integrating shoot and root in the regulation of nutrient uptake" by HD Cooper and DT Clarkson, Journal of Experimental Botany (1989) 40:753-762 AU - Rufty, Thomas W. AU - Sinclair, Thomas R. T2 - CROP SCIENCE AB - Abstract This article is part of a series of brief commentaries to highlight papers that have resulted in important and distinctly new perspectives in crop science. A criterion for selection of papers is that they must have been published at least 20 yr ago to allow for a long‐range perspective in assessment of the papers. The current article briefly reviews the paper by H.D. Cooper and D.T. Clarkson published in 1989 that offered an original analysis of internal movement of nitrogen in wheat ( Triticum aestivum L.). Using 15 NO 3 − fed to a split‐root system, they found that a large fraction of absorbed nitrogen was rapidly cycled around the plant as a result of exchanges between the xylem and phloem. They concluded that cycling in the plant ensured tissues had access to a common pool of soluble nitrogen from which nitrogen could be removed and incorporated into protein depending on the demands of tissue growth. The cycling pool of nitrogen also provided a possible whole‐plant signaling mechanism that coordinates growth activities with the feedback control system regulating nitrate uptake by the root. DA - 2020/// PY - 2020/// DO - 10.1002/csc2.20192 VL - 60 IS - 5 SP - 2192-2194 SN - 1435-0653 ER - TY - JOUR TI - Identification and validation of Fusarium head blight resistance QTL in the US soft red winter wheat cultivar 'Jamestown' AU - Carpenter, Neal R. AU - Wright, Emily AU - Malla, Subas AU - Singh, Lovepreet AU - Van Sanford, David AU - Clark, Anthony AU - Harrison, Stephen AU - Murphy, J. Paul AU - Costa, Jose AU - Chao, Shiaoman AU - Brown-Guedira, Gina L. AU - McMaster, Nicole AU - Schmale, David G., III AU - Griffey, Carl A. AU - Rawat, Nidhi T2 - CROP SCIENCE AB - Abstract Use of genetic resistance is one of the most important strategies to manage the devastating disease Fusarium head blight (FHB) in wheat. Numerous quantitative trait loci (QTL) having varying effects on reducing FHB and the mycotoxin deoxynivalenol (DON) accumulation have been reported from Asian, European, or distant sources such as wild relatives of wheat ( Triticum aestivum L.). However, coming from nonadapted backgrounds, the incorporation of such QTL into regional breeding programs has often resulted in the simultaneous transfer of other undesirable traits. Therefore, it is important to identify, characterize, and deploy sources of genetic resistance that do not suffer from poor adaptability and/or linkage drag. In the present work, QTL associated with FHB resistance in a high‐yielding, moderately resistant soft red winter wheat cultivar ‘Jamestown’ were mapped and validated. The QTL mapping was done using a recombinant inbred line (RIL) population of Pioneer ‘25R47’ × Jamestown having 186 individuals. Phenotyping over 2 yr at three locations, and genotyping using the 90K single nucleotide polymorphism (SNP) platform identified two new QTL, named QFHB.vt‐1B.1 and QFHB.vt‐1B.2 , on the chromosome 1B long arm. The QTL contributed to FHB incidence, FHB severity, Fusarium‐damaged kernels, and DON content. Independent mapping of these QTL using two additional RIL populations of FG95195 × Jamestown (170 RILs) and Jamestown × LA97113UC‐124 (77 RILs) validated their stability and effectiveness in different genetic backgrounds. Kompetitive allele specific polymerase chain reaction (KASP) assays were developed using linked SNPs for marker‐assisted selection of the QTL. These QTL are being used in breeding programs to develop FHB‐resistant, high‐yielding varieties. DA - 2020/// PY - 2020/// DO - 10.1002/csc2.20307 VL - 60 IS - 6 SP - 2919-2930 SN - 1435-0653 ER - TY - JOUR TI - Genome-wide analysis and prediction of Fusarium head blight resistance in soft red winter wheat AU - Larkin, Dylan L. AU - Holder, Amanda L. AU - Mason, R. Esten AU - Moon, David E. AU - Brown-Guedira, Gina AU - Price, Paul P. AU - Harrison, Stephen A. AU - Dong, Yanhong T2 - CROP SCIENCE AB - Abstract Fusarium head blight (FHB) is a disease in wheat ( Triticum aestivum L.) caused by the fungal pathogen Fusarium graminearum Schwabe. Fusarium head blight poses potential economic losses and health risks due to the accumulation of the mycotoxin deoxynivalenol (DON) on infected seed heads. The objectives of this study were to identify novel FHB resistance loci using a genome‐wide association study (GWAS) approach and to evaluate two genomic selection (GS) approaches to improve prediction accuracies for FHB traits in a population of 354 soft red winter wheat (SRWW) genotypes. The GS approaches included GS+GWAS, where markers associated with a trait were used as fixed effects, and multivariate GS (MVGS), where correlated traits were used as covariates. The population was evaluated in FHB nurseries in Fayetteville and Newport, AR, and Winnsboro, LA, from 2014 to 2017. Genotypes were phenotyped for DON, Fusarium‐damaged kernels (FDK), incidence (INC), and severity (SEV). Forty‐two single nucleotide polymorphism (SNP) markers were significantly (false discovery rate, q [FDR q ] ≤ .10) associated with resistance traits across 17 chromosomes. Ten significant SNPs were identified for DON, notably on chromosomes 2BL and 3BL. Eleven were identified for FDK, notably on chromosomes 4BL, 3AL, 1BL, 5BL, and 5DL. Nine were identified for INC, notably on chromosomes 2BS, 2BL, 7BL, 5DL, 6AS, and 5DS. Twelve were identified for SEV, notably on chromosomes 3BL, 4AL, and 4BL. The naïve GS models significantly outperformed the GS+GWAS model for all traits, whereas MVGS models significantly outperformed the naïve GS models for all traits. Results from this study will facilitate the development of SRWW cultivars with improved FHB resistance. DA - 2020/// PY - 2020/// DO - 10.1002/csc2.20273 VL - 60 IS - 6 SP - 2882-2900 SN - 1435-0653 ER - TY - JOUR TI - Registration of 'Purple Bounty' and 'Purple Prosperity' hairy vetch AU - Moore, Virginia Mae AU - Maul, Jude E. AU - Wilson, Dave AU - Curran, William S. AU - Brainard, Daniel C. AU - Devine, Thomas E. AU - Mirsky, Steven B. T2 - JOURNAL OF PLANT REGISTRATIONS AB - Abstract The hairy vetch ( Vicia villosa Roth) cultivars ‘Purple Bounty’ (Reg. no. CV‐12, PI 648342) and ‘Purple Prosperity’ (Reg. no. CV‐11, PI 654047) were released in 2007 and 2008, respectively, by the USDA–ARS in collaboration with the Rodale Institute and the agricultural experiment stations of Pennsylvania State University and Cornell University. Hairy vetch is a commonly used annual legume cover crop grown for its cold tolerance, fast growth, large biomass production, and ability to fix N 2 . However, this species has not been selected for the traits needed to optimize its use as a cover crop. Our breeding program focused on developing a cultivar that was both early flowering and had adequate winter survival and therefore adapted to mechanical termination in organic no‐till production in the U.S. Northeast and Mid‐Atlantic. Purple Bounty and Purple Prosperity were developed between 1998 and 2005 using recurrent selection at nurseries in Beltsville and Keedysville, MD. In 2005–2006, selections were evaluated against commercial checks for flowering time in Maryland and Pennsylvania, and in the 2006–2007 and 2007–2008 seasons they were evaluated in 10 locations (12 total site‐years) across the United States for winter survival. Purple Bounty and Purple Prosperity both flowered earlier than the commercial material against which they were tested (significance depended on the date and site); Purple Bounty was the earlier flowering of the two cultivars. Purple Bounty and Purple Prosperity also had equivalent or improved winter survival compared with ‘AU Early Cover’, an early‐maturing cultivar developed in the southern United States, at all test locations. Purple Prosperity is no longer commercially available, but Purple Bounty is currently licensed and distributed by Allied Seed (Nampa, ID). DA - 2020/9// PY - 2020/9// DO - 10.1002/plr2.20044 VL - 14 IS - 3 SP - 340-346 SN - 1940-3496 ER - TY - JOUR TI - Using statistical learning algorithms to predict cover crop biomass and cover crop nitrogen content AU - Marcillo, Guillermo S. AU - Mirsky, Steven AU - Poncet, Aurelie AU - Reberg-Horton, Chris AU - Timlin, Dennis AU - Schomberg, Harry AU - Ramos, Paula T2 - AGRONOMY JOURNAL AB - Abstract Cereal rye ( Secale cereale sp.) is a cover crop species known to improve soil and water quality. Late‐season biomass production is information growers need to maximize cover crop benefits and schedule field operations. Statistical learning, built upon statistical and computational algorithms that “learn” from data, may help to improve predictions of cover crop biomass as a function of initial soil inorganic nitrogen levels. Three models—Least Absolute Shrinkage and Selection Operator (LASSO), Ridge, and Random Forest (RF)—were trained and optimized on a 3‐yr allometric and remote sensing dataset of cereal rye responses to N fertilization in the mid‐Atlantic northern and southeastern United States. Shoot biomass (mean, 9,800 kg ha −1 ) was accurately predicted with a RF model (RMSE, 2,039 kg ha −1 ). Targeting shoot N content (mean, 107 kg ha −1 ), on the other hand, LASSO made accurate and more stable predictions (RMSE, 34 kg ha −1 ). Early‐season information (cover crop C/N ratio, tiller counts, and ground‐sensed normalized difference vegetation index) contributed to enhancing biomass and N content predictions. A final test on untrained data revealed that 92 and 73% of the predictions from either algorithm corresponded to ground‐truthed biomass and shoot N content observed under different N regimes. Modern data‐intensive approaches, such as statistical learning, show promise to characterize end‐season performance of a cover crop and may contribute to better farm decision‐making. DA - 2020/// PY - 2020/// DO - 10.1002/agj2.20429 VL - 112 IS - 6 SP - 4898-4913 SN - 1435-0645 ER - TY - JOUR TI - Registration of three soft red winter wheat germplasm lines with exceptional milling and cookie baking performance AU - Meier, Nicholas A. AU - Malla, Subas AU - Oakes, Joseph C. AU - Murphy, J. Paul AU - Baik, Byung-Kee AU - Chao, Shiaoman AU - Griffey, Carl A. T2 - JOURNAL OF PLANT REGISTRATIONS AB - Abstract The release of soft red winter wheat ( Triticum aestivum , L.) germplasm lines VA11DH‐P46xTrib‐28 (Reg. no. GP‐1048, PI 691656), VA11DH‐P46xTrib‐99 (Reg. no. GP‐1049, PI 691657), and VA11DH‐P46xTrib‐103 (Reg. no. GP‐1050, PI 691658) is intended to provide breeders with genetic material having exceptional milling and baking quality performance. The quantitative nature of milling and baking performance makes improvement and early generation selection difficult. Marker assisted and genomic selection breeding schemes can be improved by introducing breeding material with superior end‐use quality and use of known predictive DNA markers. These three lines have acceptable agronomic performance with grain yields (4605–5733 kg ha −1 ) similar to or higher than those of Pioneer ‘26R46’ (4568 kg ha −1 ). The lines have exceptional milling and baking performance with mean flour yields (733–736 g kg −1 ), softness equivalence (550–573 g kg −1 ), flour protein (89–94 g kg −1 ), solvent retention capacity for lactic acid (1162–1189 g kg −1 ) and sodium carbonate (672–697 g kg −1 ), and cookie diameters (19.1–19.5 cm) that are better than or similar to ( p < .05) those of Pioneer 26R46 (721 g kg −1 , 531 g kg −1 , 93 g kg −1 , 1221 g kg −1 , 703 g kg −1 , and 18.9 cm). DA - 2020/9// PY - 2020/9// DO - 10.1002/plr2.20055 VL - 14 IS - 3 SP - 450-456 SN - 1940-3496 ER - TY - JOUR TI - Inheritance of rhizobitoxine-induced chlorosis in soybean AU - Robinson, K. O. AU - Burton, J. W. AU - Taliercio, E. W. AU - Israel, D. W. AU - Carter, T. E., Jr. T2 - CROP SCIENCE AB - Abstract There are two species of Bradyrhizobium that nodulate soybean [ Glycine max (L.) Merr.] and fix nitrogen (N): B. japonicum and B. elkanii . Bradyrhizobium elkanii is endemic to soils in the southeastern region of the United States. Some strains of B. elkanii produce rhizobitoxine (RT), a toxin that causes chlorosis on newly developing trifoliates of some field‐grown soybean, in root nodules. Some soybean genotypes are resistant to rhizobitoxine‐induced (RI) chlorosis. The objective of this research was to determine the inheritance of soybean resistance to RI chlorosis. Crosses were made between resistant and susceptible cultivars. Progeny were identified as susceptible, resistant, or segregating in the first, second, and third self‐pollinated generations. All F 1 hybrids from crosses between resistant and susceptible soybean exhibited seedling chlorosis, indicating that genes for resistance to chlorosis are recessive. The F 2 progeny segregated in a ratio of nine susceptible to seven resistant, indicating that there are two genes responsible for the soybean resistance to RI chlorosis. This ratio was confirmed in F 2:3 population screening. One hundred forty‐one simple sequence repeat (SSR) markers polymorphic in both a susceptible parent and a resistant parent were used to locate the genes responsible for resistance to chlorosis. A gene found near marker Satt 657 on linkage group (LG) F (chromosome 13) explained a statistically significant 32% of the phenotypic variation among F 2 plants based on the p ‐value and R 2 of a single factor ANOVA. The second gene was not located. DA - 2020/// PY - 2020/// DO - 10.1002/csc2.20193 VL - 60 IS - 6 SP - 3027-3034 SN - 1435-0653 ER - TY - JOUR TI - Cover crop biomass production across establishment methods in mid-Atlantic corn AU - Moore, Virginia M. AU - Mirsky, Steven B. T2 - AGRONOMY JOURNAL AB - Abstract Drill‐interseeding, broadcast‐interseeding, and post‐harvest drilling for establishment of overwintering cover crops after no‐till corn ( Zea mays L.) each present distinct challenges and benefits. Experiments were conducted at the Beltsville Agricultural Research Center (Beltsville, MD) across three growing seasons (2013–2014, 2014–2015, 2015–2016) to evaluate the relative performance of these three establishment methods across four cover crop treatments: (a) cereal rye ( Secale cereale L.), (b) annual ryegrass [ Lolium perenne L. ssp. multiflorum (Lam.) Husnot], (c) a legume mixture including red clover ( Trifolium pratense L.), crimson clover ( Trifolium incarnatum L.), and hairy vetch ( Vicia villosa Roth), and (d) a grass–legume mixture including annual ryegrass, red clover, crimson clover, and hairy vetch. Both fall and spring biomass showed a significant three‐way interaction effect among cover crop, establishment method, and year. Cereal rye had the greatest biomass with late post‐harvest drilling but produced less fall and spring biomass than other cover crops in the drill‐interseeded treatments in two of the three growing seasons. The drill‐interseeded legume mixture produced less spring biomass than annual ryegrass and the grass–legume mixture when established at a later corn growth stage. Our results highlight potential pitfalls of each establishment method and cover crop, depending on annual variability in weather and management. DA - 2020/// PY - 2020/// DO - 10.1002/agj2.20414 VL - 112 IS - 6 SP - 4765-4774 SN - 1435-0645 ER - TY - JOUR TI - Registration of USDA-N7004 soybean germplasm with good yield, elevated seed protein, and 25% exotic pedigree from Tamahikari AU - McNeece, Brant T. AU - Bagherzadi, Laleh AU - Carter, Thomas E., Jr. AU - Mian, M. A. Rouf T2 - JOURNAL OF PLANT REGISTRATIONS AB - Abstract USDA‐N7004 (Reg. no. GP‐438, PI 692263) is a conventional late maturity group VII soybean [ Glycine max (L.) Merr.] germplasm with good yield potential, elevated seed protein content, and 25% exotic pedigree from Japanese cultivar Tamahikari (PI 423897). USDA‐N7004 was jointly released as a non‐GM germplasm by the USDA‐ARS and the North Carolina Agricultural Research Service in September 2019. USDA‐N7004, experimental name N10‐711, was derived from a cross of USDA‐ARS breeding lines NTCPR01‐163 (‘Dillon’ × Tamahikari) and N03‐832. Across 27 environments of the USDA Uniform Soybean Tests‐Southern States (Uniform Tests), USDA‐N7004 yielded 97 and 94% of elite checks ‘N7003CN’ and ‘NC‐Wilder’, respectively. Over 20 environments of United Soybean Board Southern Diversity Yield Trials (Diversity Trials), USDA‐N7004 yielded 98 and 94% of the same two checks, respectively. In the Uniform Tests, seed protein content of USDA‐N7004 (421 g kg −1 ) was significantly higher than N7003CN and NC‐Wilder on a zero‐moisture basis (405 and 399 g kg −1 , respectively). The meal protein content of USDA‐N7004 (49%) was significantly higher than N7003CN or NC‐Wilder (47%) in the Uniform Tests as well as in the Diversity Trials. USDA‐N7004 should be a useful parent in breeding programs aimed at broadening the genetic base of soybean along with improving seed protein and seed yield. DA - 2020/9// PY - 2020/9// DO - 10.1002/plr2.20039 VL - 14 IS - 3 SP - 431-436 SN - 1940-3496 ER - TY - JOUR TI - Exploration of Nutrient Needs of Brassica carinata and Other Brassica sp. AU - Cockson, Paul DA - 2020/// PY - 2020/// UR - https://www.lib.ncsu.edu/resolver/1840.20/38344 ER - TY - JOUR TI - Nitrogen Management of Barley for Malt Quality in the Mountains, Piedmont, Sandhills, and Coastal Plain areas of North Carolina. AU - Whelan, Joshua DA - 2020/// PY - 2020/// UR - https://www.lib.ncsu.edu/resolver/1840.20/38072 ER - TY - JOUR TI - Critical Period of Grass Weed Control in Grain Sorghum (Sorghum bicolor) and Wheat (Triticum aestivum). AU - Contreras Gamero, Diego Jose DA - 2020/// PY - 2020/// UR - https://www.lib.ncsu.edu/resolver/1840.20/37479 ER - TY - JOUR TI - FRST: A national soil testing database to improve fertility recommendations AU - Lyons, Sarah E. AU - Osmond, Deanna L. AU - Slaton, Nathan A. AU - Spargo, John T. AU - Kleinman, Peter J. A. AU - Arthur, Dan K. AU - McGrath, Joshua M. T2 - AGRICULTURAL & ENVIRONMENTAL LETTERS AB - Abstract Soil testing is an important practice for nutrient management in agricultural production systems. In the United States, soil‐test methods and interpretations vary across state lines, making institutional collaborations challenging and crop fertilization guidelines inconsistent. Uniformity and transparency in P and K soil fertility testing and fertilizer recommendations are needed to enhance end‐user adoption. The Fertilizer Recommendation Support Tool (FRST) project is developing a comprehensive database of P and K correlation–calibration results that can be accessed through an online tool for use in research and fertilizer recommendation development. This collaborative project, which includes over 30 land‐grant universities, the USDA‐ARS, the USDA‐NRCS, and several not‐for‐profit organizations, contains a national survey describing the current status of soil testing, minimum requirements for correlation–calibration data inclusion, and database population and creating FRST as a user‐friendly online decision support tool. The FRST project will provide more consistent, transparent, and science‐based information for crop nutrient recommendations across the United States. DA - 2020/// PY - 2020/// DO - 10.1002/ael2.20008 VL - 5 IS - 1 SP - SN - 2471-9625 ER - TY - JOUR TI - Registration of soybean germplasm lines R10-2436 and R10-2710 with drought tolerance traits and high yield under moderate water stress AU - Manjarrez-Sandoval, Pedro AU - Chen, Pengyin AU - Mozzoni, Leandro AU - Florez-Palacios, Liliana AU - Orazaly, Moldir AU - Wu, Chengjun AU - Sinclair, Thomas R. AU - Carter, Thomas E., Jr. AU - Purcell, Larry C. AU - King, C. Andy T2 - JOURNAL OF PLANT REGISTRATIONS AB - Abstract Soybean [ Glycine max (L.) Merr.] lines R10‐2436 (Reg. no. GP‐439, PI 692971) and R10‐2710 (Reg. no. GP‐440, PI 692972) are high‐yielding and drought‐tolerant conventional germplasm released by the Arkansas Agricultural Experiment Station in February 2017. R10‐2436 and R10‐2710 have a relative maturity of 5.6 and 5.8, respectively. R10‐2436 is an F 4 –derived line from the cross R01‐52F × R02‐6268F, and R10‐2710 is an F 2 –derived line from R01‐52F × ‘USDA‐N7002’. In 6 yr of testing, R10‐2436 and R10‐2710 significantly outyielded the maturity group 5 check mean under moderate water‐deficit stress in Stuttgart, AR (2,893, 2,889, and 2,506 kg ha −1 , respectively) and were on a par with the checks under full irrigation in Stuttgart (4,644, 4,511, and 4,613 kg ha −1 , respectively) and in five additional irrigated Arkansas environments. The water‐deficit treatment consisted of normal irrigation until blooming, after which irrigation was suspended for the rest of the season. In greenhouse pot studies, both releases exhibited sustained nitrogen fixation during a dry‐down cycle. This trait was presumably inherited from their ancestor ‘Jackson’. R10‐2436 also exhibited slow wilting in multiple drought‐stressed environments in Arkansas and North Carolina, likely inherited from PI 416937. Because of their yield potential under drought and irrigation, as well as their good agronomic characteristics, R10‐2436 and R10‐2710 can be easily incorporated in applied breeding programs to transfer drought tolerance into elite high‐yielding cultivars. DA - 2020/5// PY - 2020/5// DO - 10.1002/plr2.20048 VL - 14 IS - 2 SP - 189-196 SN - 1940-3496 ER - TY - JOUR TI - Quantitative trait loci sequencing-derived molecular markers for selection of stem rot resistance in peanut AU - Cui, Renjie AU - Clevenger, Josh AU - Chu, Ye AU - Brenneman, Timothy AU - Isleib, Thomas G. AU - Holbrook, C. Corley AU - Ozias-Akins, Peggy T2 - CROP SCIENCE AB - Abstract Developing markers linked to key traits has been a focus of peanut ( Arachis hypogaea L.) genomics in the postgenome era. Multiple disease resistance traits have been found to be qualitative and controlled by major quantitative trait loci (QTL) or even single genes while others are more complex. Southern stem rot (stem rot in short) is a devastating disease of peanut caused by the fungus Sclerotium rolfsii . It has been one of the most damaging diseases of peanut with regard to both cost of control and yield loss in the southeastern United States for the last decade. The disease is initiated annually from sclerotia in the soil. The nonuniform distribution of these propagules leads to the nonuniform development of disease, which makes phenotyping and genetic mapping of resistance difficult. Here we report the mapping of two QTL regions controlling stem rot resistance in peanut. Using careful field evaluation, resistant and susceptible bulks were identified from a recombinant inbred line (RIL) population and subjected to QTL sequencing (QTL‐seq). Developed SNP markers linked to the QTL were validated in a blind selection test by selecting only with markers in a part of the population not used for initial analysis. The lines selected for bulk sequencing also were shown to have strong separation for resistance in an independent field experiment. This work not only delivers markers for marker‐assisted selection (MAS) for an important disease in peanut but shows that QTL‐seq can work effectively even when considering highly complex, and quantitative traits. DA - 2020/// PY - 2020/// DO - 10.1002/csc2.20047 VL - 60 IS - 4 SP - 2008-2018 SN - 1435-0653 ER - TY - JOUR TI - Quantification of palmer amaranth seed number using a computerized particle analyzer AU - Bertucci, Matthew B. AU - Bartley, Paul C., III AU - Jennings, Katherine M. AU - Monks, David W. AU - Jackson, Brian E. T2 - AGRICULTURAL & ENVIRONMENTAL LETTERS AB - Abstract We evaluated the accuracy of a computerized particle analyzer (CPA) for high‐throughput counting of Palmer amaranth ( Amaranthus palmeri S. Watson) seeds and subsequently used the CPA to verify the accuracy of two subsampling methods for estimation of Palmer amaranth seed production. To determine accuracy of the CPA, 55 hand‐counted samples, ranging from 500 to 5000 Palmer amaranth seeds, were drawn from field samples and counted with the CPA. The relationship between hand and CPA seed counts was described by a linear model ( R 2 = 0.99) with a slope of 0.987 and a y ‐intercept of 3.49. Thus, very little discrepancy exists between seed counts conducted by hand or the CPA. Additionally, two published methods for estimation of Palmer amaranth seed production were compared to the CPA and proven to be highly accurate. We conclude from these findings that the CPA offers a high‐throughput alternative for weed scientists who frequently count large quantities of seed. DA - 2020/// PY - 2020/// DO - 10.1002/ael2.20003 VL - 5 IS - 1 SP - SN - 2471-9625 ER - TY - JOUR TI - Focusing the future of farming on agroecology AU - Franzluebbers, Alan J. AU - Wendroth, Ole AU - Creamer, Nancy G. AU - Feng, Gary G. T2 - AGRICULTURAL & ENVIRONMENTAL LETTERS AB - Abstract The future of humanity and how agriculture can continue to support the food and fiber needs of a burgeoning population are threatened by agriculture's persistent negative effects on the environment. Essential natural resources that will be needed in increasingly greater capacity are being undermined by agricultural practices that continue to deplete the soil resource base, pollute freshwater and coastal estuaries needed for life support, reduce habitat to support biodiversity, and emit harmful greenhouse gases that compromise our ability to withstand changes to the climate. Solutions to these problems are available in known and increasingly well documented approaches using agroecological principles that manage food production in harmony with nature, not against it. This commentary provides a message that we should be seeking healing of our planet, not just less harm than in the past. It is an important distinction that needs to be considered for the future health of people and the planet. DA - 2020/// PY - 2020/// DO - 10.1002/ael2.20034 VL - 5 IS - 1 SP - SN - 2471-9625 ER - TY - JOUR TI - Risk to sustainability of pest management tools in peanut AU - Jordan, David L. AU - Dunne, Jeffrey AU - Stalker, H. Thomas AU - Shew, Barbara B. AU - Brandenburg, Rick L. AU - Anco, Dan AU - Mehl, Hillary AU - Taylor, Sally AU - Balota, Maria T2 - AGRICULTURAL & ENVIRONMENTAL LETTERS AB - Abstract A diversity of pests can adversely affect peanut ( Arachis hypogaea L.) yield, quality, and financial return. Farmers rely heavily on applied chemicals to suppress many of the economically important pests present in peanut. The effectiveness of this approach to pest management may not be sustainable, however, due to evolved resistance in pests to chemicals, reluctance of basic chemical manufacturers to invest in product development because of the relatively small market for peanut compared with other crops, cost to initially register or re‐register chemicals, and the desire for peanut buyers and processors to capture international markets that may have varying agrochemical residue restrictions for peanut. Heavy reliance on chemical control could leave peanut production systems vulnerable to yield loss; thus, a more concerted research effort is needed to increase the number and availability of nonchemical tools that protect peanut from pests in order to ensure long‐term sustainability of peanut production systems. DA - 2020/// PY - 2020/// DO - 10.1002/ael2.20018 VL - 5 IS - 1 SP - SN - 2471-9625 ER - TY - JOUR TI - Registration of GP-VT NC 01 peanut germplasm AU - Balota, M. AU - Isleib, T. G. T2 - JOURNAL OF PLANT REGISTRATIONS AB - Abstract GP‐VT NC 01 (Reg. no. GP‐238, PI 691613) is a virginia‐type peanut ( Arachis hypogaea L. subsp. hypogaea var. hypogaea ) with good agronomic characteristics and improved drought tolerance. GP‐VT NC 01 was tested under the experimental designation N05006. Replicated yield tests started in the F 6 generation in North Carolina in 2005. From 2008 through 2010, GP‐VT NC 01 was tested in replicated trials in the Peanut Variety and Quality Evaluation, multistate project S1038, in Virginia, North Carolina, and South Carolina. In 2013 and 2014, GP‐VT NC 01 was tested in the field at the Tidewater Agricultural Research and Experiment Station in Suffolk, VA, under rain exclusion shelters with controlled water regimes ranging from optimum soil moisture to severe drought. In these tests, GP‐VT NC 01 was compared with the current cultivars grown in Virginia and the Carolinas—‘Bailey’, ‘Sugg’, ‘Sullivan’, and ‘Wynne’—and a drought‐tolerant species derived germplasm line (GP‐NC WS17). Under “normal” weather, in rainfed production, GP‐VT NC 01 had similar yield to Bailey and Sugg and significantly better yield than Sullivan or Wynne. Extra‐large kernels content was least, although not significantly smaller than Sullivan and Wynne. No significant differences in sound mature kernels were noted among the cultivars tested. However, during dry and hot years, and under drought‐controlled conditions, the yield of GP‐VT NC 01 was significantly higher than that of the other cultivars tested. Thus, the release of GP‐VT NC 01 provides producers with a profitable option that will perform well under drought stress. DA - 2020/5// PY - 2020/5// DO - 10.1002/plr2.20028 VL - 14 IS - 2 SP - 172-178 SN - 1940-3496 ER - TY - JOUR TI - Program Chair Poster Pick: Late-Breaking Abstract: A Rapid Consumer Survey Capturing the Perceptions of Beef Marketing Before and During COVID-19 AU - Snyder, Lori Unruh AU - Fisher, Melanie T2 - JOURNAL OF ANIMAL SCIENCE AB - Abstract In today’s marketplace, consumers have a plethora of options when it comes to purchasing beef, whether that be conventional, all-natural, organic, or any other feed based labeling. They also have the freedom to make that purchasing decision based on the brand, packaging, and price just to name a few. However, the supply of beef that is on the shelves for consumers changed since the beginning of the COVID-19 outbreak. This poster reveals that no significant differences were recorded with purchasing decisions nor marketing decisions; however, data was analyzed for themes that are present during this pandemic.The purpose of this study is to find out how the purchasing behaviors of consumers have changed since the COVID-19 outbreak in terms of beef. Are specialty labels less important? Does brand loyalty still matter? In order to evaluate this, we asked consumers several questions to better understand current behaviors and trends for the marketing of beef products. The poster will provide the coded data and summaries of the total population of 54 participants. DA - 2020/11// PY - 2020/11// DO - 10.1093/jas/skaa278.601 VL - 98 SP - 338-338 SN - 1525-3163 KW - beef KW - marketing KW - attitudes ER - TY - JOUR TI - Conservation and divergence in sorgoleone production of sorghum species AU - Besançon, Thierry E. AU - Dayan, Franck E. AU - Gannon, Travis W. AU - Everman, Wesley J. T2 - Journal of Environmental Quality AB - Abstract Sorgoleone‐358 is an important allelochemical of the oily droplets exuded from root hairs of various species in the Sorghum genus. Due to its hydrophobic nature, sorgoleone‐358 can be strongly adsorbed onto soil organic matter, resulting in increased sorgoleone soil persistence. Because of the herbicidal activity of sorgoleone on many small‐seeded weeds, concerns have been raised that sorghum residues may have a detrimental effect on emergence of wheat used as a double crop in the southeastern United States. Laboratory experiments were conducted to evaluate root exudate production and its sorgoleone‐358 content for 36 cultivated sorghum cultivars as well as eight shattercane [ Sorghum bicolor (L.) Moench ssp. arundinaceum (Desv.) de Wet & Harlan] accessions and one johnsongrass [ S. halepense (L.) Pers.] accession. Using a capillary growing mat system, root exudate was extracted with dichloromethane and subjected to chromatography analysis to determine sorgoleone‐358 content. Root biomass of 7‐ to 12‐d‐old seedlings averaged 18.8 mg g −1 seed, and root exudate production ranged from 0.2 and 4.8 mg g −1 root fresh weight (RFW). The amount of sorgoleone produced varied greatly among sorghum accessions. Sorgoleone‐358 amount in the root exudate averaged 0.5 mg g −1 RFW and varied from 0.13 to 1.05 mg g −1 for shattercane cultivar S7 and cultivated sorghum cultivar 992123, respectively. Regarding volume of root biomass, sorgoleone‐358 levels averaged 0.49 mg g −1 (range, 0.06–1.46 mg g −1 ) for sorghum cultivar AAS3479 and shattercane cultivar S2, respectively. Segregation of commercial sorghum cultivars according to their maturity group did not show any difference in root biomass and dry extract production, but early‐maturing cultivars produced on average 18% less sorgoleone‐358 compared with medium‐ and late‐maturing cultivars. These results suggest that sorgoleone production may be genetically constitutive because sorghum growing conditions were identical across cultivars. DA - 2020/3// PY - 2020/3// DO - 10.1002/jeq2.20038 VL - 49 IS - 2 SP - 368-377 UR - https://doi.org/10.1002/jeq2.20038 ER - TY - JOUR TI - Genome-wide association analysis of the strength of the MAMP-elicited defense response and resistance to target leaf spot in sorghum AU - Samira, Rozalynne AU - Kimball, Jennifer A. AU - Samayoa, Luis Fernando AU - Holland, James B. AU - Jamann, Tiffany M. AU - Brown, Patrick J. AU - Stacey, Gary AU - Balint-Kurti, Peter J. T2 - SCIENTIFIC REPORTS AB - Plants have the capacity to respond to conserved molecular features known as microbe-associated molecular patterns (MAMPs). The goal of this work was to assess variation in the MAMP response in sorghum, to map loci associated with this variation, and to investigate possible connections with variation in quantitative disease resistance. Using an assay that measures the production of reactive oxygen species, we assessed variation in the MAMP response in a sorghum association mapping population known as the sorghum conversion population (SCP). We identified consistent variation for the response to chitin and flg22-an epitope of flagellin. We identified two SNP loci associated with variation in the flg22 response and one with the chitin response. We also assessed resistance to Target Leaf Spot (TLS) disease caused by the necrotrophic fungus Bipolaris cookei in the SCP. We identified one strong association on chromosome 5 near a previously characterized disease resistance gene. A moderately significant correlation was observed between stronger flg22 response and lower TLS resistance. Possible reasons for this are discussed. DA - 2020/11/30/ PY - 2020/11/30/ DO - 10.1038/s41598-020-77684-w VL - 10 IS - 1 SP - SN - 2045-2322 ER - TY - JOUR TI - Genetic and genomic resources to study natural variation in Brassica rapa AU - Lou, Ping AU - Woody, Scott AU - Greenham, Kathleen AU - VanBuren, Robert AU - Colle, Marivi AU - Edger, Patrick P. AU - Sartor, Ryan AU - Zheng, Yakun AU - Levendoski, Nathan AU - Lim, Jan AU - So, Calvin AU - Stoveken, Brian AU - Woody, Timothy AU - Zhao, Jianjun AU - Shen, Shuxing AU - Amasino, Richard M. AU - McClung, C. Robertson T2 - PLANT DIRECT AB - Abstract The globally important crop Brassica rapa, a close relative of Arabidopsis, is an excellent system for modeling our current knowledge of plant growth on a morphologically diverse crop. The long history of B. rapa domestication across Asia and Europe provides a unique collection of locally adapted varieties that span large climatic regions with various abiotic and biotic stress‐tolerance traits. This diverse gene pool provides a rich source of targets with the potential for manipulation toward the enhancement of productivity of crops both within and outside the Brassicaceae. To expand the genetic resources available to study natural variation in B. rapa, we constructed an Advanced Intercross Recombinant Inbred Line (AI‐RIL) population using B. rapa subsp. trilocularis (Yellow Sarson) R500 and the B. rapa subsp. parachinensis (Cai Xin) variety L58. Our current understanding of genomic structure variation across crops suggests that a single reference genome is insufficient for capturing the genetic diversity within a species. To complement this AI‐RIL population and current and future B. rapa genomic resources, we generated a de novo genome assembly of the B. rapa subsp. trilocularis (Yellow Sarson) variety R500, the maternal parent of the AI‐RIL population. The genetic map for the R500 x L58 population generated using this de novo genome was used to map Quantitative Trait Loci (QTL) for seed coat color and revealed the improved mapping resolution afforded by this new assembly. DA - 2020/12// PY - 2020/12// DO - 10.1002/pld3.285 VL - 4 IS - 12 SP - SN - 2475-4455 KW - Advanced-Intercross Recombinant Inbred Lines KW - Brassica rapa KW - natural variation KW - Quantitative Trait Loci KW - seed coat color ER - TY - JOUR TI - Phosphate solubilization from adsorbents and precipitates by different AVAIL polymers AU - Doydora, Sarah AU - Thompson, Margaret AU - Hesterberg, Dean T2 - SOIL SCIENCE SOCIETY OF AMERICA JOURNAL AB - Abstract Less than 40% of phosphate fertilizer applied to soils is typically taken up by the intended crop within the year of application because of strong soil retention. AVAIL polymers are fertilizer additives that were commercially developed to enhance availability of fertilizer phosphate. Knowledge of underlying mechanisms of phosphate solubilization would help to optimize the effectiveness of these polymers for different soils. This study compared different types and levels of AVAIL polymers in solubilizing (ad)sorbed and precipitated phosphate to gain insights into the mechanisms involved. Varying inputs of four newer forms of polymers and the original AVAIL (Original) were co‐reacted with one level of phosphate (ad)sorbed on ferrihydrite or noncrystalline Al hydroxide in batch (ad)sorption experiments or with Fe and Ca phosphate precipitates in dissolution experiments. Dissolved phosphate increased with increasing levels of co‐added polymers reacted with (ad)sorbents or phosphate precipitates. Across input levels evaluated, the Original AVAIL generally solubilized more phosphate from ferrihydrite than any of the new formulations. The Original and the new Liquid 2 formulation equally solubilized the greatest phosphate from Fe phosphate, whereas Liquid 2 solubilized more phosphate from Al hydroxide and Ca phosphate. (Ad)sorption and dissolution results implied competitive (ad)sorption and complexometric dissolution as key mechanisms. Our results suggest that the effectiveness of AVAIL polymers in soils depends on the level of added polymer charge relative to phosphate adsorption capacities or the types of phosphate minerals present. DA - 2020/11// PY - 2020/11// DO - 10.1002/saj2.20168 VL - 84 IS - 6 SP - 1833-1845 SN - 1435-0661 ER - TY - JOUR TI - Root-induced changes in soil thermal and dielectric properties should not be ignored AU - Fu, Y. AU - Lu, Y. AU - Heitman, J. AU - Ren, T. T2 - Geoderma AB - There is a lack of quantitative understandings on root-mediated changes of soil physical properties. Here we investigated the influences of maize roots on soil heat capacity (C), thermal conductivity (λ) and dielectric constant (ε) of the root zone. Root-zone soil cores were collected at different depths and horizontal positions from the eighth leaf to milk stage of maize, and C, λ and ε of the samples were measured with the thermo-TDR technique. Improved C, λ and ε models that included the influences of roots were developed and validated. The patterns and magnitudes of root effects on C, λ and ε generally followed the configurations of root distribution. On average, the presence of roots caused increases in soil C, λ and ε by 8.8%, 7.1% and 13.6%, respectively. For the root-zone soils, root influences on thermal properties and dielectric constant were significant and could be described quantitatively by using the proposed models. DA - 2020/// PY - 2020/// DO - 10.1016/j.geoderma.2020.114352 VL - 370 IS - 114352 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-85082710178&partnerID=MN8TOARS ER - TY - JOUR TI - New Pedotransfer Functions for Soil Water Retention Curves that Better Account for Bulk Density Effects AU - Tian, Z. AU - Chen, J. AU - Cai, C. AU - Gao, W. AU - Ren, T. AU - Heitman, J.L. AU - Horton, R. T2 - Soil and Tillage Research DA - 2020/// PY - 2020/// VL - 205 IS - 104812 ER - TY - JOUR TI - Modeling water fluxes through containerized soilless substrates using HYDRUS AU - Fields, Jeb S. AU - Owen, James S., Jr. AU - Stewart, Ryan D. AU - Heitman, Josh L. AU - Caron, Jean T2 - VADOSE ZONE JOURNAL AB - Abstract Containerized crop production can enhance plant health and ensure environmental sustainability, yet proper management requires improved understanding of water fluxes and storage within soilless substrates. Numerical simulation tools developed to simulate water movement in porous media, such as HYDRUS‐3D, may help to quantify effective hydraulic properties of soilless substrates but have not yet been tested in this capacity. Therefore, this study had three main objectives: (a) to assess the accuracy of HYDRUS‐3D for simulating water flow through peat‐ and bark‐based soilless substrates by comparing measured and modeled drainage and water storage; (b) to determine sensitivity of model outputs to individual hydraulic parameters; and (c) to compare model parameterization using three laboratory characterization methods (instantaneous profile sorption, instantaneous profile desorption, and evaporation) vs. inverse modeling with HYDRUS. The results showed that the modeled water contents and drainage timing and amounts were most sensitive to saturated volumetric water content (θ s ) and least sensitive to saturated hydraulic conductivity ( K s ). With regard to parameterization methods, the inverse modeling approach provided the most accurate water balance simulations for both substrates, followed by the sorption method. These two methods estimated lower peak water contents and greater drainage compared with simulations parameterized using desorption and evaporation measurements. Overall, the study results showed that the Richards equation, as calculated using HYDRUS, can provide accurate simulations of water flux through containers when properly calibrated, though sorption‐derived parameters may suffice when model optimization is impractical. DA - 2020/// PY - 2020/// DO - 10.1002/vzj2.20031 VL - 19 IS - 1 SP - SN - 1539-1663 ER - TY - JOUR TI - Comparison of Water Capture Efficiency through Two Irrigation Techniques of Three Common Greenhouse Soilless Substrate Components AU - Fields, J.S. AU - Fonteno, W.C. AU - Jackson, B.E. AU - Heitman, J.L. AU - Owen, J.S. T2 - Agronomy DA - 2020/// PY - 2020/// VL - 10 IS - 1393 ER - TY - JOUR TI - Differential Ozone Responses Identified among Key Rust-Susceptible Wheat Genotypes AU - Mashaheet, Alsayed M. AU - Burkey, Kent O. AU - Saitanis, Costas J. AU - Abdelrhim, Abdelrazek S. AU - Rafiullah AU - Marshall, David S. T2 - AGRONOMY-BASEL AB - Increasing ambient ozone (O3) concentrations and resurgent rust diseases are two concomitant limiting factors to wheat production worldwide. Breeding resilient wheat cultivars bearing rust resistance and O3 tolerance while maintaining high yield is critical for global food security. This study aims at identifying ozone tolerance among key rust-susceptible wheat genotypes [Rust near-universal susceptible genotypes (RnUS)], as a first step towards achieving this goal. Tested RnUS included seven bread wheat genotypes (Chinese Spring, Line E, Little Club, LMPG 6, McNair 701, Morocco and Thatcher), and one durum wheat line (Rusty). Plants were treated with five O3 concentrations (CF, 50, 70, 90, and 110 ppb), in two O3 exposure systems [continuous stirred tank reactors (CSTR) and outdoor-plant environment chambers (OPEC)], at 21–23 Zadoks decimal growth stage. Visible injury and biomass accumulation rate were used to assess O3 responses. Visible injury data showed consistent order of genotype sensitivity (Thatcher, LMPG 6 > McNair 701, Rusty > Line E, Morocco, Little Club > Chinese Spring). Additionally, leaves at different orders showed differential O3 responses. Biomass accumulation under O3 stress showed similar results for the bread wheat genotypes. However, the durum wheat line “Rusty” had the most O3-sensitive biomass production, providing a contrasting O3 response to the tolerance reported in durum wheat. Chinese Spring was the most tolerant genotype based on both parameters and could be used as a source for O3 tolerance, while sensitive genotypes could be used as sensitive parents in mapping O3 tolerance in bread wheat. The suitability of visible symptoms and biomass responses in high-throughput screening of wheat for O3 tolerance was discussed. The results presented in this research could assist in developing future approaches to accelerate breeding wheat for O3 tolerance using existing breeding materials. DA - 2020/12// PY - 2020/12// DO - 10.3390/agronomy10121853 VL - 10 IS - 12 SP - SN - 2073-4395 KW - global food security KW - resilient wheat KW - relative growth rate KW - ozone injury ER - TY - JOUR TI - Abscisic Acid and Sulfate Offer a Possible Explanation for Differences in Physiological Drought Response of Two Maize Near-Isolines AU - Shekoofa, Avat AU - Sinclair, Thomas R. T2 - PLANTS-BASEL AB - The hypothesis was tested that differences in response to water-deficits between low osmotic potential (LOP) and high osmotic potential (HOP) maize (Zea mays L.) near-isolines were associated with differences in transpiration rate sensitivity to abscisic acid (ABA) and/or sulfate. In a series of four experiments, decreases in transpiration rate (DTR) of whole plants and fully expanded leaves were measured in response to treatments of 1.0 µM ABA and 15 mM MgSO4 singly and in combination following long (2 day) and short (180 min) exposures. There was little evidence that intact plants grown on soil were responsive to the treatments. For hydroponically grown plants subjected to long exposure, there was similarly no response to treatments. Further, the short exposure of hydroponically grown plants to solely ABA or a combination of chemicals resulted in no sensitivity in DTR for either of the near-isolines. On the other hand, when these plants were fed sulfate, the transpiration was stimulated by about 20% for the LOP and 60% for the HOP. Detached leaves proved to be the most sensitive to treatment. Treatment with the two chemicals singly caused essentially equivalent DTR in the two near-isolines. However, treatment with ABA plus sulfate resulted in different DTR between the two near-isolines with values of 65% for the LOP and 16% for the HOP near-isoline. Overall, these results showed that the short exposure treatment of hydroponically grown plants or detached leaves supported the hypothesis of different transpiration rate sensitivities of the near-isolines in response to ABA and sulfate treatments. DA - 2020/12// PY - 2020/12// DO - 10.3390/plants9121713 VL - 9 IS - 12 SP - SN - 2223-7747 KW - maize near-isolines KW - abscisic acid KW - sulfate KW - osmotic potential ER - TY - JOUR TI - The trade credit channel and monetary policy transmission: Empirical evidence from US panel data AU - Altunok, Fatih AU - Mitchell, Karlyn AU - Pearce, Douglas K. T2 - QUARTERLY REVIEW OF ECONOMICS AND FINANCE AB - We investigate the US trade credit channel proposed by Meltzer (1960). We estimate reduced-form trade credit supply and demand models on quarterly firm-level data for most public corporations from 1988 to 2007. We use a novel method of distinguishing firms by access to funds using the indexes of Whited and Wu (2006) and Altman (1968). Tight monetary policy produced greater expansion of receivables than payables, expansion of receivables that varied by funds-access, and some expansion of payables by firms with poor access. Tight policy produced expansion of net trade credit by corporations which flowed to entities like private businesses, a major component of the channel. DA - 2020/11// PY - 2020/11// DO - 10.1016/j.qref.2020.03.001 VL - 78 SP - 226-250 SN - 1878-4259 KW - Trade credit KW - Monetary policy KW - Corporate finance KW - Credit cycle KW - Credit rationing ER - TY - JOUR TI - Eleven biosynthetic genes explain the majority of natural variation for carotenoid levels in maize grain AU - Diepenbrock, Christine H. AU - Ilut, Daniel C. AU - Magallanes-Lundback, Maria AU - Kandianis, Catherine B. AU - Lipka, Alexander E. AU - Bradbury, Peter J. AU - Holland, James B. AU - Hamilton, John P. AU - Wooldridge, Edmund AU - Vaillancourt, Brieanne AU - Góngora-Castillo, Elsa AU - Wallace, Jason G. AU - Cepela, Jason AU - Mateos-Hernandez, Maria AU - Owens, Brenda F. AU - Tiede, Tyler AU - Buckler, Edward S. AU - Rocheford, Torbert AU - Buell, C. Robin AU - Gore, Michael A. AU - DellaPenna, Dean AB - ABSTRACT Vitamin A deficiency remains prevalent in parts of Asia, Latin America, and sub-Saharan Africa where maize is a food staple. Extensive natural variation exists for carotenoids in maize grain; to understand its genetic basis, we conducted a joint linkage and genome-wide association study in the U.S. maize nested association mapping panel. Eleven of the 44 detected quantitative trait loci (QTL) were resolved to individual genes. Six of these were correlated expression and effect QTL (ceeQTL), showing strong correlations between RNA-seq expression abundances and QTL allelic effect estimates across six stages of grain development. These six ceeQTL also had the largest percent phenotypic variance explained, and in major part comprised the three to five loci capturing the bulk of genetic variation for each trait. Most of these ceeQTL had strongly correlated QTL allelic effect estimates across multiple traits. These findings provide the most comprehensive genome-level understanding of the genetic and molecular control of carotenoids in any plant system, and a roadmap to accelerate breeding for provitamin A and other priority carotenoid traits in maize grain that should be readily extendable to other cereals. DA - 2020/7/15/ PY - 2020/7/15/ DO - 10.1101/2020.07.15.203448 VL - 7 UR - https://doi.org/10.1101/2020.07.15.203448 ER - TY - JOUR TI - Corn Yield Loss Estimates Due to Diseases in the United States and Ontario, Canada, from 2016 to 2019 AU - Mueller, Daren S. AU - Wise, Kiersten A. AU - Sisson, Adam J. AU - Allen, Tom W. AU - Bergstrom, Gary C. AU - Bissonnette, Kaitlyn M. AU - Bradley, Carl A. AU - Byamukama, Emmanuel AU - Chilvers, Martin I AU - Collins, Alyssa A. AU - Esker, Paul D. AU - Faske, Travis R. AU - Friskop, Andrew J. AU - Hagan, Austin K. AU - Heiniger, Ron W. AU - Hollier, Clayton A. AU - Isakeit, Tom AU - Jackson-Ziems, Tamra A. AU - Jardine, Douglas J. AU - Kelly, Heather M. AU - Kleczewski, Nathan M. AU - Koehler, Alyssa M. AU - Koenning, Steve R. AU - Malvick, Dean K. AU - Mehl, Hillary L. AU - Meyer, Ron F. AU - Paul, Pierce A. AU - Peltier, Angie J. AU - Price, Paul P. AU - Robertson, Alison E. AU - Roth, Gregory W. AU - Sikora, Edward J. AU - Smith, Damon L. AU - Tande, Connie A. AU - Telenko, Darcy E. P. AU - Tenuta, Albert U. AU - Thiessen, Lindsey D. AU - Wiebold, William J. T2 - PLANT HEALTH PROGRESS AB - Annual reductions in corn (Zea mays L.) yield caused by diseases were estimated by university Extension-affiliated plant pathologists in 26 corn-producing states in the United States and in Ontario, Canada, from 2016 through 2019. Estimated loss from each disease varied greatly by state or province and year. Gray leaf spot (caused by Cercospora zeae-maydis Tehon & E.Y. Daniels) caused the greatest estimated yield loss in parts of the northern United States and Ontario in all years except 2019, and Fusarium stalk rot (caused by Fusarium spp.) also greatly reduced yield. Tar spot (caused by Phyllachora maydis Maubl.), a relatively new disease in the United States, was estimated to cause substantial yield loss in 2018 and 2019 in several northern states. Gray leaf spot and southern rust (caused by Puccinia polysora Underw.) caused the most estimated yield losses in the southern United States. Unfavorable wet and delayed harvest conditions in 2018 resulted in an estimated 2.5 billion bushels (63.5 million metric tons) of grain contaminated with mycotoxins. The estimated mean economic loss due to reduced yield caused by corn diseases in the United States and Ontario from 2016 to 2019 was US$55.90 per acre (US$138.13 per hectare). Results from this survey provide scientists, corn breeders, government agencies, and educators with data to help inform and prioritize research, policy, and educational efforts in corn pathology and disease management. DA - 2020/// PY - 2020/// DO - 10.1094/PHP-05-20-0038-RS VL - 21 IS - 4 SP - 238-247 SN - 1535-1025 KW - corn KW - maize KW - disease KW - yield loss KW - economic loss ER - TY - JOUR TI - Phenology affects differentiation of crop and weed species using hyperspectral remote sensing AU - Basinger, Nicholas T. AU - Jennings, Katherine M. AU - Hestir, Erin L. AU - Monks, David W. AU - Jordan, David L. AU - Everman, Wesley J. T2 - WEED TECHNOLOGY AB - Abstract The effect of plant phenology and canopy structure of four crops and four weed species on reflectance spectra were evaluated in 2016 and 2017 using in situ spectroscopy. Leaf-level and canopy-level reflectance were collected at multiple phenologic time points in each growing season. Reflectance values at 2 wk after planting (WAP) in both years indicated strong spectral differences between species across the visible (VIS; 350–700 nm), near-infrared (NIR; 701–1,300 nm), shortwave-infrared I (SWIR1; 1,301–1,900 nm), and shortwave-infrared II (SWIR2; 1,901–2,500 nm) regions. Results from this study indicate that plant spectral reflectance changes with plant phenology and is influenced by plant biophysical characteristics. Canopy-level differences were detected in both years across all dates except for 1 WAP in 2017. Species with similar canopy types (e.g., broadleaf prostrate, broadleaf erect, or grass/sedge) were more readily discriminated from species with different canopy types. Asynchronous phenology between species also resulted in spectral differences between species. SWIR1 and SWIR2 wavelengths are often not included in multispectral sensors but should be considered for species differentiation. Results from this research indicate that wavelengths in SWIR1 and SWIR2 in conjunction with VIS and NIR reflectance can provide differentiation across plant phenologies and, therefore should be considered for use in future sensor technologies for species differentiation. DA - 2020/12// PY - 2020/12// DO - 10.1017/wet.2020.92 VL - 34 IS - 6 SP - 897-908 SN - 1550-2740 KW - Hyperspectral remote sensing KW - plant morphology KW - species differentiation KW - spectral discrimination KW - spectral variability KW - spectroscopy ER - TY - JOUR TI - Tolerance of pintoi peanut to PRE and POST herbicides AU - Martin, Logan J. AU - Dias, Jose Luiz C. S. AU - Sellers, Brent A. AU - Ferrell, Jason A. AU - Leon, Ramon G. AU - Vendramini, Joao M. B. T2 - WEED TECHNOLOGY AB - Abstract Pintoi peanut is a warm-season perennial legume that shows promise as a forage crop for the southeastern United States, however, little is known about the proper methods of weed management during establishment for this species. The objective of this study was to determine the ability of pintoi peanut to tolerate applications of PRE and POST herbicides during the year of and year after planting. The effects of herbicide treatments on percentage of visual estimates of injury and stand counts of pintoi peanut were investigated at Ona and Marianna, FL, in 2015 and 2016. All PRE herbicides did not result in significant injury or stand reduction. Pintoi peanut’s tolerance to POST herbicides was higher when plants were emerged for at least 2 wk prior to herbicide application. Stands of pintoi peanut that were planted the previous year appear to tolerate all herbicides examined in this work, except sulfosulfuron. Results of this study indicate that at the year of planting pintoi peanut is tolerant to PRE applications of pendimethalin, imazethapyr, and imazapic. Pintoi peanut appears to tolerate applications of 2,4-D, carfentrazone, imazapic and imazethapyr the year after planting at the rates utilized in this study. Future research should evaluate the effects of multiple herbicide applications and tank-mixes to obtain satisfactory weed control and selectivity in pintoi peanut swards. DA - 2020/12// PY - 2020/12// DO - 10.1017/wet.2020.82 VL - 34 IS - 6 SP - 870-875 SN - 1550-2740 KW - 2,4-D KW - carfentrazone KW - imazapic KW - imazethapyr KW - pendimethalin KW - sulfosulfuron KW - pintoi peanut KW - Arachis pintoi Krap. and Greg. KW - 'Amarillo' ER - TY - JOUR TI - Scarification effects on germination of perennial soybean (Nenotonia wightii) AU - Flores, Enrique M. AU - Caceres, Wilfredo E. AU - Aguirre, Lucrecia T. AU - Castillo, Miguel S. T2 - REVISTA DE INVESTIGACIONES VETERINARIAS DEL PERU AB - El objetivo del estudio fue comparar la germinación de semilla de soya perenne (Nenotonia wightii) cv. Cooper en función de dos métodos de escarificación (agua caliente y escarificación mecánica) versus tratamiento control (sin escarificación). La escarificación mecánica consistió en raspar las cubiertas de las semillas friccionándolas a mano, utilizando papel lija #125 durante 5 minutos. La escarificación con agua caliente consistió en colocar las semillas en agua al punto de ebullición en proporción 1:3 semilla:agua durante 24 horas. El porcentaje de semillas germinadas fue mayor en el tratamiento con escarificación mecánica con papel lija (p<0.05) y similar entre el tratamiento con agua caliente y el control. El mayor porcentaje de germinación fue 37.5, 40, y 96% en los días 14, 12, y 9 para los tratamientos control, agua caliente, y escarificación mecánica, respectivamente. DA - 2020/// PY - 2020/// DO - 10.15381/rivep.v31i3.16728 VL - 31 IS - 3 SP - SN - 1609-9117 KW - sandpaper KW - scarification KW - germination KW - perennial soybeans ER - TY - JOUR TI - Surveying for Potential Diseases and Abiotic Disorders of Industrial Hemp (Cannabis sativa) Production AU - Thiessen, Lindsey D. AU - Schappe, Tyler AU - Cochran, Sarah AU - Hicks, Kristin AU - Post, Angela R. T2 - PLANT HEALTH PROGRESS AB - Industrial hemp (Cannabis sativa L.) has recently been reintroduced as an agricultural commodity in the United States, and, through state-led pilot programs, growers and researchers have been investigating production strategies. Diseases and disorders of industrial hemp in the United States are largely unknowns because record-keeping and taxonomy have improved dramatically in the last several decades. In 2016, North Carolina launched a pilot program to investigate industrial hemp, and diseases and abiotic disorders were surveyed in 2017 and 2018. Producers, consultants, and agricultural extension agents submitted samples to the North Carolina Department of Agriculture and Consumer Services Agronomic Services Division (n = 572) and the North Carolina Plant Disease and Insect Clinic (n = 117). Common field diseases found included Fusarium foliar and flower blights (Fusarium graminearum), Fusarium wilt (Fusarium oxysporum), and Helminthosporium leaf spot (Exserohilum rostratum). Greenhouse diseases were primarily caused by Pythium spp. and Botrytis cinerea. Common environmental disorders were attributed to excessive rainfall flooding roots and poor root development of transplanted clones. DA - 2020/// PY - 2020/// DO - 10.1094/PHP-03-20-0017-RS VL - 21 IS - 4 SP - 321-332 SN - 1535-1025 KW - Fusarium graminearum KW - Fusarium oxysporum KW - Exseiohilum rostratum KW - Pythium KW - Botrytis cinerea ER - TY - RPRT TI - Sustainable Practices for Plasticulture Strawberry Production in the South AU - McWhirt, A. AU - Fernandez, G. AU - Schroeder-Moreno, M. AU - Hoffmann, M. A3 - North Carolina State University DA - 2020/// PY - 2020/// M1 - AG-796 M3 - North Carolina Cooperative Extension Publication PB - North Carolina State University SN - AG-796 UR - https://content.ces.ncsu.edu/sustainable-practices-for-plasticulture-strawberry-production-in-the-south ER - TY - JOUR TI - Accessing Legacy Phosphorus in Soils AU - Doydora, Sarah AU - Gatiboni, Luciano AU - Grieger, Khara AU - Hesterberg, Dean AU - Jones, Jacob AU - McLamore, Eric AU - Peters, Rachel AU - Sozzani, Rosangela AU - Broeck, Lisa Van AU - Duckworth, Owen T2 - Soil Systems AB - Repeated applications of phosphorus (P) fertilizers result in the buildup of P in soil (commonly known as legacy P), a large fraction of which is not immediately available for plant use. Long-term applications and accumulations of soil P is an inefficient use of dwindling P supplies and can result in nutrient runoff, often leading to eutrophication of water bodies. Although soil legacy P is problematic in some regards, it conversely may serve as a source of P for crop use and could potentially decrease dependence on external P fertilizer inputs. This paper reviews the (1) current knowledge on the occurrence and bioaccessibility of different chemical forms of P in soil, (2) legacy P transformations with mineral and organic fertilizer applications in relation to their potential bioaccessibility, and (3) approaches and associated challenges for accessing native soil P that could be used to harness soil legacy P for crop production. We highlight how the occurrence and potential bioaccessibility of different forms of soil inorganic and organic P vary depending on soil properties, such as soil pH and organic matter content. We also found that accumulation of inorganic legacy P forms changes more than organic P species with fertilizer applications and cessations. We also discuss progress and challenges with current approaches for accessing native soil P that could be used for accessing legacy P, including natural and genetically modified plant-based strategies, the use of P-solubilizing microorganisms, and immobilized organic P-hydrolyzing enzymes. It is foreseeable that accessing legacy P will require multidisciplinary approaches to address these limitations. DA - 2020/12// PY - 2020/12// DO - 10.3390/soilsystems4040074 UR - https://www.mdpi.com/2571-8789/4/4/74 KW - legacy phosphorus KW - speciation KW - transformation KW - accessibility ER - TY - JOUR TI - Response of sweetpotato to diquat applied pretransplanting AU - Meyers, Stephen L. AU - Jennings, Katherine M. AU - Miller, Donnie K. AU - Shankle, Mark W. T2 - WEED TECHNOLOGY AB - Abstract Field trials were conducted in North Carolina in 2017 and Louisiana and Mississippi in 2018 to determine the effect of pretransplanting applications of diquat on sweetpotato crop tolerance, yield, and storage root quality. In North Carolina treatments consisted of two rates of diquat (560 or 1,120 g ai ha −1 ) alone or mixed with 107 g ai ha −1 flumioxazin and applied 1 d before transplanting (DBP), sequential applications of diquat (560 or 1,120 g ha −1 ) 1 and 17 DBP, 107 g ha −1 flumioxazin alone, and a nontreated check. In Louisiana and Mississippi treatments consisted of diquat (560 or 1,120 g ha −1 ) applied 1 DBP either alone or followed by (fb) rehipping rows or 107 g ha −1 flumioxazin immediately prior to transplanting. Additional treatments included 546 g ha −1 paraquat applied 1 DBP and a nontreated check. In North Carolina injury was ≤3% for all treatments through 23 d after transplanting (DAP), and no injury was observed after 23 DAP. Visual sweetpotato stunting pooled across the Mississippi and Louisiana trials ranged from 1% to 14%, 0% to 6%, and 0% to 3% at 2, 4, and 6 wk after planting (WAP), respectively, and no crop injury was observed after 6 WAP. Diquat applied 1 DBP and not fb rehipping resulted in greater crop injury (12%) than comparable treatments that were rehipped (2%). In North Carolina single and sequential diquat applications resulted in reduced No. 1 sweetpotato yield (24,230 and 24,280 kg ha −1 , respectively) compared with the nontreated check, but No. 1 yield when diquat plus flumioxazin (26,330 kg ha −1 ) was used was similar to that of the nontreated check. No. 1 yield did not differ by treatment in Louisiana and Mississippi. DA - 2020/10// PY - 2020/10// DO - 10.1017/wet.2020.27 VL - 34 IS - 5 SP - 637-641 SN - 1550-2740 KW - Crop injury KW - crop tolerance KW - storage root ER - TY - JOUR TI - Editorial: Legacy Phosphorus in Agriculture: Role of Past Management and Perspectives for the Future AU - Gatiboni, Luke AU - Brunetto, Gustavo AU - Pavinato, Paulo S. AU - George, Timothy S. T2 - FRONTIERS IN EARTH SCIENCE AB - EDITORIAL article Front. Earth Sci., 20 November 2020 | https://doi.org/10.3389/feart.2020.619935 DA - 2020/11/20/ PY - 2020/11/20/ DO - 10.3389/feart.2020.619935 VL - 8 SP - SN - 2296-6463 KW - legacy phosphorus KW - agriculture KW - fertilizers KW - phosphates KW - soil fertility ER - TY - JOUR TI - Impact of reduced rates of 2,4-D and glyphosate on sweetpotato growth and yield AU - Batts, Thomas M. AU - Miller, Donnie K. AU - Griffin, James L. AU - Villordon, Arthur O. AU - Stephenson, Daniel O. AU - Jennings, Kathrine M. AU - Chaudhari, Sushila AU - Blouin, David C. AU - Copes, Josh T. AU - Smith, Tara P. T2 - WEED TECHNOLOGY AB - Abstract Commercialization of 2,4-D–tolerant crops is a major concern for sweetpotato producers because of potential 2,4-D drift that can cause severe crop injury and yield reduction. A field study was initiated in 2014 and repeated in 2015 to assess impacts of reduced rates of 2,4-D, glyphosate, or a combination of 2,4-D with glyphosate on sweetpotato. In one study, 2,4-D and glyphosate were applied alone and in combination at 1/10, 1/100, 1/250, 1/500, 1/750, and 1/1,000 of anticipated field use rates (1.05 kg ha −1 for 2,4-D and 1.12 kg ha −1 for glyphosate) to ‘Beauregard’ sweetpotato at storage root formation (10 days after transplanting [DAP]). In a separate study, all these treatments were applied to ‘Beauregard’ sweetpotato at storage root development (30 DAP). Injury with 2,4-D alone or in combination with glyphosate was generally equal or greater than with glyphosate applied alone at equivalent herbicide rates, indicating that injury is attributable mostly to 2,4-D in the combination. There was a quadratic increase in crop injury and quadratic decrease in crop yield (with respect to most yield grades) with increased rate of 2,4-D applied alone or in combination with glyphosate applied at storage root development. However, neither the results of this relationship nor of the significance of herbicide rate were observed on crop injury or sweetpotato yield when herbicide application occurred at storage root formation, with a few exceptions. In general, crop injury and yield reduction were greatest at the highest rate (1/10×) of 2,4-D applied alone or in combination with glyphosate, although injury observed at lower rates was also a concern after initial observation by sweetpotato producers. However, in some cases, yield reduction of U.S. no.1 and marketable grades was also observed after application of 1/250×, 1/100×, or 1/10× rates of 2,4-D alone or with glyphosate when applied at storage root development. DA - 2020/10// PY - 2020/10// DO - 10.1017/wet.2020.57 VL - 34 IS - 5 SP - 631-636 SN - 1550-2740 KW - crop injury KW - off-target herbicide injury KW - reduced rate ER - TY - JOUR TI - Emerging lanthanum (III)-containing materials for phosphate removal from water: A review towards future developments AU - Zhi, Yue AU - Zhang, Chuhui AU - Hjorth, Rune AU - Baun, Anders AU - Duckworth, Owen W. AU - Call, Douglas F. AU - Knappe, Detlef R. U. AU - Jones, Jacob L. AU - Grieger, Khara T2 - ENVIRONMENT INTERNATIONAL AB - The last two decades have seen a rise in the development of lanthanum (III)-containing materials (LM) for controlling phosphate in the aquatic environment. >70 papers have been published on this topic in the peer-reviewed literature, but mechanisms of phosphate removal by LM as well as potential environmental impacts of LM remain unclear. In this review, we summarize peer-reviewed scientific articles on the development and use of 80 different types of LM in terms of prospective benefits, potential ecological impacts, and research needs. We find that the main benefits of LM for phosphate removal are their ability to strongly bind phosphate under diverse environmental conditions (e.g., over a wide pH range, in the presence of diverse aqueous constituents). The maximum phosphate uptake capacity of LM correlates primarily with the La content of LM, whereas reaction kinetics are influenced by LM formulation and ambient environmental conditions (e.g., pH, presence of co-existing ions, ligands, organic matter). Increased La solubilization can occur under some environmental conditions, including at moderately acidic pH values (i.e., < 4.5–5.6), highly saline conditions, and in the presence of organic matter. At the same time, dissolved La will likely undergo hydrolysis, bind to organic matter, and combine with phosphate to precipitate rhabdophane (LaPO4·H2O), all of which reduce the bioavailability of La in aquatic environments. Overall, LM use presents a low risk of adverse effects in water with pH > 7 and moderate-to-high bicarbonate alkalinity, although caution should be applied when considering LM use in aquatic systems with acidic pH values and low bicarbonate alkalinity. Moving forward, we recommend additional research dedicated to understanding La release from LM under diverse environmental conditions as well as long-term exposures on ecological organisms, particularly primary producers and benthic organisms. Further, site-specific monitoring could be useful for evaluating potential impacts of LM on both biotic and abiotic systems post-application. DA - 2020/12// PY - 2020/12// DO - 10.1016/j.envint.2020.106115 VL - 145 SP - SN - 1873-6750 KW - Lanthanum KW - Lanthanum-containing materials KW - Phosphate KW - Surface water restoration KW - Eutrophication control KW - Phosphorus inactivation ER - TY - JOUR TI - Quantitative Trait Loci Associated with Gray Leaf Spot Resistance in St. Augustinegrass AU - Yu, Xingwang AU - Mulkey, Steve E. AU - Zuleta, Maria C. AU - Arellano, Consuelo AU - Ma, Bangya AU - Milla-Lewis, Susana R. T2 - PLANT DISEASE AB - Gray leaf spot (GLS), caused by Magnaporthe grisea, is a major fungal disease of St. Augustinegrass (Stenotaphrum secundatum), causing widespread blighting of the foliage under warm, humid conditions. To identify quantitative trait loci (QTL) controlling GLS resistance, an F 1 mapping population consisting of 153 hybrids was developed from crosses between cultivar Raleigh (susceptible parent) and plant introduction PI 410353 (resistant parent). Single-nucleotide polymorphism (SNP) markers generated from genotyping-by-sequencing constituted nine linkage groups for each parental linkage map. The Raleigh map consisted of 2,257 SNP markers and spanned 916.63 centimorgans (cM), while the PI 410353 map comprised 511 SNP markers and covered 804.27 cM. GLS resistance was evaluated under controlled environmental conditions with measurements of final disease incidence and lesion length. Additionally, two derived traits, area under the disease progress curve and area under the lesion expansion curve, were calculated for QTL analysis. Twenty QTL were identified as being associated with these GLS resistance traits, which explained 7.6 to 37.2% of the total phenotypic variation. Three potential GLS QTL “hotspots” were identified on two linkage groups: P2 (106.26 to 110.36 cM and 113.15 to 116.67 cM) and P5 (17.74 to 19.28 cM). The two major effect QTL glsp2.3 and glsp5.2 together reduced 20.2% of disease incidence in this study. Sequence analysis showed that two candidate genes encoding β-1,3-glucanases were found in the intervals of two QTL, which might function in GLS resistance response. These QTL and linked markers can be potentially used to assist the transfer of GLS resistance genes to elite St. Augustinegrass breeding lines. DA - 2020/11// PY - 2020/11// DO - 10.1094/PDIS-04-20-0905-RE VL - 104 IS - 11 SP - 2799-2806 SN - 1943-7692 KW - gray leaf spot KW - Magnaporthe grisea KW - quantitative trait loci KW - St. Augustinegrass ER - TY - JOUR TI - Locke and Tocqueville on Religious Foundationalism AU - Kessler, Sanford T2 - AMERICAN POLITICAL THOUGHT AB - In this article, I offer a fresh perspective on John Locke’s and Alexis de Tocqueville’s religious statesmanship that sheds light on the moral and political problems facing America today. Both thinkers maintain that a firmly held set of religious beliefs must ground the popular mores, or character traits, that support liberty. According to most scholars, Locke considers popular enlightenment the best means for promoting these beliefs. I argue, however, that Locke mistrusts intellectual freedom and seeks to use authority to promote the core doctrines of reasonable Christianity, which is his preferred faith. I also compare Locke’s version of religious foundationalism with Tocqueville’s more well-known case for this concept and show how Tocqueville modifies reasonable Christianity to strengthen it against democratic skepticism. I conclude by briefly reflecting on the weakening of America’s religious foundations today and on what this portends for the future. DA - 2020/9/1/ PY - 2020/9/1/ DO - 10.1086/711032 VL - 9 IS - 4 SP - 594-622 SN - 2161-1599 ER - TY - JOUR TI - Multi-Trait Genomic Prediction of Yield-Related Traits in US Soft Wheat under Variable Water Regimes AU - Guo, Jia AU - Khan, Jahangir AU - Pradhan, Sumit AU - Shahi, Dipendra AU - Khan, Naeem AU - Avci, Muhsin AU - Mcbreen, Jordan AU - Harrison, Stephen AU - Brown-Guedira, Gina AU - Murphy, Joseph Paul AU - Johnson, Jerry AU - Mergoum, Mohamed AU - Esten Mason, Richanrd AU - Ibrahim, Amir M. H. AU - Sutton, Russel AU - Griffey, Carl AU - Babar, Md Ali T2 - GENES AB - The performance of genomic prediction (GP) on genetically correlated traits can be improved through an interdependence multi-trait model under a multi-environment context. In this study, a panel of 237 soft facultative wheat (Triticum aestivum L.) lines was evaluated to compare single- and multi-trait models for predicting grain yield (GY), harvest index (HI), spike fertility (SF), and thousand grain weight (TGW). The panel was phenotyped in two locations and two years in Florida under drought and moderately drought stress conditions, while the genotyping was performed using 27,957 genotyping-by-sequencing (GBS) single nucleotide polymorphism (SNP) makers. Five predictive models including Multi-environment Genomic Best Linear Unbiased Predictor (MGBLUP), Bayesian Multi-trait Multi-environment (BMTME), Bayesian Multi-output Regressor Stacking (BMORS), Single-trait Multi-environment Deep Learning (SMDL), and Multi-trait Multi-environment Deep Learning (MMDL) were compared. Across environments, the multi-trait statistical model (BMTME) was superior to the multi-trait DL model for prediction accuracy in most scenarios, but the DL models were comparable to the statistical models for response to selection. The multi-trait model also showed 5 to 22% more genetic gain compared to the single-trait model across environment reflected by the response to selection. Overall, these results suggest that multi-trait genomic prediction can be an efficient strategy for economically important yield component related traits in soft wheat. DA - 2020/11// PY - 2020/11// DO - 10.3390/genes11111270 VL - 11 IS - 11 SP - SN - 2073-4425 KW - genomic prediction KW - multi-trait model KW - multi-environment genomic best linear unbiased predictor KW - Bayesian multi-trait multi-environment model KW - Bayesian multi-output regressor stacking model KW - deep learning multi-trait multi-environment model ER - TY - JOUR TI - Interactive Effects of Elevated Ozone and Temperature on Growth and Yield of Soybean (Glycine max (L.) Merr.) under Field Conditions AU - Burkey, Kent AU - Tisdale, Ripley AU - Zobel, Richard AU - Ray, Samuel AU - Pursley, Walter T2 - AGRONOMY-BASEL AB - Elevated ozone and rising temperature are both factors in climate change, but they are difficult to study in combination due to exposure system requirements. We developed and deployed an air exclusion exposure system to treat soybean (Glycine max (L.) Merr.) cultivar “Jake” with season-long combinations of sub-ambient ozone (18 ppb, 12 h mean), elevated ozone (66 ppb, 12 h mean), and elevated temperature (+3.5 °C daytime, +2.4 °C nighttime) in irrigated field plots. Warming caused a shift in biomass partitioning from reproductive tissues into stems and petioles at mid-season that resulted in a significant 25% reduction in final seed yield and a significant reduction in harvest index. The elevated ozone treatment delayed mid-season biomass production, and final seed yield was reduced by a non-significant 2%. However, there were significant underlying effects of elevated ozone on seed production. The non-significant impact of ozone on seed yield of cultivar “Jake” resulted from significant increases in pod number (+16%) and seed number (+18%) that were offset by a significant reduction in seed size (−16%). No evidence of significant warming–ozone interactions was found in biomass or seed yield responses. In general, significant impacts of the individual warming or ozone treatments were found to be additive. DA - 2020/11// PY - 2020/11// DO - 10.3390/agronomy10111803 VL - 10 IS - 11 SP - SN - 2073-4395 KW - biomass KW - harvest index KW - ozone KW - seed yield KW - soybean KW - temperature ER - TY - JOUR TI - Physiological and transcriptomic response of Medicago truncatula to colonization with high and low benefit arbuscular mycorrhizal fungi AU - Cope, Kevin R. AU - Kafle, Arjun AU - Yakha, Jaya K. AU - Pfeffer, Philip E. AU - Strahan, Gary D. AU - Garcia, Kevin AU - Subramanian, Senthil AU - Bücking, Heike AB - ABSTRACT Arbuscular mycorrhizal (AM) fungi form a root endosymbiosis with many agronomically important crop species and both enhance the ability of their host to obtain nutrients from the soil and increase host tolerance to biotic and abiotic stressors. However, AM fungal species differ in the benefits they provide to their host plants. Here, we examined the putative molecular mechanisms involved in the regulation of the physiological response of Medicago truncatula to either Rhizophagus irregularis or Glomus aggregatum, a high or a low benefit AM fungus, respectively. Colonization with R. irregularis led to higher growth and nutrient uptake benefits than the colonization with G. aggregatum . These benefits were linked to an elevated expression in the roots of genes involved in strigolactone biosynthesis ( NSP1 , NSP2 , CCD7 , and MAX1a ), mycorrhiza-induced phosphate ( PT8 ), ammonium ( AMT2;3 ), and nitrate ( NPF4.12 ) transporters and the putative ammonium transporter NIP1;5 . R. irregularis also stimulated the expression of photosynthesis-related genes in the shoot and the upregulation of the sugar transporters SWEET1.2, SWEET3.3 and SWEET 12 and the lipid biosynthesis gene RAM2 in the roots. In contrast, G. aggregatum induced the expression of biotic stress defense response genes in the shoots and several genes associated with abiotic stress in the roots. This suggests that either the host perceives colonization by G. aggregatum as a pathogen attack or that G. aggregatum can prime host defense responses. Our findings reveal novel insights into the molecular mechanisms that control the host plant response to colonization with high- and low-benefit arbuscular mycorrhizal fungal symbionts. DA - 2020/12/12/ PY - 2020/12/12/ DO - 10.1101/2020.12.11.421693 VL - 12 UR - https://doi.org/10.1101/2020.12.11.421693 ER - TY - JOUR TI - Short-term effects of bioenergy cropping on soil carbon and nitrogen dynamics in a Florida Ultisol AU - Silveira, M. L. AU - Brandani, C. B. AU - Kohmann, M. M. AU - Erickson, J. E. AU - Reyes-Cabrera, J. AU - Leon, R. G. AU - Sollenberger, L. E. AU - Piotto, V. AU - Quadros, D. G. AU - Mello, S. Q. S. T2 - SOIL SCIENCE SOCIETY OF AMERICA JOURNAL AB - Abstract Although perennial bioenergy crops provide a potential for soil C sequestration, high fertilizer inputs are required to sustain yields. Land application of bioenergy byproducts can be an effective strategy to reduce the use of inorganic fertilizer. This study examined the impacts of elephantgrass [ Pennisetum purpureum (L.) Schum.] bioenergy cropping and conventional pasture on soil C and N responses. Treatments included (a) bahiagrass + 50 kg N ha −1 yr −1 (BHG), (b) elephantgrass + 50 kg N ha −1 yr −1 (E50), (c) elephantgrass + 50 kg N ha −1 yr −1 + fermentation residual (E50FR), (d) elephantgrass + 50 kg N ha −1 yr −1 + biochar (E50BC), and (e) elephantgrass + 250 kg N ha −1 yr −1 (E250). Soil C and N responses occurred mainly at the 0‐ to 10‐cm depth. Biochar resulted in the largest increase in soil C stocks at the 0‐ to 10‐cm depth (5.8 Mg C ha −1 in 2012 vs. 40 Mg C ha −1 in 2016), but no differences were observed among the other treatments. Conversely, greater soil N stocks at the 0‐ to 10‐cm depth were associated with the BHG (0.8 and 0.34 Mg N ha −1 for other treatments). Biochar favored N and C accumulation in the mineral‐associated (<53 μm) fraction, possibly from the accumulation of fine biochar fragments. In contrast, fermentation residual promoted C accumulation in unprotected light fraction. These results are supported by the δ 13 C signature and C/N ratios of the fractions. Results underscore the value of recycling biochar in bioenergy cropping systems as a means of improving C in coarse‐textured soils. DA - 2020/// PY - 2020/// DO - 10.1002/saj2.20081 VL - 84 IS - 4 SP - 1233-1246 SN - 1435-0661 ER - TY - JOUR TI - Advances in heat-pulse methods: Measuring soil water evaporation with sensible heat balance AU - Heitman, J. L. AU - Zhang, X. AU - Xiao, X. AU - Ren, T. AU - Horton, R. T2 - SOIL SCIENCE SOCIETY OF AMERICA JOURNAL AB - Abstract Soil water evaporation is an important process in hydrology, engineering, and agriculture. Few techniques are capable of measuring soil water evaporation in situ. An approach has been developed to measure in situ subsurface soil water evaporation using a soil sensible heat balance (SHB) with measurement data obtained from multi‐needle heat‐pulse sensors. Terms in the SHB (i.e., sensible heat flux and change in sensible heat storage) are calculated from heat‐pulse sensor derived soil temperature and thermal property (i.e., thermal conductivity and heat capacity) measurements for a thin soil layer with thickness corresponding to the sensor geometry. The quantity of latent heat required for soil water vaporization can be determined as the residual to the SHB (i.e., change in heat flux with depth minus change in sensible heat storage with time) for the soil layer. Dividing latent heat (per unit time) by heat of vaporization for water allows data to be converted to evaporation rate. Numerical analysis indicates that the SHB approach is most sensitive to the heat flux component of the SHB. Laboratory and field tests indicate that SHB results compare favorably with mass‐balance and micrometeorologic approaches for evaporation measurement, with SHB typically differing by <0.2 mm d −1 from the reference methods. DA - 2020/// PY - 2020/// DO - 10.1002/saj2.20149 VL - 84 IS - 5 SP - 1371-1375 SN - 1435-0661 ER - TY - JOUR TI - Advances in thermo-time domain reflectometry technique: Measuring ice content in partially frozen soils AU - Tian, Zhengchao AU - Kojima, Yuki AU - Heitman, Joshua L. AU - Horton, Robert AU - Ren, Tusheng T2 - SOIL SCIENCE SOCIETY OF AMERICA JOURNAL AB - Abstract Ice content (θ i ) is a critical parameter affecting soil thermal, mechanical, and hydraulic properties in cold regions. Few techniques are available for accurately determining θ i in laboratory samples and in situ. A combined heat‐pulse and time domain reflectometry (thermo‐TDR) sensor, which measures soil thermal properties and electrical properties simultaneously, can be used to estimate θ i . The thermo‐TDR method determines θ i by using a heat‐capacity‐based ( C ‐based) approach or a thermal‐conductivity‐based (λ‐based) approach. Here, we describe the principles and procedures of such approaches. The C ‐based thermo‐TDR approach is simple to use and provides reasonable θ i values at temperatures below −5°C, but it fails at higher temperatures. The λ‐based approach, which solves for θ i from thermo‐TDR measurements with an iterative method, gives more accurate θ i estimates than does the C ‐based approach and extends the thermo‐TDR measurement range to temperatures near the freezing point of water. Therefore, the λ‐based thermo‐TDR method is preferred for determining θ i in partially frozen soils. DA - 2020/// PY - 2020/// DO - 10.1002/saj2.20160 VL - 84 IS - 5 SP - 1519-1526 SN - 1435-0661 ER - TY - JOUR TI - Estimating thermal conductivity of frozen soils from air-filled porosity AU - Tian, Zhengchao AU - Ren, Tusheng AU - Heitman, Joshua L. AU - Horton, Robert T2 - SOIL SCIENCE SOCIETY OF AMERICA JOURNAL AB - Abstract Soil thermal conductivity (λ) is an important thermal property for environmental, agricultural, and engineering heat transfer applications. Existing λ models for frozen soils are complicated to use because they require estimates of both liquid water content and ice content. This study introduces a new approach to estimate λ of partially frozen soils from air‐filled porosity ( n a ), which can be determined by using an oven‐drying method. A λ and n a relationship was established based on measurements for 28 partially frozen soils. A strong exponential relationship between λ and n a was found (with R 2 of 0.82). Independent tests on 10 partially frozen soils showed that the exponential λ– n a model produced reliable λ estimates with a RMSE of 0.319 W m −1 K −1 , which was smaller than those of two widely used λ models for partially frozen soils. The λ– n a model is easier to use than existing models, because it requires fewer parameters. Note that the λ‐ n a model ignores the effect of temperature on λ of frozen soils and is most applicable to soil at temperatures of at least −4 °C. DA - 2020/// PY - 2020/// DO - 10.1002/saj2.20102 VL - 84 IS - 5 SP - 1650-1657 SN - 1435-0661 ER - TY - JOUR TI - Seed Dormancy in Hairy Vetch (Vicia villosa Roth) Is Influenced by Genotype and Environment AU - Kissing Kucek, L. AU - Azevedo, M. D. AU - Eagen, S. S. AU - Ehlke, N. J. AU - Hayes, R. J. AU - Mirsky, S. B. AU - Reberg-Horton, C. AU - Ryan, M. R. AU - Wayman, S. AU - Wiering, N. P. AU - Riday, H. T2 - AGRONOMY-BASEL AB - Seed dormancy complicates the agricultural use of many legume species. Understanding the genetic and environmental drivers of seed dormancy is necessary for advancing crop improvement for legumes, such as Vicia villosa. In this study, we quantify the magnitude of genetic and environmental effects on physical dormancy among 1488 maternal V. villosa plants from 18 diverse environments. Furthermore, we explore the relationship between physical dormancy and environmental conditions during seed development. Additive genetic variance (h2) accounted for 40% of the variance, while the growing environment explained 28% of the variance in physical dormancy. Maternal lines showed complete variance in physical dormancy, as one line was 100% dormant, and 56 lines were 0% dormant. Distributions of physical dormancy varied widely among seed production environments, with some site-years strongly skewed toward physically dormant seed, while other site-years exhibited little dormant seed. Twenty-three weather variables were associated with environmental and error effects of physical dormancy. High mean and minimum relative humidity, low mean and maximum temperature, and high precipitation weakly grouped with low physical dormancy. Weather variables calculated from fixed time windows approximating seed maturity to seed harvest at each site-year tended to be less predictive than biological seed drying windows calculated based on seed maturity of each maternal line. Overall, individual and cumulative effects of weather variables were poor predictors of physical dormancy. Moderate heritability indicates that breeding programs can select against physical dormancy and improve V. villosa for agricultural use. Marker-based approaches would maximize selection for physical dormancy by reducing the influence of unpredictable environmental effects. DA - 2020/11// PY - 2020/11// DO - 10.3390/agronomy10111804 VL - 10 IS - 11 SP - SN - 2073-4395 KW - seed dormancy KW - vetch KW - genotypes KW - environmental control ER - TY - JOUR TI - Expansion of the circadian transcriptome in Brassica rapa and genome-wide diversification of paralog expression patterns AU - Greenham, Kathleen AU - Sartor, Ryan C. AU - Zorich, Stevan AU - Lou, Ping AU - Mockler, Todd C. AU - McClung, C. Robertson T2 - ELIFE AB - An important challenge of crop improvement strategies is assigning function to paralogs in polyploid crops. Here we describe the circadian transcriptome in the polyploid crop Brassica rapa . Strikingly, almost three-quarters of the expressed genes exhibited circadian rhythmicity. Genetic redundancy resulting from whole genome duplication is thought to facilitate evolutionary change through sub- and neo-functionalization among paralogous gene pairs. We observed genome-wide expansion of the circadian expression phase among retained paralogous pairs. Using gene regulatory network models, we compared transcription factor targets between B. rapa and Arabidopsis circadian networks to reveal evidence for divergence between B. rapa paralogs that may be driven in part by variation in conserved non-coding sequences (CNS). Additionally, differential drought response among retained paralogous pairs suggests further functional diversification. These findings support the rapid expansion and divergence of the transcriptional network in a polyploid crop and offer a new approach for assessing paralog activity at the transcript level. DA - 2020/9/30/ PY - 2020/9/30/ DO - 10.7554/eLife.58993 VL - 9 SP - SN - 2050-084X ER - TY - JOUR TI - Advances in heat-pulse methods: Measuring near-surface soil water content AU - Zhang, Xiao AU - Ren, Tusheng AU - Heitman, Joshua AU - Horton, Robert T2 - SOIL SCIENCE SOCIETY OF AMERICA JOURNAL AB - Abstract Soil water content (θ) influences physical, chemical, and biological processes in the soil. Near‐surface θ (<1‐cm depth) is particularly important for surface energy partitioning, but few techniques are available for near‐surface in situ θ measurements. Heat‐pulse sensors can be used to determine the soil volumetric heat capacity, which is linearly related to θ. Here we describe the principles and procedures of determining near‐surface in situ θ with a heat pulse sensor. The main limitations and potential errors associated with the method are also presented. When ambient soil temperature drift and the soil–air interface effects are addressed, the error in the heat‐pulse‐determined θ is greatly reduced. For an example, data series with θ data determined by gravimetric initial θ and heat‐pulse‐based change in θ (Δθ), results agree well with gravimetric θ values, yielding a coefficient of determination of 0.95. We conclude that heat‐pulse sensors are useful tools for continuously and nondestructively determining near‐surface θ of non‐shrink–swell soils. DA - 2020/// PY - 2020/// DO - 10.1002/saj2.20150 VL - 84 IS - 5 SP - 1376-1383 SN - 1435-0661 ER - TY - JOUR TI - Thermo-time domain reflectometry method: Advances in monitoring in situ soil bulk density AU - Lu, Yili AU - Liu, Xiaona AU - Zhang, Meng AU - Heitman, Joshua AU - Horton, Robert AU - Ren, Tusheng T2 - SOIL SCIENCE SOCIETY OF AMERICA JOURNAL AB - Abstract Soil bulk density (ρ b ) is a critical parameter for describing soil structure and physical processes, yet traditional methods are unable to capture spatial and temporal changes in ρ b . Recently the thermo–time domain reflectometry (thermo‐TDR) technique has been applied to determine in situ ρ b on the basis of soil thermal property and water content measurements. Here, we present theory, instrumentation, procedures, and comments for monitoring in situ ρ b with the thermo‐TDR sensor. We conclude that the thermo‐TDR sensor offers a useful tool for determining ρ b continuously and nondestructively. DA - 2020/// PY - 2020/// DO - 10.1002/saj2.20147 VL - 84 IS - 5 SP - 1354-1360 SN - 1435-0661 ER - TY - JOUR TI - Characterization of Silvopastoral Systems in the livestock basin of Molinopampa, Northwestern Zone of Peru AU - Vasquez, Hector V. AU - Valqui, Leandro AU - Castillo, Miguel S. AU - Alegre, Julio AU - Gomez, Carlos A. AU - Bobadilla, Leidy G. AU - Maicelo, Jorge L. T2 - TEMAS AGRARIOS AB - Los productores de la región Amazonas vienen implementando Sistemas Silvopastoriles (SSP), para contrarrestar los efectos en el suelo y deterioro del ecosistema debido al manejo de una ganadería tradicional; sin embargo, se desconocen las características asociadas a estos sistemas, planteándose como objetivo caracterizar los SSP en la cuenca ganadera de Molinopampa. Se aplicaron encuestas a productores de 130 Unidades Agropecuarias, las cuales se analizaron con multivariada (conglomerados, correlación de Spearman y Análisis de Componentes Principales). El análisis de conglomerados permitió la clasificación de los productores en cinco grupos, diferenciados por el área de SSP que maneja, número de animales y producción de leche por hato ganadero. El grupo que presentó los mejores indicadores fue el cuarto, quienes se dedican a la ganadería en un 57%, cuentan con un área mayor a 6 ha, poseen más de 51 cabezas de ganado vacuno y tienen una producción de leche de 70 litros/hato/día. El análisis de componentes principales mostró correlaciones positivas entre las variables de conocimiento y capacitación, área total del terreno y diseño del sistema, especie del árbol y actividad principal, especie del árbol y diseño del sistema, preferencia del árbol y conocimiento. Las técnicas de análisis multivariado permitieron la clasificación de SSP, indicando que mientras mayor conocimiento y capacitación reciban, el desarrollo de una ganadería sostenible con SSP se incrementa. DA - 2020/// PY - 2020/// DO - 10.21897/rta.v25i1.1908 VL - 25 IS - 1 SP - 23-34 SN - 2389-9182 KW - Multivariate Analysis KW - Sustainable Livestock KW - Cattle Her KW - Dairy Production KW - Ecosystem Services ER - TY - JOUR TI - Soil carbon and nitrogen fractions after 19 years of farming systems research in the Coastal Plain of North Carolina AU - Franzluebbers, Alan J. AU - Reberg-Horton, S. Chris AU - Creamer, Nancy G. T2 - SOIL SCIENCE SOCIETY OF AMERICA JOURNAL AB - Abstract Long‐term agricultural experiments in the Coastal Plain of the southeastern United States are needed to understand biogeochemical processes and design better systems to overcome a changing climate and other perturbations. We determined a suite of soil organic C and N fractions after 19 yr of management from a diverse farming system project in Goldsboro, NC. Soil was collected at 0‐ to 6‐, 6‐ to 12‐, and 12‐ to 20‐cm depth increments from 14 treatments that were subsets of five overarching treatments of conventional cropping, integrated crop–livestock systems, organic cropping, plantation forestry, and old‐field successional land use. Surface residue C and N were greater with woody (i.e. plantation forestry and successional) than with cropping systems (7,491 and 2,896 kg C ha −1 , respectively; 138 and 60 kg N ha −1 , respectively). Soil‐test biological activity was greater with alternative cropping (i.e. integrated crop–livestock and organic systems) than conventional cropping (314 vs. 220 kg CO 2 –C ha −1 3 d −1 , respectively). An integrated crop–livestock system with grazed pasture in long rotations with crops had greater net N mineralization than hayed forage in shorter rotations (111 vs. 92 kg N ha −1 24 d −1 , respectively). Total organic C and particulate organic N concentrations were highly stratified with depth, but stocks were not different between conventional and no‐till cropping when summed to 20 cm. We conclude that alternative cropping systems with forage‐based rotations, limited tillage, and organic inputs can create long‐lasting improvements in soil organic C and N fractions than conventional agricultural and more naturalized systems. DA - 2020/// PY - 2020/// DO - 10.1002/saj2.20072 VL - 84 IS - 3 SP - 856-876 SN - 1435-0661 ER - TY - JOUR TI - Extending Cut Paeonia Lactiflora Pall. Storage Duration Using Sub-Zero Storage Temperatures AU - Jahnke, Nathan J. AU - Dole, John M. AU - Bergmann, Ben A. AU - Ma, Guoying AU - Perkins-Veazie, Penelope T2 - AGRONOMY-BASEL AB - Cut peonies (Paeonia lactiflora Pall.) have a relatively short vase life and limited availability due to seasonal production. Cultivars Festiva Maxima (FM), Monsieur Jules Elie (MJE), and Sarah Bernhardt (SB) stored at 0.7 °C had a longer flower open time at 12 weeks of storage compared to those held at −3.1 or 3.5 °C, while the flower bud time was unaffected. The flower open time of FM and MJE was no different for stems stored at a sub-zero temperature of −0.6 °C for 16 weeks compared to non-stored stems. Flower quality, opening, and lack of deformity was reduced at 16 weeks of storage in comparison to non-stored flowers, but higher for stems stored at −0.6 °C compared to 0.7 °C. Pre-treating stems before storage with pulses of a commercial hydrator solution or a 200 g·L−1 sucrose solution for 2 h at 4 °C had little commercial significance compared to non-pulsed control stems. The total phenolic content, malondialdehyde, and superoxide dismutase were not effective indicators of open time or quality loss. This study is the first to demonstrate the successful use of a non-freezing, sub-zero storage temperature for peony, and the first to store cut peonies for 16 weeks, despite an increased risk of reduced flower quality. DA - 2020/11// PY - 2020/11// DO - 10.3390/agronomy10111694 VL - 10 IS - 11 SP - SN - 2073-4395 KW - peony KW - long-term storage KW - flower deformity KW - total phenolic content KW - malondialdehyde KW - superoxide dismutase ER - TY - JOUR TI - Relative utility of agronomic, phenological, and morphological traits for assessing genotype-by-environment interaction in maize inbreds AU - Falcon, C.M. AU - Kaeppler, S.M. AU - Spalding, E.P. AU - Miller, N.D. AU - Haase, N. AU - AlKhalifah, N. AU - Bohn, M. AU - Buckler, E.S. AU - Campbell, D.A. AU - Ciampitti, I. AU - Coffey, L. AU - Edwards, J. AU - Ertl, D. AU - Flint-Garcia, S. AU - Gore, M.A. AU - Graham, C. AU - Hirsch, C.N. AU - Holland, J.B. AU - Jarquín, D. AU - Knoll, J. AU - Lauter, N. AU - Lawrence-Dill, C.J. AU - Lee, E.C. AU - Lorenz, A. AU - Lynch, J.P. AU - Murray, S.C. AU - Nelson, R. AU - Romay, M.C. AU - Rocheford, T. AU - Schnable, P.S. AU - Scully, B. AU - Smith, M. AU - Springer, N. AU - Tuinstra, M.R. AU - Walton, R. AU - Weldekidan, T. AU - Wisser, R.J. AU - Xu, W. AU - Leon, N. T2 - Crop Science AB - Abstract Plant breeders face the challenge of genotype × environment interaction (G × E) in comprehensively breeding for expanded geographic regions. An improved understanding of G × E sensitivity of traits and the environmental features that effectively discriminate among genotypes will enable more efficient breeding efforts. In this study of 31 maize ( Zea mays L.) inbreds grown in 36 environments that are part of the Genomes to Fields Initiative, we measured 14 traits, including flowering date, height, and yield components (i.e., ear and kernel dimensions) to (i) identify traits that are the most sensitive indicators of G × E; (ii) determine how geographic location and weather factors influence environments’ discriminability of inbreds; and (iii) detect patterns of stability in better and worse discriminating environments. Genotype × environment interaction explained between 9.0–20.4% of the phenotypic variance with greater effects in the yield‐component traits. Discriminability of environments varied by trait. Midwest locations (where 26 of the 31 inbreds were developed) were among the most discriminating environments for more traits, while environments in the West and East tended to be less discriminating. Weather factors during silking were significantly different between the most and least discriminating environments more often than average weather across the season or during the period from planting to silking. Stability of genotypes varied by trait, and performance was usually not correlated with stability. The dissection of complex traits, such as yield into component traits, appears to be a useful approach to understand how environmental factors differentially affect phenotype. DA - 2020/// PY - 2020/// DO - 10.1002/csc2.20035 VL - 60 IS - 1 SP - 62-81 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-85078817946&partnerID=MN8TOARS ER - TY - JOUR TI - Maize genomes to fields (G2F): 2014-2017 field seasons: Genotype, phenotype, climatic, soil, and inbred ear image datasets AU - McFarland, B.A. AU - Alkhalifah, N. AU - Bohn, M. AU - Bubert, J. AU - Buckler, E.S. AU - Ciampitti, I. AU - Edwards, J. AU - Ertl, D. AU - Gage, J.L. AU - Falcon, C.M. AU - Flint-Garcia, S. AU - Gore, M.A. AU - Graham, C. AU - Hirsch, C.N. AU - Holland, J.B. AU - Hood, E. AU - Hooker, D. AU - Jarquin, D. AU - Kaeppler, S.M. AU - Knoll, J. AU - Kruger, G. AU - Lauter, N. AU - Lee, E.C. AU - Lima, D.C. AU - Lorenz, A. AU - Lynch, J.P. AU - McKay, J. AU - Miller, N.D. AU - Moose, S.P. AU - Murray, S.C. AU - Nelson, R. AU - Poudyal, C. AU - Rocheford, T. AU - Rodriguez, O. AU - Romay, M.C. AU - Schnable, J.C. AU - Schnable, P.S. AU - Scully, B. AU - Sekhon, R. AU - Silverstein, K. AU - Singh, M. AU - Smith, M. AU - Spalding, E.P. AU - Springer, N. AU - Thelen, K. AU - Thomison, P. AU - Tuinstra, M. AU - Wallace, J. AU - Walls, R. AU - Wills, D. AU - Wisser, R.J. AU - Xu, W. AU - Yeh, C.-T. AU - De Leon, N. T2 - BMC Research Notes AB - Abstract Objectives Advanced tools and resources are needed to efficiently and sustainably produce food for an increasing world population in the context of variable environmental conditions. The maize genomes to fields (G2F) initiative is a multi-institutional initiative effort that seeks to approach this challenge by developing a flexible and distributed infrastructure addressing emerging problems. G2F has generated large-scale phenotypic, genotypic, and environmental datasets using publicly available inbred lines and hybrids evaluated through a network of collaborators that are part of the G2F’s genotype-by-environment (G × E) project. This report covers the public release of datasets for 2014–2017. Data description Datasets include inbred genotypic information; phenotypic, climatic, and soil measurements and metadata information for each testing location across years. For a subset of inbreds in 2014 and 2015, yield component phenotypes were quantified by image analysis. Data released are accompanied by README descriptions. For genotypic and phenotypic data, both raw data and a version without outliers are reported. For climatic data, a version calibrated to the nearest airport weather station and a version without outliers are reported. The 2014 and 2015 datasets are updated versions from the previously released files [1] while 2016 and 2017 datasets are newly available to the public. DA - 2020/// PY - 2020/// DO - 10.1186/s13104-020-4922-8 VL - 13 IS - 1 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-85079338248&partnerID=MN8TOARS KW - Maize KW - Genome KW - Genotype KW - GBS KW - G x E KW - Hybrid KW - Inbred KW - Phenotype KW - Environment KW - Field metadata ER - TY - JOUR TI - Association mapping and genomic prediction for ear rot disease caused by Fusarium verticillioides in a tropical maize germplasm AU - Kuki, Mauricio Carlos AU - Barth Pinto, Ronald Jose AU - Bengosi Bertagna, Filipe Augusto AU - Tessmann, Dauri Jose AU - Amaral Junior, Antonio Teixeira AU - Scapim, Carlos Alberto AU - Holland, James Brendan T2 - CROP SCIENCE AB - Abstract Fusarium ear rot (FER), caused by Fusarium verticillioides (Sacc.) Nirenberg, is one of the major ear diseases that affect both yield and grain quality in maize ( Zea mays L.), especially in tropical environments. Fusarium genetic resistance is a complex trait, controlled by several small‐effect genes and strongly influenced by the environment. We applied a comprehensive genome‐wide association study and genomic prediction for ear rot and starburst symptoms, using 291,633 high‐quality single nucleotide polymorphism (SNPs) markers in 320 tropical maize inbred lines, in two distinct locations in Brazil's southern region. Three SNPs were significantly associated with starburst symptoms, each associated with 6–8% of the phenotypic variance, and with gene models that have expression levels in ears, pericarp, and kernels, corresponding to disease infection period and suggesting some role in FER resistance. No significant SNP was associated with FER, which is an indication that the genetic architecture for this trait is highly polygenic, with potentially many variants having small effects that are not detectable in the association mapping analysis. We observed genomic prediction accuracies ranging from 0.34 to 0.4 for FER and starburst, respectively. Further research is required to validate these significant SNPs and their relationship to genes affecting FER resistance, and also to improve genomic prediction accuracies across different genetic backgrounds. DA - 2020/// PY - 2020/// DO - 10.1002/csc2.20272 VL - 60 IS - 6 SP - 2867-2881 SN - 1435-0653 UR - https://doi.org/10.1002/csc2.20272 ER - TY - JOUR TI - Heterosis of leaf and rhizosphere microbiomes in field‐grown maize AU - Wagner, Maggie R. AU - Roberts, Joseph H. AU - Balint‐Kurti, Peter AU - Holland, James B. T2 - New Phytologist AB - Summary Macroorganisms’ genotypes shape their phenotypes, which in turn shape the habitat available to potential microbial symbionts. This influence of host genotype on microbiome composition has been demonstrated in many systems; however, most previous studies have either compared unrelated genotypes or delved into molecular mechanisms. As a result, it is currently unclear whether the heritability of host‐associated microbiomes follows similar patterns to the heritability of other complex traits. We take a new approach to this question by comparing the microbiomes of diverse maize inbred lines and their F 1 hybrid offspring, which we quantified in both rhizosphere and leaves of field‐grown plants using 16S‐v4 and ITS1 amplicon sequencing. We show that inbred lines and hybrids differ consistently in the composition of bacterial and fungal rhizosphere communities, as well as leaf‐associated fungal communities. A wide range of microbiome features display heterosis within individual crosses, consistent with patterns for nonmicrobial maize phenotypes. For leaf microbiomes, these results were supported by the observation that broad‐sense heritability in hybrids was substantially higher than narrow‐sense heritability. Our results support our hypothesis that at least some heterotic host traits affect microbiome composition in maize. DA - 2020/11// PY - 2020/11// DO - 10.1111/nph.16730 VL - 228 IS - 3 SP - 1055-1069 UR - https://doi.org/10.1111/nph.16730 KW - heterosis KW - hybridization KW - maize KW - microbiome KW - phyllosphere KW - rhizosphere ER - TY - JOUR TI - Genetic variation for response to mixed triazole and strobilurin application in diverse maize AU - Woore, Matthew Smith AU - Holland, James Brendan T2 - Agrosystems, Geosciences & Environment AB - Abstract Strobilurin and triazole classes of fungicides have been reported to have growth‐regulating effects on crops in the absence of their target pathogens and to increase maize yield. Because the response of maize ( Zea mays L.) plants to a commercially marketed mixture of strobilurin and triazole may not be uniform across genotypes, it may be possible to breed selectively for higher yield responses to application of this chemical treatment. To test this hypothesis, diverse samples of maize inbred lines and hybrids were evaluated for response to a combined mixture of a treatment of strobilurin and triazole. Main effects of treatment and genotype and treatment × genotype interactions were measured on agronomic traits including grain yield and several yield components, lodging, and delayed leaf senescence. Hybrid and inbred genotype main effect variation was significant for all measured traits. Favorable main effects of strobilurin and triazole treatment were observed only for leaf senescence and foliar disease, and genotype × treatment interactions were not significant for yield or yield components. Yield was significantly increased only in two inbred varieties and did not correlate with any known pedigree or genetic relationships. These results suggest that breeding to enhance the response to strobilurin and triazole treatment is not likely to be effective in maize. DA - 2020/1// PY - 2020/1// DO - 10.1002/agg2.20054 VL - 3 IS - 1 UR - https://doi.org/10.1002/agg2.20054 ER - TY - JOUR TI - Genomic prediction for resistance to Fusarium ear rot and fumonisin contamination in maize AU - Holland, James B. AU - Marino, Thiago P. AU - Manching, Heather C. AU - Wisser, Randall J. T2 - CROP SCIENCE AB - Abstract Fusarium ear rot (FER) disease of maize ( Zea mays L.) is caused by Fusarium verticillioides (Sacc.) Nirenberg, which produces fumonisin (FUM), a mycotoxin linked to human and animal health risks. Extensive field trials, laborious inoculations and ear evaluations, and expensive antibody assays are required to reliably assess resistances to FER and FUM contamination in breeding populations. To evaluate the potential utility of genomic selection (GS) to improve FER and FUM in maize, we genotyped 6086 single nucleotide polymorphisms (SNPs) on 449 S 0:1 lines from a recurrent selection population. Two different partitions of the S 0:1 evaluation data were made to test the ability of models trained on 251 or 201 lines evaluated at three locations in 2014–2015 to predict FER and FUM of 198 or 248 different lines evaluated at three locations in 2016. Single‐stage univariate and multivariate genomic best linear unbiased predictor (GBLUP) models and two‐stage GBLUP, Bayes Cπ, Bayesian LASSO, and extreme gradient boosting models were compared for prediction. Maximum prediction accuracy for untested lines in a new year was 0.46 for FER and 0.67 for FUM. Bayesian models optimized for predicting traits influenced by major‐effect loci were best for FUM in one set, despite no evidence for significant individual SNP–trait associations from genome‐wide association study (GWAS) in the training sets; otherwise, GBLUP models were best. These results suggest that GS can help improve resistance to FER and FUM contamination in an applied breeding program. DA - 2020/// PY - 2020/// DO - 10.1002/csc2.20163 VL - 60 IS - 4 SP - 1863-1875 SN - 1435-0653 UR - https://doi.org/10.1002/csc2.20163 ER - TY - JOUR TI - Impact of Phosphorus on Cannabis sativa Reproduction, Cannabinoids, and Terpenes AU - Cockson, Paul AU - Schroeder-Moreno, Michelle AU - Veazie, Patrick AU - Barajas, Gabby AU - Logan, David AU - Davis, Matthew AU - Whipker, Brian E. T2 - APPLIED SCIENCES-BASEL AB - Many abiotic factors, such as mineral nutrients—including phosphorus (P)—fertility, can impact the yield and growth of Cannabis sativa. Given the economic portion of C. sativa is the inflorescence, the restriction of P fertility could impact floral development and quality could be detrimental. This study sought to track the impacts of varying P concentrations (3.75, 7.50, 11.25, 15.0, 22.50, and 30.0 mg·L−1) utilizing a modified Hoagland’s solution. This experiment examined plant height, diameter, leaf tissue mineral nutrient concentrations, and final fresh flower bud weight as well as floral quality metrics, such as cannabinoids and terpenes. The results demonstrated that during different life stages (vegetative, pre-flowering, flowering), P concentrations impact C. sativa growth and development and yield. Regarding the cannabinoid pools, results varied for the individual cannabinoid types. For the acid pools, increasing fertility concentrations above 11.25 mg·L−1 P did not result in any increase in cannabinoid concentrations. These results indicate that, if a crop is being produced under greenhouse conditions, specifically for cannabinoid production, an excessive P supply did not result in higher cannabinoid production. However, plants grown with a higher rate of P fertility (30.0 mg·L−1) had greater plant width and may result in more buds per plant. DA - 2020/11// PY - 2020/11// DO - 10.3390/app10217875 VL - 10 IS - 21 SP - SN - 2076-3417 KW - macronutrients KW - cannabis KW - hemp KW - cannabinoids KW - terpenes KW - life-cycle KW - phosphorus (P) KW - cannabidiol (CBD) KW - tetrahydrocannabinol (THC) KW - foliar ER - TY - JOUR TI - Leaf gas exchange recovery of soybean from water-deficit stress AU - Rosas-Anderson, Pablo AU - Sinclair, Thomas R. AU - Locke, Anna AU - Carter, Thomas E. AU - Rufty, Thomas W. T2 - Journal of Crop Improvement AB - As the risk of drought attributable to climate change increases, the development of high-yielding, drought-adapted cultivars will be critical for minimizing yield losses in crops like soybean (Glycine max (L.) Merr.). In this study, the ability of soybean genotypes to recover transpiration and leaf gas exchange capacity following re-watering from soil drying was investigated. The plants were subjected to controlled water-deficit stress and recovery in growth-chamber experiments. Transpiration was measured on five soybean genotypes and photosynthesis rates on two select genotypes. After water re-supply, transpiration was initially low but increased until a stable rate was reached on day 3, to about 50% to 100% of the rates of reference plants that had not been stressed. The largest difference in maximum transpiration recovery was between the varieties USDA-N8002 and Benning compared to the landrace Geden Shirazu, with Geden Shirazu having the lowest recovery. Photosynthesis and vapor-pressure-deficit response measurements did not show that restricted plant stomatal conductance was responsible for the limitation observed in Geden Shirazu recovery. Since all genotypes showed rapid recovery from water-deficit stress in 3 d, more rapid recovery was not indicated as a major candidate for improving soybean drought tolerance. However, the extent of recovery varied among genotypes and those genotypes that fully recovered to rates of well-watered plants such as Benning and USDA-N8002 would seemingly be advantageous for drought conditions. DA - 2020/5/20/ PY - 2020/5/20/ DO - 10.1080/15427528.2020.1764429 VL - 34 IS - 6 SP - 785-799 J2 - Journal of Crop Improvement LA - en OP - SN - 1542-7528 1542-7536 UR - http://dx.doi.org/10.1080/15427528.2020.1764429 DB - Crossref KW - Fraction transpirable oil water (FTSW) KW - gas exchange KW - photosynthesis KW - transpiration KW - vapor pressure deficit (VPD) KW - water-deficit stress ER - TY - JOUR TI - Thermal Property Values of a Central Iowa Soil as Functions of Soil Water Content and Bulk Density or of Soil Air Content AU - Tong, B. AU - Kool, D. AU - Heitman, J.L. AU - Sauer, T.J. AU - Gao, Z. AU - Horton, R. T2 - European Journal of Soil Sciences AB - Abstract Soil thermal properties play important roles in dynamic heat and mass transfer processes, and they vary with soil water content ( θ ) and bulk density ( ρ b ). Both θ and ρ b change with time, particularly in recently tilled soil. However, few studies have addressed the full extent of soil thermal property changes with θ and ρ b . The objective of this study is to examine how changes in ρ b with time after tillage impact soil thermal properties (volumetric heat capacity, C v , thermal diffusivity, k , and thermal conductivity, λ ). The study provides thermal property values as functions of θ and ρ b and of air content ( n air ) on undisturbed soil cores obtained at selected times following tillage. Heat pulse probe measurements of thermal properties were obtained on each soil core at saturated, partially saturated ( θ at pressure head of −50 kPa) and oven‐dry conditions. Generally, k and λ increased with increasing ρ b at the three water conditions. The C v increased as ρ b increased in the oven‐dry and unsaturated conditions and decreased as ρ b increased in the saturated condition. For a given θ , a larger ρ b was associated with larger thermal property values, especially for λ . The figures of C v , k and λ versus θ and ρ b , as well as C v , k and λ versus n air , represented the range of soil conditions following tillage. Trends in the relationships of thermal property values with θ and ρ b were described by 3‐D surfaces, whereas each thermal property had a linear relationship with n air . Clearly, recently tilled soil thermal property values were quite dynamic temporally due to varying θ and ρ b . The dynamic soil thermal property values should be considered in soil heat and mass transfer models either as 3‐D functions of θ and ρ b or as linear functions of n air . Highlights Thermal property values for a range of θ and ρ b were measured on undisturbed soil cores. Freshly tilled soil thermal property values were quite dynamic temporally. The thermal property values of a tilled soil were described as 3‐D surfaces with θ and ρ b . The thermal property values of a tilled soil varied linearly with n air . DA - 2020/6/17/ PY - 2020/6/17/ DO - https://doi.org/10.1111/ejss.12856 VL - 71 IS - 2 SP - 169-178 ER - TY - JOUR TI - In silico structure prediction of full-length cotton cellulose synthase protein (GhCESA1) and its hierarchical complexes AU - Singh, Abhishek AU - Kwansa, Albert L. AU - Kim, Ho Shin AU - Williams, Justin T. AU - Yang, Hui AU - Li, Nan K. AU - Kubicki, James D. AU - Roberts, Alison W. AU - Haigler, Candace H. AU - Yingling, Yaroslava G. T2 - Cellulose DA - 2020/4/30/ PY - 2020/4/30/ DO - 10.1007/s10570-020-03194-7 VL - 27 IS - 10 SP - 5597-5616 J2 - Cellulose LA - en OP - SN - 0969-0239 1572-882X UR - http://dx.doi.org/10.1007/s10570-020-03194-7 DB - Crossref KW - Plant KW - Cellulose synthesis complex KW - Homotrimer KW - Protein structure prediction KW - Molecular dynamics simulation ER - TY - JOUR TI - A Comparison of Stocking Methods for Pasture-Based Growing-Finishing Pig Production Systems AU - Pietrosemoli, Silvana AU - Green, James T. AU - Villamide, Maria Jesus T2 - ANIMALS AB - Two alternative stocking methods (rotational and strip-grazing) were compared to continuous stocking at a stocking rate of 47 pigs ha−1 in tall fescue pastures. The research was conducted during two twelve-weeks grazing periods in North Carolina (USA). In total 144 (females and castrated males, 17.5 and 29.1 kg initial body weight) crossbred Yorkshire X Berkshire, Yorkshire/Landrace X Hampshire and Yorkshire/Landrace X Duroc pigs without nose rings were used. Greater soil bulk density and soil concentrations of NO3−, P, K, Mn, Zn and Cu were observed in paddocks managed continuously, while greater final ground cover (+22%) was recorded in paddocks managed with rotational and strip-grazing stocking methods. No differences were detected in botanical composition of the paddocks. Greater weight gains (+8.5%) were registered for rotationally managed pigs. Feed efficiency was better (+8%) for rotationally than for continuously stocked pigs, while strip-grazed pigs presented intermediate values. The results indicated the potential of both alternative stocking methods to be implemented in sustainable pasture-based pig production systems. DA - 2020/10// PY - 2020/10// DO - 10.3390/ani10101885 VL - 10 IS - 10 SP - SN - 2076-2615 KW - growing-finishing pigs KW - pasture-based pig production KW - stocking methods KW - tall fescue (schedonorus arundinaceus) KW - ground cover KW - soil nutrients ER - TY - JOUR TI - Fungal Shaker-like channels beyond cellular K+ homeostasis: A role in ectomycorrhizal symbiosis between Hebeloma cylindrosporum and Pinus pinaster AU - Garcia, Kevin AU - Guerrero-Galán, Carmen AU - Frank, Hannah E. R. AU - Haider, Muhammad Zulqurnain AU - Delteil, Amandine AU - Conéjéro, Geneviève AU - Lambilliotte, Raphaël AU - Fizames, Cécile AU - Sentenac, Hervé AU - Zimmermann, Sabine D. T2 - PLOS ONE AB - Potassium (K + ) acquisition, translocation and cellular homeostasis are mediated by various membrane transport systems in all organisms. We identified and described an ion channel in the ectomycorrhizal fungus Hebeloma cylindrosporum ( Hc SKC) that harbors features of animal voltage-dependent Shaker -like K + channels, and investigated its role in both free-living hyphae and symbiotic conditions. RNAi lines affected in the expression of HcSKC were produced and used for in vitro mycorrhizal assays with the maritime pine as host plant, under standard or low K + conditions. The adaptation of H . cylindrosporum to the downregulation of HcSKC was analyzed by qRT-PCR analyses for other K + -related transport proteins: the transporters HcTrk1 , HcTrk2 , and HcHAK , and the ion channels HcTOK1 , HcTOK2 . 1 , and HcTOK2 . 2 . Downregulated HcSKC transformants displayed greater K + contents at standard K + only. In such conditions, plants inoculated with these transgenic lines were impaired in K + nutrition. Taken together, these results support the hypothesis that the reduced expression of HcSKC modifies the pool of fungal K + available for the plant and/or affects its symbiotic transfer to the roots. Our study reveals that the maintenance of K + transport in H . cylindrosporum , through the regulation of HcSKC expression, is required for the K + nutrition of the host plant. DA - 2020/11/20/ PY - 2020/11/20/ DO - 10.1371/journal.pone.0242739 UR - https://doi.org/10.1371/journal.pone.0242739 ER - TY - JOUR TI - Comparison of benchtop and handheld near-infrared spectroscopy devices to determine forage nutritive value AU - Acosta, J. J. AU - Castillo, M. S. AU - Hodge, G. R. T2 - CROP SCIENCE AB - Abstract The quality of predicted plant‐, soil‐, and animal‐response values from near‐infrared (NIR) reflectance spectra depends on the ability to generate appropriate NIR models. The first step in the development of NIR models is collection of spectral data. Limited work, however, has been reported that compares NIR models for prediction of forage nutritive value when the spectra are obtained from devices with different spectral ranges and resolutions. The objectives of this study were to (a) develop and evaluate NIR spectroscopy models using a benchtop‐type (FOSS) and two handheld NIR devices (microPHAZIR and DLP NIRscan Nano EVM) to predict crude protein (CP), acid detergent fiber (ADF), amylase and sodium sulfite‐treated neutral detergent fiber (aNDF), and in vitro true dry matter digestibility (IVTD) of dried ground forage grass samples and (b) compare predictions among the three NIR devices. Switchgrass ( Panicum virgatum L.) and bermudagrass [ Cynodon dactylon (L.) Pers] hay samples were scanned with the NIR devices and analyzed with wet chemistry for development of NIR prediction models. Among devices, the r 2 of validation values for aNDF models ranged from .81 to .87; all other r 2 values were >.86 and as high as .98 with standard error of prediction (SEP; g kg −1 ) ranging from 8.1 to 11.5 for CP, 19.1 to 23.8 for aNDF, 14.2 to 20.0 for ADF, and 26.8 to 49.9 for IVTD. The FOSS benchtop NIR prediction models consistently had the highest r 2 and lowest SEP values; however, the predictive power for both handheld devices was similar to the benchtop‐type device. DA - 2020/// PY - 2020/// DO - 10.1002/csc2.20264 VL - 60 IS - 6 SP - 3410-3422 SN - 1435-0653 UR - http://dx.doi.org/10.1002/csc2.20264 ER - TY - JOUR TI - Efficiency of saprolite for removing E. coli from simulated wastewater AU - Gardner, T. AU - Vepraskas, M. J. AU - Amoozegar, A. T2 - Water Science and Technology AB - Abstract Saprolite, weathered bedrock, is being used to dispose of domestic sewage through septic system drainfields, but its ability to remove coliforms is unknown. This study determined if Escherichia coli could be removed by a sandy loam saprolite material. Triplicate columns containing saprolite were prepared with lengths of 30, 45, and 60 cm. A 215-mL solution containing 1 × 105 CFU/100 mL of non-toxic E. coli was applied to the top of each column for 5 days/week for 13 weeks, and selected outflow samples were analyzed for E. coli. Control columns had only tap water applied to them at the same time. Significantly higher (p ≤ 0.10 compared to controls) E. coli concentrations were only detected in samples collected at the end of week 3 for the 30-cm columns and week 4 for the 45-cm columns. E. coli concentrations were small and ranged from approximately 2 to 3 MPN/100 mL. No E. coli were detected in any outflow from the 60-cm columns. From weeks 5 to 13, E. coli concentrations from all columns were either undetectable or not significantly different from the control. The results showed that 60 cm of sandy loam saprolite was sufficient for the removal of E. coli from simulated wastewater. DA - 2020/10/28/ PY - 2020/10/28/ DO - 10.2166/wst.2020.514 VL - 10 UR - http://dx.doi.org/10.2166/wst.2020.514 KW - coliforms KW - filtration KW - piedmont soils KW - septic systems KW - weathered bedrock ER - TY - JOUR TI - The Use of Dewpoint Hygrometry to Measure Low Water Potentials in Soilless Substrate Components and Composites AU - Fields, Jeb S. AU - Fonteno, William C. AU - Jackson, Brian E. AU - Heitman, Joshua L. AU - Owen, James S., Jr. T2 - AGRONOMY-BASEL AB - Plant water availability in soilless substrates is an important management consideration to maximize water efficiency for containerized crops. Changes in the characteristics (i.e., shrink) of these substrates at low water potential (<−1.0 MPa) when using a conventional pressure plate-base can reduce hydraulic connectivity between the plate and the substrate sample resulting in inaccurate measures of water retention. Soilless substrate components Sphagnum peatmoss, coconut coir, aged pine bark, shredded pine wood, pine wood chips, and two substrate composites were tested to determine the range of volumetric water content (VWC) of surface-bound water at water potentials between −1.0 to −2.0 MPa. Substrate water potentials were measured utilizing dewpoint hygrometry. The VWC for all components or composites was between 5% and 14%. These results were considerably lower compared to previous research (25% to 35% VWC) utilizing conventional pressure plate extraction techniques. This suggests that pressure plate measurements may overestimate this surface-bound water which is generally considered unavailable for plant uptake. This would result in underestimating available water by as much as 50%. DA - 2020/9// PY - 2020/9// DO - 10.3390/agronomy10091393 VL - 10 IS - 9 SP - SN - 2073-4395 KW - available water KW - coconut coir KW - dewpoint potentiometer KW - peat KW - pine bark KW - pine tree substrate KW - substrate processing KW - surface-bound water KW - unavailable water KW - wood substrate ER - TY - JOUR TI - Effects of Growing-Finishing Pig Stocking Rates on Bermudagrass Ground Cover and Soil Properties AU - Pietrosemoli, Silvana AU - Raczkowski, Charles AU - Green, James T., Jr. AU - Villamide, Maria Jesus T2 - ANIMALS AB - This study compares four stocking rates (37, 74, 111 and 148 pigs ha-1) for growing to finishing pigs (18.4 ± 0.5 kg and 118.5 ± 2.0 kg and 35.7 ± 2.1 kg and 125.7 ± 2.3 kg initial and final BW for grazing periods 1 and 2, respectively) and their effect on ground cover and soil traits in bermudagrass (Cynodon dactylon [L.] Pers) pastures, over two 14-week grazing periods (July-September and May-August). The study was conducted at the Center for Environmental Farming systems at the Cherry Research Station, Goldsboro North Carolina. A continuous stocking method was implemented to manage the pasture. The percent ground cover was estimated with a modified step point technique. Soil samples were collected in three sampling positions (center, inner and outer areas of the paddocks) and two soil sampling depths (0-30 and 30-90 cm). The experimental design was a completely randomized block with three field replicates. Data were analyzed using the PROC GLIMMIX procedure of SAS/STAT ® Version 9.4. Greater ground cover and lesser soil nutrient concentrations were registered in bermudagrass paddocks managed with 37 pigs ha-1. The results of this study also validated the existence of a spatial pattern of soil properties, which differed among sampling positions and depths. DA - 2020/9// PY - 2020/9// DO - 10.3390/ani10091666 VL - 10 IS - 9 SP - SN - 2076-2615 KW - pasture pigs KW - bermudagrass KW - stocking rates KW - soil sampling position KW - soil depth KW - ground cover KW - soil properties KW - soil nutrients KW - nutrients distribution KW - outdoor pigs ER - TY - JOUR TI - Phenotypic and Nodule Microbial Diversity among Crimson Clover (Trifolium incarnatum L.) Accessions AU - Moore, Virginia AU - Davis, Brian AU - Poskaitis, Megan AU - Maul, Jude E. AU - Kucek, Lisa Kissing AU - Mirsky, Steven T2 - AGRONOMY-BASEL AB - Crimson clover (Trifolium incarnatum L.) is the most common legume cover crop in the United States. Previous research found limited genetic variation for crimson clover within the National Plant Germplasm System (NPGS) collection. The aim of this study was to assess the phenotypic and nodule microbial diversity within the NPGS crimson clover collection, focusing on traits important for cover crop performance. Experiments were conducted at the Beltsville Agricultural Research Center (Maryland, USA) across three growing seasons (2012–2013, 2013–2014, 2014–2015) to evaluate 37 crimson clover accessions for six phenotypic traits: fall emergence, winter survival, flowering time, biomass per plant, nitrogen (N) content in aboveground biomass, and proportion of plant N from biological nitrogen fixation (BNF). Accession effect was significant across all six traits. Fall emergence of plant introductions (PIs) ranged from 16.0% to 70.5%, winter survival ranged from 52.8% to 82.0%, and growing degree days (GDD) to 25% maturity ranged from 1470 GDD to 1910 GDD. Biomass per plant ranged from 1.52 to 6.51 g, N content ranged from 1.87% to 2.24%, and proportion of plant N from BNF ranged from 50.2% to 85.6%. Accessions showed particularly clear differences for fall emergence and flowering time, indicating greater diversity and potential for selection in cover crop breeding programs. Fall emergence and winter survival were positively correlated, and both were negatively correlated with biomass per plant and plant N from BNF. A few promising lines performed well across multiple key traits, and are of particular interest as parents in future breeding efforts, including PIs 369045, 418900, 561943, 561944, and 655006. In 2014–2015, accessions were also assessed for nodule microbiome diversity, and 11 genera were identified across the sampled nodules. There was large variation among accessions in terms of species diversity, but this diversity was not associated with observed plant traits, and the functional implications of nodule microbiome diversity remain unclear. DA - 2020/9// PY - 2020/9// DO - 10.3390/agronomy10091434 VL - 10 IS - 9 SP - SN - 2073-4395 KW - cover crop KW - crimson clover KW - germplasm diversity KW - legume ER - TY - JOUR TI - Comparison of Water Capture Efficiency through Two Irrigation Techniques of Three Common Greenhouse Soilless Substrate Components AU - Schulker, Brian A. AU - Jackson, Brian E. AU - Fonteno, William C. AU - Heitman, Joshua L. AU - Albano, Joseph P. T2 - AGRONOMY-BASEL AB - Substrate wettability is an important factor in determining effective and efficient irrigation techniques for container-grown crops. Reduced substrate wettability can lead to lower substrate water capture, excessive leaching and poor plant growth. This research examined substrate water capture using surface and subirrigation under three initial moisture contents (IMC). Sphagnum peat moss, coconut coir, and pine bark were tested at IMCs of 67% 50%, and 33%. Substrate water capture was influenced by both IMC and irrigation technique. Surface irrigation increased the water capture of coir and peat, regardless of IMC, whereas IMC influenced pine bark water capture more than irrigation method. Surface-irrigated coir at or above 50% IMC provided the greatest water capture across all treatments. The first irrigation had the highest capture rate compared to all other events combined. Container capacities of pine bark and coir were unaffected by IMC and irrigation type, but the CC of peat was less by ~ 40% volumetrically under low IMC conditions. Coir, had the greatest ability to capture water, followed by pine bark and peat, respectively. Moisture content, irrigation type and component selection all influence the water capture efficiency of a container substrate. DA - 2020/9// PY - 2020/9// DO - 10.3390/agronomy10091389 VL - 10 IS - 9 SP - SN - 2073-4395 KW - irrigation KW - soilless substrates KW - water KW - coconut coir KW - initial moisture KW - mass wetness KW - peatmoss KW - pine bark KW - wettability KW - capillary rise KW - container capacity KW - capture rate ER - TY - JOUR TI - Integrating emergence and phenology models to determine windows of action for weed control: A case study using Senna obtusifolia AU - Piskackova, Theresa A. Reinhardt AU - Reberg-Horton, Chris AU - Richardson, Robert J. AU - Jennings, Katie M. AU - Leon, Ramon G. T2 - FIELD CROPS RESEARCH AB - The success of integrated weed management strategies is contingent on the accuracy of control actions in both time and space. While emphasis has been given to spatial accuracy, timing accuracy has been largely neglected. Weed control timing must consider not only the total duration of weed interference with the crop, as done by the traditional critical period of weed control (CPWC) based on yield protection only, but also weed growth, size, and susceptible phenological stages. In this study, we expand upon the idea of using weed emergence models for timing weed control by integrating them with phenology probability models for key weed growth stages to optimize timing of control actions, here referred as Critical Control Windows (CCW). Combining the CCW with thresholds for yield loss due to weed interference and thresholds for weed survival risk makes it possible determining the frequency with which control actions should be implemented to maintain crop yield and weed populations at desired levels. Using Senna obtusifolia as a study case, vegetative and reproductive phenological stages were modeled as a function of seedling emergence for different cohorts. Chronological and thermal-time models provided robust predictions of S. obtusifolia phenology. CCW did not always coincided with CPWC for several crops when considering 10-cm tall plants as the threshold for control. In general, for summer row crops, CCW required 2 postemergence control actions and sometimes 1 action outside the CPWC. The results of the present research illustrate how predictive models can be used to develop CCW that will complement the traditional CPWC. These two concepts when used complementary can increase not only timing accuracy, but also efficiency of weed control. DA - 2020/11/1/ PY - 2020/11/1/ DO - 10.1016/j.fcr.2020.107959 VL - 258 SP - SN - 1872-6852 KW - Weed predictive modeling KW - Thermal time KW - Hydrothermal time KW - Vulnerable stages KW - Integrated weed management KW - Critical period of weed control ER - TY - JOUR TI - Soil Fertility Management for Better Crop Production AU - Havlin, John AU - Heiniger, Ron T2 - AGRONOMY-BASEL AB - Increasing crop productivity per unit of land area to meet future food and fiber demand increases both soil nutrient removal and the importance of replenishing soil fertility through efficient nutrient management practices. Significant progress in enhancing nutrient-use efficiency in production agriculture requires improved estimates of plant-available nutrients in the root zone, enhanced crop response to applied nutrients, and reduced offsite nutrient transport. This special issue, Soil Fertility Management for Better Crop Production, presents 15 manuscripts that advance our knowledge of interrelated soil, plant, and management factors important to increasing the nutrient availability and crop recovery of applied nutrients. DA - 2020/9// PY - 2020/9// DO - 10.3390/agronomy10091349 VL - 10 IS - 9 SP - SN - 2073-4395 KW - nutrient use efficiency KW - nutrient management KW - rhizosphere KW - soil fertility KW - nutrient cycling KW - soil testing KW - plant analysis ER - TY - JOUR TI - Extraction and Detection of Structurally Diverse Siderophores in Soil AU - Rai, Vineeta AU - Fisher, Nathaniel AU - Duckworth, Owen W. AU - Baars, Oliver T2 - FRONTIERS IN MICROBIOLOGY AB - Although the biochemistry of bacterial and fungal siderophores has been intensively studied in laboratory cultures, their distribution and impacts on nutrient cycling and microbial communities in soils remain poorly understood. The detection of siderophores in soil is an analytical challenge because of the complexity of the soil matrix and their structural diversity. Liquid chromatography-mass spectrometry (LC-MS) is a suitable method for the sensitive analysis of siderophores in complex samples; however, siderophore extraction into liquid phases for analysis by LC-MS is problematic because of their adsorption to soil particles and organic matter. To determine extraction efficiencies of structurally diverse siderophores, spike-recovery experiments were set up with standards representing the three main siderophore classes: the hydroxamate desferrioxamine B (DFOB), the α-hydroxycarboxylate rhizoferrin, and the catecholate protochelin. Previously used solvent extractions with water or methanol recovered only a small fraction (< 35%) of siderophores, including < 5% for rhizoferrin and protochelin. We designed combinatorial chemical extractions (22 total solutions) to target siderophores associated with different soil components. A combination of calcium chloride and ascorbate achieved high and, for some soils, quantitative extraction of DFOB and rhizoferrin. Protochelin analysis was complicated by potential fast oxidation and interactions with colloidal soil components. Using the optimized extraction method, we detected α-hydroxycarboxylate type siderophores (viz. rhizoferrin, vibrioferrin, and aerobactin) in soil for the first time. Concentrations reached 461 pmol g-1, exceeding previously reported concentrations of siderophores in soil and suggesting a yet unrecognized importance of α-hydroxycarboxylate siderophores for biological interactions and biogeochemical processes in soil. DA - 2020/9/17/ PY - 2020/9/17/ DO - 10.3389/fmicb.2020.581508 VL - 11 SP - SN - 1664-302X KW - siderophores KW - extraction KW - recovery KW - iron KW - soil KW - adsorption KW - alpha-hydroxycarboxylate KW - catecholate ER - TY - JOUR TI - Susceptibility of Palmer amaranth (Amaranthus palmeri) to herbicides in accessions collected from the North Carolina Coastal Plain AU - Mahoney, Denis J. AU - Jordan, David L. AU - Roma-Burgos, Nilda AU - Jennings, Katherine M. AU - Leon, Ramon G. AU - Vann, Matthew C. AU - Everman, Wesley J. AU - Cahoon, Charles W. T2 - WEED SCIENCE AB - Abstract Palmer amaranth ( Amaranthus palmeri S. Watson) populations resistant to acetolactate synthase (ALS)-inhibiting herbicides and glyphosate are fairly common throughout the state of North Carolina (NC). This has led farm managers to rely more heavily on herbicides with other sites of action (SOA) for A. palmeri control, especially protoporphyrinogen oxidase and glutamine synthetase inhibitors. In the fall of 2016, seeds from A. palmeri populations were collected from the NC Coastal Plain, the state’s most prominent agricultural region. In separate experiments, plants with 2 to 4 leaves from the 110 populations were treated with field use rates of glyphosate, glufosinate-ammonium, fomesafen, mesotrione, or thifensulfuron-methyl. Percent visible control and survival were evaluated 3 wk after treatment. Survival frequencies were highest following glyphosate (99%) or thifensulfuron-methyl (96%) treatment. Known mutations conferring resistance to ALS inhibitors were found in populations surviving thifensulfuron-methyl application (Ala-122-Ser, Pro-197-Ser, Trp-574-Leu, and/or Ser-653-Asn), in addition to a new mutation (Ala-282-Asp) that requires further investigation. Forty-two populations had survivors after mesotrione application, with one population having 17% survival. Four populations survived fomesafen treatment, while none survived glufosinate. Dose–response studies showed an increase in fomesafen needed to kill 50% of two populations (LD 50 ); however, these rates were far below the field use rate (less than 5 g ha −1 ). In two populations following mesotrione dose–response studies, a 2.4- to 3.3-fold increase was noted, with LD 90 values approaching the field use rate (72.8 and 89.8 g ha −1 ). Screening of the progeny of individuals surviving mesotrione confirmed the presence of resistance alleles, as there were a higher number of survivors at the 1X rate compared with the parent population, confirming resistance to mesotrione. These data suggest A. palmeri resistant to chemistries other than glyphosate and thifensulfuron-methyl are present in NC, which highlights the need for weed management approaches to mitigate the evolution and spread of herbicide-resistant populations. DA - 2020/11// PY - 2020/11// DO - 10.1017/wsc.2020.67 VL - 68 IS - 6 SP - 582-593 SN - 1550-2759 UR - http://dx.doi.org/10.1017/wsc.2020.67 KW - Herbicide resistance KW - multiple resistance ER - TY - JOUR TI - Influence of timing of Palmer amaranth control in dicamba-resistant cotton on yield and economic return AU - Inman, Matthew D. AU - Jordan, David L. AU - Vann, Matthew C. AU - Hare, Andrew T. AU - York, Alan C. AU - Cahoon, Charles W. T2 - Weed Technology AB - Abstract Glyphosate-resistant (GR) Palmer amaranth continues to be challenging to control across the U.S. cotton belt. Timely application of POST herbicides and herbicides applied at planting or during the season with residual activity are utilized routinely to control this weed. Although glyphosate controls large Palmer amaranth that is not GR, herbicides such as glufosinate used in resistance management programs for GR Palmer amaranth must be applied when weeds are small. Dicamba can complement both glyphosate and glufosinate in controlling GR and glyphosate-susceptible (GS) biotypes in resistant cultivars. Two studies were conducted to determine Palmer amaranth control, weed biomass, and cotton yield, as well as to estimate economic net return when herbicides were applied 2, 3, 4, and 5 wk after planting (WAP). In one experiment POST-only applications were made. In the second experiment PRE herbicides were included. In general, Palmer amaranth was controlled at least 98% by herbicides applied at least three times regardless of timing of application or herbicide sequence. Glyphosate plus dicamba applied at 4 and 5 WAP controlled Palmer amaranth similarly compared to three applications by 8 WAP; however, yield was reduced 23% because of early-season interference. The inclusion of PRE herbicides benefited treatments that did not include herbicides applied 2 or 3 WAP. Glyphosate plus dicamba applied as the only herbicides 5 WAP provided 69% control of Palmer amaranth. PRE herbicides increased control to 96% for this POST treatment. Economic returns were similar when three or more POST applications were applied, with or without PRE herbicides. DA - 2020/4/2/ PY - 2020/4/2/ DO - 10.1017/wet.2020.37 VL - 4 SP - 1-7 UR - http://dx.doi.org/10.1017/wet.2020.37 KW - Dicamba KW - glyphosate KW - Palmer amaranth KW - Amaranthus palmeri S KW - Wats KW - AMAPA KW - cotton KW - Gossypium hirsutum (L KW - ) GOSHI KW - Herbicide-resistant weeds KW - herbicide resistance management KW - economic return KW - early-season weed competition ER - TY - JOUR TI - Evaluation of dicamba retention in spray tanks and its impact on flue-cured tobacco AU - Inman, Matthew D. AU - Vann, Matthew C. AU - Fisher, Loren R. AU - Gannon, Travis W. AU - Jordan, David L. AU - Jennings, Katie M. T2 - Weed Technology AB - Abstract In recent years, there has been increased use of dicamba due to the introduction of dicamba-resistant cotton and soybean in the United States. Therefore, there is a potential increase in off-target movement of dicamba and injury to sensitive crops. Flue-cured tobacco is extremely sensitive to auxin herbicides, particularly dicamba. In addition to yield loss, residue from drift or equipment contamination can have severe repercussions for the marketability of the crop. Studies were conducted in 2016, 2017, and 2018 in North Carolina to evaluate spray-tank cleanout efficiency of dicamba using various cleaning procedures. No difference in dicamba recovery was observed regardless of dicamba formulation and cleaning agent. Dicamba residue decreased with the number of rinses. There was no difference in dicamba residue recovered from the third rinse compared with residue from the tank after being refilled for subsequent tank use. Recovery ranged from 2% to 19% of the original concentration rate among the three rinses. Field studies were also conducted in 2018 to evaluate flue-cured tobacco response to reduced rates of dicamba ranging, from 1/5 to 1/10,000 of a labeled rate. Injury and yield reductions varied by environment and application timing. When exposed to 1/500 of a labeled rate at 7 and 11 wk after transplanting, tobacco injury ranged from 39% to 53% and 10% to 16% 24 days after application, respectively. The maximum yield reduction was 62%, with a 55% reduction in value when exposed to 112 g ha −1 of dicamba. Correlations showed significant relationships between crop injury assessment and yield and value reductions, with Pearson values ranging from 0.24 to 0.63. These data can provide guidance to growers and stakeholders and emphasize the need for diligent stewardship when using dicamba technology. DA - 2020/7/9/ PY - 2020/7/9/ DO - 10.1017/wet.2020.73 VL - 7 SP - 1-8 UR - http://dx.doi.org/10.1017/wet.2020.73 KW - tank contamination KW - contamination KW - off-target movement KW - simulated drift KW - auxin KW - yield KW - quality KW - Dicamba KW - cotton KW - Gossypium hirsutum L KW - flue-cured tobacco KW - Nicotiana tabacum L KW - soybean KW - Glycine max (L KW - ) Merr ER - TY - JOUR TI - Simulation Models on the Ecology and Management of Arable Weeds: Structure, Quantitative Insights, and Applications AU - Bagavathiannan, Muthukumar V. AU - Beckie, Hugh J. AU - Chantre, Guillermo R. AU - Gonzalez-Andujar, Jose L. AU - Leon, Ramon G. AU - Neve, Paul AU - Poggio, Santiago L. AU - Schutte, Brian J. AU - Somerville, Gayle J. AU - Werle, Rodrigo AU - Acker, Rene Van T2 - Agronomy AB - In weed science and management, models are important and can be used to better understand what has occurred in management scenarios, to predict what will happen and to evaluate the outcomes of control methods. To-date, perspectives on and the understanding of weed models have been disjointed, especially in terms of how they have been applied to advance weed science and management. This paper presents a general overview of the nature and application of a full range of simulation models on the ecology, biology, and management of arable weeds, and how they have been used to provide insights and directions for decision making when long-term weed population trajectories are impractical to be determined using field experimentation. While research on weed biology and ecology has gained momentum over the past four decades, especially for species with high risk for herbicide resistance evolution, knowledge gaps still exist for several life cycle parameters for many agriculturally important weed species. More research efforts should be invested in filling these knowledge gaps, which will lead to better models and ultimately better inform weed management decision making. DA - 2020/10/21/ PY - 2020/10/21/ DO - 10.3390/agronomy10101611 VL - 10 IS - 10 SP - 1611 UR - https://doi.org/10.3390/agronomy10101611 KW - weed seedling emergence KW - crop-weed competition KW - weed population dynamics KW - gene flow KW - herbicide resistance KW - decision-support tools KW - predictive models ER - TY - JOUR TI - Phosphorus speciation and iron mineralogy in an oxisol after 11 years of pig slurry application AU - Abdala, D. B. AU - Gatiboni, L. C. AU - Schmitt, D. E. AU - Mumbach, G. L. AU - Dall'Orsoletta, D. J. AU - Bonfada, E. B. AU - Veiga, M. T2 - SCIENCE OF THE TOTAL ENVIRONMENT AB - Application of phosphate fertilizers beyond plants needs favors phosphorus (P) accumulation in soils, which may alter its reactivity and chemical speciation. The objective of this study was to assess the changes in P speciation in a Brazilian oxisol that received consecutive applications of varying rates of pig slurry (PS) over 11 years. The soils were treated with PS at rates of 50, 100 and 200 m3 ha−1 year−1, whereas a control plot received P and potassium (K) to replenish the amounts removed by harvest. The soils were sampled and characterized for its P sorption capacity (PSC) as determined by Langmuir sorption isotherms, P partitioning by sequential chemical fractionation (SCF), P chemical speciation via P K-edge XANES and iron (Fe) mineralogy via Fe K-edge EXAFS spectroscopies. Increases in applied PS rates were accompanied by increases in PSC at the 0 to 2.5 and 0 to 10 cm soil layers. P accumulation was observed to be restricted up to the depth of 20 cm, regardless of the PS rate applied. The P K-edge XANES analysis indicated that P accumulation in the topmost soil layers, occurred predominantly associated with Fe-(hydr)oxide minerals. In this soil layer (0 to 2.5 cm), the organic P pool was of particular importance likely due to no-tillage. A dramatic change in Fe mineralogy in the topmost soil layer was observed across the studied soils, with the predominance of hematite in the reference soil and in the control plot, whereas the occurrence of goethite and ferrihydrite was followed by the application of PS. DA - 2020/11/15/ PY - 2020/11/15/ DO - 10.1016/j.scitotenv.2020.140487 VL - 743 SP - SN - 1879-1026 KW - P partitioning KW - P speciation KW - Sorption isotherms KW - Organic fertilization KW - P K-edge XANES KW - Fe-EXAFS ER - TY - JOUR TI - DRAINMOD Simulation of macropore flow at subsurface drained agricultural fields: Model modification and field testing AU - Askar, Manal H. AU - Youssef, Mohamed A. AU - Chescheir, George M. AU - Negm, Lamyaa M. AU - King, Kevin W. AU - Hesterberg, Dean L. AU - Amoozegar, Aziz AU - Skaggs, R. Wayne T2 - AGRICULTURAL WATER MANAGEMENT AB - Macropores are critical pathways through which water and pollutants can bypass the soil matrix and be rapidly transported to subsurface drains and freshwater bodies. We modified the DRAINMOD model to simulate macropore flow using a simple approach as part of developing the DRAINMOD-P model to simulate phosphorus dynamics in artificially drained agricultural lands. The Hagen-Poiseuille’s law was used to estimate the flow capacity of macropores. When ponding depths on the soil surface are greater than Kirkham’s depth, water is assumed to flow through macropores directly to tile drains without interaction with the soil matrix. In the modified model, macropore size is adjusted based on wet or dry conditions while connectivity is altered by tillage. The model was tested using a 4-year data set from a subsurface drained field in northwest Ohio. The soils at the field are classified as very poorly drained and are prone to desiccation cracking. The modified model predicted the daily and monthly subsurface drainage with average Nash-Sutcliffe efficiency (NSE) values of 0.48 and 0.59, respectively. The cumulative drainage over the 4-year simulation period was under-predicted by 8%. The new macropore component was able to capture about 75% of 60 peak drainage flow events. However, surface runoff was over-predicted for the entire study period. Annual water budgets using measured data (precipitation, subsurface drainage, and surface runoff) and model predictions (evapotranspiration, vertical seepage, and change in storage) were not balanced with an average annual imbalance of 6.4 cm. The lack of closure in the water balance suggests that errors may have occurred in field measurements, particularly, surface runoff. Overall, incorporating macropore flow into DRAINMOD improved predictions of daily drainage peaks and enabled the model to predict subsurface drainage flux contributed by macropore flow, which is critical for expanding DRAINMOD to simulate phosphorus transport in subsurface drained agricultural land. DA - 2020/12/1/ PY - 2020/12/1/ DO - 10.1016/j.agwat.2020.106401 VL - 242 SP - SN - 1873-2283 KW - Agricultural drainage KW - Preferential flow KW - Cracking soil KW - Hydrologic modeling ER - TY - JOUR TI - Sweet corn nitrogen accumulation, leaf photosynthesis rate, and radiation use efficiency under variable nitrogen fertility and irrigation AU - Jafarikouhini, Nahid AU - Kazemeini, Seyed Abdolreza AU - Sinclair, Thomas R. T2 - FIELD CROPS RESEARCH AB - Virtually no information exists on the response of sweet corn (Zea mays L. saccharata) to nitrogen fertility and irrigation treatments in terms of leaf nitrogen accumulation and the consequent impact on leaf CO2 assimilation rate and on crop growth as measured as radiation use efficiency (RUE). A two-year field experiment was undertaken in which a sweet corn cultivar was subjected to all combinations of five nitrogen fertility and three irrigation treatments. Leaf photosynthesis measurements were made at stages of 7–9 leaves, tasseling, silking, blistering, and milking. Leaf nitrogen per unit area was also measured at these five stages plus two additional stages before and after the five core measurements. Total nitrogen and plant mass was accumulated at the seven stages to track total nitrogen accumulation and to calculate RUE. The overall patterns in the measured variables were similar to those reported for field maize. However, leaf nitrogen per unit area for sweet corn under optimum conditions was greater than reported for field maize. The higher leaf nitrogen per unit area in sweet corn did not, however, result in greater leaf photosynthesis rates and RUE than reported for field maize. The results of these unique observations on sweet corn indicate the possibility of greater nitrogen storage in sweet corn leaves that is not directly linked with photosynthesis and carbon accumulation. DA - 2020/10/15/ PY - 2020/10/15/ DO - 10.1016/j.fcr.2020.107913 VL - 257 SP - SN - 1872-6852 KW - Leaf nitrogen KW - Nitrogen accumulation KW - Photosynthesis KW - Radiation use efficiency KW - Sweet corn ER - TY - JOUR TI - Basis of limited-transpiration rate under elevated vapor pressure deficit and high temperature among sweet corn cultivars AU - Jafarikouhini, Nahid AU - Pradhan, Deepti AU - Sinclair, Thomas R. T2 - ENVIRONMENTAL AND EXPERIMENTAL BOTANY AB - One plant trait that has been developed in several crop species to increase the effectiveness in water use through the cropping season is limited-transpiration under elevated atmospheric vapor pressure deficit (VPD). This trait allows water conservation early in the season so that there is more soil water available late in the season for sustained physiological activity during seed development. In sweet corn (Zea mays L. saccharata), where the quality of the kernels is important, this trait could prove to be especially beneficial. The background objective of this study was to explore 16 sweet corn cultivars for expression of the limited-transpiration trait. It was found at 32 °C that 13 of the 16 cultivars expressed the trait. It was found in a subset of eight of these cultivars, however, only half retained the limited-transpiration trait at 38 °C. The additional objectives were to explore the hypotheses that expression of the limited-transpiration trait was related to plant hydraulic conductance, and to the abundance of silver-sensitive aquaporins in the leaves. In cultivars that lost expression of the limited-transpiration trait at 38 °C there were large increases in plant hydraulic conductance at 38 °C as compared to 32 °C. Abundance of silver-sensitive aquaporins was related to the transpiration rate under low VPD conditions. That is, those cultivars with more abundant silver-sensitive aquaporins had greater transpiration rates as a result of greater stomatal conductance. These results showed that while expression of the limited-transpiration trait in sweet corn at 32 °C was common, differences in expression of the trait at 38 °C were observed due to differences in plant hydraulic conductance and stomatal conductance. DA - 2020/11// PY - 2020/11// DO - 10.1016/j.envexpbot.2020.104205 VL - 179 ER - TY - JOUR TI - Ammonia volatilization, nitrous oxide emissions, and corn yields as influenced by nitrogen placement and enhanced efficiency fertilizers AU - Woodley, Alex L. AU - Drury, Craig F. AU - Yang, Xueming Y. AU - Phillips, Lori A. AU - Reynolds, Daniel W. AU - Calder, Wayne AU - Oloya, Tom Okello T2 - Soil Science Society of America Journal AB - Abstract Ensuring sufficient fertilizer nitrogen (N) for crops while minimizing N losses requires best management practices optimized for climate, crop, soil, and root zone hydrology. In Ontario, pre‐plant N fertilization of corn ( Zea mays L.) is common; however, this practice extends the time between application and significant root interception of N by the plant, potentially increasing the risk of N loss through soil nitrous oxide emissions, ammonia (NH 3 ) volatilization, and nitrate leaching. These losses contribute to greenhouse gas emissions, affect air quality (NH 3 ), and are a substantial financial loss. This study compared three N placement methods (broadcast urea [BrUrea], broadcast incorporated urea [BrIncUrea], and injected urea ammonium nitrate [InjUAN]) and the presence or absence of N metabolite inhibitors (urease inhibitor [UI], urease plus nitrification inhibitor [UI+NI]). Fertilizer N was applied immediately before planting (150 kg N ha −1 ) to all treatments except for the control. Averaged over 3 yr (2015–2017), NH 3 losses were reduced by 34% from BrIncUrea, by 42–55% from BrUrea+UI+NI and BrIncUrea+UI+NI, and by 99% from InjUAN relative to BrUrea (21 kg N ha −1 ). On average, N application increased corn grain yields by 83% relative to the control (6 t ha −1 ). There were no annual yield differences among N placement methods. It was concluded that incorporation or injection of N in soil and use of urease and nitrification inhibitors reduced NH 3 emissions when N fertilizer was applied pre‐plant. DA - 2020/7// PY - 2020/7// DO - 10.1002/saj2.20079 UR - https://doi.org/10.1002/saj2.20079 ER - TY - DATA TI - Vicia villosa seed physical dormancy dataset from 2017-2019 DA - 2020/// PY - 2020/// DO - 10.15482/usda.adc/1519580 ER - TY - JOUR TI - Bahiagrass pasture and elephantgrass bioenergy cropping systems differ in root traits AU - Reyes-Cabrera, Joel AU - Erickson, John E. AU - Leon, Ramon G. AU - Quadros, Danilo G. AU - Silveira, Maria L. AU - Sollenberger, Lynn E. T2 - AGRONOMY JOURNAL AB - Abstract Root morphology and production are important for soil nutrient acquisition and C sequestration, but these traits are poorly understood in the bioenergy crop elephantgrass [ Pennisetum purpureum (L.) Schum.]. Our objective was to characterize root traits of elephantgrass receiving different nutrient management practices in comparison with bahiagrass ( Paspalum notatum Flüggé) pasture grown in the southeastern U.S. Treatments were bahiagrass + 50 kg N ha −1 (BHG), and elephantgrass receiving either: 50 kg N ha −1 (E50), 50 kg N ha −1 + biochar (E50BC), 50 kg N ha −1 + lignocellulosic fermentation residual (E50FR), or 250 kg N ha −1 (E250). Roots were sampled annually for 4 yr (2013‐2016). Root C and N concentration were measured at termination (2016) of the study. Both crop species exhibited similar root length density (RLD) and root mass density (RMD) across all depths in 2014 and 2015. BHG root diameter was 55% greater than all elephantgrass treatments. By 2016, E50FR increased elephantgrass RLD and RMD in the shallow soil layers (< 0.2 m). Root N content was 15–39% lower for all elephantgrass treatments than BHG in the 0‐0.1 m depth, and 22–25% lower for E50 and E50BC in the 0.1‐ to 0.2‐m depth compared with BHG. Additionally, roots C content was 6% higher in the 0‐0.1 m compared with the 0.1‐ to 0.2‐m soil depth irrespective of treatment. Application of biochar and lignocellulosic fermentation residual as amendments produced a stimulatory effect on elephantgrass root growth in soil shallow layers, which could affect nutrient and water acquisition. DA - 2020/// PY - 2020/// DO - 10.1002/agj2.20382 VL - 112 IS - 6 SP - 4810-4821 SN - 1435-0645 UR - https://doi.org/10.1002/agj2.20382 ER - TY - JOUR TI - Weed Management Guide for Florida Lawns AU - Unruh, J. Bryan AU - Trenholm, Laurie AU - Harlow, Erin AU - Leon, Ramon G. T2 - EDIS AB - Weeds can be defined as unwanted plants or plants growing out of place. Proper identification and some understanding of how and why weeds are present in a lawn are important when selecting the best control strategy. Knowing if weeds were previously present in an area also helps homeowners prepare control measures in the future. Weed control should be a carefully planned and coordinated program.https://edis.ifas.ufl.edu/ep141 Previous version: Unruh, Joseph, Ramon Leon, Barry Brecke, and Laurie Trenholm. 2013. “Weed Management Guide for Florida Lawns”. EDIS 2013 (7). https://journals.flvc.org/edis/article/view/121086. DA - 2020/9/21/ PY - 2020/9/21/ DO - 10.32473/edis-ep141-2019 UR - https://doi.org/10.32473/edis-ep141-2019 ER - TY - JOUR TI - Soil microbial diversity and composition: Links to soil texture and associated properties AU - Xia, Qing AU - Rufty, Thomas AU - Shi, Wei T2 - SOIL BIOLOGY & BIOCHEMISTRY AB - Soil texture is an essential component of soil survey for estimating potentials and limitations of land use and management. It has been appreciated as an important predictor for numerous soil processes. However, its connections with the diversity and composition of the soil microbial community remain less understood. This work employed a marker gene high-throughput sequencing approach to determine soil texture-based patterns of bacterial and fungal distribution. Thirty-six intact soil cores were sampled from bermudagrass ecosystems across seven soil texture classes with sand fraction varying from 30.3 to 83.4% and clay fraction from 4.4 to 53.0%. These soil cores were arranged into three sets of equal numbers, and each set of 12 was subjected to three moisture regimes (dry spell, field moisture, and saturation-field capacity), respectively, for 15 days. Soil cores were further stratified into top and bottom sections, leading to a total of 72 samples with varying soil physical and chemical properties. Our data revealed that fungal alpha diversity was more strongly related to soil texture than bacterial alpha diversity, with fungal species richness and Shannon diversity being positively correlated with the sand fraction. Soil texture was the second most important factor after soil pH in shaping the soil microbial community. Relative abundances of some fungi (Basidiomycota and Eurotiomycetes) and filamentous bacteria (Actinobacteria, Chloroflexi) significantly increased with silt and/or clay content. The genetic potential for the degradation of organic compounds also appeared to be higher in finer textured soils than the coarse-textured soils. By identifying sand, silt or clay-preferred microbial taxa and characterizing mineral particle-dependent genetic potential of organic carbon degradation and nitrogen cycling, this work highlighted the significance of soil texture and texture-associated pores, and resource locality, in regulating microbial diversity and community composition. DA - 2020/10// PY - 2020/10// DO - 10.1016/j.soilbio.2020.107953 VL - 149 SP - SN - 0038-0717 KW - Soil texture KW - Microbial community KW - 16S KW - ITS KW - Organic C degradation KW - N cycling ER - TY - JOUR TI - Early response of organic matter dynamics to pine‐biochar in sandy soil under peach trees AU - Frene, Juan Pablo AU - Frazier, Mattie AU - Rutto, Edwin AU - Jones, McGwire AU - Liu, Shuang AU - Clark, Bernadette AU - Parker, Michael AU - Gardner, Terrence G. T2 - Agrosystems, Geosciences & Environment AB - Abstract Biochar may enhance soil health in sandy soils under peach [ Prunus persica (L.) Batsch] tree production. A study was initiated in the Sandhills of North Carolina by applying pine‐biochar at two different rates (5 and 10%, v/v) and types of application (incorporation to 30 cm [‐Inc] and surface [‐Sur]) in 2017. Soil organic matter (SOM) dynamics was assessed via soil organic carbon (SOC), total nitrogen (TN), permanganate‐oxidizable carbon (POXC), aggregate fractions (macro‐, micro‐aggregates, and clay + silt particles), and enzyme activities (CNPS activity) at 0–15 and 15–30 cm in 2018 and 2019. After the first year of pine‐biochar application, POXC decreased in all biochar treatments, SOC was higher in the 10%‐Inc treatment, whereas CNPS activities and macroaggregates were highest in the 5%‐Sur compared with the non‐treated control. These results suggest early changes in SOM dynamics and biogeochemical cycling and have the potential to guide producers with the long‐term application of pine‐biochar to sandy soils. DA - 2020/1// PY - 2020/1// DO - 10.1002/agg2.20094 UR - https://doi.org/10.1002/agg2.20094 ER - TY - JOUR TI - Establishing environmental soil phosphorus thresholds to decreases the risk of losses to water in soils from Rio Grande do Sul, Brazil AU - Gatiboni, Luciano Colpo AU - Nicoloso, Rodrigo da Silveira AU - Mumbach, Gilmar Luiz AU - Souza Junior, Abelino Anacleto AU - Dall'Orsoletta, Daniel Joao AU - Schmitt, Djalma Eugenio AU - Smyth, Thomas Jot T2 - REVISTA BRASILEIRA DE CIENCIA DO SOLO AB - The overloading of soil with manure or mineral fertilizers enhances phosphorus (P) availability, promoting its loss to water bodies and increasing the risk of eutrophication. In this sense, the establishment of an environmental P threshold is a simple and useful tool to classify soils regards its risk of P losses. Here we propose a P-threshold for soils from the state of Rio Grande do Sul (RS) in Brazil, with the soil clay content as the principal variable of the [...] DA - 2020/// PY - 2020/// DO - 10.36783/18069657rbcs20200018 VL - 44 SP - SN - 1806-9657 UR - https://doi.org/10.36783/18069657rbcs20200018 KW - P-threshold KW - phosphate fertilization KW - phosphate adsorption KW - clay KW - mineralogy ER - TY - JOUR TI - In Vitro Safening of Bentazon by Melatonin in Sweetpotato (Ipomoea batatas) AU - Caputo, Giovanni A. AU - Wadl, Phillip A. AU - McCarty, Lambert AU - Adelberg, Jeff AU - Jennings, Katherine M. AU - Cutulle, Matthew T2 - HORTSCIENCE AB - Weed competition is a main factor limiting sweetpotato [ Ipomoea batatas (L.) Lam] production. Yellow nutsedge ( Cyperus esculentus L.) is a problematic weed to control due to its ability to quickly infest a field and generate high numbers of tubes and shoots. Compounding this is the lack of a registered herbicide for selective postemergence control of yellow nutsedge. Research was conducted to evaluate the bentazon dose response of two sweetpotato cultivars and one advanced clone and to evaluate the plant hormone melatonin to determine its ability to safen bentazon post emergence. Bioassays using Murashige and Skoog (MS) media supplemented with melatonin (0.232 g a.i./L and 0.023 g a.i./L) and bentazon (0.24 g a.i./L) were conducted to evaluate the effect of bentazon on sweetpotato and to determine the interactive response of the Beauregard cultivar to bentazon and exogenous applications of melatonin. Beauregard swas the most tolerant cultivar and required dosages of bentazon that were two-times higher to cause the same injury compared with other cultivars. MS media containing melatonin and bentazon showed fewer injuries and higher plant mass than plants treated with bentazon alone. These results indicate that sweetpotato injury caused by bentazon may be reduced by melatonin. DA - 2020/9// PY - 2020/9// DO - 10.21273/HORTSCI15128-20 VL - 55 IS - 9 SP - 1406-1410 SN - 2327-9834 KW - antioxidant KW - tissue culture KW - Ipomoea batatas KW - weed management ER - TY - JOUR TI - Effect of bicyclopyrone herbicide on sweetpotato and Palmer amaranth (Amaranthus palmeri) AU - Lindley, Jennifer J. AU - Jennings, Katherine M. AU - Monks, David W. AU - Chaudhari, Sushila AU - Schultheis, Jonathan R. AU - Waldschmidt, Matthew AU - Brownie, Cavell T2 - WEED TECHNOLOGY AB - Abstract Management options are needed to limit sweetpotato yield loss due to weeds. Greenhouse studies were conducted in 2018 in Greensboro, NC, and in the field from 2016 to 2018 in Clinton, NC, to evaluate the effect of bicyclopyrone on sweetpotato and Palmer amaranth (field only). In greenhouse studies, Covington and NC04-531 clones were treated with bicyclopyrone (0, 25, 50, 100, or 150 g ai ha −1 ) either preplant (PP; i.e., immediately before transplanting) or post-transplant (PT; i.e., on the same day after transplanting). Sweetpotato plant injury and stunting increased, and vine length and shoot dry weight decreased with increasing rate of bicyclopyrone regardless of clone or application timing. In field studies, Beauregard (2016) or Covington (2017 and 2018) sweetpotato clones were treated with bicyclopyrone at 50 g ha −1 PP, flumioxazin at 107 g ai ha −1 PP, bicyclopyrone at 50 or 100 g ha −1 PP followed by (fb) S -metolachlor at 800 g ai ha −1 PT, flumioxazin at 107 g ha −1 PP fb S -metolachlor at 800 g ha −1 PT, flumioxazin at 107 g ha −1 PP fb S -metolachlor at 800 g ha −1 PT fb bicyclopyrone at 50 g ha −1 PT-directed, and clomazone at 420 g ai ha −1 PP fb S -metolachlor at 800 g ha −1 PT. Bicyclopyrone PP at 100 g ha −1 fb S- metolachlor PT caused 33% or greater crop stunting and 44% or greater marketable yield reduction compared with the weed-free check in 2016 (Beauregard) and 2017 (Covington). Bicyclopyrone PP at 50 g ha −1 alone or fb S- metolachlor PT resulted in 12% or less injury and similar no. 1 and jumbo yields as the weed-free check in 2 of 3 yr. Injury to Covington from bicyclopyrone PT-directed was 4% or less at 4 or 5 wk after transplanting and marketable yield was similar to that of the weed-free check in 2017 and 2018. DA - 2020/8// PY - 2020/8// DO - 10.1017/wet.2020.13 VL - 34 IS - 4 SP - 552-559 SN - 1550-2740 KW - Greenhouse KW - weed control KW - crop injury KW - interference ER - TY - JOUR TI - Critical timing of Palmer amaranth (Amaranthus palmeri) removal in sweetpotato AU - Smith, Stephen C. AU - Jennings, Katherine M. AU - Monks, David W. AU - Chaudhari, Sushila AU - Schultheis, Jonathan R. AU - Reberg-Horton, Chris T2 - WEED TECHNOLOGY AB - Abstract Palmer amaranth is the most common and troublesome weed in North Carolina sweetpotato. Field studies were conducted in Clinton, NC, in 2016 and 2017 to determine the critical timing of Palmer amaranth removal in ‘Covington’ sweetpotato. Palmer amaranth was grown with sweetpotato from transplanting to 2, 3, 4, 5, 6, 7, 8, and 9 wk after transplanting (WAP) and maintained weed-free for the remainder of the season. Palmer amaranth height and shoot dry biomass increased as Palmer amaranth removal was delayed. Season-long competition by Palmer amaranth interference reduced marketable yields by 85% and 95% in 2016 and 2017, respectively. Sweetpotato yield loss displayed a strong inverse linear relationship with Palmer amaranth height. A 0.6% and 0.4% decrease in yield was observed for every centimeter of Palmer amaranth growth in 2016 and 2017, respectively. The critical timing for Palmer amaranth removal, based on 5% loss of marketable yield, was determined by fitting a log-logistic model to the relative yield data and was determined to be 2 WAP. These results show that Palmer amaranth is highly competitive with sweetpotato and should be managed as early as possible in the season. The requirement of an early critical timing of weed removal to prevent yield loss emphasizes the importance of early-season scouting and Palmer amaranth removal in sweetpotato fields. Any delay in removal can result in substantial yield reductions and fewer premium quality roots. DA - 2020/8// PY - 2020/8// DO - 10.1017/wet.2020.1 VL - 34 IS - 4 SP - 547-551 SN - 1550-2740 KW - Critical period of weed control KW - competition KW - control KW - interference ER - TY - JOUR TI - Rhizobium leguminosarum strain combination effects on nodulation and biological nitrogen fixation with Vicia villosa AU - Roper, Wayne R. AU - Duckworth, Owen W. AU - Grossman, Julie M. AU - Israel, Daniel W. T2 - APPLIED SOIL ECOLOGY AB - Biological nitrogen fixation (BNF) resulting from symbiosis between legumes and rhizobia helps improve soil N fertility. Inoculated soils with specific strains of rhizobia may increase potential BNF in legumes, but the efficacy of these rhizobia in promoting BNF may be limited by competition from resident rhizobia already present in soils. We evaluated the ability of four strains to nodulate and increase BNF in Vicia villosa (hairy vetch) as individual and combined inoculants in a laboratory experiment. Plants were inoculated with a single rhizobia strain or equal ratios of 2–4 strains and grown under controlled conditions. After 46 d, entire plant shoots were harvested and analyzed for biomass, N content, nodule number, and nodule mass. Nodule occupancy was assessed using DNA fingerprinting of characteristic rhizobia genes. Negative-N and positive-N control plants averaged 6.3 and 83.2 mg total shoot N, respectively. Average total shoot N of inoculated vetch treatments was between that of uninoculated control treatments. Nodule number, total nodule mass, and BNF efficiency (total shoot N mass per total nodule mass) did not significantly differ between individual strains. Neither BNF efficiency nor nodule number were indicative of competitive ability for nodule occupancy. The rhizobia did not display any consistent synergistic or antagonistic effect on BNF when combined in inoculants and nodule occupancy did not favor any specific strain. Because vetch inoculated with local Rlv strains produced similar amounts of N as uninoculated plants fertilized with N, our work suggests that rhizobia sourced from local soils may produce sufficient BNF with vetch. DA - 2020/12// PY - 2020/12// DO - 10.1016/j.apsoil.2020.103703 VL - 156 SP - SN - 1873-0272 KW - Rhizobia KW - Nitrogen fixation KW - Vicia villosa KW - Legume KW - Root nodule KW - Hairy vetch ER - TY - JOUR TI - An Efficient Stevia rebaudiana Transformation System and In vitro Enzyme Assays Reveal Novel Insights into UGT76G1 Function AU - Wu, Qian AU - La Hovary, Christophe AU - Chen, Han-Yi AU - Li, Xu AU - Eng, Hayde AU - Vallejo, Veronica AU - Qu, Rongda AU - Dewey, Ralph E. T2 - SCIENTIFIC REPORTS AB - Abstract Stevia rebaudiana (Bertoni) is one of a very few plant species that produce zero calorie, sweet compounds known as steviol glycosides (SG). SGs differ in their sweetness and organoleptic properties depending on the number and positioning of sugar groups on the core steviol backbone. There is great interest of modulating the SG profiles of the Stevia plant to enhance the flavor profile for a given application in the food and beverage industries. Here, we report a highly efficient Agrobacterium-mediated stable transformation system using axillary shoots as the initial explant. Using this system, we generated over 200 transgenic Stevia plants overexpressing a specific isoform of UGT76G1 . By comparing the SG profiles among independent transgenic events, we demonstrated that altering UGT76G1 expression can change the ratios of specific SG species. Furthermore, using recombinant proteins produced in E . coli , we show that two closely related UGT76G1 isoforms differ in their substrate specificities, providing new insights into mechanisms underlying the diversity of SG profiles that are observed across Stevia germplasm. Finally, we found evidence suggesting that alternative and/or aberrant splicing may serve to influence the ability of the plant to produce functional UGT76G1 transcripts, and possibly produce enzyme variants within the plant. DA - 2020/2/28/ PY - 2020/2/28/ DO - 10.1038/s41598-020-60776-y VL - 10 IS - 1 SP - SN - 2045-2322 ER - TY - JOUR TI - Effects of exogenous citric acid on the concentration and spatial distribution of Ni, Zn, Co, Cr, Mn and Fe in leaves of Noccaea caerulescens grown on a serpentine soil AU - Nascimento, Clistenes Williams Araujo AU - Hesterberg, Dean AU - Tappero, Ryan T2 - Journal of Hazardous Materials AB - The aim of this study was to show the potential of citric acid in increasing the concentration of Ni, Zn, Co, Cr, Mn and Fe in leaves of the hyperaccumulator Noccaea caerulescens. Synchrotron x-ray fluorescence (μ-XRF) images were collected to assess the distribution of metals in leaves. Applying citric acid (20 mmol kg-1) to soil increased in 14-, 10-, 7-, 2- and 1.4- fold the concentration of Mn, Fe, Co, Ni, and Cr, respectively, compared to the control. The μ-XRF imaging revealed that Ni and Zn were not spatially correlated across the leaf. We observed a clear partitioning of Zn between veins and surrounding leaf cells while Ni was more evenly distributed between veins and leaf blade. The accumulation of metals in citric acid treated plants did not change the Ni and Zn distribution pattern in leaves but altered the Mn distribution. It seems that Mn reached toxic concentrations in leaves and we hypothesize that a mechanism driven by transpiration through the xylem was used to excrete the metal. Our results show that citric acid can enhance metal accumulation by N. caerulescens and have impact for soil remediation by either decreasing the time for clean up or increasing the access to non-labile pools of metals in soil. DA - 2020/11// PY - 2020/11// DO - 10.1016/j.jhazmat.2020.122992 VL - 398 SP - 122992 UR - https://doi.org/10.1016/j.jhazmat.2020.122992 KW - Hyperaccumulation KW - phytoremediation KW - phytomining KW - x-ray fluorescence ER - TY - JOUR TI - Lipo-chitooligosaccharides as regulatory signals of fungal growth and development AU - Rush, Tomas Allen AU - Puech-Pages, Virginie AU - Bascaules, Adeline AU - Jargeat, Patricia AU - Maillet, Fabienne AU - Haouy, Alexandra AU - Maes, Arthur QuyManh AU - Carriel, Cristobal Carrera AU - Khokhani, Devanshi AU - Keller-Pearson, Michelle AU - Tannous, Joanna AU - Cope, Kevin R. AU - Garcia, Kevin AU - Maeda, Junko AU - Johnson, Chad AU - Kleven, Bailey AU - Choudhury, Quanita J. AU - Labbe, Jessy AU - Swift, Candice AU - Michelle A. O'Malley, AU - Bok, Jin Woo AU - Cottaz, Sylvain AU - Fort, Sebastien AU - Poinsot, Verena AU - Sussman, Michael R. AU - Lefort, Corinne AU - Nett, Jeniel AU - Keller, Nancy P. AU - Becard, Guillaume AU - Ane, Jean-Michel T2 - NATURE COMMUNICATIONS AB - Abstract Lipo-chitooligosaccharides (LCOs) are signaling molecules produced by rhizobial bacteria that trigger the nodulation process in legumes, and by some fungi that also establish symbiotic relationships with plants, notably the arbuscular and ecto mycorrhizal fungi. Here, we show that many other fungi also produce LCOs. We tested 59 species representing most fungal phyla, and found that 53 species produce LCOs that can be detected by functional assays and/or by mass spectroscopy. LCO treatment affects spore germination, branching of hyphae, pseudohyphal growth, and transcription in non-symbiotic fungi from the Ascomycete and Basidiomycete phyla. Our findings suggest that LCO production is common among fungi, and LCOs may function as signals regulating fungal growth and development. DA - 2020/8/4/ PY - 2020/8/4/ DO - 10.1038/s41467-020-17615-5 VL - 11 IS - 1 SP - SN - 2041-1723 ER - TY - JOUR TI - Phosphorus Extraction with Soil Test Methods Affected by Soil P Sorption Capacity AU - Mumbach, Gilmar Luiz AU - Gatiboni, Luciano Colpo AU - Dall'Orsoletta, Daniel Joao AU - Schmitt, Djalma Eugenio AU - Pessotto, Patricia Pretto AU - Oliveira, Clovisson Menotti T2 - JOURNAL OF SOIL SCIENCE AND PLANT NUTRITION DA - 2020/12// PY - 2020/12// DO - 10.1007/s42729-020-00259-1 VL - 20 IS - 4 SP - 1882-1890 SN - 0718-9516 KW - Buffer capacity KW - Mehlich 1 and Mehlich 3 KW - Anion exchange resin ER - TY - JOUR TI - Identification of regions under selection and loci controlling agronomic traits in a soft red winter wheat population AU - Gaire, Rupesh AU - Ohm, Herbert AU - Brown-Guedira, Gina AU - Mohammadi, Mohsen T2 - PLANT GENOME AB - Abstract Comprehensive information of a breeding population is a necessity to design promising crosses. This study was conducted to characterize a soft red winter wheat breeding population that was subject of intensive germplasm introductions and introgression from exotic germplasm. We used genome‐wide markers and phenotypic assessment to identify signatures of selection and loci controlling agronomic traits in a soft red winter wheat population. The study of linkage disequilibrium (LD) revealed that the extent of LD and its decay varied among chromosomes with chromosomes 2B and 7D showing the most extended islands of high‐LD with slow rates of decay. Four sub‐populations, two with North American origin and two with Australian and Chinese origins, were identified. Genome‐wide scans for selection signatures using F ST and hapFLK identified 13 genomic regions under selection, of which five loci ( LT , Fr‐A2 , Vrn‐A1 , Vrn‐B1 , Vrn3 ) were associated with environmental adaptation and two loci were associated with disease resistance genes ( Sr36 and Fhb1 ). Genome‐wide association studies identified major loci controlling yield and yield related traits. For days to heading and plant height, major loci with effects sizes of 2.2 days and 5 cm were identified on chromosomes 7B and 6A respectively. For test weight, number of spikes per square meter, and number of kernels per square meter, large effect loci were identified on chromosomes 1A, 4B, and 5A, respectively. However, for yield alone, no major loci were detected. A combination of selection for large effect loci for yield components and genomic selection could be a promising approach for yield improvement. DA - 2020/7// PY - 2020/7// DO - 10.1002/tpg2.20031 VL - 13 IS - 2 SP - SN - 1940-3372 ER - TY - JOUR TI - Incorporating environmental factors to describe wild radish (Raphanus raphanistrum) seedling emergence and plant phenology AU - Piskackova, Theresa Reinhardt AU - Reberg-Horton, S. Chris AU - Richardson, Robert J. AU - Jennings, Katie M. AU - Leon, Ramon G. T2 - WEED SCIENCE AB - Abstract Wild radish ( Raphanus raphanistrum L.) is a weed found globally in agricultural systems. The facultative winter annual nature of this plant and high genetic variability makes modeling its growth and phenology difficult. In the present study, R. raphanistrum natural seedbanks exhibited a biphasic pattern of emergence, with emergence peaks occurring in both fall and spring. Traditional sigmoidal models were inadequate to fit this pattern, regardless of the predictive environmental variable, and a corresponding biphasic model (sigmoidal + Weibull) was used to describe emergence based on the best parameters. Each best-fit chronological, thermal, and hydrothermal model accounted for at least 85% of the variation of the validation data. Observations on phenology progression from four cohorts were used to create a common model that described all cohorts adequately. Different phenological stages were described using chronological, thermal, hydrothermal, daylength-dependent thermal time, and daylength-dependent hydrothermal time. Integrating daylength and temperature into the models was important for predicting reproductive stages of R. raphanistrum . DA - 2020/11// PY - 2020/11// DO - 10.1017/wsc.2020.64 VL - 68 IS - 6 SP - 627-638 SN - 1550-2759 UR - https://doi.org/10.1017/wsc.2020.64 KW - Hydrothermal time KW - integrated weed management KW - predictive models KW - thermal time KW - weed growth ER - TY - JOUR TI - Training Population Design With the Use of Regional Fusarium Head Blight Nurseries to Predict Independent Breeding Lines for FHB Traits AU - Verges, Virginia L. AU - Lyerly, Jeanette AU - Dong, Yanhong AU - Van Sanford, David A. T2 - FRONTIERS IN PLANT SCIENCE AB - Fusarium head blight (FHB) is a devastating disease in cereals around the world. Because it is quantitatively inherited and technically difficult to reproduce, breeding to increase resistance in wheat germplasm is difficult and slow. Genomic selection (GS) is a form of marker-assisted selection (MAS) that simultaneously estimates all locus, haplotype, or marker effects across the entire genome to calculate genomic estimated breeding values (GEBVs). Since its inception, there have been many studies that demonstrate the utility of GS approaches to breeding for disease resistance in crops. In this study, the Uniform Northern (NUS) and Uniform Southern (SUS) soft red winter wheat scab nurseries (a total 452 lines) were evaluated as possible training populations (TP) to predict FHB traits in breeding lines of the UK (University of Kentucky) wheat breeding program. DON was best predicted by the SUS; Fusarium damaged kernels (FDK), FHB rating, and two indices, DSK index and DK index were best predicted by NUS. The highest prediction accuracies were obtained when the NUS and SUS were combined, reaching up to 0.5 for almost all traits except FHB rating. Highest prediction accuracies were obtained with bigger TP sizes (300-400) and there were not significant effects of TP optimization method for all traits, although at small TP size, the PEVmean algorithm worked better than other methods. To select for lines with tolerance to DON accumulation, a primary breeding target for many breeders, we compared selection based on DON BLUES with selection based on DON GEBVs, DSK GEBVs, and DK GEBVs. At selection intensities (SI) of 30-40%, DSK index showed the best performance with a 4-6% increase over direct selection for DON. Our results confirm the usefulness of regional nurseries as a source of lines to predict GEBVs for local breeding programs, and shows that an index that includes DON, together with FDK and FHB rating could be an excellent choice to identify lines with low DON content and an overall improved FHB resistance. DA - 2020/7/16/ PY - 2020/7/16/ DO - 10.3389/fpls.2020.01083 VL - 11 SP - SN - 1664-462X KW - genomic selection KW - Fusariumhead blight KW - training population KW - DON content KW - disease resistance KW - prediction accuracy ER - TY - JOUR TI - High-Resolution Measurement of Soil Thermal Properties and Moisture Content Using a Novel Heated Fiber Optics Approach AU - Shehata, Mahmoud AU - Heitman, Joshua AU - Ishak, Joseph AU - Sayde, Chadi T2 - WATER RESOURCES RESEARCH AB - Abstract Hydrological parameters are scale dependent. Efficient monitoring techniques capable of measuring hydrological parameters, such as soil moisture content ( θ ), over a wide range of spatial scales are essential for understanding the complexity of water and energy movement across the landscape. Techniques to measure θ over spatial scales in the range from centimeters to thousands of meters, however, are sorely lacking. Recent improvements in the distributed temperature sensing (DTS) technology supported the development of novel techniques to fill that gap. However, improvements in the accuracy and applicability of DTS techniques are still needed. This study investigates the possibility of improving the accuracy of the fiber optics dual‐probe heat‐pulse (FO‐DPHP) DTS technique by using a new design to maintain the spacing between the FO‐DPHP probes and by introducing a novel data interpretation approach. The accuracy of the novel FO‐DPHP design was tested at different θ in a sand column experiment. The FO‐DPHP measurements obtained using traditional and novel data interpretation approaches were compared against independent measurements from several calibrated soil water content (EC5) sensors. Monte‐Carlo analyses were also performed to assess the impact of DTS measurement errors on the accuracy achieved using the data interpretation approaches. The novel design and data interpretation approach allowed for accurate measurements of soil thermal properties and θ without the need to perform a hard‐to‐achieve soil‐specific calibration. Measured θ had mean errors and standard deviations <0.03 and <0.01 m 3 m −3 , respectively, for moisture conditions ranging from dry to near saturation. The standard deviation in the measured heat capacity was <0.01 MJ m −3 K −1 . DA - 2020/7// PY - 2020/7// DO - 10.1029/2019WR025204 VL - 56 IS - 7 SP - SN - 1944-7973 KW - precision agriculture KW - soil thermal properties KW - soil moisture content KW - distributed temperature sensing KW - dual-probe heat-pulse KW - fiber-optic sensors ER - TY - JOUR TI - Pod and Seed Trait QTL Identification To Assist Breeding for Peanut Market Preferences AU - Chavarro, Carolina AU - Chu, Ye AU - Holbrook, Corley AU - Isleib, Thomas AU - Bertioli, David AU - Hovav, Ran AU - Butts, Christopher AU - Lamb, Marshall AU - Sorensen, Ronald AU - Jackson, Scott A. AU - Ozias-Akins, Peggy T2 - G3-GENES GENOMES GENETICS AB - Abstract Although seed and pod traits are important for peanut breeding, little is known about the inheritance of these traits. A recombinant inbred line (RIL) population of 156 lines from a cross of Tifrunner x NC 3033 was genotyped with the Axiom_Arachis1 SNP array and SSRs to generate a genetic map composed of 1524 markers in 29 linkage groups (LG). The genetic positions of markers were compared with their physical positions on the peanut genome to confirm the validity of the linkage map and explore the distribution of recombination and potential chromosomal rearrangements. This linkage map was then used to identify Quantitative Trait Loci (QTL) for seed and pod traits that were phenotyped over three consecutive years for the purpose of developing trait-associated markers for breeding. Forty-nine QTL were identified in 14 LG for seed size index, kernel percentage, seed weight, pod weight, single-kernel, double-kernel, pod area and pod density. Twenty QTL demonstrated phenotypic variance explained (PVE) greater than 10% and eight more than 20%. Of note, seven of the eight major QTL for pod area, pod weight and seed weight (PVE &gt;20% variance) were attributed to NC 3033 and located in a single linkage group, LG B06_1. In contrast, the most consistent QTL for kernel percentage were located on A07/B07 and derived from Tifrunner. DA - 2020/7// PY - 2020/7// DO - 10.1534/g3.120.401147 VL - 10 IS - 7 SP - 2297-2315 SN - 2160-1836 KW - Peanut KW - seed KW - pod KW - linkage map KW - QTL KW - single nucleotide polymorphism (SNP) ER - TY - JOUR TI - A Probabilistic Approach to Phosphorus Speciation of Soils Using P K-edge XANES Spectroscopy with Linear Combination Fitting AU - Gustafsson, Jon Petter AU - Braun, Sabina AU - Tuyishime, J. R. Marius AU - Adediran, Gbotemi A. AU - Warrinnier, Ruben AU - Hesterberg, Dean T2 - SOIL SYSTEMS AB - A common technique to quantitatively estimate P speciation in soil samples is to apply linear combination fitting (LCF) to normalized P K-edge X-ray absorption near-edge structure (XANES) spectra. Despite the rapid growth of such applications, the uncertainties of the fitted weights are still poorly known. Further, there are few reports to what extent the LCF standards represent unique end-members. Here, the co-variance between 34 standards was determined and their significance for LCF was discussed. We present a probabilistic approach for refining the calculation of LCF weights based on Latin hypercube sampling of normalized XANES spectra, where the contributions of energy calibration and normalization to fit uncertainty were considered. Many of the LCF standards, particularly within the same standard groups, were strongly correlated. This supports an approach in which the LCF standards are grouped. Moreover, adsorbed phytates and monetite were well described by other standards, which puts into question their use as end-members in LCF. Use of the probabilistic method resulted in uncertainties ranging from 2 to 11 percentage units. Uncertainties in the calibrated energy were important for the LCF weights, particularly for organic P, which changed with up to 2.7 percentage units per 0.01 eV error in energy. These results highlight the necessity of careful energy calibration and the use of frequent calibration checks. The probabilistic approach, in which at least 100 spectral variants are analyzed, improves our ability to identify the most likely P compounds present in a soil sample, and a procedure for this is suggested in the paper. DA - 2020/6// PY - 2020/6// DO - 10.3390/soilsystems4020026 VL - 4 IS - 2 SP - SN - 2571-8789 KW - XANES KW - linear combination fitting KW - uncertainty KW - phosphorus KW - Latin hypercube sampling KW - energy calibration ER - TY - JOUR TI - Edaphic filters as abiotic drivers of Myrtaceae assemblages in subtropical Araucaria Forest AU - Gomes, Juliano Pereira AU - Stedille, Lilian Iara Bet AU - Milani, Jacanan Eloisa de Freitas AU - Montibeller-Silva, Karina AU - Costa, Newton Clovis Freitas AU - Gatiboni, Luciano Colpo AU - Mantovani, Adelar AU - Bortoluzzi, Roseli Lopes da Costa T2 - PLANT AND SOIL DA - 2020/9// PY - 2020/9// DO - 10.1007/s11104-020-04645-7 VL - 454 IS - 1-2 SP - 187-206 SN - 1573-5036 UR - https://doi.org/10.1007/s11104-020-04645-7 KW - Atlantic forest KW - Indicator species KW - Edaphic niche KW - Environmental filters KW - Soil fertility gradient ER - TY - JOUR TI - Sleep tight and wake-up early: nocturnal transpiration traits to increase wheat drought tolerance in a Mediterranean environment AU - Schoppach, Remy AU - Sinclair, Thomas R. AU - Sadok, Walid T2 - FUNCTIONAL PLANT BIOLOGY AB - In wheat, night-time transpiration rate (TRN) could amount to 14–55% of daytime transpiration rate (TR), depending on the cultivar and environment. Recent evidence suggests that TRN is much less responsive to soil drying than daytime TR, and that such ‘wasteful’ water losses would increase the impact of drought on yields. In contrast, other evidence indicates that pre-dawn, circadian increases in TRN may enable enhanced radiation use efficiency, resulting in increased productivity under water deficit. Until now, there have been no attempts to evaluate these seemingly conflicting hypotheses in terms of their impact on yields in any crop. Here, using the Mediterranean environment of Tunisia as a case study, we undertook a simulation modelling approach using SSM-Wheat to evaluate yield outcomes resulting from these TRN trait modifications. TRN represented 15% of daytime TR-generated yield penalties of up to 20%, and these worsened when TRN was not sensitive to soil drying TR. For the same TRN level (15%), simulating a predawn increase in TRN alleviated yield penalties, leading to yield gains of up to 25%. Overall, this work suggests that decreasing TRN but increasing pre-dawn circadian control would be a viable breeding target to increase drought tolerance in a Mediterranean environment. DA - 2020/// PY - 2020/// DO - 10.1071/FP20044 VL - 47 IS - 12 SP - 1117-1127 SN - 1445-4416 KW - circadian clock KW - food security KW - physiological trade-offs KW - process-based crop model KW - water conservation ER - TY - JOUR TI - Sows-Gilts Stocking Rates and Their Environmental Impact in Rotationally Managed Bermudagrass Paddocks AU - Pietrosemoli, Silvana AU - Green, James T., Jr. AU - Jesus Villamide, Maria T2 - ANIMALS AB - Ground cover maintenance and nutrients management are key elements to reduce the environmental impact of outdoor swine production. The objective of this study was to determine the effects of sows-gilts stocking rates on vegetative ground cover and soil nutrient concentrations in rotationally stocked bermudagrass (Cynodon dactylon L. Pers) pastures. Three stocking rates (10, 15 and 25 sows-gilts ha−1) were compared during three 8-week grazing periods. Increasing the stocking rate from 10 to 25 sows-gilts ha−1 decreased the ground cover of the paddocks from 65 to 48%, and increased soil nutrient concentrations (ammonium 47%; nitrate 129%; phosphorus 53%; zinc 84%; and copper 29%). DA - 2020/6// PY - 2020/6// DO - 10.3390/ani10061046 VL - 10 IS - 6 SP - SN - 2076-2615 KW - bermudagrass KW - sows-gilts KW - stocking rate KW - ground cover KW - soil nutrients KW - pasture-based pig systems KW - outdoor pig systems KW - grazing pigs ER - TY - JOUR TI - Animal Welfare and Production Challenges Associated with Pasture Pig Systems: A Review AU - Pietrosemoli, Silvana AU - Tang, Clara T2 - AGRICULTURE-BASEL AB - A review of published literature was conducted to identify pasture pig production system features that pose risks to animal welfare, and to develop recommendations aimed at improving the wellbeing of the animals managed in those systems. Pasture pig production systems present specific challenges to animal welfare that are inherent to the nature of these systems where producers have little room to make improvements. However, these systems present other challenges that could be reduced with a carefully designed system, by adopting appropriate management strategies and by avoiding management practices that are likely to negatively affect animal wellbeing. In pasture pig production systems, exposure to extreme temperatures, potential contact with wildlife and pathogens (especially parasites), vulnerability to predators, risk of malnutrition, pre-weaning piglet mortality, complexity of processes for monitoring and treating sick animals, and for cleaning and disinfection of facilities and equipment are among the main threats to animal welfare. DA - 2020/6// PY - 2020/6// DO - 10.3390/agriculture10060223 VL - 10 IS - 6 SP - SN - 2077-0472 KW - pasture pig systems KW - threats KW - animal welfare KW - pasture-based pig systems KW - pig production KW - alternative pig production ER - TY - JOUR TI - Nitrogen supply methods affect the root growth dynamics in Eucalyptus grandis AU - Souza Kulmann, Matheus Severo AU - Stefanello, Lincon Oliveira AU - Arruda, Wagner Squizani AU - Sans, Gabriel Alberto AU - Parcianello, Carolina Fogliarini AU - Hindersmann, Jacson AU - Pasquetti Berghetti, Alvaro Luis AU - Araujo, Maristela Machado AU - Gatiboni, Luciano Colpo AU - Brunetto, Gustavo T2 - FOREST ECOLOGY AND MANAGEMENT AB - Sandy soils presenting low organic matter levels do not provide enough N to meet Eucalyptus sp. demands. Nitrogen fertilizers can be applied to soil surface, although N losses tend to happen and to decrease the amounts of this component used by plants. Alternatively, N can be applied to planting pits at seedling transplantation time or to small holes dug close to the plants. However, aspects such as the impact of different N supply modes applied to the soil on the growth parameters of root systems and the way these supply modes can affect morphological and physiological parameters of the shoot remain poorly known. The aim of the current study is to assess shoot and root growth in Eucalyptus grandis trees grown in soil subjected to different N supply modes. Eucalyptus grandis clones (GPC 23) were subjected to three N supply modes, namely: control (without N application) (C), N application to soil surface (SN) and N application to the pit (PN). Plant height, stem diameter, N concentration and chlorophyll a fluorescence in leaves, morphological parameters of the root system (total root surface area and mean root diameter), total length of active roots and total number of living and dead roots were analyzed. The PN supply mode has led to the highest mineral N levels (NH4+ and NO3−) in the soil, as well as increased the total length of active roots, the number of living roots and the root surface area in soil layers 20–40 cm and 40–60 cm. This process has enabled greater N uptake by plants, which, in its turn, has increased N concentrations in leaves, favored photosynthetic processes and resulted in taller plants presenting greater stem diameter. The SN supply method did not increase the mineral N in the soil, and it restricted the total length of active roots in soil layer (0–20 cm) and resulted in higher mean root diameter. DA - 2020/10/1/ PY - 2020/10/1/ DO - 10.1016/j.foreco.2020.118320 VL - 473 SP - SN - 1872-7042 KW - Eucalypt KW - Fine roots KW - Minirhizotron KW - Application mode KW - Root system morphology ER - TY - JOUR TI - Soil-geomorphology relationships of alluvial fans in Costa Rica AU - Camacho, Manuel E. AU - Quesada-Roman, Adolfo AU - Mata, Rafael AU - Alvarado, Alfredo T2 - GEODERMA REGIONAL AB - The precise determination of landforms and their formation processes are key to accomplish detailed soil mapping and better understand of soil genesis. The Upper General River Basin is located at the southeast of Costa Rica on the transition between Cordillera de Talamanca and General River Valley, forming an extensive alluvial fan sequence. Our work aims to determine the soil–geomorphology relationships on these alluvial fans. The methods employed consisted of geomorphological mapping using 1:25,000 aerial photographs to determine five alluvial fans: buried inactive, modeled inactive, early, intermediate, and late. Soil maps were established by combining landforms with soil survey data that allowed to differentiate twelve soil units of Ultisols associated with Oxisols, Inceptisols and Entisols. The most weathered soils were classified as Anionic and were Acrustox found on the oldest landforms located on buried inactive and early alluvial fans. These soils were found associated with Typic Rhodustults and Ustic Haplohumults. Typic Ustifluvents occurred on early alluvial fans and modeled inactive alluvial fans. Similar morphologic and chemical characteristics of the evaluated Oxisols were found for soils previously classified as Ultisols. These findings support the hypothesis that many soil currently classified as Ultisols could be reclassified as Oxisols (if the appropriate mineralogical analyses were conducted). These results put in perspective that the origin of the fans and hence their ages control the consequent soil development. In addition, the study contextualizes the implications of mapping and classifying highly weathered tropical soils for territorial planning, agricultural management and natural resources conservation. DA - 2020/6// PY - 2020/6// DO - 10.1016/j.geodrs.2020.e00258 VL - 21 SP - SN - 2352-0094 KW - Tropical geomorphology KW - Soil mapping KW - Alluvial fans KW - Oxisols KW - Tropical weathered soils KW - Tropics ER - TY - JOUR TI - First report of cigar tobacco production in western North Carolina AU - Vann, Matthew C. AU - Cheek, Joseph A. AU - Machacek, Jeremey L. AU - Whitley, D. Scott AU - Moody, Chad AU - Council, John AU - Hartley, Michael AU - Green, Benjamin T2 - CROP FORAGE & TURFGRASS MANAGEMENT AB - Over the last two decades, burley tobacco (Nicotiana tabacum L.) production has declined by 5,300 acres in western North Carolina (North Carolina Department of Agriculture and Consumer Services, 2005; USDA-NASS, 2019). The loss of burley tobacco has left a void in the agricultural economy. Cigar wrapper tobacco types, such as Pennsylvania seedleaf (PA41) and Connecticut broadleaf, may be suitable replacements for burley because of their overlapping production practices. Cigar tobacco has not been produced in western North Carolina; therefore, knowledge gaps exist regarding its growth habits in the region. The objective of this study was to quantify the days to flower removal, yield, and grade distribution of six cigar tobacco varieties. In 2019, experiments were initiated at the Mountain Research Station in Waynesville, NC (35.48N, –82.96W) and the Upper Mountain Research Station in Laurel Springs, NC (36.39N, –81.30W). Treatments were arranged in a randomized complete block design replicated four times. Plots consisted of a single row measuring 4 by 33 ft with a planting density of 7,260 plants acre–1. At each location, three PA41 varieties (‘Eshbach’, ‘Grower's Choice’, and ‘Welk's Pride’) and three Connecticut broadleaf varieties (‘B2’, ‘D1’, and ‘PAB’) were compared. Tobacco was transplanted on 31 May in Waynesville and 6 June in Laurel Springs. Plants were deflowered at CORESTA growth stage 65 (CORESTA, 2019), leaving 18 to 20 leaves per plant. Twenty plants per plot were then stalk-cut 2.5 wk later and air-cured according to existing burley recommendations (Swetnam & Bailey, 2019). Once cured, the leaves were stripped from the stalk and classified into wrapper (uniform color and structure, free of holes, >9 inches wide), binder (the same qualities as wrapper but with no more than two holes on one side of the leaf), straight strip (leaf that is not classified as wrapper or binder), or filler grades (small, inconsistent in color, moldy, rotten, or damaged). Data for days to deflowering, yield per acre, and grade distribution were subject to ANOVA via the PROC GLIMMIX procedure (SAS Institute Inc., Cary, NC). Within each analysis, replication was considered as a random factor, whereas variety and tobacco type were fixed factors. Treatment means were reported as least square means. Contrast statements were used to compare PA41 and Connecticut broadleaf types. Variety means within each type were separated by Fisher's Protected LSD at P ≤ .05. Figures were created using Sigma Plot (Systat Software, Inc., San Jose, CA). At Waynesville (P < .001) and Laurel Springs (P < .001), PA41 yielded more than Connecticut broadleaf by 684 to 1,164 lb acre–1, depending on the location (Figure 1a). Days to flower removal was also significant at both locations (P < .001), with PA41 varieties requiring 10 to 12 additional days to reach this stage of management (Figure 1b). Cured leaf grades were less consistent, as tobacco type was only significant for wrapper at Waynesville (P = .039) and binder at Laurel Springs (P = .002). The frequency of wrapper grade was extremely low, regardless of the type or location (0.5–5.3%), although PA41 produced more wrapper than Connecticut broadleaf in Waynesville (3.4% vs. 0.5%, respectively) (Figure 1c). Binder grades were more prevalent in Connecticut broadleaf at Laurel Springs (Figure 1d). Designations of straight strip and filler were not influenced by tobacco type at either of the locations (Figure 1e,f). Cured leaf yield and days to flower removal were similar within each tobacco type at Laurel Springs (Table 1). The same observations were made for wrapper, binder, and filler grades (Table 1). Eshbach produced a smaller percentage of straight strip grades relative to Grower's Choice (Table 1); however, straight strip grades were similar within Connecticut broadleaf varieties (Table 1). In contrast, cured leaf yield differed between PA41 and Connecticut broadleaf varieties at the Waynesville location. Within the PA41 varieties, Grower's Choice had a higher yield than Welk's Pride, with Eshbach being intermediate (Table 2). The yield potential of PAB was greater than that of D1 and B2 within the Connecticut broadleaf type (Table 2). Days to flower removal and grade distribution were similar among varieties within each tobacco type at this location (Table 2). Direct comparisons of these tobacco types and varieties have not been reported; therefore, this information is novel and provides useful insights to stakeholders as cigar tobacco is offered as an alternative to burley tobacco. Cigar tobacco production will not occur without substantial change and education. For example, deflowering may occur 2 wk earlier in cigar production, with fewer leaves remaining on the plant relative to burley (12–14 vs. 18–20). Farmers will also have to harvest and handle cigar tobacco much more delicately than burley to reduce physical leaf damage. The adoption of pesticide application programs that are more proactive than what is allowed by current practices will also be required. The failure to produce substantial proportions of wrapper grades in our study is a reflection of having too many leaves per plant, reactive pest control, and aggressive handling. Each of these factors will be addressed in later field studies and shared with farmers at Extension events. In addition, other research agronomists should consider that the current practices used to evaluate burley tobacco trials may not prove suitable for cigar and they should therefore be adapted accordingly. The authors declare no conflicts of interest. DA - 2020/// PY - 2020/// DO - 10.1002/cft2.20063 VL - 6 IS - 1 SP - SN - 2374-3832 UR - https://doi.org/10.1002/cft2.20063 ER - TY - JOUR TI - Measures of Canopy Structure from Low-Cost UAS for Monitoring Crop Nutrient Status AU - Montgomery, Kellyn AU - Henry, Josh B. AU - Vann, Matthew C. AU - Whipker, Brian E. AU - Huseth, Anders S. AU - Mitasova, Helena T2 - DRONES AB - Deriving crop information from remotely sensed data is an important strategy for precision agriculture. Small unmanned aerial systems (UAS) have emerged in recent years as a versatile remote sensing tool that can provide precisely-timed, fine-grained data for informing management responses to intra-field crop variability (e.g., nutrient status and pest damage). UAS sensors with high spectral resolution used to compute informative vegetation indices, however, are practically limited by high cost and data dimensionality. This research extends spectral analysis for remote crop monitoring to investigate the relationship between crop health and 3D canopy structure using low-cost UAS equipped with consumer-grade RGB cameras. We used flue-cured tobacco as a case study due to its known sensitivity to fertility variation and nutrient-specific symptomology. Fertilizer treatments were applied to induce plant health variability in a 0.5 ha field of flue-cured tobacco. Multi-view stereo images from three UAS surveys collected during crop development were processed into orthoimages used to compute a visible band spectral index and photogrammetric point clouds using Structure from Motion (SfM). Plant structural metrics were then computed from detailed high resolution canopy surface models (0.05 m resolution) interpolated from the photogrammetric point clouds. The UAS surveys were complimented by nutrient status measurements obtained from plant tissues. The relationships between foliar nitrogen (N), phosphorus (P), potassium (K), and boron (B) concentrations and the UAS-derived metrics were assessed using multiple linear regression. Symptoms of N and K deficiencies were well captured and differentiated by the structural metrics. The strongest relationship observed was between canopy shape and N foliar concentration (adj. r2 = 0.59, increasing to adj. r2 = 0.81 when combined with the spectral index). B foliar concentration was consistently better predicted by canopy structure with a maximum adj. r2 = 0.41 observed at the latest growth stage surveyed. Overall, combining information about canopy structure and spectral reflectance increased model fit for all measured nutrients compared to spectral alone. These results suggest that an important relationship exists between relative canopy shape and crop health that can be leveraged to improve the usefulness of low cost UAS for precision agriculture. DA - 2020/9// PY - 2020/9// DO - 10.3390/drones4030036 VL - 4 IS - 3 SP - SN - 2504-446X UR - https://doi.org/10.3390/drones4030036 KW - unmanned aerial systems KW - precision agriculture KW - canopy structure KW - crop surface model KW - visible band index KW - flue-cured tobacco ER - TY - JOUR TI - Creeping bentgrass summer decline as influenced by climatic conditions and cultural practices AU - Miller, Grady L. AU - Brotherton, Mark A. T2 - Agronomy Journal AB - Abstract Despite its popularity as a putting surface in North Carolina, creeping bentgrass ( Agrostsis stolonifera L.) is highly susceptible to summer bentgrass decline (SBD) during hot summer months. Cultural practices have been shown to help alleviate the pressure of SBD. The objectives of this study were to detail the impacts of N fertility, soil water content, and hollow‐ and solid‐tine cultivation on creeping bentgrass quality. Cultural treatments included four N rates (97, 195, 293, and 391 kg ha −1 yr −1 ), four hollow‐tine core cultivation programs (6.4 mm diam. tines two times yr −1 , 9.5 mm diam. tines two and three times yr −1 , and a non‐cored control), two soil water content levels (low and high), and two summer solid‐tine spiking cultivation treatments (spiked and not spiked). Visual turfgrass quality was measured. A N rate greater than 195 kg ha −1 was needed to maintain acceptable turfgrass quality. High soil water content consistently provided better summer turfgrass quality compared to low soil water content conditions. Nitrogen fertility and soil water content interacted where higher levels of both resulted in the best quality ratings. Hollow‐core cultivation reduced turfgrass quality at the lower N rates; whereas, solid‐tine spiking had no effect on turfgrass quality. Although weather plays a large role in SBD in North Carolina, results from this study show that cultural practices can influence its severity. DA - 2020/9// PY - 2020/9// DO - 10.1002/agj2.20362 VL - 112 IS - 5 SP - 3500-3512 UR - https://doi.org/10.1002/agj2.20362 ER - TY - JOUR TI - Soil-test biological activity with the flush of CO2: VII. Validating nitrogen needs for fall-stockpiled forage AU - Franzluebbers, Alan J. AU - Poore, Matt H. T2 - AGRONOMY JOURNAL AB - Abstract Nitrogen fertilizer is an expensive input, and its necessity in grazed tall fescue ( Schedonorus arundinaceus ) pastures can be questioned when sufficient soil N mineralization occurs. A soil‐testing tool that could predict the need for N fertilizer inputs would be beneficial to producers to optimize profit and avoid environmental contamination. Thirty‐seven on‐farm trials were conducted in the Piedmont and Blue Ridge regions of Georgia, South Carolina, North Carolina, and Virginia in 2018 to evaluate fall‐stockpiled tall fescue yield response to N and P fertilizer inputs. Carbon and N characteristics of the soil surface (0‐ to 10‐cm depth) and surface residue varied among sites. Forage mass responses to P fertilizer input were below the economic threshold, regardless of Mehlich‐III extractable P. Forage mass responses to N fertilizer input did not exceed a low cost/value threshold of 5 kg forage kg −1 N in 24 of the trials. Economically optimum N rate was greatest when soil N mineralization and soil‐test biological activity (STBA) were at low levels. Results validated those of an earlier study on 55 fields, and taken together, suggest that N fertilizer for fall‐stockpiled tall fescue could be as high as 80 kg N ha −1 on fields with very low STBA (<100 mg CO 2 –C kg −1 soil 3 d −1 ) and declining to nil with medium STBA (>250 mg CO 2 –C kg −1 soil 3 d −1 ), depending on cost/value threshold. Healthy soils with high STBA can be managed effectively without N fertilizer inputs to recycle nutrients and promote more sustainable agricultural systems. DA - 2020/// PY - 2020/// DO - 10.1002/agj2.20153 VL - 112 IS - 3 SP - 2240-2255 SN - 1435-0645 ER - TY - JOUR TI - Response of agronomic crops to planting date and double-cropping with wheat AU - Hare, Andrew T. AU - Jordan, David L. AU - Edmisten, Keith L. AU - Leon, Ramon G. AU - Post, Angela R. AU - Vann, Rachel AU - Dunphy, E. James AU - Heiniger, Ronnie AU - Collins, Guy AU - Washburn, Derek T2 - AGRONOMY JOURNAL AB - Abstract Planting date can affect crop yield and is an important management decision for practitioners. Although wheat ( Triticum aestivum L.) and soybean [ Glycine max (L.) Merr.] can be effectively double‐cropped in North Carolina, if commodity prices and projected economic returns are higher for crops other than soybean, growers might consider a nontraditional, double‐crop system. Direct comparisons of major agronomic crops with different planting dates or in a double‐crop system with wheat are limited in North Carolina. Therefore, research was conducted in North Carolina from 2013 through 2017 to determine yield potential of corn ( Zea mays L.), cotton ( Gossypium hirsutum L.), grain sorghum [ Sorghum bicolor (L.) Moench], peanut ( Arachis hypogaea L.), and soybean planted at two dates within the recommended planting window for full‐season production versus planting these crops after wheat harvest. The experimental design was a split plot, with summer crop serving as the whole plot unit and planting date within a crop serving as the subplot unit. Yield of corn, cotton, grain sorghum, peanut, and soybean in full‐season production exceeded that of double‐cropping with wheat in 5, 5, 2, 4, and 5 yr out of 5 yr of the study, respectively. Estimated economic returns were generated using the 10‐yr average (2008–2017) summer crop prices with the 10‐yr average wheat price. When considering all possible combinations of years and crops (n = 25), in only 20% of the possible combinations was the economic return of the double‐cropping system greater than economic return of full‐season crop production when compared with at least one of the planting dates within the traditional planting window. DA - 2020/// PY - 2020/// DO - 10.1002/agj2.20164 VL - 112 IS - 3 SP - 1972-1980 SN - 1435-0645 UR - https://doi.org/10.1002/agj2.20164 ER - TY - JOUR TI - Identification and editing of a hybrid lethality gene expands the range of interspecific hybridization potential in Nicotiana AU - Ma, Justin AU - Hancock, Wesley G. AU - Nifong, Jessica M. AU - Kernodle, Sheri P. AU - Lewis, Ramsey S. T2 - THEORETICAL AND APPLIED GENETICS DA - 2020/10// PY - 2020/10// DO - 10.1007/s00122-020-03641-w VL - 133 IS - 10 SP - 2915-2925 SN - 1432-2242 ER - TY - JOUR TI - Impacts of lower-leaf removal timing, number, and nitrogen application to flue-cured tobacco AU - Finch, Camden E. AU - Vann, Matthew C. AU - Wells, Randy AU - Fisher, Loren R. AU - Brown, A. Blake T2 - CROP FORAGE & TURFGRASS MANAGEMENT AB - Abstract The removal and exclusion of lower‐stalk tobacco ( Nicotiana tobacum L.) from harvest continues to be encouraged by industry. Very little information addresses the timing aspect of leaf removal, specifically when it occurs near floral initiation. Research was conducted in 2016 and 2017 to evaluate each possible treatment combination of two lower‐leaf removal programs (0 and 8 leaves/plant), three removal timings (2 wk before topping, at topping, and 2 wk after topping), and two N application rates (0 and 10 lb/ac). Soil plant analysis development (SPAD) measurements consistently revealed a lighter leaf color in treatments consisting of leaf removal 2 wk before topping, regardless of N application rate. Foliar cured leaf samples from upper‐stalk positions also contained less total N when eight leaves (2.25%) were removed relative to zero leaves (2.32%). These results indicate that subsequent N fertilizer application did not supply N as efficiently as remobilization from lower, older leaves. In the 8‐leaf removal program, both cured leaf yield and value declined by 27% relative to the 0‐leaf program. Despite significant losses in yield and value, the 8‐leaf program completely eliminated lug grades of tobacco. Leaf removal timing and N application rate did not affect yield, quality, value, or grade distribution. Our results suggest that there is no agronomic or cost to removing lower leaves 2 wk before or after topping; however, commercial farmers may find this information to be of use from a time management perspective, should they decide to implement this practice. DA - 2020/// PY - 2020/// DO - 10.1002/cft2.20059 VL - 6 IS - 1 SP - SN - 2374-3832 UR - https://doi.org/10.1002/cft2.20059 ER - TY - JOUR TI - Genotype-by-environment interaction for turfgrass quality in bermudagrass across the southeastern United States AU - Gouveia, Beatriz Tome AU - Rios, Esteban Fernando AU - Rodrigues Nunes, Jose Airton AU - Gezan, Salvador A. AU - Munoz, Patricio R. AU - Kenworthy, Kevin E. AU - Unruh, J. Bryan AU - Miller, Grady L. AU - Milla-Lewis, Susana R. AU - Schwartz, Brian M. AU - Raymer, Paul L. AU - Chandra, Ambika AU - Wherley, Benjamin G. AU - Wu, Yanqi AU - Martin, Dennis AU - Moss, Justin Q. T2 - CROP SCIENCE AB - Abstract Estimation of genotype‐by‐environment interaction (GEI) is important in breeding programs because it provides critical information to guide selection decisions. In general, multienvironment trials exhibit heterogeneity of variances and covariances at several levels. Thus, the objectives of this study were (a) to find the best genetic covariance matrix to model GEI and compare changes in genotypic rankings between the best covariance structure against a compound symmetry structure, (b) to define mega‐environments for turfgrass performance across the southeastern United States, and (c) to estimate genetic correlations between drought or nondrought and growing or nongrowing conditions to determine the extent of GEI under specific environments. Three nurseries with 165, 164, and 154 genotypes were evaluated in 2011–2012, 2012–2013, and 2013–2014, respectively. These nurseries were conducted at eight locations (Citra, FL; Hague, FL; College Station, TX; Dallas, TX; Griffin, GA; Tifton, GA; Stillwater, OK; and Jackson Springs, NC). The response variables were averaged turfgrass quality (TQ), TQ under drought (TQD), nondrought TQ (TQND), TQ under actively growing months (TQG), and TQ under nongrowing months (TQNG). This study demonstrated that (a) the best variance structure varied among traits and seasons, and changes in genotype rankings were dependent on GEI; (b) considering TQ and TQND, mega‐environments formed between Jackson Springs and College Station, and between Citra, Dallas, and Griffin, whereas Stillwater, Hague, and Tifton represented unique environments across the southeastern United States; and (c) genetic correlations between drought or nondrought and growing or nongrowing conditions suggested that indirect selection can be efficient in multienvironment trials for contrasting environmental conditions. DA - 2020/// PY - 2020/// DO - 10.1002/csc2.20260 VL - 60 IS - 6 SP - 3328-3343 SN - 1435-0653 UR - https://doi.org/10.1002/csc2.20260 ER - TY - JOUR TI - Identification of seedling resistance to stem rust in advanced wheat lines and varieties from Pakistan AU - Rehman, Monsif Ur AU - Gale, Sam AU - Brown-Guedira, Gina AU - Jin, Yue AU - Marshall, David AU - Whitcher, Lynda AU - Williamson, Sharon AU - Rouse, Matthew AU - Ahmad, Javed AU - Ahmad, Gulzar AU - Shah, Irfan Ahmad AU - Sial, Mahboob Ali AU - Raufl, Yahya AU - Rattu, Atiq Ur Rehman AU - Mirza, Javed Iqbal AU - Ward, Rick AU - Nadeem, Majid AU - Ullah, Ghulam AU - Imtiaz, Muhammad T2 - CROP SCIENCE AB - Abstract Stem rust is a major disease of wheat ( Triticum aestivum L.) worldwide and new Puccinia graminis f. sp. tritici ( Pgt ) races including TTKSK (Ug99) pose a serious threat to wheat production. The protection of new varieties against Pgt races can be increased by identifying and combining several types of stem rust resistance genes ( Sr ). We screened a set of 707 wheat lines and cultivars against 11 Pgt races under glass house conditions. Of the tested lines, groups of 99, 513, 289, and 515 exhibited low infection type (IT < 3) to races TTKSK, TRTTF, TTTTF, and RRTTF, respectively. Screening against Pgt races (QFCSC, QTHJC, MCCFC, RCRSC, RKRQC, TPMKC, and QCCSM) showed that most of the tested lines were resistant. These lines were screened with eight DNA markers for the presence of Sr2 , Sr9a , Sr24 , Sr25 , Sr31 , Sr36 , Sr38 , and Sr57 genes. Sr36 was absent from all the tested lines, whereas Sr9a was detected in four lines. The marker Sr2_ger93p predicted the presence of Sr2 in 40 lines, and marker barc71 suggested the presence of Sr24 in 12 lines. Sr25 and Sr38 were present in 13 and 54 lines, respectively. The highest frequency of Sr genes was observed for Sr57 (199 lines) and Sr31 (177 lines). Except for lines carrying Sr25 and/or Sr24 genes, most lines were susceptible to Pgt race TTKSK. Since Ug99 is overcoming Sr genes worldwide, including Sr24 and Sr36 , a strategy to pyramid multiple Sr genes in new cultivars should be pursued to achieve a durable control of stem rust. The effectiveness of lines such as NRL0902, 11050, B‐2(RF)‐11, and CCRI‐6, found in the current study and featuring other Sr genes, warrants further investigation to identify the source of their resistance and use it in Pakistan wheat breeding programs. DA - 2020/// PY - 2020/// DO - 10.1002/csc2.20056 VL - 60 IS - 2 SP - 804-811 SN - 1435-0653 ER - TY - JOUR TI - Geospatial assessment for crop physiological and management improvements with examples using the simple simulation model AU - Sinclair, Thomas R. AU - Soltani, Afshin AU - Marrou, Helene AU - Ghanem, Michel AU - Vadez, Vincent T2 - CROP SCIENCE AB - Abstract Physiological and management modifications to increase crop yields require an appreciation of the impact of these changes on a geospatial basis. It is quite possible that the yield response to any modification may vary from positive in one location to negative in another location. Therefore, tools to undertake geospatial analysis are required to assess the overall impact. It is argued that mechanistic models based on the physics and physiology of plant development, growth, and yield formation are required for such tasks. Several criteria in selecting model tools are discussed. First, models that need to be “calibrated” are not suited for geospatial assessments because the calibration processes causes the model to be an empirical representation of the calibration data and limited to the calibration environment. Extreme caution is needed to extrapolate model use beyond the domain of calibration, since geospatial analysis requires the model to be run for a range of geographical locations over a number of growing seasons. Second, to readily understand the output from simulations across space and time, models needs to be compact and transparent so output that seems inconsistent or not intuitively obvious can be tracked to the critical features in the model. Models with a smaller number of parameters are likely to be more transparent. Finally, it is necessary that the robustness of the model has been tested against a range of environmental conditions. In this paper, we discuss the example of the Simple Simulation Model (SSM) as an option that meets these criteria. DA - 2020/// PY - 2020/// DO - 10.1002/csc2.20106 VL - 60 IS - 2 SP - 700-708 SN - 1435-0653 ER - TY - JOUR TI - Temporal water use by two maize lines differing in leaf osmotic potential AU - Beseli, Amber L. AU - Shekoofa, Avat AU - Ali, Mujahid AU - Sinclair, Thomas R. T2 - CROP SCIENCE AB - Abstract Two lines of maize which had different levels of expressions of leaf osmotic potential (OP) under water‐deficit conditions in the field were previously found to differ in leaf area duration and water extraction at soil depths greater than 0.80 m. In the current study, the hypothesis was explored that the difference in leaf OP between the two lines was associated with differences in transpiration rate which in turn had a major effect on the temporal dynamics of soil water use. The line with the lowest (most negative) OP in the early stages of the soil drying cycle was found to have the greatest transpiration rate and delayed wilting which was consistent with the original field observations. However, with further soil drying, the line with higher OP was able to sustain transpiration over a longer time period and actually reached the end point of transpirable soil water at a later date. The results of these experiments highlighted the necessity of accounting for temporal dynamics when interpreting crop water use in response to soil drying, particularly when comparing genotypes with differing OP. DA - 2020/// PY - 2020/// DO - 10.1002/csc2.20062 VL - 60 IS - 2 SP - 945-953 SN - 1435-0653 ER - TY - JOUR TI - Plant-based predictions of canopy transpiration instead of meteorological approximations AU - Sinclair, Thomas R. AU - Ghanem, Michel Edmond T2 - CROP SCIENCE AB - Abstract Estimation of plant water use is critical, both now and under future climate‐changed environments, to understanding water limitation on plant production and hydrologic cycling. Currently, such predictions are based on meteorological approaches that are inherently empirical and should not be extrapolated beyond the empirical database. An alternative approach to calculating transpiration that relies on fundamental physiological and physical descriptors of canopy water use efficiency is reviewed. Re‐arrangement of the water use efficiency expression results in a definition of transpiration based on explicitly defined and readily observed, if necessary, parameters. The key plant parameters are photosynthate conversion to plant mass, photosynthesis pathway (C4 vs. C3), and canopy radiation use efficiency. The parameters tend to be stable within a species under non‐stressed conditions, although fully defined differences exist among species. Also, the consequences of stresses such as temperature, water deficit, and nitrogen deficit can be readily accounted for by their effect on canopy carbon accumulation. The capability of this approach in predicting canopy transpiration is illustrated in a comparison between calculated and measured transpiration by turf grasses. Water use predictions by natural and managed plant canopies need not to be handicapped by empirical meteorological approaches, but rather explicit parameters associated with various species traits can be used to define transpiration rate. DA - 2020/// PY - 2020/// DO - 10.1002/csc2.20067 VL - 60 IS - 3 SP - 1133-1141 SN - 1435-0653 ER - TY - JOUR TI - "Water dynamics in the soil-plant-atmosphere system" by JT Ritchie, Plant and Soil (1981) 58:81-96 AU - Sinclair, Thomas R. T2 - CROP SCIENCE AB - Abstract This article is part of a series of brief commentaries to highlight papers that have resulted in important and distinctly new perspectives in crop science. A criterion for selection of papers is that they must have been published at least 20 yr ago to allow for a long‐range perspective in assessment of the papers. The current article briefly reviews the paper by J.T. Ritchie published in 1981 that explored the use of extractable soil water as an independent variable for defining plant response to water deficit conditions. Recognizing the difficulty of using leaf water potential in defining plant response, he proposed an independent variable based on volumetric soil water content. Specifically, plant response was based on extractable soil water described as a function of ‘fraction of total extractable water in the root zone.’ Ritchie proposed a template for sensitivity of plant processes to soil drying based on fraction of total extractable water. Response functions based on this template have now been extensively studied and are key parts of many approaches to describing water use in both experimental and modeling studies. DA - 2020/// PY - 2020/// DO - 10.1002/csc2.20037 VL - 60 IS - 2 SP - 541-543 SN - 1435-0653 ER - TY - JOUR TI - Amaranthus palmeri a New Invasive Weed in Spain with Herbicide Resistant Biotypes AU - Torra, Joel AU - Royo-Esnal, Aritz AU - Romano, Yolanda AU - Osuna, María AU - León, Ramón AU - Recasens, Jordi T2 - Agronomy AB - Amaranthus palmeri is the most prominent invasive weed in agricultural land from North America, partly due to its propensity to evolve resistance to multiple herbicide sites of action. In the last two decades, reports of this species have increased throughout the American continent and occasionally in other continents. In 2007, A. palmeri populations were found in three localities in northeastern Spain, and they are still present today. To determine whether these three populations resulted from a common or independent introduction events—and when and from where they could have occurred—research was carried out aiming to characterize the resistance profile and mechanisms to 5-enolpyruvylshikimate-3-phosphate synthase-and acetolactate synthase (ALS)-inhibiting herbicides and to analyze the relationship between these three populations using inter simple sequence repeat DNA fingerprinting. Dose–response trials confirmed that the three populations were susceptible to glyphosate but resistant to nicosulfuron-methyl. Resistance to ALS inhibitors was due to several amino acid substitutions in positions Pro197, Trp574 and Ser653. Moreover, the substitutions Ser653Ile and Pro197Thr are described for the first time in this species. At field-labeled rates, all populations were fully controlled with alternative herbicides with other sites of action. Amaranthus palmeri individuals were clustered in three groups based on unweighted pair group method with arithmetic mean analysis, which corresponded to the three sampled populations, with a 67% of genetic relationship among them. Considering this high genetic variability and the different positions and amino acid substations found between populations, it was hypothesized that different colonization events occurred from the American continent probably prior to the introduction of glyphosate resistant crops. Prevention from new introductions is warranted because new herbicide resistance traits could arrive, complicating the management of this invasive weed species, while managing or eradicating the already established populations. DA - 2020/7/10/ PY - 2020/7/10/ DO - 10.3390/agronomy10070993 VL - 10 IS - 7 SP - 993 UR - https://doi.org/10.3390/agronomy10070993 KW - alien plant KW - ALS inhibitors KW - dendrogram KW - glyphosate KW - inter simple sequence repeat (ISSR) DNA fingerprinting KW - maize KW - nicosulfuron-methyl KW - target-site resistance ER - TY - JOUR TI - Current outlook and future research needs for harvest weed seed control in North American cropping systems AU - Shergill, Lovreet S AU - Schwartz‐Lazaro, Lauren M AU - Leon, Ramon AU - Ackroyd, Victoria J AU - Flessner, Michael L AU - Bagavathiannan, Muthukumar AU - Everman, Wesley AU - Norsworthy, Jason K AU - VanGessel, Mark J AU - Mirsky, Steven B T2 - Pest Management Science AB - Abstract Harvest weed seed control (HWSC) comprises a set of tools and tactics that prevents the addition of weed seed to the soil seed bank, attenuating weed infestations and providing a method to combat the development and spread of herbicide‐resistant weed populations. Initial HWSC research efforts in North America are summarized and, combined with the vast area of crops suitable for HWSC, clearly indicate strong potential for this technology. However, potential limitations exist that are not present in Australian cropping systems where HWSC was developed. These include rotations with crops that are not currently amenable to HWSC (e.g. corn), high moisture content at harvest, untimely harvest, and others. Concerns about weeds becoming resistant to HWSC (i.e. adapting) exist, as do shifts in weed species composition, particularly with the diversity of weeds in North America. Currently the potential of HWSC vastly outweighs any drawbacks, necessitating further research. Such expanded efforts should foremost include chaff lining and impact mill commercial scale evaluation, as this will address potential limitations as well as economics. Growers must be integrated into large‐scale, on‐farm research and development activities aimed at alleviating the problems of using HWSC systems in North America and drive greater adoption subsequently. © 2020 Society of Chemical Industry DA - 2020/12// PY - 2020/12// DO - 10.1002/ps.5986 UR - https://doi.org/10.1002/ps.5986 KW - herbicide resistance management KW - integrated weed management KW - soil seed bank ER - TY - JOUR TI - In vitro screening of technical lignins to determine their potential as hay preservatives AU - Reyes, D. C. AU - Annis, S. L. AU - Rivera, S. A. AU - Leon-Tinoco, A. Y. AU - Wu, C. AU - Perkins, L. B. AU - Perry, J. J. AU - Ma, Z. X. AU - Knight, C. W. AU - Castillo, M. S. AU - Romero, J. J. T2 - JOURNAL OF DAIRY SCIENCE AB - Our objectives were to evaluate technical lignins for their antifungal properties against 3 molds and 1 yeast causing hay spoilage, and their ability to preserve ground high-moisture alfalfa hay nutritive value in vitro. In experiment 1, 8 technical lignins and propionic acid (PRP; positive control) were tested at a dose of 40 mg/mL. The experiment had a randomized complete block design (RCBD, 4 runs) and a factorial arrangement of 3 molds × 10 additives (ADV). The effects of the ADV on yeast were evaluated separately with a RCBD. Sodium lignosulfonate (NaL) and PRP were the only treatments with 100 ± 2.8% inhibition of fungi. In experiment 2, the minimum inhibitory concentration (MIC) for selected lignins and PRP were determined. At pH 4, NaL had the lowest MIC across the molds (20–33.3 mg/mL) and magnesium lignosulfonate (MgL) for the yeast (26.7) among the lignins. However, PRP had MIC values that were several-fold lower across all fungi (1.25–3.33). In experiment 3, a RCBD (5 blocks) with a 3 (ADV; NaL, MgL, and PRP) × 4 (doses: 0, 0.5, 1, and 3% wt/wt fresh basis) factorial arrangement of treatments was used to evaluate the preservative effects of ADV in ground high-moisture alfalfa hay inoculated with a mixture of the fungi previously tested and incubated under aerobic conditions in vitro. After 15 d, relative to untreated hay (14.9), dry matter (DM) losses were lessened by doses as low as 1% for NaL (3.39) and 0.5% for PRP (0.81 ± 0.77%). The mold count was reduced in both NaL at 3% (3.92) and PRP as low as 0.5% (3.94) relative to untreated hay (7.76 ± 0.55 log cfu/fresh g). Consequently, sugars were best preserved by NaL at 3% (10.1) and PRP as low as 0.5% (10.5) versus untreated (7.99 ± 0.283% DM), while keeping neutral detergent fiber values lower in NaL (45.9) and PRP-treated (45.1) hays at the same doses, respectively, relative to untreated (49.7 ± 0.66% DM). Hay DM digestibility was increased by doses as low as 3% for NaL (67.5), 1% MgL (67.0), and 0.5% PRP (68.5) versus untreated hay (61.8 ± 0.77%). The lowest doses increasing neutral detergent fiber digestibility relative to untreated hay (23.3) were 0.5% for MgL and PRP (30.5 and 30.1, respectively) and 1% for NaL (30.7 ± 1.09% DM). Across technical lignins, NaL showed the most promise as a potential hay preservative. However, its effects were limited compared with PRP at equivalent doses. Despite not having an effect on preservation, MgL improved DM digestibility by stimulating neutral detergent fiber digestibility. This study warrants further development of NaL under field conditions. DA - 2020/7// PY - 2020/7// DO - 10.3168/jds.2019-17764 VL - 103 IS - 7 SP - 6114-6134 SN - 1525-3198 ER - TY - JOUR TI - Flue-cured tobacco tolerance to S-metolachlor AU - Clapp, Andrew M. AU - Vann, Matthew C. AU - Cahoon, Charles W., Jr. AU - Jordan, David L. AU - Fisher, Loren R. AU - Inman, Matthew D. T2 - Weed Technology AB - Abstract Currently, there are seven herbicides labeled for U.S. tobacco production; however, additional modes of action are greatly needed in order to reduce the risk of herbicide resistance. Field experiments were conducted at five locations during the 2017 and 2018 growing seasons to evaluate flue-cured tobacco tolerance to S -metolachlor applied pretransplanting incorporated (PTI) and pretransplanting (PRETR) at 1.07 (1×) and 2.14 (2×) kg ai ha −1 . Severe injury was observed 6 wk after transplanting at the Whiteville environment in 2017 when S -metolachlor was applied PTI. End-of-season plant heights from PTI treatments at Whiteville were likewise reduced by 9% to 29% compared with nontreated controls, although cured leaf yield and value were reduced only when S -metolachlor was applied PTI at the 2× rate. Severe growth reduction was also observed at the Kinston location in 2018 where S -metolachlor was applied at the 2× rate. End-of-season plant heights were reduced 11% (PTI, 2×) and 20% (PRETR, 2×) compared with nontreated control plants. Cured leaf yield was reduced in Kinston when S -metolachlor was applied PRETR at the 2× rate; however, treatments did not impact cured leaf quality or value. Visual injury and reductions in stalk height, yield, quality, and value were not observed at the other three locations. Ultimately, it appears that injury potential from S -metolachlor is promoted by coarse soil texture and high early-season precipitation close to transplanting, both of which were documented at the Whiteville and Kinston locations. To reduce plant injury and the negative impacts to leaf yield and value, application rates lower than 1.07 kg ha −1 may be required in these scenarios. DA - 2020/12/30/ PY - 2020/12/30/ DO - 10.1017/wet.2020.71 VL - 6 SP - 1-6 UR - https://doi.org/10.1017/wet.2020.71 KW - S-metolachlor KW - tobacco KW - Nicotiana tabacum L KW - NITA KW - crop tolerance KW - pretransplanting KW - pretransplanting incorporated KW - residual ER - TY - JOUR TI - SSM-iCrop2: A simple model for diverse crop species over large areas AU - Soltani, A. AU - Alimagham, S. M. AU - Nehbandani, A. AU - Torabi, B. AU - Zeinali, E. AU - Dadrasi, A. AU - Zand, E. AU - Ghassemi, S. AU - Pourshirazi, S. AU - Alasti, O. AU - Hosseini, R. S. AU - Zahed, M. AU - Arabameri, R. AU - Mohammadzadeh, Z. AU - Rahban, S. AU - Kamari, H. AU - Fayazi, H. AU - Mohammadi, S. AU - Keramat, S. AU - Vadez, V. AU - Ittersum, M. K. AU - Sinclair, T. R. T2 - AGRICULTURAL SYSTEMS AB - Crop models are essential in undertaking large scale estimation of crop production of diverse crop species, especially in assessing food availability and climate change impacts. In this study, an existing model (SSM, Simple Simulation Models) was adapted to simulate a large number of plant species including orchard species and perennial forages. Simplification of some methods employed in the original model was necessary to deal with limited data availability for some of the plant species to be simulated. The model requires limited, readily available input information. The simulations account for plant phenology, leaf area development and senescence, dry matter accumulation, yield formation, and soil water balance in a daily time step. Parameterization of the model for new crops/cultivars is easy and straight-forward. The resultant model (SSM-iCrop2) was parameterized and tested for more than 30 crop species of Iran using numerous field experiments. Tests showed the model was robust in the predictions of crop yield and water use. Root mean square of error as percentage of observed mean for yield was 18% for grain field crops, 14% for non-grain crops 14% for vegetables and 28% for fruit trees. DA - 2020/6// PY - 2020/6// DO - 10.1016/j.agsy.2020.102855 VL - 182 SP - SN - 1873-2267 KW - Crop model KW - Simulation KW - Orchards KW - Perennial forages KW - Food security KW - Climate change ER - TY - JOUR TI - Modeling plant production at country level as affected by availability and productivity of land and water AU - Soltani, A. AU - Alimagham, S. M. AU - Nehbandani, A. AU - Torabi, B. AU - Zeinali, E. AU - Zand, E. AU - Ghassemi, S. AU - Vadez, V. AU - Sinclair, T. R. AU - Ittersum, M. K. T2 - AGRICULTURAL SYSTEMS AB - Assessing the food availability and food security of countries is a critical exercise in which crop simulation models are essential. Application of crop models has been limited often to estimate yield per unit area of one or a few important field crops, whereas what is really required is the total national production of diverse crops including forages, vegetables and fruit trees that compete for limited resources of land and water. In this study a simple crop model (SSM-iCrop2; Simple Simulation Models) was set up for an entire country using a bottom-up approach such that it provides representative estimates of potential yield and other crop properties at provincial level as influenced by climate, soil, management and cultivar. The information is then used to calculate total plant production at province and country levels, as influenced by available land and water resources and by the efficiency of utilizing the resources using the concepts relative yield gap and irrigation efficiency. Iran was used as a case study to develop the modeling framework and illustrative outputs. Development of the framework resulted in accumulation of large bodies of valuable geospatial information and statistics across disciplines that are critical for analysis of plant production at a country level. The framework allows different scenarios of national plant production to be evaluated. This includes assessing the possibility of increasing national plant production via intensification, optimizing water allocation across plant species at province and country levels by changing the cropping pattern, and assessing and prioritizing possible ways of adapting a country's agriculture to limited land and water resources and climate change. DA - 2020/8// PY - 2020/8// DO - 10.1016/j.agsy.2020.102859 VL - 183 SP - SN - 1873-2267 KW - Crop model KW - Simulation KW - Food security KW - Land KW - Water KW - Climate change ER - TY - JOUR TI - The genetic architecture of the maize progenitor, teosinte, and how it was altered during maize domestication AU - Chen, Qiuyue AU - Samayoa, Luis Fernando AU - Yang, Chin Jian AU - Bradbury, Peter J. AU - Olukolu, Bode A. AU - Neumeyer, Michael A. AU - Romay, Maria Cinta AU - Sun, Qi AU - Lorant, Anne AU - Buckler, Edward S. AU - Ross-Ibarra, Jeffrey AU - Holland, James B. AU - Doebley, John F. T2 - PLOS GENETICS AB - The genetics of domestication has been extensively studied ever since the rediscovery of Mendel's law of inheritance and much has been learned about the genetic control of trait differences between crops and their ancestors. Here, we ask how domestication has altered genetic architecture by comparing the genetic architecture of 18 domestication traits in maize and its ancestor teosinte using matched populations. We observed a strongly reduced number of QTL for domestication traits in maize relative to teosinte, which is consistent with the previously reported depletion of additive variance by selection during domestication. We also observed more dominance in maize than teosinte, likely a consequence of selective removal of additive variants. We observed that large effect QTL have low minor allele frequency (MAF) in both maize and teosinte. Regions of the genome that are strongly differentiated between teosinte and maize (high FST) explain less quantitative variation in maize than teosinte, suggesting that, in these regions, allelic variants were brought to (or near) fixation during domestication. We also observed that genomic regions of high recombination explain a disproportionately large proportion of heritable variance both before and after domestication. Finally, we observed that about 75% of the additive variance in both teosinte and maize is "missing" in the sense that it cannot be ascribed to detectable QTL and only 25% of variance maps to specific QTL. This latter result suggests that morphological evolution during domestication is largely attributable to very large numbers of QTL of very small effect. DA - 2020/5// PY - 2020/5// DO - 10.1371/journal.pgen.1008791 VL - 16 IS - 5 SP - SN - 1553-7404 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-85085904066&partnerID=MN8TOARS ER - TY - JOUR TI - Drought Stress Detection Using Low-Cost Computer Vision Systems and Machine Learning Techniques AU - Ramos-Giraldo, Paula AU - Reberg-Horton, Chris AU - Locke, Anna M. AU - Mirsky, Steven AU - Lobaton, Edgar T2 - IT Professional AB - The real-time detection of drought stress has major implications for preventing cash crop yield loss due to variable weather conditions and ongoing climate change. The most widely used indicator of drought sensitivity/tolerance in corn and soybean is the presence or absence of leaf wilting during periods of water stress. We develop a low-cost automated drought detection system using computer vision coupled with machine learning (ML) algorithms that document the drought response in corn and soybeans field crops. Using ML, we predict the drought status of crop plants with more than 80% accuracy relative to expert-derived visual drought ratings. DA - 2020/5/1/ PY - 2020/5/1/ DO - 10.1109/MITP.2020.2986103 VL - 22 IS - 3 SP - 27-29 J2 - IT Prof. OP - SN - 1520-9202 1941-045X UR - http://dx.doi.org/10.1109/MITP.2020.2986103 DB - Crossref KW - Agriculture KW - Stress KW - Machine learning KW - Computer vision KW - Loss measurement KW - Stress measurement KW - Cameras ER - TY - JOUR TI - Tree species effects on understory forage productivity and microclimate in a silvopasture of the Southeastern USA AU - Castillo, Miguel S. AU - Tiezzi, Francesco AU - Franzluebbers, Alan J. T2 - AGRICULTURE ECOSYSTEMS & ENVIRONMENT AB - Ecosystem services provided by silvopastoral systems are mediated by specific management practices, environmental conditions, and overall design of the system. We hypothesized that selection of tree species affects understory forage nutritive value and productivity, light/shade environment, and microclimate. The silvopastoral system was located at the Center for Environmental Farming Systems in Goldsboro, North Carolina, USA. Three overstory tree-species were Pinus palustris (PP; longleaf pine), Pinus taeda (PT; lobloblly pine), and Quercus pagoda (QP; cherrybark oak). The understory forage component consisted of a four-way mixture of native warm-season grasses [big bluestem (Andropogon gerardii, ‘Eastern’, KY origin), eastern gamagrass (Tripsacum dactyloides, MO origin), indiangrass (Sorghastrum nutans, ‘NC ecotype’), and switchgrass (Panicum virgatum, ‘Alamo’)]. The experimental design was an RCBD with 3 replicates. There was no effect of seedbed preparation (till versus no-till) on forage establishment. Understory dry matter yield, crude protein and total digestible nutrient concentrations of the harvested forage were not affected by tree species, with the exception at the 3.5 south sampling point. Overstory effects on microclimate variables were not different among tree-species, but were more noticeable during the daytime of the summer months, and were at the most 1-degree point for temperature and temperature-humidity index and 3 points for relative humidity. The silvopasture design in our study provided year-round shade by the tree-component, with varying levels of shade (ranging from 90 to 6% of incident photosynthetic active radiation) due to geographic location, tree species, and season. Our results describe and highlight the potential of trees in a silvopasture design in the southeastern USA to mitigate changes in temperature, humidity, the temperature-humidity index, and forage productivity and as a function of tree species and at different distance from the trees. DA - 2020/6/15/ PY - 2020/6/15/ DO - 10.1016/j.agee.2020.106917 VL - 295 SP - SN - 1873-2305 KW - Silvopastures KW - Agroforestry KW - Forages ER - TY - JOUR TI - Implications of chloride application rate and nitrogen fertilizer source to flue‐cured tobacco AU - Pace, C.R. AU - Vann, M.C. AU - Fisher, L.R. AU - Hardy, D.H. T2 - Agronomy Journal AB - Abstract Chloride assimilation by flue‐cured tobacco ( Nicotiana tabacum L.) can negatively impact leaf development and quality when tissue concentration exceeds 1%. The influences of Cl − application rate and N fertilizer sources have not been fully described in field research utilizing reduced‐cost or custom‐blend fertility programs that are common in modern times. Research was conducted to test the interaction of four Cl − application rates (0, 34, 67, and 101 kg ha −1 ) and four N fertilizer sources {calcium nitrate, Ca(NO 3 ) 2 ; ammonium nitrate, NH 4 NO 3 ; liquid urea‐ammonium nitrate [UAN], and ammonium sulfate, (NH 4 ) 2 SO 4 } on the growth and development of flue‐cured tobacco. The impact of N source was minimal in green leaf tissue; however, (NH 4 ) 2 SO 4 reduced cured leaf quality relative to other N sources. Two weeks after fertilizer application, Cl − rates ≥34 kg ha −1 reduced foliar total N and NO 3 − measurements by 0.12−0.42% and 789−1348 mg kg −1 , respectively. Leaf NO 3 − concentration was also reduced by Cl − application at the layby growth stage, while P, K, and Mg increased following Cl − application in late‐season measurements. After curing, total N and alkaloids were reduced by an average of 0.17 and 0.23%, respectively, while reducing sugars were increased by 1.67% where Cl − was applied. Chloride concentration exceeded 1% in application rates ≥34 kg ha −1 in early‐season and post‐curing measurements, although toxicity symptoms were not observed nor were yield, quality, or value affected. Farmers should adhere to the current recommendation of ≤34 kg Cl − ha −1 to ensure that cigarette manufacturers receive tobacco that is usable in products. DA - 2020/7// PY - 2020/7// DO - 10.1002/agj2.20251 VL - 112 IS - 4 SP - 2916-2927 UR - https://doi.org/10.1002/agj2.20251 ER - TY - JOUR TI - Green and animal manure use in organic field crop systems AU - Carr, P.M. AU - Cavigelli, M.A. AU - Darby, H. AU - Delate, K. AU - Eberly, J.O. AU - Fryer, H.K. AU - Gramig, G.G. AU - Heckman, J.R. AU - Mallory, E.B. AU - Reeve, J.R. AU - Silva, E.M. AU - Suchoff, D.H. AU - Woodley, A.L. T2 - Agronomy Journal AB - Abstract Dual‐use cover/green manure (CGM) crops and animal manure are used to supply nitrogen (N) and phosphorus (P) to organically grown field crops. A comprehensive review of previous research was conducted to identify how CGM crops and animal manure have been used to meet N and P needs of organic field crops, and to identify knowledge gaps to direct future research efforts. Results indicate that: (a) CGM crops are used to provide N to subsequent cash crops in rotations; (b) CGM‐supplied N generally can meet field crop needs in warm, humid regions but is insufficient for organic grain crops grown in cool and sub‐humid regions; (c) adoption of conservation tillage practices can create or exacerbate N deficiencies; (d) excess N and P can result where animal manures are accessible if application rates are not carefully managed; and (e) integrating animal grazing into organic field crop systems has potential benefits but is generally not practiced. Work is needed to better understand the mechanisms governing the release of N by CGM crops to subsequent cash crops, and the legacy effects of animal manure applications in cool and sub‐humid regions. The benefits and synergies that can occur by combining targeted animal grazing and CGMs on soil N, P, and other nutrients should be investigated. Improved communication and networking among researchers can aid efforts to solve soil fertility challenges faced by organic farmers when growing field crops in North America and elsewhere. DA - 2020/// PY - 2020/// DO - 10.1002/agj2.20082 VL - 112 IS - 2 SP - 648-674 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-85080050121&partnerID=MN8TOARS ER - TY - JOUR TI - Quantifying the impacts of the Conservation Effects Assessment Project watershed assessments: The first fifteen years AU - Moriasi, Daniel N. AU - Duriancik, Lisa F. AU - Sadler, E. John AU - Tsegaye, Teferi AU - Steiner, Jean L. AU - Locke, Martin A. AU - Strickland, Timothy C. AU - Osmond, Deanna L. T2 - JOURNAL OF SOIL AND WATER CONSERVATION AB - T he United States Department of Agriculture (USDA) spends about US$6 billion each year on agricultural conservation programs to help producers and landowners implement conservation practices (CPs) and systems on their land. In 2003, the USDA Natural Resources Conservation Service (NRCS) entered into partnership with USDA Agricultural Research Service (ARS), USDA National Institute of Food and Agriculture (NIFA), other federal agencies, and many external partners to create the Conservation Effects Assessment Project (CEAP). The goal of CEAP is to quantify the environmental effects of CPs and programs and develop the science base for managing the agricultural landscape for environmental quality (Mausbach and Dedrick 2004; Duriancik et al. 2008). Conservation effects are assessed at national, regional, and watershed scales on cropland, grazing lands, wetlands, and for wildlife. As part of these efforts, CEAP initiated the Watershed Assessment Studies (WAS) component … DA - 2020/// PY - 2020/// DO - 10.2489/jswc.75.3.57A VL - 75 IS - 3 SP - 57A-74A SN - 1941-3300 ER - TY - JOUR TI - Characterization of Phn15.1, a Newly Identified Phytophthora nicotianae Resistance QTL in Nicotiana tabacum AU - Ma, Justin M. AU - Heim, Crystal B. AU - Humphry, Matt AU - Nifong, Jessica M. AU - Lewis, Ramsey S. T2 - PLANT DISEASE AB - Phytophthora nicotianae is an oomycete that causes black shank, one of the most economically important diseases affecting tobacco production worldwide. Identification and introgression of novel genetic variability affecting partial genetic resistance to this pathogen is important because of the increased durability of partial resistance over time as compared with genes conferring immunity. A previous mapping study identified a quantitative trait locus (QTL), hereafter designated as Phn15.1, with a major effect on P. nicotianae resistance in tobacco. In this research, we describe significantly improved resistance of nearly isogenic lines (NILs) of flue-cured tobacco carrying the introgressed Phn15.1 region derived from highly resistant cigar tobacco cultivar Beinhart 1000. The Phn15.1 region appeared to act in an additive or partially dominant manner to positively affect resistance. To more finely resolve the position of the gene or genes underlying the Phn15.1 effect, the QTL was mapped with an increased number of molecular markers (single-nucleotide polymorphisms) identified to reside within the region. Development and evaluation of subNILs containing varying amounts of Beinhart 1000-derived Phn15.1-associated genetic material permitted the localization of the QTL to a genetic interval of approximately 2.7 centimorgans. Importantly, we were able to disassociate the Beinhart 1000 Phn15.1 resistance alleles from a functional NtCPS2 allele(s) which contributes to the accumulation of a diterpene leaf surface exudate considered undesirable for flue-cured and burley tobacco. Information from this research should be of value for marker-assisted introgression of Beinhart 1000-derived partial black shank resistance into flue-cured and burley tobacco breeding programs. DA - 2020/6// PY - 2020/6// DO - 10.1094/PDIS-10-19-2257-RE VL - 104 IS - 6 SP - 1638-1646 SN - 1943-7692 KW - black shank KW - Nicotiana KW - partial resistance KW - Phytophthora KW - plant disease resistance KW - quantitative trait locus KW - tobacco ER - TY - JOUR TI - Genotypic and phenotypic characterization of a large, diverse population of maize near-isogenic lines AU - Morales, Laura AU - Repka, A. C. AU - Swarts, Kelly L. AU - Stafstrom, William C. AU - He, Yijian AU - Sermons, Shannon M. AU - Yang, Qin AU - Lopez-Zuniga, Luis O. AU - Rucker, Elizabeth AU - Thomason, Wade E. AU - Nelson, Rebecca J. AU - Balint-Kurti, Peter J. T2 - PLANT JOURNAL AB - Genome-wide association (GWA) studies can identify quantitative trait loci (QTL) putatively underlying traits of interest, and nested association mapping (NAM) can further assess allelic series. Near-isogenic lines (NILs) can be used to characterize, dissect and validate QTL, but the development of NILs is costly. Previous studies have utilized limited numbers of NILs and introgression donors. We characterized a panel of 1270 maize NILs derived from crosses between 18 diverse inbred lines and the recurrent inbred parent B73, referred to as the nested NILs (nNILs). The nNILs were phenotyped for flowering time, height and resistance to three foliar diseases, and genotyped with genotyping-by-sequencing. Across traits, broad-sense heritability (0.4-0.8) was relatively high. The 896 genotyped nNILs contain 2638 introgressions, which span the entire genome with substantial overlap within and among allele donors. GWA with the whole panel identified 29 QTL for height and disease resistance with allelic variation across donors. To date, this is the largest and most diverse publicly available panel of maize NILs to be phenotypically and genotypically characterized. The nNILs are a valuable resource for the maize community, providing an extensive collection of introgressions from the founders of the maize NAM population in a B73 background combined with data on six agronomically important traits and from genotyping-by-sequencing. We demonstrate that the nNILs can be used for QTL mapping and allelic testing. The majority of nNILs had four or fewer introgressions, and could readily be used for future fine mapping studies. DA - 2020/8// PY - 2020/8// DO - 10.1111/tpj.14787 VL - 103 IS - 3 SP - 1246-1255 SN - 1365-313X KW - near-isogenic lines KW - genotyping-by-sequencing KW - genome-wide association KW - allelic analysis KW - maize KW - disease resistance KW - flowering time KW - plant height KW - quantitative trait loci KW - genetics KW - Zea mays ER - TY - JOUR TI - Role of cytosolic, tyrosine‐insensitive prephenate dehydrogenase in Medicago truncatula AU - Schenck, Craig A. AU - Westphal, Josh AU - Jayaraman, Dhileepkumar AU - Garcia, Kevin AU - Wen, Jiangqi AU - Mysore, Kirankumar S. AU - Ané, Jean‐Michel AU - Sumner, Lloyd W. AU - Maeda, Hiroshi A. T2 - Plant Direct AB - Abstract l ‐Tyrosine (Tyr) is an aromatic amino acid synthesized de novo in plants and microbes downstream of the shikimate pathway. In plants, Tyr and a Tyr pathway intermediate, 4‐hydroxyphenylpyruvate (HPP), are precursors to numerous specialized metabolites, which are crucial for plant and human health. Tyr is synthesized in the plastids by a TyrA family enzyme, arogenate dehydrogenase (ADH/TyrA a ), which is feedback inhibited by Tyr. Additionally, many legumes possess prephenate dehydrogenases (PDH/TyrA p ), which are insensitive to Tyr and localized to the cytosol. Yet the role of PDH enzymes in legumes is currently unknown. This study isolated and characterized Tnt1 ‐transposon mutants of MtPDH1 ( pdh1 ) in Medicago truncatula to investigate PDH function. The pdh1 mutants lacked PDH transcript and PDH activity, and displayed little aberrant morphological phenotypes under standard growth conditions, providing genetic evidence that MtPDH1 is responsible for the PDH activity detected in M. truncatula . Though plant PDH enzymes and activity have been specifically found in legumes, nodule number and nitrogenase activity of pdh1 mutants were not significantly reduced compared with wild‐type (Wt) during symbiosis with nitrogen‐fixing bacteria. Although Tyr levels were not significantly different between Wt and mutants under standard conditions, when carbon flux was increased by shikimate precursor feeding, mutants accumulated significantly less Tyr than Wt. These data suggest that MtPDH1 is involved in Tyr biosynthesis when the shikimate pathway is stimulated and possibly linked to unidentified legume‐specific specialized metabolism. DA - 2020/5/3/ PY - 2020/5/3/ DO - 10.1002/pld3.218 VL - 4 IS - 5 KW - legumes KW - prephenate dehydrogenase KW - the shikimate pathway KW - TyrA dehydrogenase KW - tyrosine ER - TY - JOUR TI - Editorial: Importance of Root Symbiomes for Plant Nutrition: New Insights, Perspectives and Future Challenges AU - Garcia, Kevin AU - Bücking, Heike AU - Zimmermann, Sabine D. T2 - Frontiers in Plant Science AB - EDITORIAL article Front. Plant Sci., 13 May 2020Sec. Plant Pathogen Interactions Volume 11 - 2020 | https://doi.org/10.3389/fpls.2020.00594 DA - 2020/5// PY - 2020/5// DO - 10.3389/fpls.2020.00594 VL - 11 KW - biological nitrogen fixation KW - mycorrhizal symbiosis KW - plant growth promoting rhizobacteria KW - plant nutrition KW - root microbiome ER - TY - JOUR TI - Dominance Effects and Functional Enrichments Improve Prediction of Agronomic Traits in Hybrid Maize AU - Ramstein, Guillaume P. AU - Larsson, Sara J. AU - Cook, Jason P. AU - Edwards, Jode W. AU - Ersoz, Elhan S. AU - Flint-Garcia, Sherry AU - Gardner, Candice A. AU - Holland, James B. AU - Lorenz, Aaron J. AU - McMullen, Michael D. AU - Millard, Mark J. AU - Rocheford, Torbert R. AU - Tuinstra, Mitchell R. AU - Bradbury, Peter J. AU - Buckler, Edward S. AU - Romay, M. Cinta T2 - GENETICS AB - Single-cross hybrids have been critical to the improvement of maize (Zea mays L.), but the characterization of their genetic architectures remains challenging. Previous studies of hybrid maize have shown the contribution of within-locus complementation effects (dominance) and their differential importance across functional classes of loci. However, they have generally considered panels of limited genetic diversity, and have shown little benefit from genomic prediction based on dominance or functional enrichments. This study investigates the relevance of dominance and functional classes of variants in genomic models for agronomic traits in diverse populations of hybrid maize. We based our analyses on a diverse panel of inbred lines crossed with two testers representative of the major heterotic groups in the U.S. (1106 hybrids), as well as a collection of 24 biparental populations crossed with a single tester (1640 hybrids). We investigated three agronomic traits: days to silking (DTS), plant height (PH), and grain yield (GY). Our results point to the presence of dominance for all traits, but also among-locus complementation (epistasis) for DTS and genotype-by-environment interactions for GY. Consistently, dominance improved genomic prediction for PH only. In addition, we assessed enrichment of genetic effects in classes defined by genic regions (gene annotation), structural features (recombination rate and chromatin openness), and evolutionary features (minor allele frequency and evolutionary constraint). We found support for enrichment in genic regions and subsequent improvement of genomic prediction for all traits. Our results suggest that dominance and gene annotations improve genomic prediction across diverse populations in hybrid maize. DA - 2020/5// PY - 2020/5// DO - 10.1534/genetics.120.303025 VL - 215 IS - 1 SP - 215-230 SN - 1943-2631 UR - https://doi.org/10.1534/genetics.120.303025 KW - dominance KW - genomic features KW - functional enrichment KW - genomic prediction KW - hybrid maize ER - TY - JOUR TI - Peanut Yield Loss in the Presence of Defoliation Caused by Late or Early Leaf Spot AU - Anco, Daniel J. AU - Thomas, James S. AU - Jordan, David L. AU - Shew, Barbara B. AU - Monfort, W. Scott AU - Mehl, Hillary L. AU - Small, Ian M. AU - Wright, David L. AU - Tillman, Barry L. AU - Dufault, Nicholas S. AU - Hagan, Austin K. AU - Campbell, H. Lee T2 - PLANT DISEASE AB - Late and early leaf spot, respectively caused by Nothopassalora personata and Passalora arachidicola, are damaging diseases of peanut (Arachis hypogaea) capable of defoliating canopies and reducing yield. Although one of these diseases may be more predominant in a given area, both are important on a global scale. To assist informed management decisions and quantify relationships between end-of-season defoliation and yield loss, meta-analyses were conducted over 140 datasets meeting established criteria. Slopes of proportion yield loss with increasing defoliation were estimated separately for Virginia and runner market type cultivars. Yield loss for Virginia types was described by an exponential function over the range of defoliation levels, with a loss increase of 1.2 to 2.2% relative to current loss levels per additional percent defoliation. Results for runner market type cultivars showed yield loss to linearly increase 2.2 to 2.8% per 10% increase in defoliation for levels up to approximately 95% defoliation, after which the rate of yield loss was exponential. Defoliation thresholds to prevent economic yield loss for Virginia and runner types were estimated at 40 and 50%, respectively. Although numerous factors remain important in mitigating overall yield losses, the integration of these findings should aid recommendations about digging under varying defoliation intensities and peanut maturities to assist in minimizing yield losses. DA - 2020/5// PY - 2020/5// DO - 10.1094/PDIS-11-19-2286-RE VL - 104 IS - 5 SP - 1390-1399 SN - 1943-7692 KW - Arachis hypogaea KW - digging KW - groundnut KW - harvest KW - inversion KW - quantitative synthesis KW - senescence ER - TY - JOUR TI - A Genome-Wide Association Study To Understand the Effect of Fusarium verticillioides Infection on Seedlings of a Maize Diversity Panel AU - Stagnati, Lorenzo AU - Rahjoo, Vahid AU - Samayoa, Luis F. AU - Holland, James B. AU - Borrelli, Virginia M. G. AU - Busconi, Matteo AU - Lanubile, Alessandra AU - Marocco, Adriano T2 - G3-GENES GENOMES GENETICS AB - Abstract Fusarium verticillioides, which causes ear, kernel and stem rots, has been reported as the most prevalent species on maize worldwide. Kernel infection by F. verticillioides results in reduced seed yield and quality as well as fumonisin contamination, and may affect seedling traits like germination rate, entire plant seedling length and weight. Maize resistance to Fusarium is a quantitative and complex trait controlled by numerous genes with small effects. In the present work, a Genome Wide Association Study (GWAS) of traits related to Fusarium seedling rot was carried out in 230 lines of a maize association population using 226,446 SNP markers. Phenotypes were scored on artificially infected kernels applying the rolled towel assay screening method and three traits related to disease response were measured in inoculated and not-inoculated seedlings: plant seedling length (PL), plant seedling weight (PW) and germination rate (GERM). Overall, GWAS resulted in 42 SNPs significantly associated with the examined traits. Two and eleven SNPs were associated with PL in inoculated and not-inoculated samples, respectively. Additionally, six and one SNPs were associated with PW and GERM traits in not-inoculated kernels, and further nine and thirteen SNPs were associated to the same traits in inoculated kernels. Five genes containing the significant SNPs or physically closed to them were proposed for Fusarium resistance, and 18 out of 25 genes containing or adjacent to significant SNPs identified by GWAS in the current research co-localized within QTL regions previously reported for resistance to Fusarium seed rot, Fusarium ear rot and fumonisin accumulation. Furthermore, linkage disequilibrium analysis revealed an additional gene not directly observed by GWAS analysis. These findings could aid to better understand the complex interaction between maize and F. verticillioides. DA - 2020/5// PY - 2020/5// DO - 10.1534/g3.119.400987 VL - 10 IS - 5 SP - 1685-1696 SN - 2160-1836 UR - https://doi.org/10.1534/g3.119.400987 KW - GWAS KW - SNPs KW - Artificial inoculation KW - Fusarium verticillioides KW - Maize ER - TY - JOUR TI - Creating Predictive Weed Emergence Models Using Repeat Photography and Image Analysis AU - Piskackova, Theresa Reinhardt AU - Reberg-Horton, Chris AU - Richardson, Robert J AU - Austin, Robert AU - Jennings, Katie M AU - Leon, Ramon G T2 - Plants AB - Weed emergence models have the potential to be important tools for automating weed control actions; however, producing the necessary data (e.g., seedling counts) is time consuming and tedious. If similar weed emergence models could be created by deriving emergence data from images rather than physical counts, the amount of generated data could be increased to create more robust models. In this research, repeat RGB images taken throughout the emergence period of Raphanus raphanistrum L. and Senna obtusifolia (L.) Irwin and Barneby underwent pixel-based spectral classification. Relative cumulative pixels generated by the weed of interest over time were used to model emergence patterns. The models that were derived from cumulative pixel data were validated with the relative emergence of true seedling counts. The cumulative pixel model for R. raphanistrum and S. obtusifolia accounted for 92% of the variation in relative emergence of true counts. The results demonstrate that a simple image analysis approach based on time-dependent changes in weed cover can be used to generate weed emergence predictive models equivalent to those produced based on seedling counts. This process will help researchers working on weed emergence models, providing a new low-cost and technologically simple tool for data collection. DA - 2020/5/15/ PY - 2020/5/15/ DO - 10.3390/plants9050635 VL - 9 IS - 5 SP - 635 UR - https://doi.org/10.3390/plants9050635 KW - emergence models KW - sigmoidal models KW - RGB KW - maximum likelihood analysis KW - supervised classification ER - TY - JOUR TI - Increased Prediction Accuracy Using Combined Genomic Information and Physiological Traits in A Soft Wheat Panel Evaluated in Multi-Environments AU - Guo, Jia AU - Pradhan, Sumit AU - Shahi, Dipendra AU - Khan, Jahangir AU - Mcbreen, Jordan AU - Bai, Guihua AU - Murphy, J. Paul AU - Babar, Md Ali T2 - SCIENTIFIC REPORTS AB - Abstract An integration of field-based phenotypic and genomic data can potentially increase the genetic gain in wheat breeding for complex traits such as grain and biomass yield. To validate this hypothesis in empirical field experiments, we compared the prediction accuracy between multi-kernel physiological and genomic best linear unbiased prediction (BLUP) model to a single-kernel physiological or genomic BLUP model for grain yield (GY) using a soft wheat population that was evaluated in four environments. The physiological data including canopy temperature (CT), SPAD chlorophyll content (SPAD), membrane thermostability (MT), rate of senescence (RS), stay green trait (SGT), and NDVI values were collected at four environments (2016, 2017, and 2018 at Citra, FL; 2017 at Quincy, FL). Using a genotyping-by-sequencing (GBS) approach, a total of 19,353 SNPs were generated and used to estimate prediction model accuracy. Prediction accuracies of grain yield evaluated in four environments improved when physiological traits and/or interaction effects (genotype × environment or physiology × environment) were included in the model compared to models with only genomic data. The proposed multi-kernel models that combined physiological and genomic data showed 35 to 169% increase in prediction accuracy compared to models with only genomic data included when heading date was used as a covariate. In general, higher response to selection was captured by the model combing effects of physiological and genotype × environment interaction compared to other models. The results of this study support the integration of field-based physiological data into GY prediction to improve genetic gain from selection in soft wheat under a multi-environment context. DA - 2020/4/27/ PY - 2020/4/27/ DO - 10.1038/s41598-020-63919-3 VL - 10 IS - 1 SP - SN - 2045-2322 ER - TY - JOUR TI - Method to Assess Climate Change Impacts on Hydrologic Boundaries of Individual Wetlands AU - Vepraskas, M. J. AU - Skaggs, R. W. AU - Caldwell, P. T2 - WETLANDS DA - 2020/4// PY - 2020/4// DO - 10.1007/s13157-019-01183-6 VL - 40 IS - 2 SP - 365-376 SN - 1943-6246 UR - https://doi.org/10.1007/s13157-019-01183-6 KW - DRAINMOD KW - Hydropedology KW - Wetland-hydrology boundary KW - Hadley model ER - TY - JOUR TI - Citric acid-assisted accumulation of Ni and other metals by Odontarrhena muralis: Implications for phytoextraction and metal foliar distribution assessed by mu-SXRF AU - Nascimento, Clistenes Williams AU - Hesterberg, Dean AU - Tappero, Ryan AU - Nicholas, Sarah AU - Silva, Fernando Bruno T2 - ENVIRONMENTAL POLLUTION AB - Odontarrhena muralis is one of the most promissing plant species for Ni phytomining, and soil amendments can further increase its Ni phytoextraction ability. Here we investigated whether Ni phytomining/phytoremediation using this Ni hyperaccumulator can benefit from applying citric acid to a serpentine soil that is naturally enriched in Ni (>1000 mg kg-1). Synchrotron micro X-ray fluorescence (μ-SXRF) was used to image Ni and other metal distributions in whole fresh leaves of O. muralis. Leaf Ni accumulation in plants grown on citric acid-amended soil increased up to 55% while Co, Cr, Fe, Mn, and Zn concentrations were 4-, 14-, 6-, 7- and 1.3-fold higher than the control treatment. O. muralis presented high bioconcentration factors (leaf to soil concentration ratio) to Ni and Zn whereas Cr was seemingly excluded from uptake. The μ-SXRF images showed a uniform distribution of Ni, preferential localization of Co in the leaf tip, and clear concentration of Mn in the base of trichomes. The citric acid treatments strongly increased the Co fluoerescence intensity in the leaf tip and altered the spatial distribution of Mn across the leaf, but there was no difference in Ni fluorescence counts between the trichome-base region and the bulk leaf. Our data from a serpentine soil suggests that citrate treatment enhances Ni uptake, but Co is excreted from leaves even in low leaf concentrations, which can make Co phytoming using O. muralis unfeasible in natural serpentine soils. DA - 2020/5// PY - 2020/5// DO - 10.1016/j.envpol.2020.114025 VL - 260 SP - SN - 1873-6424 KW - Hyperaccumulators KW - Phytoremediation KW - Alyssum murale KW - X-ray fluorescence ER - TY - JOUR TI - Genetic and Agronomic Analysis of Tobacco Genotypes Exhibiting Reduced Nicotine Accumulation Due to Induced Mutations in Berberine Bridge Like (BBL) Genes AU - Lewis, Ramsey S. AU - Drake-Stowe, Katherine E. AU - Heim, Crystal AU - Steede, Tyler AU - Smith, William AU - Dewey, Ralph E. T2 - FRONTIERS IN PLANT SCIENCE AB - Genetic methodologies for reducing nicotine accumulation in the tobacco plant (Nicotiana tabacum L.) are of interest because of potential future regulations that could mandate lowering of this alkaloid in conventional cigarettes. Inactivation of tobacco genes such as the Berberine Bridge Like (BBL) gene family believed to encode for enzymes involved in one of the latter steps of nicotine biosynthesis could be a viable strategy for producing new tobacco cultivars with ultra-low leaf nicotine accumulation. We introduced deleterious mutations generated via ethyl methanesulfonate treatment of seed or gene editing into six known members of the BBL gene family and assembled them in different combinations to assess their relative contribution to nicotine accumulation. Significant reductions (up to 17-fold) in percent leaf nicotine were observed in genotypes homozygous for combined mutations in BBL-a, BBL-b, and BBL-c. The addition of mutations in BBL-d1, BBL-d2, and BBL-e had no additional significant effect on lowering of nicotine levels in the genetic background studied. Reduced nicotine levels were associated with reductions in cured leaf yields (up to 29%) and cured leaf quality (up to 15%), evidence of physiological complexities within the tobacco plant related to the nicotine biosynthetic pathway. Further nicotine reductions were observed for a BBL mutant line cultivated under a modified production regime in which apical inflorescences were not removed, but at the expense of further yield reductions. Plants in which BBL mutations were combined with naturally occurring recessive alleles at the Nic1 and Nic2 loci exhibited further reductions in percent nicotine, but no plant produced immeasurable levels of this alkaloid. Findings may suggest the existence of a minor, alternative pathway for nicotine biosynthesis in N. tabacum. The described genetic materials may be of value for the manufacture of cigarettes with reduced nicotine levels and for future studies to better understand the molecular biology of alkaloid accumulation in tobacco. DA - 2020/4/3/ PY - 2020/4/3/ DO - 10.3389/fpls.2020.00368 VL - 11 SP - SN - 1664-462X KW - tobacco KW - Nicotiana tabacum KW - nicotine KW - alkaloids KW - gene editing KW - regulation ER - TY - JOUR TI - Peanut nitrogen credits to winter wheat are negligible under conservation tillage management in the southeastern USA AU - Jani, Arun D. AU - Mulvaney, Michael J. AU - Erickson, John E. AU - Leon, Ramon G. AU - Wood, C. Wesley AU - Rowland, Diane L. AU - Enloe, Heather A. T2 - FIELD CROPS RESEARCH AB - Agricultural extension services in many peanut (Arachis hypogaea L.)-producing regions recommend that farmers reduce nitrogen (N) fertilization rates, or apply N credits, to crops planted after peanut but do not typically specify how peanut residue management or planting schedules of subsequent crops affect the magnitude of peanut N credits. The objective of this study was to quantify peanut N credits to winter wheat (Triticum aestivum L.) in a conservation tillage cropping system in different subtropical growing environments. A five site-year study was conducted in Florida, USA beginning in 2016. A split-plot experimental design was arranged in which summer crop [peanut, cotton (Gossypium hirsutum L.), and weed-free fallow] was the main plot factor, while N rate (0, 34, 67, and 101 kg N ha−1) to winter wheat was the split plot factor. Peanut and cotton were planted under strip-tillage, while winter wheat was drilled into peanut and cotton residues and weed-free fallow plots without tillage. Although peanut residues accumulated 54–93 kg N ha−1, plant available N at winter wheat planting in the 0–15 cm soil depth range of former peanut plots was only higher than in former cotton or fallow plots for one site-year. A previous peanut crop did not affect winter wheat grain yield, but there were cases of lower grain yield, grain N removal, and agronomic efficiency following cotton relative to peanut depending on site. Nonlinear regression procedures predicted that N rates required to optimize grain yields following peanut would exceed 94 kg N ha−1, further indicating the absence of detectible peanut N credits in this study. These results suggest that assuming peanut provides N credits to subsequent crops in the southeastern USA is not justified and, if assumed, will reduce the productivity of subsequent crops. DA - 2020/4/1/ PY - 2020/4/1/ DO - 10.1016/j.fcr.2020.107739 VL - 249 SP - SN - 1872-6852 KW - Peanut (Arachis hypogaea L.) KW - Winter wheat (Triticum aestivum L.) KW - Nitrogen credits KW - Conservation tillage ER - TY - JOUR TI - Examination of models for determining saturated hydraulic conductivity by the constant head well permeameter method AU - Amoozegar, Aziz T2 - SOIL & TILLAGE RESEARCH AB - In the constant head well permeameter method the saturated hydraulic conductivity (Ks) of the vadose zone is determined by the equation Q = A × Ks, where Q is the steady state rate of water flow into the soil from a cylindrical hole of known diameter under a constant depth of water, and A is a factor that must be calculated by a model. The Glover model for determining factor A was developed approximately 70 years ago by considering the hydrostatic pressure and gravity in a saturated zone around the hole. This model does not depend on soil texture or structure. Newer models, on the other hand, consider both saturated and unsaturated flow of water, and include both Ks and the capillary factor α (sorptive number) that must be determined independently or be estimated based on soil texture and structure. The main objective here is to compare these models and demonstrate that they yield similar results for coarse-textured soils (relatively large α), but those that consider both saturated and unsaturated flow yield unrealistic results for medium- to fine-textured soils with relatively small α values. The soil water profile around a cylindrical hole under a constant depth of water is initially composed of a bulb-shaped saturation zone (pressure head h > 0), saturation front (h = 0), transmission and wetting zones (h < 0), and wetting front. At steady state, a saturated bulb with a finite volume forms around the hole, and the impact of the unsaturated zone away from the hole on water flow within the saturated bulb diminishes. In addition, the surface area of the saturated bulb is numerically equal to the factor A. Using an empirical approach, the factor A determined by the Glover model and each of the other models for different soils (i.e., different α values) was matched against the surface area of a saturated bulb. Then, the volume of the saturated bulb for each case was determined. Since the factor A determined by the models that consider unsaturated flow is inversely related to α, the volume of the saturated bulb for each model increases unrealistically as the soil texture becomes finer. For soils with α < 0.12 cm−1, the volume of the saturated bulb, and the amount of water needed to reach steady state are unrealistically high making the models that depend on α unsuitable for determining Ks by the constant head well permeameter method. DA - 2020/6// PY - 2020/6// DO - 10.1016/j.still.2020.104572 VL - 200 SP - SN - 1879-3444 KW - Constant head well permeameter method KW - Darcy's law KW - Saturated hydraulic conductivity KW - Saturated bulb KW - Sorptive number KW - Three-dimensional flow KW - Vadose zone KW - Water flow models KW - Glover model ER - TY - JOUR TI - The importance of slow canopy wilting in drought tolerance in soybean AU - Ye, Heng AU - Song, Li AU - Schapaugh, William T. AU - Ali, Liakat AU - Sinclair, Thomas R. AU - Riar, Mandeep K. AU - Raymond, Raymond N. AU - Li, Yang AU - Vuong, Tri AU - Valliyodan, Babu AU - Neto, Antonio Pizolato AU - Klepadlo, Mariola AU - Song, Qijian AU - Shannon, J. Grover AU - Chen, Pengyin AU - Nguyen, Henry T. T2 - JOURNAL OF EXPERIMENTAL BOTANY AB - Physiological mechanisms of slow canopy wilting in early maturity group soybeans were identified and the underlying QTLs were mapped and confirmed to protect soybean yield under drought in the field. DA - 2020/1/7/ PY - 2020/1/7/ DO - 10.1093/jxb/erz150 VL - 71 IS - 2 SP - 642-652 SN - 1460-2431 KW - Drought KW - QTL mapping KW - slow canopy wilting KW - soybean KW - transpiration KW - water use efficiency ER - TY - JOUR TI - Pod Dehiscence in Hairy Vetch (Vicia villosa Roth) AU - Kucek, Lisa Kissing AU - Riday, Heathcliffe AU - Rufener, Bryce P. AU - Burke, Allen N. AU - Eagen, Sarah Seehaver AU - Ehlke, Nancy AU - Krogman, Sarah AU - Mirsky, Steven B. AU - Reberg-Horton, Chris AU - Ryan, Matthew R. AU - Wayman, Sandra AU - Wiering, Nick P. T2 - FRONTIERS IN PLANT SCIENCE AB - Hairy vetch, Vicia villosa (Roth), is a cover crop that does not exhibit a typical domestication syndrome. Pod dehiscence reduces seed yield and creates weed problems for subsequent crops. De novo domestication efforts aim to reduce pod dehiscence in hairy vetch. To characterize pod dehiscence in the species, we quantified visual dehiscence and force required to cause dehiscence among 606 genotypes grown among seven environments of the United States. To identify potential secondary selection traits, we correlated pod dehiscence with various morphological pod characteristics and field measurements. Genotypes of hairy vetch exhibited wide variation in pod dehiscence, from completely indehiscent to completely dehiscent ratings. Mean force to dehiscence also varied widely, from 0.279 to 8.97 N among genotypes. No morphological traits were consistently correlated with pod dehiscence among environments where plants were grown. Results indicated that visual ratings of dehiscence would efficiently screen against genotypes with high pod dehiscence early in the de novo domestication process. Force to dehiscence may be necessary to identify the indehiscent genotypes during advanced stages of selection. DA - 2020/3/3/ PY - 2020/3/3/ DO - 10.3389/fpls.2020.00082 VL - 11 SP - SN - 1664-462X KW - pod dehiscence KW - germplasm characterization KW - vetch KW - domestication syndrome KW - phenotyping KW - legumes (Fabaceae) ER - TY - JOUR TI - Role of Effector-Sensitivity Gene Interactions and Durability of Quantitative Resistance to Septoria Nodorum Blotch in Eastern US Wheat AU - Cowger, Christina AU - Ward, Brian AU - Brown-Guedira, Gina AU - Brown, James K. M. T2 - FRONTIERS IN PLANT SCIENCE AB - Important advances have been made in understanding the relationship of necrotrophic effectors (NE) and host sensitivity (Snn) genes in the Parastagonospora nodorum-wheat pathosystem. Yet much remains to be learned about the role of these interactions in determining wheat resistance levels in the field, and there is mixed evidence on whether breeding programs have selected against Snn genes due to their role in conferring susceptibility. SNB occurs ubiquitously in the U.S. Atlantic seaboard, and the environment is especially well suited to field studies of resistance to natural P. nodorum populations, as there are no other important wheat leaf blights. Insights into the nature of SNB resistance have been gleaned from multi-year data on phenotypes and markers in cultivars representative of the region's germplasm. In this perspective article, we review the evidence that in this eastern region of the U.S., wheat cultivars have durable quantitative SNB resistance and Snn-NE interactions are of limited importance. This conclusion is discussed in light of the relevant available information from other parts of the world. DA - 2020/3/6/ PY - 2020/3/6/ DO - 10.3389/fpls.2020.00155 VL - 11 SP - SN - 1664-462X KW - Parastagonospora nodorum KW - Septoria nodorum blotch KW - quantitative resistance KW - genotyping by sequencing KW - genome-wide association study KW - necrotrophic effectors KW - necrotrophic effector sensitivity genes ER - TY - JOUR TI - Cotton response to preplant applications of 2,4-D or dicamba AU - Price, Katilyn AU - Li, Xiao AU - Leon, Ramon G. AU - Price, Andrew T2 - WEED TECHNOLOGY AB - Abstract Sensitive cotton varieties planted into soil treated with 2,4-D or dicamba utilized in burndowns can result in stunting and stand loss if use rate is too high and the plant-back interval is too short. The objective of this study was to evaluate cotton stunting and yield responses resulting from 2,4-D or dicamba residues in soil after preplant burndown applications at three locations in 2016 and 2017. Treatments with 2,4-D included 532 and 1,063 g ae ha −1 applied 3 wk before planting (WBP) and 53, 160, 266, 532, 1,063 g ae ha −1 applied at planting. Dicamba treatments included 560 and 1,120 g ae h −1 applied 3 WBP and 56, 168, 280, 560, 1,120 g ae ha −1 applied at planting. Dicamba or 2,4-D treatments applied 3 WBP resulted in no adverse effects on cotton stand, plant height, or yield. Dicamba 560 g ae h −1 applied at planting reduced cotton stand by 36% at 21 to 24 d after planting (DAP) over all locations in 2016. In 2017, stands were reduced by dicamba at 168, 280, 560, and 1,120 g ae ha −1 by 17% to 25% at 20 to 23 DAP. Moreover, cotton stands were not affected by 2,4-D in 2016, and only 266, 532, and 1,063 g ae ha −1 of 2,4-D caused stand reductions of 26% to 36% at 20 to 23 DAP over all locations in 2017. Dicamba at 560 g ae ha −1 at planting was the only treatment in this study that reduced plant height. Although stand losses were observed in both years, no yield loss occurred. The data suggest that stunting and stand reduction may occur if susceptible varieties are planted soon after burndown applications with 2,4-D or dicamba, but yield may not be affected after a full growing season. Dicamba showed greater potential to cause stunting and stand reduction than 2,4-D. DA - 2020/2// PY - 2020/2// DO - 10.1017/wet.2019.98 VL - 34 IS - 1 SP - 96-100 SN - 1550-2740 KW - 2 KW - 4-D KW - dicamba KW - cotton KW - Gossypium hirsutum L KW - Stunting KW - stand reduction KW - plant height KW - yield loss ER - TY - JOUR TI - Herbicide carryover to various fall-planted cover crop species AU - Rector, Lucas S. AU - Pittman, Kara B. AU - Beam, Shawn C. AU - Bamber, Kevin W. AU - Cahoon, Charles W. AU - Frame, William H. AU - Flessner, Michael L. T2 - WEED TECHNOLOGY AB - Abstract Residual herbicides applied to summer cash crops have the potential to injure subsequent winter annual cover crops, yet little information is available to guide growers’ choices. Field studies were conducted in 2016 and 2017 in Blacksburg and Suffolk, Virginia, to determine carryover of 30 herbicides commonly used in corn, soybean, or cotton on wheat, barley, cereal rye, oats, annual ryegrass, forage radish, Austrian winter pea, crimson clover, hairy vetch, and rapeseed cover crops. Herbicides were applied to bare ground either 14 wk before cover crop planting for a PRE timing or 10 wk for a POST timing. Visible injury was recorded 3 and 6 wk after planting (WAP), and cover crop biomass was collected 6 WAP. There were no differences observed in cover crop biomass among herbicide treatments, despite visible injury that suggested some residual herbicides have the potential to effect cover crop establishment. Visible injury on grass cover crop species did not exceed 20% from any herbicide. Fomesafen resulted in the greatest injury recorded on forage radish, with greater than 50% injury in 1 site-year. Trifloxysulfuron and atrazine resulted in greater than 20% visible injury on forage radish. Trifloxysulfuron resulted in the greatest injury (30%) observed on crimson clover in 1 site-year. Prosulfuron and isoxaflutole significantly injured rapeseed (17% to 21%). Results indicate that commonly used residual herbicides applied in the previous cash crop growing season result in little injury on grass cover crop species, and only a few residual herbicides could potentially affect the establishment of a forage radish, crimson clover, or rapeseed cover crop. DA - 2020/2// PY - 2020/2// DO - 10.1017/wet.2019.79 VL - 34 IS - 1 SP - 25-34 SN - 1550-2740 KW - Residual herbicides KW - conservation agriculture KW - cover crop injury ER - TY - JOUR TI - Herbicide selection to terminate grass, legume, and brassica cover crop species AU - Pittman, Kara B. AU - Cahoon, Charles W. AU - Bamber, Kevin W. AU - Rector, Lucas S. AU - Flessner, Michael L. T2 - WEED TECHNOLOGY AB - Abstract Cover crops provide a number of agronomic benefits, including weed suppression, which is important as cases of herbicide resistance continue to rise. To effectively suppress weeds, high cover crop biomass is needed, which necessitates later termination timing. Cover crop termination is important to mitigate potential planting issues and prevent surviving cover crop competition with cash crops. Field studies were conducted in Virginia to determine the most effective herbicide options alone or combined with glyphosate or paraquat to terminate a range of cover crop species. Results revealed that grass cover crop species were controlled (94% to 98%) by glyphosate alone 4 wk after application (WAA). Overall, legume species varied in response to the single active-ingredient treatments, and control increased with the addition of glyphosate or paraquat. Mixes with glyphosate provided better control of crimson clover and hairy vetch by 7% to 8% compared with mixes containing paraquat 4 WAA. Mix partner did not influence control of Austrian winter pea. No treatment adequately controlled rapeseed in this study, with a maximum of 58% control observed with single active-ingredient treatments and 62% control with mixes. Height reduction for all cover crop species supports visible rating data. Rapeseed should be terminated when smaller, which could negate weed suppressive benefits from this cover crop species. Growers should consider herbicide selection and termination timing in their cover crop plan to ensure effective termination. DA - 2020/2// PY - 2020/2// DO - 10.1017/wet.2019.107 VL - 34 IS - 1 SP - 48-54 SN - 1550-2740 KW - Mixes KW - cereal rye KW - cereal grains KW - annual ryegrass ER - TY - JOUR TI - 'Liz' and 'Rocco' Strawberries AU - Fernandez, Gina AU - Pattison, Jeremy AU - Perkins-Veazie, Penelope AU - Ballington, James R. AU - Clevinger, Elizabeth AU - Schiavone, Rocco AU - Gu, Sanjun AU - Samtani, Jayesh AU - Vinson, Edgar AU - McWhirt, Amanda AU - Chacon, Jose Guillermo T2 - HORTSCIENCE AB - 3ananassa, fresh market, June-bearing, short-day 'Liz' and 'Rocco' are new short-day (June-bearing) strawberry (Fragaria •ananassa Duch.ex Rozier) cultivars from the North Carolina State University strawberry breeding program in Raleigh, NC.The most outstanding characteristic of 'Liz' is its consistently high yields.Total and marketable yields of 'Liz' were higher than those of other cultivars tested most years in our trials in North Carolina.Firmness of 'Liz' is comparable to 'Camarosa'.Because of its consistent high yields and moderate firmness, 'Liz' can be considered an alternative to 'Camarosa'.The most outstanding characteristics of 'Rocco' are its early season ripening and high soluble solids content.Total yield of 'Rocco' is higher than that of 'Sweet Charlie' and comparable to cultivars that ripen later in the season.'Rocco' should be considered an alternative to 'Sweet Charlie' for early production.U.S. DA - 2020/4// PY - 2020/4// DO - 10.21273/HORTSCI14516-19 VL - 55 IS - 4 SP - 597-600 SN - 2327-9834 KW - Fragaria Xananassa KW - fresh market KW - June-bearing KW - short-day ER - TY - JOUR TI - Thermal property values of a central Iowa soil as functions of soil water content and bulk density or of soil air content AU - Tong, Bing AU - Kool, Dilia AU - Heitman, Joshua L. AU - Sauer, Thomas J. AU - Gao, Zhiqiu AU - Horton, Robert T2 - EUROPEAN JOURNAL OF SOIL SCIENCE AB - Abstract Soil thermal properties play important roles in dynamic heat and mass transfer processes, and they vary with soil water content ( θ ) and bulk density ( ρ b ). Both θ and ρ b change with time, particularly in recently tilled soil. However, few studies have addressed the full extent of soil thermal property changes with θ and ρ b . The objective of this study is to examine how changes in ρ b with time after tillage impact soil thermal properties (volumetric heat capacity, C v , thermal diffusivity, k , and thermal conductivity, λ ). The study provides thermal property values as functions of θ and ρ b and of air content ( n air ) on undisturbed soil cores obtained at selected times following tillage. Heat pulse probe measurements of thermal properties were obtained on each soil core at saturated, partially saturated ( θ at pressure head of −50 kPa) and oven‐dry conditions. Generally, k and λ increased with increasing ρ b at the three water conditions. The C v increased as ρ b increased in the oven‐dry and unsaturated conditions and decreased as ρ b increased in the saturated condition. For a given θ , a larger ρ b was associated with larger thermal property values, especially for λ . The figures of C v , k and λ versus θ and ρ b , as well as C v , k and λ versus n air , represented the range of soil conditions following tillage. Trends in the relationships of thermal property values with θ and ρ b were described by 3‐D surfaces, whereas each thermal property had a linear relationship with n air . Clearly, recently tilled soil thermal property values were quite dynamic temporally due to varying θ and ρ b . The dynamic soil thermal property values should be considered in soil heat and mass transfer models either as 3‐D functions of θ and ρ b or as linear functions of n air . Highlights Thermal property values for a range of θ and ρ b were measured on undisturbed soil cores. Freshly tilled soil thermal property values were quite dynamic temporally. The thermal property values of a tilled soil were described as 3‐D surfaces with θ and ρ b . The thermal property values of a tilled soil varied linearly with n air . DA - 2020/3// PY - 2020/3// DO - 10.1111/ejss.12856 VL - 71 IS - 2 SP - 169-178 SN - 1365-2389 KW - air-filled pore space KW - bulk density KW - soil thermal property KW - soil water content KW - thermal conductivity KW - thermal diffusivity KW - tillage KW - volumetric heat capacity ER - TY - JOUR TI - Response of sweetpotato to pendimethalin application rate and timing AU - Meyers, Stephen L. AU - Chaudhari, Sushila AU - Jennings, Katherine M. AU - Miller, Donnie K. AU - Shankle, Mark W. T2 - WEED TECHNOLOGY AB - Abstract Field trials were conducted near Pontotoc, Mississippi; Chase, Louisiana; and Clinton, North Carolina, in 2017 and 2018 to determine the effect of pendimethalin rate and timing application on sweetpotato crop tolerance, yield, and storage root quality. Treatments consisted of five pendimethalin rates (266, 532, 1,065, 1,597, and 2,130 g ai ha −1 ) by two application timings (0 to 1 or 10 to 14 d after transplanting). Additionally, a nontreated check was included for comparison. Crop injury (stunting) was minimal (≤4%) through 6 wk after transplanting (WAP) and no injury was observed from 8 to 14 WAP, regardless of application timing or rate. The nontreated check yielded 6.6, 17.6, 5.5, and 32.1 × 10 3 kg ha −1 of canner, no. 1, jumbo, and total grades, respectively. Neither pendimethalin application timing nor rate influenced jumbo, no. 1, marketable, or total sweetpotato yield. Overall, these results indicate that pendimethalin will be a valuable addition to the toolkit of sweetpotato growers. DA - 2020/4// PY - 2020/4// DO - 10.1017/wet.2019.103 VL - 34 IS - 2 SP - 301-304 SN - 1550-2740 KW - Crop injury KW - crop tolerance KW - storage root ER - TY - JOUR TI - Genome-wide association study in historical and contemporary U.S. winter wheats identifies height-reducing loci AU - Daba, Sintayehu D. AU - Tyagi, Priyanka AU - Brown-Guedira, Gina AU - Mohammadi, Mohsen T2 - CROP JOURNAL AB - Plant height has been a major target for selection of high-yielding varieties in wheat. Two height-reducing loci (Rht-B1 and Rht-D1) have been widely used since the Green Revolution. However, these genes also negatively affect other agronomic traits such as kernel weight. Identifying alternative height-reducing loci could benefit wheat improvement. This study focused on the genetics of plant height in 260 historical and contemporary winter wheat accessions via genome-wide association studies using 38,693 single nucleotide polymorphism (SNP) markers generated through genotyping by sequencing, two Kompetitive Allele Specific Polymorphism markers, and phenotypic data recorded in two seasons (2016 and 2018). The 260 accessions showed wide variation in plant height. Most accessions developed after 1960 were shorter than earlier accessions. The broad-sense heritability for plant height was high (H2 = 0.82), which was also supported by a high correlation (r = 0.82, P < 0.0001) between heights from the two years. We detected a total of 16 marker–trait associations (MTAs) for plant height at –lg (P) ≥ 4.0 on chromosomes 1A, 2B, 2D, 3B, 4D, 5A, 5D, 6A, 6B, 7A, and 7D. We detected three of the MTAs (QPLH-2D, QPLH-4B.2, and QPLH-4D) consistently in individual-year and combined-year analyses. These MTAs individually explained 10%–16% of phenotypic variation. The height-reducing alleles at these three MTAs appeared after 1960 and increased in frequency thereafter. Among the genes near these loci were gibberellic acid insensitive (GAI) and GRAS transcription factor (GIBBERELLIC-ACID INSENSITIVE (GAI), REPRESSOR of GAI (RGA), and SCARECROW (SCR)). The evidence from this study and previous reports suggests that QPLH-2D is Rht8. A gene encoding a GRAS transcription factor is located near QPLH-2D. Validation of the QPLH-2D locus and associated candidate genes awaits further study. DA - 2020/4// PY - 2020/4// DO - 10.1016/j.cj.2019.09.005 VL - 8 IS - 2 SP - 243-251 SN - 2214-5141 KW - GWAS KW - Marker-trait associations KW - Rht-B1 KW - Rht-D1 KW - Candidate genes KW - Position-dependent procedures ER - TY - JOUR TI - Nitrogen-fixation drought tolerance in virginia-type peanut AU - Pradhan, Deepti AU - Dunne, Jeffrey AU - Ramirez, Martha AU - Sinclair, Thomas R. T2 - JOURNAL OF CROP IMPROVEMENT AB - Symbiotic nitrogen-fixation activity of grain legumes commonly does not exhibit tolerance to soil drying, including in peanut (Arachis hypogaea L.). Since the demand for nitrogen of peanut is large in the synthesis of seeds with high protein concentration, loss of nitrogen-fixation activity can result in major yield decreases. The objective of this study was to search the germplasm of virginia-type peanut for sources of nitrogen-fixation drought tolerance. The first phase was a field screen in one growing season of 100 lines from which leaves were harvested and nitrogen concentration measured. Research in soybean had shown that low leaf-nitrogen concentration was associated with nitrogen-fixation drought tolerance. A wide range of leaf nitrogen concentrations was observed, and 10 lines of low leaf nitrogen (23.1 to 26.4 mg N g−1) were identified for the second phase of study. The second phase of study was done in a greenhouse with 5-week old plants sealed in pots subjected to a 2-week dry down. Each day, the plants were briefly exposed to acetylene to measure acetylene reduction activity as an indicator of nitrogen-fixation activity. The soil water content, at which a decline in nitrogen fixation was initiated, was not different among seven lines. Three of the lines exhibited high sensitivity of nitrogen fixation to soil drying. None of the lines, however, exhibited substantial tolerance of nitrogen fixation to soil drying, indicating a need to search an even more diverse population of peanut to identify a genetic source for tolerance. DA - 2020/7/3/ PY - 2020/7/3/ DO - 10.1080/15427528.2020.1740903 VL - 34 IS - 4 SP - 540-548 SN - 1542-7536 KW - Acetylene reduction activity KW - drought KW - leaf nitrogen concentration KW - nitrogen fixation KW - peanut KW - soil drying ER - TY - JOUR TI - Using Irrigation to Increase Stormwater Mitigation Potential of Rainwater Harvesting Systems AU - Gee, K. D. AU - Hunt, W. F. AU - Peacock, C. H. AU - Woodward, M. D. AU - Arellano, C. T2 - JOURNAL OF SUSTAINABLE WATER IN THE BUILT ENVIRONMENT AB - Rainwater harvesting (RWH) systems used for irrigation often provide fewer stormwater management benefits than systems used for year-round, nondiscretionary purposes because there is diminished demand for harvested rainwater during the nongrowing season or rainy periods. Thus, identifying demands during these periods would improve the stormwater mitigation potential of RWH systems. This study evaluated how irrigating bermudagrass year-round at rates exceeding those for minimum water conservation affected the stormwater benefits provided by an RWH system. Results indicated significant increases in runoff volume retention when turf was irrigated at 25 and 50 mm/week, compared to an evapotranspiration/effective precipitation (or agronomic)–based regime. While overall soil moisture content increased with irrigation rate, there were no concomitant increases in pest occurrences or runoff generation. Turf quality did not differ from the control irrigation regime for either application rate, and there were no indications of soil nitrate leaching. Irrigating at rates up to 50 mm/week resulted in stormwater volume reductions up to 65% without causing a decline in turf quality. DA - 2020/5/1/ PY - 2020/5/1/ DO - 10.1061/JSWBAY.0000913 VL - 6 IS - 2 SP - SN - 2379-6111 ER - TY - JOUR TI - Water Quality and Hydrologic Performance of Two Dry Detention Basins Receiving Highway Stormwater Runoff in the Piedmont Region of North Carolina AU - Wissler, Austin D. AU - Hunt, William F. AU - McLaughlin, Richard A. T2 - JOURNAL OF SUSTAINABLE WATER IN THE BUILT ENVIRONMENT AB - Dry detention basins (DDBs) are a stormwater control measure (SCM) designed to provide flood storage, peak discharge abatement, and some water quality improvement through sedimentation; however, little data characterize DDB water quality performance in the highway environment. In this study, two DDBs [Hughes Farm Road and Poole Road basin (HFR and PRB henceforth)], constructed in 2010, mowed twice a year, receiving highway runoff, and located in the Piedmont of North Carolina (NC), USA, were monitored for up to 11 months. Flow-weighted composite samples were collected during storm events and analyzed for total phosphorus (TP); ortho-phosphorus (OP); ammonia (NH3); nitrate-nitrite (NOX); total Kjeldahl nitrogen (TKN); total suspended solids (TSS); and total Cd, Cu, Pb, and Zn. Influent runoff concentrations were similar to other studies in NC, and the monitoring revealed significant concentration reductions for most constituents in HFR. PRB significantly reduced concentrations for all pollutants except TSS, particulate phosphorous, and NH3, while significantly exporting Zn. HFR exhibited soil infiltration that led to significant pollutant load reductions (LRs) for all analytes except Cu. PRB exhibited little infiltration but had significant LRs for dissolved nutrients. This study provides evidence that DDB inlet and outlet configuration and the presence of standing water may impact DDB water quality improvement. DA - 2020/5/1/ PY - 2020/5/1/ DO - 10.1061/JSWBAY.0000915 VL - 6 IS - 2 SP - SN - 2379-6111 ER - TY - JOUR TI - Quantitative proteomic, physiological and biochemical analysis of cotyledon, embryo, leaf and pod reveals the effects of high temperature and humidity stress on seed vigor formation in soybean AU - Wei, Jiaping AU - Liu, Xiaolin AU - Li, Linzhi AU - Zhao, Haihong AU - Liu, Sushuang AU - Yu, Xingwang AU - Shen, Yingzi AU - Zhou, Yali AU - Zhu, Yajing AU - Shu, Yingjie AU - Ma, Hao T2 - BMC PLANT BIOLOGY AB - Soybean developing seed is susceptible to high temperature and humidity (HTH) stress in the field, resulting in vigor reduction. Actually, the HTH in the field during soybean seed growth and development would also stress the whole plant, especially on leaf and pod, which in turn affect seed growth and development as well as vigor formation through nutrient supply and protection.In the present study, using a pair of pre-harvest seed deterioration-sensitive and -resistant cultivars Ningzhen No. 1 and Xiangdou No. 3, the comprehensive effects of HTH stress on seed vigor formation during physiological maturity were investigated by analyzing cotyledon, embryo, leaf, and pod at the levels of protein, ultrastructure, and physiology and biochemistry. There were 247, 179, and 517 differentially abundant proteins (DAPs) identified in cotyledon, embryo, and leaf of cv. Xiangdou No. 3 under HTH stress, while 235, 366, and 479 DAPs were identified in cotyledon, embryo, and leaf of cv. Ningzhen No. 1. Moreover, 120, 144, and 438 DAPs between the two cultivars were identified in cotyledon, embryo, and leaf under HTH stress, respectively. Moreover, 120, 144, and 438 DAPs between the two cultivars were identified in cotyledon, embryo, and leaf under HTH stress, respectively. Most of the DAPs identified were found to be involved in major metabolic pathways and cellular processes, including signal transduction, tricarboxylic acid cycle, fatty acid metabolism, photosynthesis, protein processing, folding and assembly, protein biosynthesis or degradation, plant-pathogen interaction, starch and sucrose metabolism, and oxidative stress response. The HTH stress had less negative effects on metabolic pathways, cell ultrastructure, and physiology and biochemistry in the four organs of Xiangdou No. 3 than in those of Ningzhen No. 1, leading to produce higher vigor seeds in the former.High seed vigor formation is enhanced by increasing protein biosynthesis and nutrient storage in cotyledon, stronger stability and viability in embryo, more powerful photosynthetic capacity and nutrient supply in leaf, and stronger protection in pod under HTH stress. These results provide comprehensive characteristics of leaf, pod and seed (cotyledon and embryo) under HTH stress, and some of them can be used as selection index in high seed vigor breeding program in soybean. DA - 2020/// PY - 2020/// DO - 10.1186/s12870-020-02335-1 VL - 20 IS - 1 ER - TY - JOUR TI - The effects of compost incorporation on soil physical properties in urban soils – A concise review AU - Kranz, Christina N. AU - McLaughlin, Richard A. AU - Johnson, Amy AU - Miller, Grady AU - Heitman, Joshua L. T2 - Journal of Environmental Management AB - Incorporation of compost into soil can significantly alter soil physical properties, nutrient dynamics, and vegetation establishment. Strategic compost application to disturbed, degraded urban soil may provide benefits to soil properties. This review compared twenty-five peer-reviewed studies that evaluated changes in soil bulk density, infiltration rate, hydraulic conductivity, and water retention where compost was incorporated into urban soils. A wide range of compost rates and incorporation depths were evaluated in these studies across many soil types. Compost incorporation generally reduced bulk density, enhanced infiltration and hydraulic conductivity, and increased water content and plant available water, compared to unamended controls. In the four studies on runoff water quality, compost incorporation often resulted in higher initial nutrient content in runoff water, but also enhanced grass growth and reduced sediment loss. Few studies evaluated multiple compost application rates or incorporation depths, and the ways in which compost application rates were reported varied widely between studies making it difficult to directly compare them. Four studies investigated the long-term effects of compost incorporation, and there was no clear pattern of why some soils display enhanced physical properties over time and others do not. Compost was largely reported to have a positive effect on degraded urban soils. Little research has focused on the longevity of compost in urban soils after one application, and thus, this would be a valuable topic of further investigation. DA - 2020/5// PY - 2020/5// DO - 10.1016/j.jenvman.2020.110209 VL - 261 SP - 110209 J2 - Journal of Environmental Management LA - en OP - SN - 0301-4797 UR - http://dx.doi.org/10.1016/j.jenvman.2020.110209 DB - Crossref KW - Urban soil KW - Bulk density KW - Compost amendment KW - Infiltration KW - Soil physical properties KW - Disturbed soil ER - TY - JOUR TI - Comparison of soil health metrics for a Cecil soil in the North Carolina Piedmont AU - Caudle, Caitlin AU - Osmond, Deanna AU - Heitman, Joshua AU - Ricker, Matthew AU - Miller, Grady AU - Wills, Skye T2 - Soil Science Society of America Journal AB - Abstract Soil health metric values may vary across soil types and even within the same soil series under different management systems. The goal of this study was to determine the amount of variation present in Cecil sandy loam soils (fine, kaolinitic, thermic Typic Kanhapludults) under row crop and hay management systems via field (single‐ring infiltration, Cornell Sprinkle Infiltrometer, and a farmer score card) and laboratory soil health metrics [soil respiration, phospholipid fatty acid (PLFA) analysis, permanganate‐oxidizable C (POXC), β‐glucosidase, β‐glucosaminidase, alkaline and acid phosphatase, arylsulfatase, phosphodiesterase, soil organic C (SOC), total N (TN), autoclave citrate‐extractable (ACE) protein content, aggregate stability, mean weight diameter, and bulk density]. Soil samples were collected in three hay and three crop fields. ANOVA indicated significant variations between systems, with depth and interactions among system, field, and/or slope position, depending on the metric ( p < 0.05). Infiltration measurements were highly variable and the measurement methods produced inconsistent values. The majority of laboratory metrics significantly decreased with depth. Soil respiration was significantly different between systems (crop > hay), whereas arylsulfatase, acid phosphatase, β‐glucosidase, β‐glucosaminidase, ACE, POXC, and aggregate stability had significant system × depth interactions (0–5 cm hay > crop) and POXC had a significant system × pedon interaction. Enzyme assays, PLFA measurements, POXC, TN, SOC, and ACE protein content were also significantly correlated with each other. Unexpected trends and variable results suggest that more data should be collected before effective soil health metrics and baseline values can be established. DA - 2020/5// PY - 2020/5// DO - 10.1002/saj2.20075 VL - 84 SP - 978–983 UR - https://doi.org/10.1002/saj2.20075 ER - TY - JOUR TI - Mapping quantitative trait loci (QTLs) and estimating the epistasis controlling stem rot resistance in cultivated peanut (Arachis hypogaea) AU - Luo, Ziliang AU - Cui, Renjie AU - Chavarro, Carolina AU - Tseng, Yu-Chien AU - Zhou, Hai AU - Peng, Ze AU - Chi, Ye AU - Yang, Xiping AU - Lopez, Yolanda AU - Tillman, Barry AU - Dufault, Nicholas AU - Brenneman, Timothy AU - Isleib, Thomas G. AU - Holbrook, Corley AU - Ozias-Akins, Peggy AU - Wang, Jianping T2 - THEORETICAL AND APPLIED GENETICS DA - 2020/4// PY - 2020/4// DO - 10.1007/s00122-020-03542-y VL - 133 IS - 4 SP - 1201-1212 SN - 1432-2242 ER - TY - JOUR TI - Hydrologic and water quality performance of two aging and unmaintained dry detention basins receiving highway stormwater runoff AU - Wissler, Austin D. AU - Hunt, William F. AU - McLaughlin, Richard A. T2 - JOURNAL OF ENVIRONMENTAL MANAGEMENT AB - Dry detention basins (DDBs) are a type of stormwater control measure (SCM) designed to provide flood storage, peak discharge reduction, and some water quality improvement through sedimentation. DDBs are ubiquitous in the urban environment, but are expensive to maintain. In this study, two overgrown DDBs near Raleigh, NC, receiving highway runoff were monitored for up to one year to quantify their water quality and hydrologic performance. Both basins, B1 and B2, have not received vegetation maintenance since construction in 2007. Flow-weighted composite samples were collected during storm events and analyzed for nutrients (Total Phosphorus (TP), Ortho-phosphorus (OP), Ammonia-N (NH3), NO2-3-N (NOX), and Total Kjeldahl Nitrogen (TKN)), total suspended solids (TSS), and total Cd, Cu, Pb, and Zn. An annual water balance was also conducted to quantify runoff volume reduction. Despite low influent concentrations from the highway, significant removal efficiencies were found for all constituents except NH3 in B1. TP, OP, NOX, TSS, and Zn were reduced in B2. Both basins achieved greater than 41% volume reduction through soil infiltration and evapotranspiration, resulting in significant pollutant load reductions for all detected constituents, between 59% and 79% in B1 and 35% and 81% in B2. This study provides evidence that overgrown and unmaintained DDBs can reduce pollutant concentrations comparable to those reported for maintained DDBs, while reducing more volume than standard DDBs. Moreover, carbon sequestration likely increases while maintenance costs decrease. DA - 2020/2/1/ PY - 2020/2/1/ DO - 10.1016/j.jenvman.2019.109853 VL - 255 SP - SN - 1095-8630 KW - Highway KW - Stormwater KW - Dry detention basin KW - Maintenance KW - Non-point source pollution KW - Carbon sequestration ER - TY - JOUR TI - Brassica carinata genotypes demonstrate potential as a winter biofuel crop in South East United States AU - Kumar, Shivendra AU - Seepaul, Ramdeo AU - Mulvaney, Michael J. AU - Colvin, Blaire AU - George, Sheeja AU - Marois, Jim J. AU - Bennett, Rick AU - Leon, Ramon AU - Wright, David L. AU - Small, Ian M. T2 - Industrial Crops and Products AB - Brassica carinata A. Braun, grown as a winter crop on underutilized agricultural land in the southeast United States (SE US), may provide a new rotation alternative and augment income for producers. Widespread adoption of Brassica carinata as a winter crop in the SE US requires varieties with cold tolerance, acceptable and stable seed yield, oil content, protein content so that the crop will be complementary with the normal cultivation of summer crops such as cotton (Gossypium hirsutum L.), corn (Zea mays L.), soybean (Glycine max L. Merr), sorghum (Sorghum bicolor L. Moench) and peanut (Arachis hypogaea L.). The objective of this study was to evaluate the performance of 11 Brassica carinata genotypes for agronomically important traits including seed yield, oil and protein content, oil quality, days to bolting, flowering and maturity at three locations during two growing seasons (2015–2017) as a winter crop in the SE US. Interactions between genotype and environment played a crucial role in overall agronomic performance. This study provides key information on the effect of environmental conditions, such as precipitation and temperature on the agronomic performance of carinata along with generation of information related to region-specific requirements for the crop in the SE US. Days to maturity ranged from 154 to 165 days. The average yield of the 11 genotypes tested ranged from 2814 kg/ha to 3401 kg/ha, which were improved from earlier studies, demonstrating gain due to regional selection and breeding efforts. Total oil content ranged from 42.0 % to 52.4 %, while the erucic acid (C22:1) content ranged from 40.7 % to 42.9 % on a whole seed basis. Based on these results, specific genotypes with consistently high seed yield, oil, erucic acid and protein content with shorter life cycle irrespective of location or year were identified. Brassica carinata has potential as a viable bioenergy winter crop to be integrated into the cropping systems in the SE US and other regions of the world. DA - 2020/8// PY - 2020/8// DO - 10.1016/j.indcrop.2020.112353 VL - 150 SP - 112353 UR - https://doi.org/10.1016/j.indcrop.2020.112353 KW - Biofuels KW - Renewable KW - Aviation jet fuel KW - Bio-based products KW - Oil seed ER - TY - JOUR TI - A genome-wide association study uncovers consistent quantitative trait loci for resistance to Verticillium wilt and Fusarium wilt race 4 in the US Upland cotton AU - Abdelraheem, Abdelraheem AU - Elassbli, Hanan AU - Zhu, Yi AU - Kuraparthy, Vasu AU - Hinze, Lori AU - Stelly, David AU - Wedegaertner, Tom AU - Zhang, Jinfa T2 - THEORETICAL AND APPLIED GENETICS DA - 2020/2// PY - 2020/2// DO - 10.1007/s00122-019-03487-x VL - 133 IS - 2 SP - 563-577 SN - 1432-2242 ER - TY - JOUR TI - Spatially Resolved Organomineral Interactions across a Permafrost Chronosequence AU - Sowers, Tyler D. AU - Wani, Rucha P. AU - Coward, Elizabeth K. AU - Fischel, Matthew H. H. AU - Betts, Aaron R. AU - Douglas, Thomas A. AU - Duckworth, Owen W. AU - Sparks, Donald L. T2 - ENVIRONMENTAL SCIENCE & TECHNOLOGY AB - Permafrost contains a large (1700 Pg C) terrestrial pool of organic matter (OM) that is susceptible to degradation as global temperatures increase. Of particular importance is syngenetic Yedoma permafrost containing high OM content. Reactive iron phases promote stabilizing interactions between OM and soil minerals and this stabilization may be of increasing importance in permafrost as the thawed surface region (“active layer”) deepens. However, there is limited understanding of Fe and other soil mineral phase associations with OM carbon (C) moieties in permafrost soils. To elucidate the elemental associations involved in organomineral complexation within permafrost systems, soil cores spanning a Pleistocene permafrost chronosequence (19,000, 27,000, and 36,000 years old) were collected from an underground tunnel near Fairbanks, Alaska. Subsamples were analyzed via scanning transmission X-ray microscopy–near edge X-ray absorption fine structure spectroscopy at the nano- to microscale. Amino acid-rich moieties decreased in abundance across the chronosequence. Strong correlations between C and Fe with discrete Fe(III) or Fe(II) regions selectively associated with specific OM moieties were observed. Additionally, Ca coassociated with C through potential cation bridging mechanisms. Results indicate Fe(III), Fe(II), and mixed valence phases associated with OM throughout diverse permafrost environments, suggesting that organomineral complexation is crucial to predict C stability as permafrost systems warm. DA - 2020/3/3/ PY - 2020/3/3/ DO - 10.1021/acs.est.9b06558 VL - 54 IS - 5 SP - 2951-2960 SN - 1520-5851 ER - TY - JOUR TI - Ectoparasites of Cattle AU - Leon, Adalberto A. AU - Mitchell, Robert D., III AU - Watson, David W. T2 - VETERINARY CLINICS OF NORTH AMERICA-FOOD ANIMAL PRACTICE AB - Diverse groups of ectoparasitic arthropods cause significant morbidity and mortality in most of the approximately 1.49 billion head of cattle worldwide. Hematophagous ectoparasites (ie, blood-feeding flies, myiasis-causing flies, lice, mites, ticks) are the most important in cattle. Intense use of ectoparasiticides to treat infestations can result in ectoparasite populations becoming resistant to this treatment method. Approaches integrating the use of different technologies are required to manage cattle ectoparasites effectively while addressing societal expectations regarding food safety and environmental health. Assessing the status of coparasitism with ectoparasites and endoparasites in cattle across agroecosystems is critical in advancing integrated parasite management. DA - 2020/3// PY - 2020/3// DO - 10.1016/j.cvfa.2019.12.004 VL - 36 IS - 1 SP - 173-+ SN - 1558-4240 KW - Cattle KW - Ectoparasites KW - Flies KW - Myiasis KW - Lice KW - Mites KW - Ticks KW - Integrated management ER - TY - JOUR TI - Influence of timing and intensity of weed management on crop yield and contribution to weed emergence in cotton the following year AU - Hare, Andrew T. AU - Jordan, David L. AU - Leon, Ramon G. AU - Edmisten, Keith L. AU - Post, Angela R. AU - Cahoon, Charles W. AU - Everman, Wesley J. AU - Mahoney, Denis J. AU - Inman, Matthew D. T2 - CROP FORAGE & TURFGRASS MANAGEMENT AB - Abstract Adequate weed control is important in protecting crop yield and allowing efficient harvest in North Carolina. Data in the literature are limited with respect to direct comparisons of weed control and yield across multiple crops. Research is also limited in terms of documenting the impact of weed control in one crop on weed populations in the crop planted the following season. Experiments were conducted in North Carolina to determine weed control and yield of corn ( Zea mays L.), cotton ( Gossypium hirsutum L.), and soybean [ Glycine max (L.) Merr.] in the same experiment when herbicides were applied postemergence at different timings (Year 1) and to determine how weed control translated into weed populations and cotton yield the following year (Year 2). Herbicides were applied 2 or 6 wk after planting (WAP); 2 and 4 WAP; 4 and 6 WAP; and 2, 4, and 6 WAP. At Lewiston‐Woodville, common ragweed ( Ambrosia artemisiifolia L.) and Texas millet ( Urochloa texana L.) were present. At Rocky Mount, Palmer amaranth ( Amanthus palmeri S. Wats) and large crabgrass ( Digitaria sanguinalis L.) were present. A single postemergence application of herbicide protected yield from weed interference in corn, whereas in most instances multiple herbicide applications were needed in cotton and to a degree in soybean. Weed densities in Year 2 in cotton were negatively correlated with weed control the previous year in corn, cotton, and soybean. Densities of common ragweed and Palmer amaranth 3 WAP in Year 2 were higher in cotton when the preceding crop was cotton or soybean rather than corn when herbicides were not applied; no difference was noted when comparing cotton and soybean. In some instances, sequential applications of herbicides resulted in lower weed densities the following year in cotton. These results demonstrate the importance of timely, sequential herbicide applications for weed control in cotton and soybean and in some instances the positive benefits on weed populations the following year in cotton. DA - 2020/// PY - 2020/// DO - 10.1002/cft2.20021 VL - 6 IS - 1 SP - SN - 2374-3832 UR - https://doi.org/10.1002/cft2.20021 ER - TY - JOUR TI - Do farmers manage weeds on owned and rented land differently? Evidence from US corn and soybean farms AU - Frisvold, George B. AU - Albright, Joshua AU - Ervin, David E. AU - Owen, Micheal D. K. AU - Norsworthy, Jason K. AU - Dentzman, Katherine E. AU - Hurley, Terrance M. AU - Jussaume, Raymond A. AU - Gunsolus, Jeffrey L. AU - Everman, Wesley T2 - PEST MANAGEMENT SCIENCE AB - It has been frequently argued that growers have less incentive to manage the evolution and spread of herbicide-resistant weeds on leased than on owned land. This is because resistance management provides long-term rather than short-term benefits that operators may be less assured of capturing on land they do not own. Yet, empirical evidence supporting this argument has been lacking.This study reports on results from a large-scale national survey of weed management and other crop production practices on US agricultural fields. Up to 11 weed management practices were compared across owner-operated versus renter-operated fields. Analysis of survey data from corn and soybean fields did not support the hypothesis that adoption of resistance management practices is lower on rented acres. In most instances, there were no statistically significant differences in herbicide use or weed management practices on rented versus owned land. This was true at both national and regional levels of analysis. Where there were significant differences, practices associated with greater herbicide resistance management were, as often as not, more prevalent on rented than owned land.A useful area of future research would be to test for land tenure differences in resistance management using multivariate analysis to control for confounding effects. Unobserved farmer or land characteristics may be confounding results and masking land tenure effects. Results here, however, suggest that these other effects are dominating any obvious disincentive effects of land leasing on resistance management. Of greater concern, the adoption of key resistance management practices was low on both owned and rented land. © 2020 Society of Chemical Industry. DA - 2020/6// PY - 2020/6// DO - 10.1002/ps.5737 VL - 76 IS - 6 SP - 2030-2039 SN - 1526-4998 KW - resistance management KW - weed management KW - adoption KW - land tenure KW - corn KW - soybeans ER - TY - JOUR TI - Polyacrylamide and Chitosan Biopolymer for Flocculation and Turbidity Reduction in Soil Suspensions AU - Kang, Jihoon AU - McLaughlin, Richard A. T2 - JOURNAL OF POLYMERS AND THE ENVIRONMENT DA - 2020/4// PY - 2020/4// DO - 10.1007/s10924-020-01682-2 VL - 28 IS - 4 SP - 1335-1343 SN - 1572-8919 KW - Biopolymer KW - Chitosan KW - Flocculation KW - Particle size distribution KW - Polyacrylamide KW - Turbidity ER - TY - JOUR TI - Use of exchangeable and nonexchangeable forms of calcium, magnesium, and potassium in soils without fertilization after successive cultivations with Pinus taeda in southern Brazil AU - Gatiboni, Luciano Colpo AU - Da Silva, Walquiria Chaves AU - Mumbach, Gilmar Luiz AU - Schmitt, Djalma Eugenio AU - Iochims, Daniel Alexandre AU - Stahl, James AU - Vargas, Cristiane Ottes T2 - JOURNAL OF SOILS AND SEDIMENTS DA - 2020/2// PY - 2020/2// DO - 10.1007/s11368-019-02460-x VL - 20 IS - 2 SP - 665-674 SN - 1614-7480 KW - Exchangeable and semi-total fractions KW - Forest fertilization KW - Successive crops KW - Stocks of nutrient in soil ER - TY - JOUR TI - A transcriptomic analysis reveals soybean seed pre-harvest deterioration resistance pathways under high temperature and humidity stress AU - Shu, Yingjie AU - Zhou, Yuli AU - Mu, Kebin AU - Hu, Huimin AU - Chen, Ming AU - He, Qingyuan AU - Huang, Shoucheng AU - Ma, Hao AU - Yu, Xingwang T2 - GENOME AB - Pre-harvest soybean seeds in the field are susceptible to high temperature and humidity (HTH) stress, leading to pre-harvest seed deterioration, which will result in a reduction in grain quality, yield, and seed vigor. To understand the gene expression involved in seed deterioration response under HTH stress, in this study, we conducted an RNA-Seq analysis using two previously screened soybean cultivars with contrasting seed deterioration resistance. HTH stress induced 1081 and 357 differentially expressed genes (DEGs) in the sensitive cultivar Ningzhen No. 1 and resistant cultivar Xiangdou No. 3, respectively. The majority of DEGs in the resistant cultivar were up-regulated, while down-regulated DEGs were predominant in the sensitive cultivar. KEGG pathway analysis revealed that metabolic pathways, biosynthesis of secondary metabolites, and protein processing in endoplasmic reticulum were the predominant pathways in both cultivars during seed deterioration under HTH stress. The genes involved in photosynthesis, carbohydrate metabolism, lipid metabolism, and heat shock proteins pathways might contribute to the different response to seed deterioration under HTH treatment in the two soybean cultivars. Our study extends the knowledge of gene expression in soybean seed under HTH stress and further provides insight into the molecular mechanism of seed deterioration as well as new strategies for breeding soybean with improved seed deterioration resistance. DA - 2020/2// PY - 2020/2// DO - 10.1139/gen-2019-0094 VL - 63 IS - 2 SP - 115-124 SN - 1480-3321 KW - soybean KW - high temperature and humidity KW - RNA-Seq KW - pre-harvest seed deterioration ER - TY - JOUR TI - Xylem vessel radii comparison between soybean genotypes differing in tolerance to drought AU - Nogueira, Marco AU - Livingston, David AU - Tuong, Tan AU - Sinclair, Thomas R. T2 - JOURNAL OF CROP IMPROVEMENT AB - Xylem element radius can be a key factor in determining plant hydraulic conductance and vulnerability to cavitation. Most studies of xylem element radius have been on woody species with a focus on plant survival under severe water-deficit stress. However, xylem element radius, particularly the largest radius elements, can potentially have an influence on hydraulic flow at more moderate water-deficits. Few studies have offered a detailed distribution of xylem element radii, and even fewer on the distribution in crop species. In this study, the xylem element radii of two genotypes of soybean (Glycine max L. Merr.) were compared because these two genotypes had been documented to react differently to drying soil. The stems of young plants were harvested from three positions, and in stem cross-sections, the number of xylem elements and the radius of each element were determined. While the number of xylem elements did not differ significantly between the two genotypes, the distribution of the radii was skewed to smaller radii in drought-tolerant PI 4719386 as compared to Hutcheson. This contrast extended to a difference between the genotypes in the radii of the largest elements, which are considered most vulnerable to cavitation. DA - 2020/5/3/ PY - 2020/5/3/ DO - 10.1080/15427528.2020.1724225 VL - 34 IS - 3 SP - 404-413 SN - 1542-7536 KW - Drought KW - hydraulic conductance KW - microscopy KW - stem xylem KW - xylem anatomy ER - TY - JOUR TI - Seasonal and climatic variation of weighted VPD for transpiration estimation AU - Ghanem, Michel Edmond AU - Kehel, Zakaria AU - Marrou, Helene AU - Sinclair, Thomas R. T2 - EUROPEAN JOURNAL OF AGRONOMY AB - Vapor pressure deficit (VPD) is one of the critical variables that drives evapotranspiration, and is of fundamental importance in crop physiology and modeling in the face of climate change. Unfortunately, direct records of atmospheric moisture are rarely available at short temporal scales, e.g. hourly, and country or regional scales. Most models use approximations to estimate daily transpiration-weighted VPD. Tanner and Sinclair (1983) suggested an approach to calculate weighted daily VPD as a fraction (0.75) of the difference between daily maximum and minimum vapor pressure based on estimates calculated from daily maximum and minimum temperatures, respectively. A test of the Tanner-Sinclair suggestion is reported by obtaining daily weighted VPD from hourly measurements of humidity and temperature. The objective of this study was to assess the fractional value to obtained daily weighted VPD estimations. This study was based on ten years of hourly weather data collected at thirty five stations across the wide diversity of environments that exist in France. DA - 2020/2// PY - 2020/2// DO - 10.1016/j.eja.2019.125966 VL - 113 SP - SN - 1873-7331 KW - Daily vapor pressure deficit KW - France KW - Seasonal vapor pressure deficit KW - Weighted vapor pressure deficit ER - TY - JOUR TI - Impacts of carbohydrate pulses and short-term sub-zero temperatures on vase life and quality of cut Paeonia lactiflora Pall. hybrids AU - Jahnke, Nathan J. AU - Dole, John M. AU - Livingston, David P., III AU - Bergmann, Ben A. T2 - POSTHARVEST BIOLOGY AND TECHNOLOGY AB - Abstract Flower quality of cut Paeonia lactiflora (peony) Pall. hybrids is best preserved between 0 and 1 °C. However, cut flower traits such as vase life and flower size often decline following 4 or more weeks of storage. While the use of sub-zero temperatures is avoided in the cut flower industry due to fears of freeze injury, sub-zero temperatures may allow extended storage of cut flowers. Peonies are a candidate for sub-zero storage due to their natural cold tolerance, exposure to spring freezes before harvest, and limited seasonal availability. Three cultivars: Karl Rosenfield, Monsieur Jules Elie, and Sarah Bernhardt were used to evaluate freeze tolerance of cut peonies by holding cut stems at three temperatures: 0, −2, −4 °C for 5 h. Pre-cold treatment pulses consisting of 24 h in either 100 g·L−1 sucrose, 100 g·L−1 fructose, or tap water did not improve total vase life, summation of the time spent as a bud and time open. Total vase life was 10.5, 7.1, and 9.3 d for ‘Karl Rosenfield’, ‘Monsieur Jules Elie’, and ‘Sarah Bernhardt’, respectively. Sucrose-pulsed stems of ‘Karl Rosenfield’ and ‘Sarah Bernhardt’ had the lowest total vase life. Pulses and cold-treatments decreased bud time for ‘Karl Rosenfield’ and ‘Monsieur Jules Elie’ by 2–3 d and 0.5–1 d, respectively. Petals were the only tissue to develop water-soaked spotting (freeze injury) following 5 h at -4 °C. Stems kept dry (not pulsed) prior to cold treatment were uninjured. Fructose-pulsed stems of ‘Karl Rosenfield’ and ‘Monsieur Jules Elie’ had the highest injury ratings when held at -4 °C. Carbohydrate-pulsing did not influence injury ratings on ‘Sarah Bernhardt’. Supercooling and multiple freeze events were observed with infrared video in all tissues when held at -4 °C. Typically, ice nucleation started at the base of the cut stems and propagated throughout the stem, leaves, and bud within 3–5 min of initiation. Stems that were not pulsed remained in a supercooled state longer than those that were pulsed. These findings indicate that storage temperatures between 0 and -2 °C may be a good option for longer periods of dry storage for peonies and other cold tolerant cut flower species. DA - 2020/3// PY - 2020/3// DO - 10.1016/j.postharvbio.2019.111083 VL - 161 SP - SN - 1873-2356 KW - Fructose KW - Ice nucleation KW - Infrared thermography KW - Peony KW - Sucrose ER - TY - JOUR TI - Biohybrid nanofibers containing manganese oxide-forming fungi for heavy metal removal from water AU - Park, Yaewon AU - Liu, Shuang AU - Gardner, Terrence AU - Johnson, Drake AU - Keeler, Aaron AU - Ortiz, Nathalia AU - Rabah, Ghada AU - Ford, Ericka T2 - JOURNAL OF ENGINEERED FIBERS AND FABRICS AB - Manganese-oxidizing fungi support bioremediation through the conversion of manganese ions into manganese oxide deposits that in turn adsorb manganese and other heavy metal ions from the environment. Manganese-oxidizing fungi were immobilized onto nanofiber surfaces to assist remediation of heavy metal–contaminated water. Two fungal isolates, Coniothyrium sp. and Coprinellus sp., from a Superfund site (Lot 86, Farm Unit #1) water treatment system were incubated in the presence of nanofibers. Fungal hyphae had strong association with nanofiber surfaces. Upon fungal attachment to manganese chloride–seeded nanofibers, Coniothyrium sp. catalyzed the conformal deposition of manganese oxide along hyphae and nanofibers, but Coprinellus sp. catalyzed manganese oxide only along its hyphae. Fungi–nanofiber hybrids removed various heavy metals from the water. Heavy metal ions were adsorbed into manganese oxide crystalline structure, possibly by ion exchange with manganese within the manganese oxide. Hybrid materials of fungal hyphae and manganese oxides confined to nanofiber-adsorbed heavy metal ions from water. DA - 2020/1// PY - 2020/1// DO - 10.1177/1558925019898954 VL - 15 SP - SN - 1558-9250 KW - Fungi KW - heavy metal KW - nanofibers KW - manganese oxide KW - water purification ER - TY - JOUR TI - Can an amino sugar test estimate potentially available nitrogen from biosolids? AU - White, Jeffrey G. AU - Dodd, Ryan AU - Walters, Robert T2 - Soil Science Society of America Journal AB - Abstract Biosolids land application is governed by N content and estimates of potentially available N (PAN). Amino sugar test N (AST‐N) has been used with varying success to estimate soil responsiveness to N and optimum N rates. We investigated the utility of an amino sugar test (AST) in estimating PAN and hypothesized that this would depend on biosolids type, rate, and receiving soil. In vitro, we applied three dissimilar biosolids at five rates to four representative southeastern US soils, measured AST‐N, and estimated recovery of biosolids AST‐N. Target PAN rates were zero to two times a realistic yield expectation rate (127 kg N ha −1 ) for a common biosolids‐receiving grass. Rates were based on biosolids type, total N, and book‐value availability coefficients. Biosolids AST‐N varied from 263 to 9790 mg kg −1 (3.8–20.1% of total N). Soil AST‐N was 66–93 mg kg −1 and differed among soils. Treatment interactions indicated that AST‐N of the biosolids–soil mixtures differed from what might be predicted from biosolids and soil AST‐N and rate. Rate response was linear; thus, the AST did not saturate at the rates tested. Biosolids AST‐N recovery ranged from −303 to 152% depending on biosolids, rate, soil, and their interactions. The AST‐N was related linearly to total N from anaerobic incubation ( R 2 = 0.10–0.67), depending on biosolids. The weakness of these relationships; the biosolids, rate, and soil interactions; and the potential confounding effects of biosolids and soil NH 4 –N suggest that AST‐N would not be a good estimator of PAN. DA - 2020/1// PY - 2020/1// DO - 10.1002/saj2.20020 UR - https://doi.org/10.1002/saj2.20020 ER - TY - JOUR TI - Modeling and measurements of ammonia from poultry operations: Their emissions, transport, and deposition in the Chesapeake Bay AU - Baker, Jordan AU - Battye, William H. AU - Robarge, Wayne AU - Arya, S. Pal AU - Aneja, Viney P. T2 - SCIENCE OF THE TOTAL ENVIRONMENT DA - 2020/3/1/ PY - 2020/3/1/ DO - 10.1016/j.scitotenv.2019.1115290 VL - 706 SP - SN - 1879-1026 KW - Ammonia deposition KW - Delmarva Peninsula KW - Chesapeake Bay KW - Poultry KW - CAFO ER - TY - JOUR TI - Windbreak Wall-Vegetative Strip System to Reduce Air Emissions from Mechanically Ventilated Livestock Barns—Part 3: Layer House Evaluation T2 - Water, Air, & Soil Pollution DA - 2020/1// PY - 2020/1// DO - 10.1007/s11270-019-4345-0 UR - http://dx.doi.org/10.1007/s11270-019-4345-0 KW - TSP KW - Odor KW - Ammonia KW - Hydrogen sulfide KW - Porous windbreak wall KW - Switchgrass ER - TY - JOUR TI - A Single, Shared Triploidy in Three Species of Parasitic Nematodes AU - Schoonmaker, Ashley AU - Hao, Yue AU - Bird, David McK. AU - Conant, Gavin C. T2 - G3-GENES GENOMES GENETICS AB - The root-knot nematodes of the genus Meloidogyne are important and damaging parasites capable of infecting most flowering plants. Within this genus, several species of the Meloidogyne incognita group show evidence of paleopolyploidy in their genomes. We used our software tool POInT, the Polyploidy Orthology Inference Tool, to phylogenetically model the gene losses that followed that polyploidy. These models, and simulations based on them, show that three of these species (M. incognita, M. arenaria and M. javanica) descend from a single common hybridization event that yielded triplicated genomes with three distinguishable subgenomes. While one of the three subgenomes shows elevated gene loss rates relative to the other two, this subgenome does not show elevated sequence divergence. In all three species, ancestral loci where two of the three gene copies have been lost are less likely to have orthologs in Caenorhabditis elegans that are lethal when knocked down than are ancestral loci with surviving duplicate copies. DA - 2020/1// PY - 2020/1// DO - 10.1534/g3.119.400650 VL - 10 IS - 1 SP - 225-233 SN - 2160-1836 KW - polyploidy KW - evolutionary model KW - root-knot nematode ER - TY - JOUR TI - Nested-association mapping (NAM)-based genetic dissection uncovers candidate genes for seed and pod weights in peanut (Arachis hypogaea) AU - Gangurde, Sunil S. AU - Wang, Hui AU - Yaduru, Shasidhar AU - Pandey, Manish K. AU - Fountain, Jake C. AU - Chu, Ye AU - Isleib, Thomas AU - Holbrook, C. Corley AU - Xavier, Alencar AU - Culbreath, Albert K. AU - Ozias-Akins, Peggy AU - Varshney, Rajeev K. AU - Guo, Baozhu T2 - PLANT BIOTECHNOLOGY JOURNAL AB - Summary Multiparental genetic mapping populations such as nested‐association mapping (NAM) have great potential for investigating quantitative traits and associated genomic regions leading to rapid discovery of candidate genes and markers. To demonstrate the utility and power of this approach, two NAM populations, NAM_Tifrunner and NAM_Florida‐07, were used for dissecting genetic control of 100‐pod weight (PW) and 100‐seed weight (SW) in peanut. Two high‐density SNP‐based genetic maps were constructed with 3341 loci and 2668 loci for NAM_Tifrunner and NAM_Florida‐07, respectively. The quantitative trait locus (QTL) analysis identified 12 and 8 major effect QTLs for PW and SW, respectively, in NAM_Tifrunner, and 13 and 11 major effect QTLs for PW and SW, respectively, in NAM_Florida‐07. Most of the QTLs associated with PW and SW were mapped on the chromosomes A05, A06, B05 and B06. A genomewide association study (GWAS) analysis identified 19 and 28 highly significant SNP–trait associations (STAs) in NAM_Tifrunner and 11 and 17 STAs in NAM_Florida‐07 for PW and SW, respectively. These significant STAs were co‐localized, suggesting that PW and SW are co‐regulated by several candidate genes identified on chromosomes A05, A06, B05, and B06. This study demonstrates the utility of NAM population for genetic dissection of complex traits and performing high‐resolution trait mapping in peanut. DA - 2020/6// PY - 2020/6// DO - 10.1111/pbi.13311 VL - 18 IS - 6 SP - 1457-1471 SN - 1467-7652 KW - nested-association mapping KW - pod weight KW - seed weight KW - association mapping KW - linkage mapping KW - candidate genes KW - peanut ER - TY - JOUR TI - Estimating soil bulk density with combined commercial soil water content and thermal property sensors AU - Tian, Zhengchao AU - Ren, Tusheng AU - Horton, Robert AU - Heitman, Joshua L. T2 - SOIL & TILLAGE RESEARCH AB - Accurate information of soil bulk density (ρb) is essential for many models that predict soil water, gas, and heat transfer processes and for estimating soil carbon pools. Several indirect methods have been used to estimate ρb as a derivative of various soil properties. One approach is to estimate ρb from soil thermal conductivity (λ) and volumetric water content (θw) measured with a custom fabricated sensor (thermo-TDR). In this study, we introduce a new approach to determine ρb with a combination of commercially available θw and thermal property sensors. Repacked samples of four differently-textured soils and a field experiment on a clay soil were used to evaluate the ability of four available sensors from METER Group, Inc. (Pullman, WA, USA) to estimate ρb. The θw was measured with the GS3 and EC-5 sensors, and soil λ was determined with the TR-1 and SH-1 thermal property sensors. The θw and λ measurements were used to determine ρb inversely from a λ-model. Compared with the GS3 sensor, the EC-5 sensor provided more accurate measurements of θw for the investigated soils, and thus, the EC-5 sensor was used with the new ρb estimation approach. Both TR-1 and SH-1 sensors gave accurate λ estimates when compared to modeled values. The ρb estimates with the TR-1/EC-5 and SH-1/EC-5 sensor combination methods agreed well with independent gravimetrically-derived ρb values of the repacked samples and the in-situ measurements, with average root mean square errors of 0.12 and 0.13 Mg m−3, respectively. Thus, the commercial multi-sensor combinations can provide accurate ρb estimates similar to those with custom fabricated thermo-TDR sensors, and they are simpler to operate than the custom fabricated sensors. DA - 2020/2// PY - 2020/2// DO - 10.1016/j.still.2019.104445 VL - 196 SP - SN - 1879-3444 KW - Soil bulk density KW - Multi-sensor combination method KW - Soil water content sensors KW - Soil thermal property sensors ER - TY - JOUR TI - Peanut residues supply minimal plant-available nitrogen on a major soil series in the USA peanut basin AU - Jani, Arun D. AU - Mulvaney, Michael J. AU - Balkcom, Kipling S. AU - Wood, Charles Wesley AU - Jordan, David L. AU - Wood, Brenda H. AU - Devkota, Pratap T2 - SOIL USE AND MANAGEMENT AB - Abstract Field observations have shown that a substantial portion of peanut leaves abscise in windrows during pod curing, leading to an uneven distribution of leaves and stems when intact residues are spread during harvest. Possible differences in nitrogen (N) mineralization rates between peanut leaf and stem residues may lead to spatial and temporal variability in available N during subsequent crops. The objective of this study was to quantify N mineralization in soil amended with different peanut residue components under simulated conventional and conservation tillage practices. A 252‐day microlysimeter incubation was conducted in which peanut leaves, stems and a 1:1 mixture of leaves:stems from three varieties were incorporated or placed on the soil surface to simulate conventional or conservation tillage, respectively. Soils were periodically leached to assess N mineralization compared with a soil‐only control. Nitrogen mineralization was only affected by residue component. Averaged over variety and residue placement, soil amended with leaves mineralized 10% more N relative to the control or soil containing stems. It was estimated that leaves supplied 25 kg N ha −1 over 252 days at 0–15 cm soil depth, which would likely be insufficient to induce a yield response by a subsequent crop. This study suggests that uneven distribution of peanut leaf and stem residues following harvest causes only minor spatial and temporal variability in available N during subsequent crop growth. These results support the growing body of evidence indicating that peanut residue N contributions to subsequent crops are negligible in the peanut basin of the south‐eastern USA . DA - 2020/4// PY - 2020/4// DO - 10.1111/sum.12563 VL - 36 IS - 2 SP - 274-284 SN - 1475-2743 KW - Arachis hypogaea L. KW - mineralization KW - nitrogen KW - tillage ER - TY - JOUR TI - Biomass of the Cyanobacterium Lyngbya wollei Alters Copper Algaecide Exposure and Risks to a Non-target Organism AU - Bishop, West M. AU - Willis, Ben E. AU - Cope, W. Gregory AU - Richardson, Robert J. T2 - BULLETIN OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY DA - 2020/// PY - 2020/// DO - 10.1007/s00128-019-02755-2 VL - 104 SP - 228-234 KW - Copper KW - Cyanobacteria KW - Algaecide KW - Lyngbya wollei KW - Management ER - TY - JOUR TI - Biological controls over the abundances of terrestrial ammonia oxidizers AU - Xiao, Rui AU - Qiu, Yunpeng AU - Tao, Jinjin AU - Zhang, Xuelin AU - Chen, Huaihai AU - Reberg-Horton, S. Chris AU - Shi, Wei AU - Shew, H. David AU - Zhang, Yi AU - Hu, Shuijin T2 - GLOBAL ECOLOGY AND BIOGEOGRAPHY AB - Abstract Aim Ammonia‐oxidizing archaea (AOA) and bacteria (AOB) are the primary agents for nitrification, converting ammonia (NH 4 + ) into nitrate (NO 3 − ) and modulating plant nitrogen (N) utilization and terrestrial N retention. However, there is still lack of a unifying framework describing the patterns of global AOA and AOB distribution. In particular, biotic interactions are rarely integrated into any of the conceptual models. Location World‐wide. Time period 2005–2016. Major taxa studied Ammonia‐oxidizing archaea and ammonia‐oxidizing bacteria. Methods A meta‐analysis and synthesis were conducted to obtain a general picture of global AOA and AOB distribution and identify the primary driving factors. A microcosm experiment was then conducted to assess effects of relative carbon to nitrogen availability for heterotrophic microbes on AOA and AOB in two distinct soils. A mesocosm experiment was further carried out to characterize the effects of plant roots and their arbuscular mycorrhizal fungi (AMF) on AOA and AOB abundances using hyphae‐ or root‐ingrowth techniques. Results Our meta‐analysis showed that soil carbon to nitrogen (C/N) ratios explained the most variance in AOA and AOB abundances, although soil pH had a significant effect. Experimental results demonstrated that high cellulose and mineral N inputs increased total microbial biomass and microbial activities, but inhibited AOA and AOB, suggesting microbial inhibition of AOA and AOB. Also, AMF and roots suppressed AOA and AOB, respectively. Main conclusions Our study provides convincing evidence illustrating that relative carbon to nitrogen availability can predominantly affect the abundances of AOA and AOB. Our experimental results further validate that biotic competition among plants, heterotrophic microbes and ammonia oxidizers for substrate N is the predominant control upon AOA and AOB abundances. Together, these findings provide new insights into the role of abiotic and biotic factors in modulating terrestrial AOA and AOB abundances and their potential applications for management of nitrification in an increasing reactive N world. DA - 2020/2// PY - 2020/2// DO - 10.1111/geb.13030 VL - 29 IS - 2 SP - 384-399 SN - 1466-8238 KW - ammonia-oxidizing archaea KW - ammonia-oxidizing bacteria KW - competition KW - meta-analysis KW - nitrification KW - soil C KW - N ratio ER - TY - JOUR TI - Enhancing Upland cotton for drought resilience, productivity, and fiber quality: comparative evaluation and genetic dissection AU - Ulloa, Mauricio AU - De Santiago, Luis M. AU - Hulse-Kemp, Amanda M. AU - Stelly, David M. AU - Burke, John J. T2 - MOLECULAR GENETICS AND GENOMICS DA - 2020/1// PY - 2020/1// DO - 10.1007/s00438-019-01611-6 VL - 295 IS - 1 SP - 155-176 SN - 1617-4623 UR - https://doi.org/10.1007/s00438-019-01611-6 KW - Genetic mapping KW - Linkage analysis KW - Quantitative trait loci (QTLs) KW - Drought KW - Plant stress KW - Breeding KW - Molecular markers KW - SNP KW - Mapping population KW - Recombinant inbred line (RIL) ER - TY - JOUR TI - Integration of remote‐weed mapping and an autonomous spraying unmanned aerial vehicle for site‐specific weed management AU - Hunter, Joseph E, III AU - Gannon, Travis W AU - Richardson, Robert J AU - Yelverton, Fred H AU - Leon, Ramon G T2 - Pest Management Science AB - Unmanned aerial vehicles (UAVs) have been used in agriculture to collect imagery for crop and pest monitoring, and for decision-making purposes. Spraying-capable UAVs are now commercially available worldwide for agricultural applications. Combining UAV weed mapping and UAV sprayers into an UAV integrated system (UAV-IS) can offer a new alternative to implement site-specific pest management.The UAV-IS was 0.3- to 3-fold more efficient at identifying and treating target weedy areas, while minimizing treatment on non-weedy areas, than ground-based broadcast applications. The UAV-IS treated 20-60% less area than ground-based broadcast applications, but also missed up to 26% of the target weedy area, while broadcast applications covered almost the entire experimental area and only missed 2-3% of the target weeds. The efficiency of UAV-IS management practices increased as weed spatial aggregation increased (patchiness).Integrating UAV imagery for pest mapping and UAV sprayers can provide a new strategy for integrated pest management programs to improve efficiency and efficacy while reducing the amount of pesticide being applied. The UAV-IS has the potential to improve the detection and control of weed escapes to reduce/delay herbicide resistance evolution. © 2019 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry. DA - 2020/4// PY - 2020/4// DO - 10.1002/ps.5651 UR - https://doi.org/10.1002/ps.5651 KW - UAV KW - precision agriculture KW - site-specific KW - off-target KW - droplet KW - pesticide application KW - resistance KW - detection ER - TY - JOUR TI - Sequence-based mapping identifies a candidate transcription repressor underlying awn suppression at the B1 locus in wheat AU - DeWitt, Noah AU - Guedira, Mohammed AU - Lauer, Edwin AU - Sarinelli, Martin AU - Tyagi, Priyanka AU - Fu, Daolin AU - Hao, QunQun AU - Murphy, J. Paul AU - Marshall, David AU - Akhunova, Alina AU - Jordan, Katherine AU - Akhunov, Eduard AU - Brown-Guedira, Gina T2 - NEW PHYTOLOGIST AB - Summary Awns are stiff, hair‐like structures which grow from the lemmas of wheat ( Triticum aestivum ) and other grasses that contribute to photosynthesis and play a role in seed dispersal. Variation in awn length in domesticated wheat is controlled primarily by three major genes, most commonly the dominant awn suppressor Tipped1 ( B1 ). This study identifies a transcription repressor responsible for awn inhibition at the B1 locus. Association mapping was combined with analysis in biparental populations to delimit B1 to a distal region of 5 AL colocalized with QTL for number of spikelets per spike, kernel weight, kernel length, and test weight. Fine‐mapping located B1 to a region containing only two predicted genes, including C2H2 zinc finger transcriptional repressor Traes CS 5A02G542800 upregulated in developing spikes of awnless individuals. Deletions encompassing this candidate gene were present in awned mutants of an awnless wheat. Sequence polymorphisms in the B1 coding region were not observed in diverse wheat germplasm whereas a nearby polymorphism was highly predictive of awn suppression. Transcriptional repression by B1 is the major determinant of awn suppression in global wheat germplasm. It is associated with increased number of spikelets per spike and decreased kernel size. DA - 2020/1// PY - 2020/1// DO - 10.1111/nph.16152 VL - 225 IS - 1 SP - 326-339 SN - 1469-8137 KW - awns KW - B1 locus KW - fine mapping KW - positional cloning KW - wheat (Triticum aestivum) KW - zinc finger protein ER - TY - JOUR TI - Coverage and drift potential associated with nozzle and speed selection for herbicide applications using an unmanned aerial sprayer AU - Hunter, Joseph E., III AU - Gannon, Travis W. AU - Richardson, Robert J. AU - Yelverton, Fred H. AU - Leon, Ramon G. T2 - Weed Technology AB - Abstract In recent years, unmanned aerial vehicle (UAV) technology has expanded to include UAV sprayers capable of applying pesticides. Very little research has been conducted to optimize application parameters and measure the potential of off-target movement from UAV-based pesticide applications. Field experiments were conducted in Raleigh, NC during spring 2018 to characterize the effect of different application speeds and nozzle types on target area coverage and uniformity of UAV applications. The highest coverage was achieved with an application speed of 1 m s −1 and ranged from 30% to 60%, whereas applications at 7 m s −1 yielded 13% to 22% coverage. Coverage consistently decreased as application speed increased across all nozzles, with extended-range flat-spray nozzles declining at a faster rate than air-induction nozzles, likely due to higher drift. Experiments measuring the drift potential of UAV-applied pesticides using extended-range flat spray, air-induction flat-spray, turbo air–induction flat-spray, and hollow-cone nozzles under 0, 2, 4, 7, and 9 m s −1 perpendicular wind conditions in the immediate 1.75 m above the target were conducted in the absence of natural wind. Off-target movement was observed under all perpendicular wind conditions with all nozzles tested but was nondetectable beyond 5 m away from the target. Coverage from all nozzles exhibited a concave-shaped curve in response to the increasing perpendicular wind speed due to turbulence. The maximum target coverage in drift studies was observed when the perpendicular wind was 0 and 8.94 m s −1 , but higher turbulence at the two highest perpendicular wind speeds (6.71 and 8.94 m s −1 ) increased coverage variability, whereas the lowest variability was observed at 2.24 m s −1 wind speed. Results suggested that air-induction flat-spray and turbo air–induction flat-spray nozzles and an application speed of 3 m s −1 provided an adequate coverage of target areas while minimizing off-target movement risk. DA - 2020/4/9/ PY - 2020/4/9/ DO - 10.1017/wet.2019.101 VL - 34 IS - 2 SP - 235-240 UR - https://doi.org/10.1017/wet.2019.101 KW - Bradley Hanson KW - University of California KW - Davis KW - UAV KW - precision agriculture KW - site-specific KW - off-target KW - droplet KW - pesticide application ER - TY - JOUR TI - Micronutrient transport in mycorrhizal symbiosis; zinc steals the show AU - Ruytinx, Joske AU - Kafle, Arjun AU - Usman, Muhammad AU - Coninx, Laura AU - Zimmermann, Sabine D. AU - Garcia, Kevin T2 - Fungal Biology Reviews AB - Mycorrhizas are mutually beneficial associations between soil-borne fungi and plant roots. Mycorrhizal fungi provide their host plant with essential nutrients in exchange for sugars and/or lipids. Traditionally, transport and translocation of macronutrients, including nitrogen and phosphorus, throughout the fungal mycelium and towards the host plant are well studied. However, the regulation of nutrient exchange and their contribution in the morphogenesis and development of mycorrhizas remains unclear. In this Opinion, we argue that adding micronutrients in the current models of symbiotic transport is essential to fully understand the establishment, maintenance, and functioning of mycorrhizal associations. Homeostatic mechanisms at the cellular level and the first transport proteins involved have been recently documented for zinc (Zn) in arbuscular mycorrhizal, ectomycorrhizal, and ericoid mycorrhizal fungi. Mycorrhizal plants benefit from an improved Zn status in control conditions and are better protected when environmental Zn availability fluctuates. These recent progresses are paving the way for a better understanding of micronutrient allocation in mycorrhizas. Revising our vision on the role of micronutrients, particularly of Zn, in these interactions will allow a better use of mycorrhizal fungi in sustainable agriculture and forestry, and will increase management practices in waste land, as well as in agricultural and natural ecosystems. DA - 2020/3// PY - 2020/3// DO - 10.1016/j.fbr.2019.09.001 UR - https://doi.org/10.1016/j.fbr.2019.09.001 KW - Arbuscular mycorrhizal symbiosis KW - Cation diffusion facilitator KW - Ectomycorrhizal symbiosis KW - Fungal homeostasis KW - Nutrient transport KW - Zinc-iron permease ER - TY - JOUR TI - HOW DID UNCONVENTIONAL MONETARY POLICY AFFECT ECONOMIC FORECASTS? AU - Mitchell, Karlyn AU - Pearce, Douglas K. T2 - CONTEMPORARY ECONOMIC POLICY AB - We study how unconventional monetary policy announcements affected professional forecasters' predictions of bond rates, gross domestic product growth and inflation using data from the monthly survey by the Wall Street Journal . We find that unconventional monetary policy (UMP) announcements moved predicted bond rates in the direction the Fed intended. UMP announcements had differential impacts on forecasters' predictions; they also tended to move growth and inflation predictions in directions opposite those the Fed intended due to Fed information effects. A policy implication of our study is that the Fed should communicate economic projections to the public separately from monetary policy announcements to mitigate Fed information effects. ( JEL E52, E58) DA - 2020/1// PY - 2020/1// DO - 10.1111/coep.12440 VL - 38 IS - 1 SP - 206-220 SN - 1465-7287 ER -