TY - JOUR TI - Phosphorus dynamics in the rhizosphere of two wheat cultivars in a soil with high organic matter content AU - Arruda, Bruna AU - Dall’orsoletta, Daniel João AU - Heidemann, Joice Crescencio AU - Gatiboni, Luciano Colpo T2 - Archives of Agronomy and Soil Science AB - Soil organic matter (SOM) is a key of most nutrient cycling and its content influences labile phosphorus (P) pool. In order to promote P availability from SOM, some plant strategies could be important to increase organic P mineralization, which may change among cultivars of the same crop. This study evaluated phosphorus dynamics in the rhizosphere of two wheat cultivars in soil with high organic matter content. Experiment was established in a greenhouse using a Humic Cambisol in a randomized block design using Quartzo and Abalone as wheat cultivars and harvested 20 days after seedling. Pots with a horizontal mesh (25 µm) were used to isolate the soil from roots. At harvest, the soil under the mesh was sliced in five distances from the rhizoplane (0–3; 3–6; 6–10; 10–20; 20–30 mm). Organic P was the buffer to maintain P dynamics in the rhizosphere and there was phosphorus depletion in the first slice near the rhizoplane due to the root effect, regardless the cultivar. Quartzo showed high labile inorganic P, presumably due to the high amount of root hairs, which increased the acid phosphatase activity and consequently root P uptake. Quartzo was more efficient in changing rhizosphere regarding the P acquisition. DA - 2018/6/7/ PY - 2018/6/7/ DO - 10.1080/03650340.2017.1407028 VL - 64 IS - 7 SP - 1011-1020 UR - https://doi.org/10.1080/03650340.2017.1407028 ER - TY - JOUR TI - Formation of ternary organic acids-Fe-P complexes on the growth of wheat (Triticum aestivum) AU - Schmitt, Djalma E. AU - Gatiboni, Luciano C. AU - Orsoletta, Daniel J. D. AU - Brunetto, Gustavo T2 - Revista Brasileira de Engenharia Agrícola e Ambiental AB - ABSTRACT Phosphorus (P) reacts with chemical and mineralogical constituents in the soil, mainly in tropical and subtropical soils. Therefore, strategies have been used to reduce the adsorption of P to the soil, among them, the formation of complexes that could decrease P adsorption to the soil. Two experiments were carried out to evaluate the formation of organic acid-Fe-P complexes in the laboratory and the efficiency of these complexes on the growth of wheat plants (T. aestivum) grown under greenhouse conditions. In experiment 1, seven low-molecular-weight organic acids (OA) were selected and a protocol for the formation of complexes between organic acid and Fe3+ at pH 4.0 was performed. After stirring, P was added to the organic acid-Fe complex to form the ternary complex. The remaining P was evaluated to determine the amount of P in the complex. In experiment 2, the three OAs which had the largest amount of complexes were selected, together with a treatment with soluble P and a control. Wheat was grown in potted soil in a greenhouse for 34 days. The amount of ternary organic acid-Fe-P complexes formed varied from 5 to 42% of the added P. However, when these complexes were added to the soil, in treatments with greater amount of complex formed there was lower growth of wheat. Thus, the ternary complex with organic acid-Fe-P has little effect on the performance of wheat plants. DA - 2018/10// PY - 2018/10// DO - 10.1590/1807-1929/agriambi.v22n10p702-706 UR - https://doi.org/10.1590/1807-1929/agriambi.v22n10p702-706 ER - TY - JOUR TI - Do enzyme inhibitors dicyandiamide and NBPT influence the microbial immobilization of phosphorus in Humic Cambisol? AU - Dall’Orsoletta, Daniel J. AU - Gatiboni, Luciano C. AU - Schmitt, Djalma E. AU - Arruda, Bruna AU - Heidemann, Joice C. T2 - Revista Brasileira de Engenharia Agrícola e Ambiental AB - ABSTRACT The application of nitrogen fertilizers, both organic and mineral, can cause nitrate losses by leaching. To minimize this effect, enzyme inhibitors are used. However, the effects on microbial biomass, which is the most sensitive and dynamic compartment of nutrients in the soil, as well as its effect on nutrients such as phosphorus (P) are unknown. This study aimed to evaluate the influence of the enzyme inhibitor (EI) on soil microbial phosphorus (Pm) when mineral fertilizer (NPK) or liquid swine manure (LSM) was applied in corn cultivation. The experiment was installed in a Humic Cambisol in Lages – SC, Brazil (27° 47’ 08” S; 50° 18’ 09” W) in the 2012/2013 season. The treatments consisted of: i) NPK; ii) NPK + EI; iii) LSM; iv) LSM + EI, applied before sowing of corn, and v) control (without application of fertilizer and enzyme inhibitor) arranged in a randomized block design, under no-tillage system. Soil samples were collected from the 0-0.10 m layer at 0, 10, 25, 58, 90, 135 and 202 days after application of the treatments. The Pm content was not affected by the enzyme inhibitor application but was influenced throughout the crop cycle in response to water balance and corn cultivation. DA - 2018/11// PY - 2018/11// DO - 10.1590/1807-1929/agriambi.v22n11p788-792 VL - 22 IS - 11 SP - 788-792 UR - https://doi.org/10.1590/1807-1929/agriambi.v22n11p788-792 ER - TY - JOUR TI - Accuracy of methods to estimate potential acidity and lime requirement in soils of west region of Santa Catarina AU - Predebon, Rodrigo AU - Gatiboni, Luciano Colpo AU - Mumbach, Gilmar Luiz AU - Schmitt, Djalma Eugenio AU - Dall’Orsoletta, Daniel João AU - Brunetto, Gustavo T2 - Ciência Rural AB - ABSTRACT: The objective of this study was to compare two methods of evaluation of potencial acidity (H+Al) and two methods to estimate liming requirement (LR) for soils from the west region of Santa Catarina State, Brazil. Fourteen soils were incubated with 7 lime rates for 120 days, obtaining the real values of H+Al at pH 7.0 and LR. These values were used as reference to evaluate the accuracy of two H+Al estimating methods: SMP buffer and calcium acetate at pH 7.0, and to evaluate the accuracy of two LR methods: base saturation (BS) and SMP index. On average, H+Al was underestimated in 6 and 40% by SMP and calcium acetate methods, respectively, especially in soils with high buffer capacity. The LR was underestimated in 20 and 30% by SMP index and BS, respectively. The SMP Index showed a better LR estimative than BS, especially in soils with high buffer capacity. DA - 2018/4/26/ PY - 2018/4/26/ DO - 10.1590/0103-8478cr20160935 VL - 48 IS - 4 UR - https://doi.org/10.1590/0103-8478cr20160935 ER - TY - JOUR TI - Vulnerability to contamination by phosphorus in a zero-order basin with a high density of pigs and a history of slurry addition: extrapolation of an index AU - Rosa Couto, R. AU - Martini, L.C.P. AU - Gatiboni, L.C. AU - Filho, P.B. AU - Martins, S.R. AU - Lazzari, C.J.R. AU - Júnior, V.M. AU - Comin, J.J. AU - Withers, P.J.A. AU - Schenato, R.B. AU - Brunetto, G. T2 - Environmental Earth Sciences DA - 2018/// PY - 2018/// DO - 10.1007/s12665-018-7301-1 VL - 77 IS - 4 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-85042328324&partnerID=MN8TOARS ER - TY - JOUR TI - Transitions to sustainable management of phosphorus in Brazilian agriculture AU - Withers, P.J.A. AU - Rodrigues, M. AU - Soltangheisi, A. AU - De Carvalho, T.S. AU - Guilherme, L.R.G. AU - Benites, V.D.M. AU - Gatiboni, L.C. AU - De Sousa, D.M.G. AU - Nunes, R.D.S. AU - Rosolem, C.A. AU - Andreote, F.D. AU - Oliveira, A.D. AU - Coutinho, E.L.M. AU - Pavinato, P.S. T2 - Scientific Reports AB - Brazil's large land base is important for global food security but its high dependency on inorganic phosphorus (P) fertilizer for crop production (2.2 Tg rising up to 4.6 Tg in 2050) is not a sustainable use of a critical and price-volatile resource. A new strategic analysis of current and future P demand/supply concluded that the nation's secondary P resources which are produced annually (e.g. livestock manures, sugarcane processing residues) could potentially provide up to 20% of crop P demand by 2050 with further investment in P recovery technologies. However, the much larger legacy stores of secondary P in the soil (30 Tg in 2016 worth over $40 billion and rising to 105 Tg by 2050) could provide a more important buffer against future P scarcity or sudden P price fluctuations, and enable a transition to more sustainable P input strategies that could reduce current annual P surpluses by 65%. In the longer-term, farming systems in Brazil should be redesigned to operate profitably but more sustainably under lower soil P fertility thresholds. DA - 2018/// PY - 2018/// DO - 10.1038/s41598-018-20887-z VL - 8 IS - 1 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-85041665400&partnerID=MN8TOARS ER - TY - JOUR TI - Nitrogen availability in an apple orchard with weed management AU - Brunetto, Gustavo AU - Oliveira, Bruno Salvador AU - Ambrosini, Vítor Gabriel AU - Rosa Couto, Rafael AU - Sete, Paula Beatriz AU - Santos Junior, Elano AU - Loss, Arcângelo AU - Silva, Lincon Oliveira Stefanello AU - Gatiboni, Luciano Colpo T2 - Ciência Rural AB - ABSTRACT: Weed management in apple orchards (Malus domestica) can affect the leaching of nitrogen (N) in soil. The study aimed to evaluate the potential leaching of N forms in soil of an apple orchard with different weed management treatments. The experiment was conducted in an apple orchard implanted in 2008. In October 2011, 80 plants were selected and the following treatments were implemented: no weed management (NM), desiccation of weeds on the tree row with herbicide use (DR) and mechanical mowing of weeds on the tree row (MR). Yield was evaluated in the 2011/2012, 2012/2013 and 2013/2014 crop seasons. In May 2012 porous cup lysimeters were installed in the NM, DR and MR treatments. In the solution collected at 0.20m, NH4 +-N and NO3 --N were analyzed sixteen times and mineral N concentration was calculated. The highest concentrations of NO3 --N and mineral N occurred in soil solution with DR, which increases availability of the nutrient to apple trees, but also enhances the potential losses. Weed management and N flow in the solution did not affect apple yield. DA - 2018/5/10/ PY - 2018/5/10/ DO - 10.1590/0103-8478cr20160895 VL - 48 IS - 5 UR - https://doi.org/10.1590/0103-8478cr20160895 ER - TY - JOUR TI - Fate of phosphorus applied to soil in pig slurry under cropping in southern Brazil AU - Boitt, G. AU - Schmitt, D.E. AU - Gatiboni, L.C. AU - Wakelin, S.A. AU - Black, A. AU - Sacomori, W. AU - Cassol, P.C. AU - Condron, L.M. T2 - Geoderma AB - Strongly weathered soils (such as Oxisols), are inherently phosphorus (P) limiting and highly P-sorptive thus requiring continued P inputs for productive agriculture. Constant P inputs result in accumulation of soil P with increasing risk of eutrophication of waterways. The state of Santa Catarina is the largest pork producer in Brazil. Production is concentrated in confined systems, with large generation of nutrient rich waste, commonly utilised as fertiliser. The objective of this work was to investigate and quantify the impact of long-term P inputs in pig slurry to a high P-sorbing Oxisol under cropping in southern Brazil. Fifteen years of pig-slurry addition resulted in P accumulation and vertical movement down the soil profile in proportion to application rates, but significant effects were confined to the 0–20 cm soil layer. Phosphorus accumulated mainly in inorganic forms. Slurry input rates of 25, 50, 100, and 200 m3 ha−1 y−1 resulted in accumulations of 25, 57, 106, and 159 kg P ha−1 y−1 (0–40 cm), of which only 8, 10, 23, and 28 kg P ha−1 y−1 were organic P forms. Mass balance showed that between 62 and 94% of the P inputs in slurry were accounted for in grain exports (7–35%), soil storage (58–83%), minimal amounts were estimated in crop residues (<1%), while the remainder (6–38%) was presumed to have been lost in drainage by overland flow. DA - 2018/// PY - 2018/// DO - 10.1016/j.geoderma.2018.02.010 VL - 321 SP - 164-172 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-85041931194&partnerID=MN8TOARS ER - TY - JOUR TI - Copper and zinc accumulation, fractionation and migration in vineyard soils from Santa Catarina State, Brazil AU - Brunetto, G. AU - Comin, J.J. AU - Miotto, A. AU - Moraes, M.P. AU - Sete, P.B. AU - Schmitt, D.E. AU - Gatiboni, L.C. AU - Melo, G.W.B. AU - Morais, G.P. T2 - Bragantia AB - The purpose of this study was to evaluate Cu and Zn migration and fractions in sandy soil of vineyards. In Urussanga (SC), Brazil, soil samples were collected from a 4-year-old and 15-yearold vineyard, and from a forested area. In the soils, the chemical characteristics of Cu and Zn were analyzed by the EDTA method, which determines the fraction available in soil; 3050B method of the USEPA for total concentrations, which represents the pseudo-soil contents in the soil; and chemical fractionation, which estimates soluble fraction, exchangeable fraction, fraction associated with clay minerals, fraction associated with organic matter and residual fraction. The results show that there is accumulation of Cu and Zn in sandy soils cultivated with grapevines and with frequent fungicide applications. These higher levels were found in soils with longer cultivation time (15 years old), but were restricted to the superficial layers of the soil. Most of the Cu was extracted by EDTA method, and it may be considered as available to plants. The EDTA also extracted a small part of Zn. Most of the Cu in the vineyard soils can be characterized by low geochemical mobility, but in the uppermost soil layers of the oldest vineyard, there was an increase in Cu content associated with soil organic matter. Most of the Zn in the vineyard soil was associated with minerals, which indicates low mobility and also low potential for toxicity to plants and microorganisms. DA - 2018/// PY - 2018/// DO - 10.1590/1678-4499.2016391 VL - 77 IS - 1 SP - 141-151 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-85041708009&partnerID=MN8TOARS ER - TY - JOUR TI - Modern Academic Data Library and Management Using Geo-Computing Technologies AU - Ozlu, Ekrem AU - Kaler, Avjinder T2 - CSA News AB - CSA NewsVolume 63, Issue 1 p. 30-31 Student Modern Academic Data Library and Management Using Geo-Computing Technologies Ekrem Ozlu, Ekrem OzluSearch for more papers by this authorAvjinder Kaler, Avjinder KalerSearch for more papers by this author Ekrem Ozlu, Ekrem OzluSearch for more papers by this authorAvjinder Kaler, Avjinder KalerSearch for more papers by this author First published: 04 January 2018 https://doi.org/10.2134/csa2018.63.0124Read 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 No abstract is available for this article. Volume63, Issue1January 2018Pages 30-31 RelatedInformation DA - 2018/1// PY - 2018/1// DO - 10.2134/csa2018.63.0124 VL - 63 IS - 1 SP - 30-31 J2 - CSA News LA - en OP - SN - 1529-9163 UR - http://dx.doi.org/10.2134/csa2018.63.0124 DB - Crossref ER - TY - JOUR TI - Different land use influences on amino acid, organic acid, hormone and mineral nutrient contents of dry beans AU - Erdogan, U. AU - Kitir, N. AU - Adem, G. AU - Tuan, M. AU - Tasci, S. AU - Yildirim, E. AU - Karaman, M.R. AU - Mokhtari, N.E.P. AU - Ozlu, E. AU - Firildak, G. T2 - Fresenius Environmental Bulletin DA - 2018/// PY - 2018/// VL - 27 IS - 12 SP - 8147-8157 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-85089713967&partnerID=MN8TOARS ER - TY - JOUR TI - Response of Soil Organic Carbon, pH, Electrical Conductivity, and Water Stable Aggregates to Long-Term Annual Manure and Inorganic Fertilizer AU - Ozlu, E. AU - Kumar, S. T2 - Soil Science Society of America Journal AB - Core Ideas Long‐term annual application of manure maintained the soil pH but inorganic fertilizer decreased it. Manure application increased soil organic carbon (SOC) and total nitrogen (TN). Higher manure rate helps in improving the water stable aggregates compared to inorganic fertilizer at 0‐ to 10‐cm depth. Manure enhances soil fertility and crop yield; however, an optimum rate of manure application is important to avoid any negative impacts to soils and the environment. This study was conducted to assess the long‐term impacts of manure and inorganic fertilizer rates on soil organic carbon (SOC), total nitrogen (TN), water stable aggregate (WSA), pH, and electrical conductivity (EC) under corn ( Zea mays L.)‐soybean ( Glycine max L.) rotation at Beresford (established in 2003) and Brookings (established in 2008), South Dakota (SD). Study treatments included low (LM), medium (MM) and high (HM) manure, medium (MF) and high (HF) inorganic fertilizer, and control (CK). Soil samples were extracted from four replicates at 0‐ to 10‐cm, 10‐ to 20‐cm, 20‐ to 30‐cm and 30‐ to 40‐cm depths from either site in 2015. Results showed that manure application maintained the soil pH at 0 to 10 cm depth; whereas, inorganic fertilizer decreased it compared to the control treatment at either site. The highest SOC concentrations at 0‐ to 10‐cm depth were observed under HM (38.3 g kg –1 ) as compared to that under MM (30.9 g kg –1 ), LM (27.6 g kg –1 ), MF application (24.0 g kg –1 ), HF (25.8 g kg –1 ) and CK (23.3 g kg –1 ). Furthermore, HM treatment significantly increased SOC for each depth increment from 0‐ to 40‐cm compared to the inorganic fertilizer at either site. A similar trend was observed for the TN but differences were not always significant. On an average, manure increased the EC (1.56 dS m –1 ) by 2.2 times compared to that of fertilizer (0.71 dS m –1 ) for 0‐ to 10‐cm depth. Similarly, manure significantly increased WSA by 7.2 and 5.6% compared to that of fertilizer at 0‐ to 10‐cm depth for Brookings and Beresford, respectively. Data from this study concluded that the long‐term annual application of manure improved selected soil properties compared to that of inorganic fertilizer. DA - 2018/9// PY - 2018/9// DO - 10.2136/sssaj2018.02.0082 VL - 82 IS - 5 SP - 1243-1251 UR - http://dx.doi.org/10.2136/sssaj2018.02.0082 ER - TY - JOUR TI - Response of surface GHG fluxes to long-term manure and inorganic fertilizer application in corn and soybean rotation AU - Ozlu, Ekrem AU - Kumar, Sandeep T2 - Science of The Total Environment AB - This study was conducted to investigate the impacts of dairy manure and inorganic fertilizer on soil surface greenhouse gases (GHG) [carbon dioxide (CO2), nitrous oxide (N2O) and methane (CH4)] fluxes from soils managed under corn (Zea mays L.)-soybean (Glycine max L.) rotation. The experiment was established on a silty loam soil, and the treatments included three manure application rates [phosphorus based recommended rate (low manure, LM), nitrogen based recommended rate (medium manure, MM) and two times recommended nitrogen rate (high manure, HM)], two inorganic fertilizer levels [recommended fertilizer (medium fertilizer, MF) and high rate of fertilizer (HF)], and control (CK) replicated four times. Soil GHG fluxes were monitored once a week during the growing season for 2015 and 2016. Data from this study showed that there were not any significant impacts from manure and inorganic fertilizer applications on the annual CH4 fluxes in 2015 and 2016. However, annual soil surface CO2 fluxes were increased by manure treatments compared to inorganic fertilizer treatments in both the years. In contrast, manure treatments decreased N2O fluxes, but significantly increased net GWP than the fertilizer treatments in 2016. In general, higher manure and fertilizer rates resulted in higher annual GHG emissions compared to lower manure and fertilizer rates in both years. Data from this study showed that HF application in crops can be detrimental for the environment by emitting higher GHG emissions, therefore, improved application strategies for manure and fertilizer management need to be explored to avoid any negative environmental impacts. DA - 2018/6// PY - 2018/6// DO - 10.1016/j.scitotenv.2018.01.120 VL - 626 SP - 817-825 UR - http://dx.doi.org/10.1016/j.scitotenv.2018.01.120 KW - Corn-soybean rotation KW - Dairy manure KW - Greenhouse gas emissions KW - Inorganic fertilizer KW - Global warming potential ER - TY - JOUR TI - IMPACTS OF ORGANIC AND ORGANO-MINERAL FERTILIZERS ON TOTAL PHENOLIC, FLAVONOID, ANTHOCYANIN AND ANTIRADICAL ACTIVITY OF OKUZGOZU (Vitis vinifera L.) GRAPES AU - Ozdemir, G. AU - Kitir, N. AU - Turan, M. AU - Ozlu, E. T2 - Acta Scientiarum Polonorum Hortorum Cultus DA - 2018/6/25/ PY - 2018/6/25/ DO - 10.24326/asphc.2018.3.9 VL - 17 IS - 3 SP - 91-100 UR - http://dx.doi.org/10.24326/asphc.2018.3.9 KW - organic farming KW - microbial fertilizer KW - viticulture KW - green fertilizer ER - TY - JOUR TI - Morpho-anatomical, physiological and biochemical changes in rubber tree seeds AU - De Souza, G.A. AU - Dias, D.C.F.S. AU - Pimenta, T.M. AU - Cardoso, A.?. AU - Pires, R.M.O. AU - Alvarenga, A.P. AU - Pícoli, E.A.T. T2 - Anais da Academia Brasileira de Ciencias AB - The physical, physiological and biochemical changes during the development until the dispersal of rubber tree seeds were evaluated with the purpose of estimating the point at physiological maturity. A total of 30 plants were selected at different points in a commercial planting area and had their flowers marked during the anthesis and every 15 days after marking. Fruits and seeds were collected for analysis of moisture content, dry matter, diameter and length. Details of the anatomy ultra-structure of the seeds were evaluated. The seed emergence, emergency speed index, heat resistant proteins and oxidative stress enzymes were examined. It was observed that fruits reached maximum size at 120 days after anthesis and seeds at 150 days. The seeds acquired germination capacity after 150 days. At 175 days, they presented the highest percentage of dry matter and lowest moisture, in addition to a higher percentage of germination and vigor. Therefore, it was possible to conclude that the physiological maturity of the rubber tree seeds occurs at 175 days after anthesis, and coincides with its maximum physiological quality. At 175 and 180 days post-anthesis, there is a greater expression of heat resistant proteins as well as low molecular weight and greater oxidative stress enzyme activity. DA - 2018/// PY - 2018/// DO - 10.1590/0001-3765201820170340 VL - 90 IS - 2 SP - 1625-1641 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-85048643566&partnerID=MN8TOARS KW - germination KW - oxidative stress enzymes KW - physiological maturity KW - seeds development ER - TY - JOUR TI - Similar geometric rules govern the distribution of veins and stomata in petals, sepals and leaves AU - Zhang, Feng-Ping AU - Carins Murphy, Madeline R AU - Cardoso, Amanda A AU - Jordan, Gregory J AU - Brodribb, Timothy J T2 - New Phytologist AB - Investment in leaf veins (supplying xylem water) is balanced by stomatal abundance, such that sufficient water transport is provided for stomata to remain open when soil water is abundant. This coordination is mediated by a common dependence of vein and stomatal densities on cell size. Flowers may not conform to this same developmental pattern if they depend on water supplied by the phloem or have high rates of nonstomatal transpiration. We examined the relationships between veins, stomata and epidermal cells in leaves, sepals and petals of 27 angiosperms to determine whether common spacing rules applied to all tissues. Regression analysis found no evidence for different relationships within organ types. Both vein and stomatal densities were strongly associated with epidermal cell size within organs, but, for a given epidermal cell size, petals had fewer veins and stomata than sepals, which had fewer than leaves. Although our data support the concept of common scaling between veins and stomata in leaves and flowers, the large diversity in petal vein density suggests that, in some species, petal veins may be engaged in additional functions, such as the supply of water for high cuticular transpiration or for phloem delivery of water or carbohydrates. DA - 2018/// PY - 2018/// DO - 10.1111/NPH.15210 VL - 219 IS - 4 SP - 1224-1234 UR - https://publons.com/publon/3397443/ KW - epidermal cell size KW - floral evolution KW - hydraulics KW - stomatal density KW - vein density ER - TY - JOUR TI - Leaves, not roots or floral tissue, are the main site of rapid, external pressure-induced ABA biosynthesis in angiosperms AU - Zhang, Feng-Ping AU - Sussmilch, Frances AU - Nichols, David S. AU - Cardoso, Amanda A. AU - Brodribb, Timothy J. AU - McAdam, Scott A. M. T2 - Journal of Experimental Botany AB - Rapid biosynthesis of abscisic acid (ABA) in the leaf, triggered by a decrease in cell volume, is essential for a functional stomatal response. However, it is not known whether rapid biosynthesis of ABA is also triggered in other plant tissues. Through the application of external pressure to flower, root, and leaf tissues, we test whether a reduction in cell volume can trigger rapid increases in ABA levels across the plant body in two species, Solanum lycopersicum and Passiflora tarminiana. Our results show that, in contrast to rapid ABA synthesis in the leaf, flower and root tissue did not show a significant, increase in ABA level in response to a drop in cell volume over a short time frame, suggesting that rapid ABA biosynthesis occurs only in leaf, not in flower or root tissues. A gene encoding the key, rate-limiting carotenoid cleavage enzyme (9-cis-epoxycarotenoid dioxygenase, NCED) in the ABA biosynthetic pathway in S. lycopersicum, NCED1, was upregulated to a lesser degree in flowers and roots compared with leaves in response to applied pressure. In both species, floral tissues contained substantially lower levels of the NCED substrate 9'-cis-neoxanthin than leaves, and this ABA precursor could not be detected in roots. Slow and minimal ABA biosynthesis was detected after 2 h in petals, indicating that floral tissue is capable of synthesizing ABA in response to sustained water deficit. Our results indicate that rapid ABA biosynthesis predominantly occurs in the leaves, and not in other tissues. DA - 2018/// PY - 2018/// DO - 10.1093/JXB/ERX480 VL - 69 IS - 5 SP - 1261-1267 UR - https://publons.com/wos-op/publon/3397429/ KW - Abscisic acid KW - cell volume KW - 9 '-cis-epoxycarotenoid dioxygenase KW - flowers KW - roots KW - stomata ER - TY - JOUR TI - Physiological and Agronomic Performance of the Coffee Crop in the Context of Climate Change and Global Warming: A Review AU - DaMatta, Fabio M AU - Avila, Rodrigo T AU - Cardoso, Amanda A AU - Martins, Samuel C V AU - Ramalho, Jose C T2 - Journal of Agricultural and Food Chemistry AB - Coffee is one of the most important global crops and provides a livelihood to millions of people living in developing countries. Coffee species have been described as being highly sensitive to climate change, as largely deduced from modeling studies based on predictions of rising temperatures and changing rainfall patterns. Here, we discuss the physiological responses of the coffee tree in the context of present and ongoing climate changes, including drought, heat, and light stresses, and interactions between these factors. We also summarize recent insights on the physiological and agronomic performance of coffee at elevated atmospheric CO2 concentrations and highlight the key role of CO2 in mitigating the harmful effects of heat stress. Evidence is shown suggesting that warming, per se, may be less harmful to coffee suitability than previously estimated, at least under the conditions of an adequate water supply. Finally, we discuss several mitigation strategies to improve crop performance in a changing world. DA - 2018/// PY - 2018/// DO - 10.1021/ACS.JAFC.7B04537 VL - 66 IS - 21 SP - 5264-5274 UR - https://publons.com/publon/3397435/ KW - Coffea spp KW - coffee KW - crop yield KW - drought KW - elevated [CO2] KW - global warming KW - heat KW - light stress KW - photosynthesis ER - TY - JOUR TI - Oxidative stress triggered by arsenic in a tropical macrophyte is alleviated by endogenous and exogenous nitric oxide AU - da-Silva, Cristiane Jovelina AU - Canatto, Regiane Aparecida AU - Cardoso, Amanda Avila AU - Ribeiro, Cleberson AU - Oliveira, Juraci Alves T2 - Revista Brasileira de Botanica AB - Nitric oxide (NO) plays important role in alleviating abiotic stresses in plants, including those caused by arsenic (As). Here, we examined the effects of endogenous and exogenous NO in Spirodela intermedia W. Koch (Lemnaceae) under As exposure. For this purpose, we evaluated the As content, reactive oxygen species (ROS) levels, membrane damage and enzymatic antioxidant system. The levels of endogenous NO and the activity of nitrate reductase (NR) were also addressed. The As treatment triggered the production of high endogenous levels of NO and a pronounced activation of the antioxidant enzymes; however, it was not sufficient to completely avoid the increment in ROS content and membrane damage. In contrast, exogenous NO decreased the As levels in plants exposed to As and NO donor, mitigating the ROS production and membrane damage, while maintaining a lower activity of the antioxidant enzymes compared with As-treated plants. Exogenous NO further downregulated the NR activity by a negative feedback, while As boosted the NR activity, consistent with the high endogenous levels of NO observed upon As treatment. Our results suggest that both endogenous and exogenous NO play critical roles in alleviating the As-induced oxidative stress in S. intermedia by reducing As uptake, and possibly by acting as an antioxidant molecule. DA - 2018/// PY - 2018/// DO - 10.1007/S40415-017-0431-Y VL - 41 IS - 1 SP - 21-28 UR - https://publons.com/publon/3397436/ KW - Antioxidant molecule KW - Aquatic plants KW - Cell signaling KW - Heavy metal stress ER - TY - JOUR TI - Hydraulics regulates stomatal responses to changes in leaf water status in Athyrium filix-femina. AU - Cardoso, Amanda A AU - Randall, Joshua M AU - McAdam, Scott A M T2 - Plant physiology AB - Stomatal responses to changes in leaf water status are important for the diurnal regulation of gas exchange and the survival of plants during drought. These stomatal responses in angiosperm species are well characterized, yet in species of nonseed plants, an ongoing debate surrounds the role of metabolism, particularly the role of the hormone abscisic acid (ABA), in functionally regulating stomatal responses to changes in leaf water status. Here, we measured the stomatal response to changes in vapor pressure difference (VPD) in two natural forms of the fern species Athyrium filix-femina, recently suggested to have stomata that are regulated by ABA. The two forms measured had considerable differences in key hydraulic traits, including leaf hydraulic conductance and capacitance, as well as the kinetics of stomatal response to changes in VPD. In both forms, the stomatal responses to VPD could be accurately predicted by a dynamic, mechanistic model that assumes guard cell turgor changes in concert with leaf turgor in the light, and not via metabolic processes including the level of ABA. During drought, endogenous ABA did not play a role in stomatal closure, and exogenous ABA applied to live, intact leaves did not induce stomatal closure. Our results indicate that functional stomatal responses to changes in leaf water status in ferns are regulated by leaf hydraulics and not metabolism. With ferns being sister to seed plants, this result has implications for the evolutionary reconstruction of functional stomatal responses across vascular land plant lineages. DA - 2018/// PY - 2018/// DO - 10.1104/pp.18.01412 UR - http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=ORCID&SrcApp=OrcidOrg&DestLinkType=FullRecord&DestApp=MEDLINE&KeyUT=MEDLINE:30538169&KeyUID=MEDLINE:30538169 ER - TY - JOUR TI - Extended differentiation of veins and stomata is essential forthe expansion of large leaves in Rheum rhabarbarum. AU - Cardoso, Amanda A AU - Randall, Joshua M AU - Jordan, Gregory J AU - McAdam, Scott A M T2 - American journal of botany AB - Premise of the Study The densities of veins and stomata govern leaf water supply and gas exchange. They are coordinated to avoid overproduction of either veins or stomata. In many species, where leaf area is greater at low light, this coordination is primarily achieved through differential cell expansion, resulting in lower stomatal and vein density in larger leaves. This mechanism would, however, create highly inefficient leaves in species in which leaf area is greater at high light. Here we investigate the role of cell expansion and differentiation as regulators of vein and stomatal density in Rheum rhabarbarum, which produces large leaves under high light. Methods Rheum rhabarbarum plants were grown under full sunlight and 7% of full sunlight. Leaf area, stomatal density, and vein density were measured from leaves harvested at different intervals. Key Results Leaves of R. rhabarbarum expanded at high light were six times larger than leaves expanded at low light, yet vein and stomatal densities were similar. In high light‐expanded leaves, minor veins were continuously initiated as the leaves expanded, while an extended period of stomatal initiation, compared to leaves expanded at low light, occurred early in leaf development. Conclusions We demonstrate that R. rhabarbarum adjusts the initiation of stomata and minor veins at high light, allowing for the production of larger leaves uncoupled from lower vein and stomatal densities. We also present evidence for an independent control of vein and stomatal initiation, suggesting that this adjustment must involve some unknown developmental mechanism. DA - 2018/// PY - 2018/// DO - 10.1002/ajb2.1196 VL - 105 IS - 12 SP - 1967-1974 UR - http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=ORCID&SrcApp=OrcidOrg&DestLinkType=FullRecord&DestApp=MEDLINE&KeyUT=MEDLINE:30475383&KeyUID=MEDLINE:30475383 KW - cell size KW - epidermis KW - leaf expansion KW - light intensity KW - stomatal development KW - stomatal density KW - vein density ER - TY - JOUR TI - Coordinated plasticity maintains hydraulic safety in sunflower leaves. AU - Cardoso, Amanda A AU - Brodribb, Timothy J AU - Lucani, Christopher J AU - DaMatta, Fabio M AU - McAdam, Scott A M T2 - Plant, cell & environment AB - Abstract The xylem cavitation threshold water potential establishes a hydraulic limit on the ability of woody species to survive in water‐limiting environments, but herbs may be more plastic in terms of their ability to adapt to drying conditions. Here, we examined the capacity of sunflower ( Helianthus annuus L.) leaves to adapt to reduced water availability by modifying the sensitivity of xylem and stomata to soil water deficit. We found that sunflower plants grown under water‐limited conditions significantly adjusted leaf osmotic potential, which was linked to a prolongation of stomatal opening as soil dried and a reduced sensitivity of photosynthesis to water‐stress‐induced damage. At the same time, the vulnerability of midrib xylem to water‐stress‐induced cavitation was observed to be highly responsive to growth conditions, with water‐limited plants producing conduits with thicker cell walls which were more resistant to xylem cavitation. Coordinated plasticity in osmotic potential and xylem vulnerability enabled water‐limited sunflowers to safely extract water from the soil, while protecting leaf xylem against embolism. High plasticity in sunflower xylem contrasts with data from woody plants and may suggest an alternative strategy in herbs. DA - 2018/// PY - 2018/// DO - 10.1111/pce.13335 VL - 41 IS - 11 SP - 2567-2576 UR - http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=ORCID&SrcApp=OrcidOrg&DestLinkType=FullRecord&DestApp=MEDLINE&KeyUT=MEDLINE:29748980&KeyUID=MEDLINE:29748980 KW - cavitation KW - herbaceous species KW - osmotic adjustment KW - stomatal movement KW - xylem vulnerability ER - TY - JOUR TI - Selection Signatures Underlying Dramatic Male Inflorescence Transformation During Modern Hybrid Maize Breeding. AU - Gage, JL AU - White, AU - Edwards, JW AU - Kaeppler, S AU - de, Leon N T2 - Genetics AB - Abstract Inflorescence capacity plays a crucial role in reproductive fitness in plants, and in production of hybrid crops. Maize is a monoecious species bearing separate male and female flowers (tassel and ear, respectively). The switch from open-pollinated populations of maize to hybrid-based breeding schemes in the early 20th century was accompanied by a dramatic reduction in tassel size, and the trend has continued with modern breeding over the recent decades. The goal of this study was to identify selection signatures in genes that may underlie this dramatic transformation. Using a population of 942 diverse inbred maize accessions and a nested association mapping population comprising three 200-line biparental populations, we measured 15 tassel morphological characteristics by manual and image-based methods. Genome-wide association studies identified 242 single nucleotide polymorphisms significantly associated with measured traits. We compared 41 unselected lines from the Iowa Stiff Stalk Synthetic (BSSS) population to 21 highly selected lines developed by modern commercial breeding programs, and found that tassel size and weight were reduced significantly. We assayed genetic differences between the two groups using three selection statistics: cross population extended haplotype homozogysity, cross-population composite likelihood ratio, and fixation index. All three statistics show evidence of selection at genomic regions associated with tassel morphology relative to genome-wide null distributions. These results support the tremendous effect, both phenotypic and genotypic, that selection has had on maize male inflorescence morphology. DA - 2018/9// PY - 2018/9// DO - 10.1534/genetics.118.301487 VL - 9 UR - http://europepmc.org/abstract/med/30257936 KW - maize KW - inflorescence KW - tassel KW - selection KW - GWAS ER - TY - JOUR TI - Comparing Genome-Wide Association Study Results from Different Measurements of an Underlying Phenotype. AU - Gage, JL AU - de, Leon N AU - Clayton, MK T2 - G3 (Bethesda, Md.) AB - Abstract Increasing popularity of high-throughput phenotyping technologies, such as image-based phenotyping, offer novel ways for quantifying plant growth and morphology. These new methods can be more or less accurate and precise than traditional, manual measurements. Many large-scale phenotyping efforts are conducted to enable genome-wide association studies (GWAS), but it is unclear exactly how alternative methods of phenotyping will affect GWAS results. In this study we simulate phenotypes that are controlled by the same set of causal loci but have differing heritability, similar to two different measurements of the same morphological character. We then perform GWAS with the simulated traits and create receiver operating characteristic (ROC) curves from the results. The areas under the ROC curves (AUCs) provide a metric that allows direct comparisons of GWAS results from different simulated traits. We use this framework to evaluate the effects of heritability and the number of causative loci on the AUCs of simulated traits; we also test the differences between AUCs of traits with differing heritability. We find that both increasing the number of causative loci and decreasing the heritability reduce a trait’s AUC. We also find that when two traits are controlled by a greater number of causative loci, they are more likely to have significantly different AUCs as the difference between their heritabilities increases. When simulation results are applied to measures of tassel morphology, we find no significant difference between AUCs from GWAS using manual and image-based measurements of typical maize tassel characters. This finding indicates that both measurement methods have similar ability to identify genetic associations. These results provide a framework for deciding between competing phenotyping strategies when the ultimate goal is to generate and use phenotype-genotype associations from GWAS. DA - 2018/9// PY - 2018/9// DO - 10.1534/g3.118.200700 VL - 9 UR - http://europepmc.org/abstract/med/30262522 KW - AUC KW - GWAS KW - heritability KW - ROC ER - TY - CONF TI - Prescribed burning effects on jack pine seeds from high and low serotiny regions: Microbial interactions and soil properties AU - Kranz, C.N. AU - Whitman, T. T2 - North American Forest Soil Conference C2 - 2018/// CY - Quebec City, QC DA - 2018/// PY - 2018/// ER - TY - JOUR TI - Maize Genomes to Fields: 2014 and 2015 field season genotype, phenotype, environment, and inbred ear image datasets AU - Alkhalifah, N. AU - Campbell, D.A. AU - Falcon, C.M. AU - Gardiner, J.M. AU - Miller, N.D. AU - Romay, M.C. AU - Walls, R. AU - Walton, R. AU - Yeh, C.-T. AU - Bohn, M. AU - Bubert, J. AU - Buckler, E.S. AU - Ciampitti, I. AU - Flint-Garcia, S. AU - Gore, M.A. AU - Graham, C. AU - Hirsch, C. AU - Holland, J.B. AU - Hooker, D. AU - Kaeppler, S. AU - Knoll, J. AU - Lauter, N. AU - Lee, E.C. AU - Lorenz, A. AU - Lynch, J.P. AU - Moose, S.P. AU - Murray, S.C. AU - Nelson, R. AU - Rocheford, T. AU - Rodriguez, O. AU - Schnable, J.C. AU - Scully, B. AU - Smith, M. AU - Springer, N. AU - Thomison, P. AU - Tuinstra, M. AU - Wisser, R.J. AU - Xu, W. AU - Ertl, D. AU - Schnable, P.S. AU - De Leon, N. AU - Spalding, E.P. AU - Edwards, J. AU - Lawrence-Dill, C.J. T2 - BMC Research Notes AB - Crop improvement relies on analysis of phenotypic, genotypic, and environmental data. Given large, well-integrated, multi-year datasets, diverse queries can be made: Which lines perform best in hot, dry environments? Which alleles of specific genes are required for optimal performance in each environment? Such datasets also can be leveraged to predict cultivar performance, even in uncharacterized environments. The maize Genomes to Fields (G2F) Initiative is a multi-institutional organization of scientists working to generate and analyze such datasets from existing, publicly available inbred lines and hybrids. G2F's genotype by environment project has released 2014 and 2015 datasets to the public, with 2016 and 2017 collected and soon to be made available.Datasets include DNA sequences; traditional phenotype descriptions, as well as detailed ear, cob, and kernel phenotypes quantified by image analysis; weather station measurements; and soil characterizations by site. Data are released as comma separated value spreadsheets accompanied by extensive README text descriptions. For genotypic and phenotypic data, both raw data and a version with outliers removed are reported. For weather data, two versions are reported: a full dataset calibrated against nearby National Weather Service sites and a second calibrated set with outliers and apparent artifacts removed. DA - 2018/// PY - 2018/// DO - 10.1186/s13104-018-3508-1 VL - 11 IS - 1 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-85049778367&partnerID=MN8TOARS ER - TY - CHAP TI - Harnessing Maize Biodiversity T2 - Compendium of Plant Genomes AB - The phenotypic and genetic diversity of maize worldwide is remarkable. This chapter summarizes decades of studies of the genetic diversity of maize populations from different parts of the world, methods used to group maize into informal hierarchies, and how these groupings partition genetic and trait variation. The USA is the most important maize-producing nation, but the genetic diversity of USA maize is small relative to the available worldwide variation. Tropical maize harbors more genetic variation, but is not adapted to growing in temperate environments. Two distinct approaches to tapping the global reservoir of maize diversity to improve USA and other temperate region maize crops are outlined. One approach, allele mining, involves discovery of alleles with large favorable effects on traits in exotic germplasm, followed by marker-aided backcrossing or gene editing to introduce specific unique alleles into elite breeding populations. Alternatively, for traits conditioned mostly by many small-effect polygenes, rapid genomic selection for adaptation followed by combining ability within pure exotic populations could be used to create adapted and improved versions of exotic populations before they are crossed to elite adapted inbreds to make new breeding populations. PY - 2018/// DO - 10.1007/978-3-319-97427-9_20 UR - http://dx.doi.org/10.1007/978-3-319-97427-9_20 ER - TY - JOUR TI - Structure/function relationships in the rosette cellulose synthesis complex illuminated by an evolutionary perspective AU - Haigler, Candace H. AU - Roberts, Alison W. T2 - Cellulose AB - Cellulose microfibrils are a key component of plant cell walls, which in turn compose most of our renewable biomaterials. Consequently, there is considerable interest in understanding how cellulose microfibrils are made in living cells by the plant cellulose synthesis complex (CSC). This remarkable multi-subunit complex contains cellulose synthase (CESA) proteins, and it is often called a rosette due to its six-lobed shape. Each CSC moves within the plasma membrane as it spins a strong cellulose microfibril in its wake. To accomplish this biological manufacturing process, the CESAs harvest an activated sugar substrate from the cytoplasm for use in the polymerization of glucan chains. An elongating glucan is simultaneously translocated across the plasma membrane by each CESA, where the group of chains emanating from one CSC co-crystallizes into a cellulose microfibril that becomes part of the assembling cell wall. Here we review major advances in understanding CESA and CSC structure/function relationships since 2013, when ground-breaking insights about the structure of cellulose synthases in bacteria and plants were published. We additionally discuss: (a) the relationship of CSC substructure to the size of the fundamental cellulose fibril; (b) an evolutionary perspective on the driving force behind the existence of hetero-oligomeric CSCs that currently appear to dominate in land plants; and (c) how cellulose properties may be regulated by CESA and CSC activity. We also pose major questions that still remain in this rapidly changing and exciting research field. DA - 2018/12/13/ PY - 2018/12/13/ DO - 10.1007/s10570-018-2157-9 VL - 26 IS - 1 SP - 227-247 J2 - Cellulose LA - en OP - SN - 0969-0239 1572-882X UR - http://dx.doi.org/10.1007/s10570-018-2157-9 DB - Crossref KW - Cellulose synthase KW - Constructive neutral evolution KW - Cellulose microfibril KW - Protein structure KW - Rosette cellulose synthesis complex ER - TY - JOUR TI - High-definition infrared thermography of ice nucleation and propagation in wheat under natural frost conditions and controlled freezing AU - Livingston, David P. AU - Tuong, Tan D. AU - Murphy, J. Paul AU - Gusta, Lawrence V. AU - Willick, Ian AU - Wisniewski, Micheal E. T2 - Planta AB - An extremely high resolution infrared camera demonstrated various freezing events in wheat under natural conditions. Many of those events shed light on years of misunderstanding regarding freezing in small grains. Infrared thermography has enhanced our knowledge of ice nucleation and propagation in plants through visualization of the freezing process. The majority of infrared analyses have been conducted under controlled conditions and often on individual organs instead of whole plants. In the present study, high-definition (1280 × 720 pixel resolution) infrared thermography was used under natural conditions to visualize the freezing process of wheat plants during freezing events in 2016 and 2017. Plants within plots were found to freeze one at a time throughout the night and in an apparently random manner. Leaves on each plant also froze one at a time in an age-dependent pattern with oldest leaves freezing first. Contrary to a common assumption that freezing begins in the upper parts of leaves; freezing began at the base of the plant and spread upwards. The high resolution camera used was able to verify that a two stage sequence of freezing began within vascular bundles. Neither of the two stages was lethal to leaves, but a third stage was demonstrated at colder temperatures that was lethal and was likely a result of dehydration stress; this stage of freezing was not detectable by infrared. These results underscore the complexity of the freezing process in small grains and indicate that comprehensive observational studies are essential to identifying and selecting freezing tolerance traits in grain crops. DA - 2018/4// PY - 2018/4// DO - 10.1007/S00425-017-2823-4 VL - 247 IS - 4 SP - 791–806 SN - 0032-0935 1432-2048 UR - http://dx.doi.org/10.1007/S00425-017-2823-4 KW - Triticum aestivum KW - Crown KW - Xylem KW - Radiative cooling KW - Supercooled ER - TY - JOUR TI - Tennessee icon and STMA leader Bobby Campbell passes AU - Miller, G.L. AU - Heck, K. AU - Price, C. AU - McNeal, A. AU - Andersen, M. AU - Boekholder, M. T2 - SportsTurf DA - 2018/1// PY - 2018/1// VL - 34 IS - 1 SP - 14,16 ER - TY - JOUR TI - Frost Damage of Carinata Grown in the Southeastern US AU - Mulvaney, Michael J. AU - Seepaul, Ramdeo AU - Small, Ian M. AU - Wright, David L. AU - Paula-Moraes, Silvana V. AU - Crozier, Carl AU - Cockson, Paul AU - Whipker, Brian AU - Leon, Ramon T2 - EDIS AB - Brassica carinata is an annual oilseed crop used for the commercial production of jet fuel. One of the challenges to commercialization of this crop in the southeastern United States has been frost damage. This 4-page fact sheet discusses symptomology and ways to minimize risk of frost damage to carinata. Written by Michael J. Mulvaney, Ramdeo Seepaul, Ian Small, David Wright, Silvana Paula-Moraes, Carl Crozier, Paul Cockson, Brian Whipker, and Ramon Leon, and published by the UF/IFAS Agronomy Department, May 2018. https://edis.ifas.ufl.edu/ag420 DA - 2018/5/11/ PY - 2018/5/11/ DO - 10.32473/edis-ag420-2018 VL - 2018 IS - 3 UR - https://doi.org/10.32473/edis-ag420-2018 ER - TY - JOUR TI - Streaming urea ammonium nitrate with or without enhanced efficiency products impacted corn yields, ammonia, and nitrous oxide emissions AU - Woodley, A.L. AU - Drury, C.F. AU - Yang, X.M. AU - Reynolds, W.D. AU - Calder, W. AU - Oloya, T.O. T2 - Agronomy Journal AB - Core Ideas Streaming urea ammonium nitrate resulted in 11% lower corn yields compared to injected urea ammonium nitrate. Ammonia volatilization (NH 3 ) begins immediately after application for streaming urea ammonium nitrate. In 2015–2016, NH 3 loss was 3.6 fold greater for streaming urea ammonium nitrate compared to injected urea ammonium nitrate. Urease and nitrification inhibitors did not increase corn yields with streaming urea ammonium nitrate. Streaming urea ammonium nitrate with a urease inhibitor increased N 2 O emissions by 18.7%. Surface streaming urea ammonium nitrate (UAN) into corn ( Zea mays L.) at side‐dress (v4–v6) or later in the season (v12–v14) is an emerging N fertilizer application method as it is rapid, reduces soil disturbance, and allows for flexible application times. In 2013 and 2014, side‐dress N application (130 kg N ha −1 ) using three streaming UAN sources was evaluated for their ability to maintain grain yield, reduce ammonia (NH 3 ) volatilization, and mitigate nitrous oxide (N 2 O) emissions. The products included streaming of urea ammonium nitrate (StrUAN), urea ammonium nitrate with a urease inhibitor (StrUAN‐UI), urea ammonium nitrate with urease inhibitor plus nitrification inhibitor (StrUAN‐UI+NI), and a control (no N). The efficacy of streaming relative to traditional shallow‐injected urea ammonium nitrate (InjUAN) was also assessed. Delayed NH 3 sampling related to wind‐tunnel installation in 2013 and 2014 led to additional NH 3 measurements in 2015 and 2016. Average yields from StrUAN were 11% lower relative to InjUAN. The use of inhibitors did not improve yields relative to StrUAN. Ammonia volatilization was not significantly different between StrUAN and InjUAN losing 14 and 20% of applied N (2‐yr average), respectively. However in 2015 and 2016, NH 3 volatilization from StrUAN was 3.6‐fold greater than InjUAN when measurements were started immediately after application. Hence lower yields in 2013 and 2014 from StrUAN likely reflect N loss to rapid volatilization during or shortly after application. The StrUAN‐UI treatment increased 2‐yr average N 2 O emissions by 17.3 to 18.7% relative to StrUAN or StrUAN‐UI+NI. For humid‐temperate clay loam soil, UAN streaming with/without inhibitors was not effective for maintaining yields or reducing NH 3 volatilization. DA - 2018/// PY - 2018/// DO - 10.2134/agronj2017.07.0406 VL - 110 IS - 2 SP - 444-454 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-85042845695&partnerID=MN8TOARS ER - TY - JOUR TI - Long-term cropping effects on partitioning of water flow and nitrate loss between surface runoff and tile drainage AU - Woodley, A.L. AU - Drury, C.F. AU - Reynolds, W.D. AU - Tan, C.S. AU - Yang, X.M. AU - Oloya, T.O. T2 - Journal of Environmental Quality AB - Surface runoff and tile drainage are the main pathways for water movement and entry of agricultural nitrate into water resources. The objective of this 5-yr study was to characterize the partitioning of water flow and nitrate loss between these pathways for a humid-temperate Brookston clay loam soil under 54 to 59 yr of consistent cropping and fertilization. Cropping treatments included monoculture corn ( L., MC), continuous bluegrass ( L.) sod (CS), and a corn-oat-alfalfa ( L.)-alfalfa rotation (RC-RO-RA1-RA2). Fertilization treatments included annual fertilizer addition (F) and no fertilizer addition (NF). Tile drainage and surface runoff occurred primarily during the nongrowing season (November-April), and they were highly correlated with the mean saturated hydraulic conductivity of the near-surface soil profile. Tile drainage accounted for 69 to 90% of cumulative water flow and 79 to 96% of cumulative nitrate loss from fertilized rotation and CS, whereas surface runoff accounted for the majority of the nitrate losses in MC (i.e., 75-93% of water flow and 65-96% of nitrate loss). Cumulative nitrate losses were highest in the RC-F (152 kg N ha), RC-NF (101 kg N ha), RA2-F (121 kg N ha), and RA2-NF (75 kg N ha) plots, and these high losses are attributed to N mineralization from the plowed alfalfa and fertilization (if applicable). Fertilization increased cumulative nitrate loss in tile drainage from all treatments, whereas no fertilization increased cumulative nitrate loss in surface runoff from the rotation. Cropping system and fertilization on clay loam soil changed how water flow and nitrate loss were partitioned between tile drainage and surface runoff. DA - 2018/// PY - 2018/// DO - 10.2134/jeq2017.07.0292 VL - 47 IS - 4 SP - 820-829 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-85049473924&partnerID=MN8TOARS ER - TY - JOUR TI - Improved acid trap methodology for determining ammonia volatilization in wind tunnel experiments AU - Woodley, A.L. AU - Drury, C.F. AU - Reynolds, W.D. AU - Calder, W. AU - Yang, X.M. AU - Oloya, T.O. T2 - Canadian Journal of Soil Science AB - Nitrogen loss through ammonia volatilization is an environmental and economic concern. When acid traps are used with wind tunnels to measure ammonia volatilization, loss of solution volume is observed. As the loss mechanism affects volatilization estimates, a field study was conducted to determine if solution loss from acid traps was due to either selective loss of water through evaporation, loss of bulk solution, or a combination. Two methods for calculating air flow volume through the acid traps were also examined. Solution losses from acid traps averaged 40 mL d−1 (±9.2 mL) from an initial 100 mL, and ammonium concentration increased in close accordance with the dilution–concentration relationship for aqueous solutions. Hence, solution loss was due to evaporation, with virtually no ammonium loss, confirming that the flux calculations using corrected acid trap volumes are required. Failure to correct for the reduced volumes resulted in 9%–224% overestimation of ammonium concentrations. Air flow volumes through acid traps were underestimated by 18.5% when initial and final air flow rates were used compared with continuous cumulative flow measurements. Using cumulative flows and accounting for evaporation loss from acid traps help ensure that treatment differences are not masked by the inherent variability in field-based measurements. DA - 2018/// PY - 2018/// DO - 10.1139/cjss-2017-0081 VL - 98 IS - 2 SP - 193-199 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-85042844678&partnerID=MN8TOARS ER - TY - JOUR TI - Daytime Surface Energy Fluxes over Soil Material Remediated Using Thermal Desorption AU - O’Brien, Peter L. AU - DeSutter, Thomas M. AU - Casey, Francis X. M. AU - Daigh, Aaron L.M. AU - Heitman, Joshua L. AU - Derby, Nathan E. AU - Khan, Eakalak T2 - Agrosystems, Geosciences & Environment AB - Core Ideas Surface energy balance was quantified with micro‐Bowen ratio instrumentation. Surface energy balance was similar over native topsoil and soils treated with thermal desorption. Thermal desorption did not alter soil temperature dynamics or evaporation. A mix of topsoil and thermal desorption–treated soil matched surface energy balance of topsoil best. Remediation efforts to reduce contaminant concentrations in soils often alter soil properties. Since these alterations can affect the capacity of soil to function, their extent and magnitude may dictate future land use. This study addresses the suitability of soils for agricultural production after remediation of petroleum hydrocarbons using ex situ thermal desorption by quantifying the daytime surface energy balance prior to the growing season. The energy balance was quantified using micro‐Bowen ratio instrumentation to compare non‐contaminated topsoil (A) to both subsoil materials treated by thermal desorption (TD) and a 1:1 mixture (v/v) of TD and A (TDA). Despite differences in soil characteristics, the net radiation, soil heat flux, latent heat flux, and sensible heat flux were each similar among the three reclamation conditions over a period of 18 d. The fluctuations in these fluxes between the three conditions were attributed to natural variability, and they were not large enough to induce apparent inconsistencies in soil temperature dynamics or evaporative losses. Overall, these findings suggest the surface energy balance in thermal desorption–treated soils is similar to that of the native topsoil and that using a mixture of treated soils with native topsoil may even be a better representation of pre‐disturbance conditions. DA - 2018/11/29/ PY - 2018/11/29/ DO - 10.2134/age2018.08.0027 VL - 1 IS - 1 SP - 180027 J2 - Agrosystems, Geosciences & Environment LA - en OP - SN - 2639-6696 UR - http://dx.doi.org/10.2134/age2018.08.0027 DB - Crossref ER - TY - JOUR TI - Below canopy radiation divergence in a vineyard: implications on interrow surface energy balance AU - Kustas, W. P. AU - Agam, N. AU - Alfieri, J. G. AU - McKee, L. G. AU - Prueger, J. H. AU - Hipps, L. E. AU - Howard, A. M. AU - Heitman, J. L. T2 - Irrigation Science DA - 2018/10/19/ PY - 2018/10/19/ DO - 10.1007/s00271-018-0601-0 VL - 37 IS - 3 SP - 227-237 J2 - Irrig Sci LA - en OP - SN - 0342-7188 1432-1319 UR - http://dx.doi.org/10.1007/s00271-018-0601-0 DB - Crossref ER - TY - JOUR TI - Domain swaps of Arabidopsis secondary wall cellulose synthases to elucidate their class specificity AU - Hill, Joseph Lee, Jr AU - Hill, Ashley Nicole AU - Roberts, Alison W. AU - Haigler, Candace H. AU - Tien, Ming T2 - Plant Direct AB - Abstract Cellulose microfibrils are synthesized by membrane‐embedded cellulose synthesis complexes (CSCs), currently modeled as hexamers of cellulose synthase (CESA) trimers. The three paralogous CESAs involved in secondary cell wall (SCW) cellulose biosynthesis in Arabidopsis (CESA4, CESA7, CESA8) are similar, but nonredundant, with all three isoforms required for assembly and function of the CSC. The molecular basis of protein–protein recognition among the isoforms is not well understood. To investigate the locations of the interfaces that are responsible for isoform recognition, we swapped three domains between the Arabidopsis CESAs required for SCW synthesis (CESA4, CESA7, and CESA8): N‐terminus, central domain containing the catalytic core, and C‐terminus. Chimeric genes with all pairwise permutations of the domains were tested for in vivo functionality within knockout mutant backgrounds of cesa4 , cesa7 , and cesa8 . Immunoblotting with isoform‐specific antibodies confirmed the anticipated protein expression in transgenic plants. The percent recovery of stem height and crystalline cellulose content was assayed, as compared to wild type, the mutant background lines, and other controls. Retention of the native central domain was sufficient for CESA8 chimeras to function, with neither its N‐terminal nor C‐terminal domains required. The C‐terminal domain is required for class‐specific function of CESA4 and CESA7, and CESA7 also requires its own N‐terminus. Across all isoforms, the results indicate that the central domain, as well as the N‐ and C‐terminal regions, contributes to class‐specific function variously in Arabidopsis CESA4, CESA7, and CESA8. DA - 2018/7// PY - 2018/7// DO - 10.1002/PLD3.61 VL - 2 IS - 7 SP - e00061 J2 - Plant Direct LA - en OP - SN - 2475-4455 UR - http://dx.doi.org/10.1002/PLD3.61 DB - Crossref KW - Arabidopsis thaliana KW - cellulose synthase KW - chimera KW - class specificity KW - domain swap KW - protein interaction KW - secondary cell wall ER - TY - JOUR TI - Effects of overexpression of jasmonic acid biosynthesis genes on nicotine accumulation in tobacco AU - Chen, Hongxia AU - Wang, Bingwu AU - Geng, Sisi AU - Arellano, Consuelo AU - Chen, Sixue AU - Qu, Rongda T2 - Plant Direct AB - Nicotine is naturally synthesized in tobacco roots and accumulates in leaves as a defense compound against herbivory attack. Nicotine biosynthesis pathway has been extensively studied with major genes and enzymes being isolated and functionally characterized. However, the molecular regulation of nicotine synthesis has not been fully understood. The phytohormone jasmonic acid (JA) mediates many aspects of plant defense responses including nicotine biosynthesis. In this study, five key genes (AtLOX2, AtAOS, AtAOC2, AtOPR3, AtJAR1) involved in JA biosynthesis from Arabidopsis were individually overexpressed, and a JA-Ile hydrolysis-related gene, NtJIH1, was suppressed by RNAi approach, to understand their effects on nicotine accumulation in tobacco. Interestingly, while transgene expression was high, levels of JA-Ile (the biologically active form of JA) were often significantly reduced. Meanwhile, nicotine content in these transgenic plants did not increase. The research revealed a tightly controlled JA signaling pathway and a complicated regulatory network for nicotine biosynthesis by JA signaling. DA - 2018/1// PY - 2018/1// DO - 10.1002/PLD3.36 VL - 2 IS - 1 SP - e00036 J2 - Plant Direct LA - en OP - SN - 2475-4455 UR - http://dx.doi.org/10.1002/PLD3.36 DB - Crossref KW - jasmonic acid biosynthesis KW - jasmonic acid signaling KW - nicotine synthesis regulation KW - tobacco KW - transgene ER - TY - JOUR TI - Acquisition of a microscope for in situ studies of hard and soft matter AU - LeBeau, James M. AU - Dickey, Elizabeth C. AU - Augustyn, Veronica AU - Hesterberg, Dean L. AU - Brown, Ashley C. T2 - Microscopy and Microanalysis AB - An abstract is not available for this content so a preview has been provided. As you have access to this content, a full PDF is available via the ‘Save PDF’ action button. DA - 2018/8// PY - 2018/8// DO - 10.1017/S143192761801214X VL - 24 IS - S1 SP - 2332-2333 J2 - Microsc Microanal LA - en OP - SN - 1431-9276 1435-8115 UR - http://dx.doi.org/10.1017/S143192761801214X DB - Crossref ER - TY - JOUR TI - The presence of algae mitigates the toxicity of copper-based algaecides to a nontarget organism AU - Bishop, West M. AU - Willis, Ben E. AU - Richardson, Robert J. AU - Cope, W. Gregory T2 - Environmental Toxicology and Chemistry AB - Abstract Copper‐based algaecides are routinely applied to target noxious algal blooms in freshwaters. Standard toxicity testing data with copper suggest that typical concentrations used to control algae can cause deleterious acute impacts to nontarget organisms. These “clean” water experiments lack algae, which are specifically targeted in field applications of algaecides and contain competing ligands. The present research measured the influence of algae on algaecide exposure and subsequent response of the nontarget species Daphnia magna to copper sulfate and an ethanolamine‐chelated copper algaecide (Captain®). Significant shifts ( p < 0.05) in D. magna 48‐h median lethal concentration (LC50) values were found when algae were present in exposures along with a copper salt or a chelated copper formulation. Copper sulfate 48‐h LC50 values shifted from 75.3 to 317.8 and 517.8 μg Cu/L, whereas Captain increased from 353.8 to 414.2 and 588.5 μg Cu/L in no algae, 5 × 10 5 , and 5 × 10 6 cells/mL algae treatments, respectively. Larger shifts were measured with copper sulfate exposures, although Captain was less toxic to D. magna in all corresponding treatments. Captain was more effective at controlling Scenedesmus dimorphus at most concentrations, and control was inversely proportional to toxicity to D. magna . Overall, incorporating target competing ligands (i.e., algae) into standard toxicity testing is important for accurate risk assessment, and copper formulation can significantly alter algaecidal efficacy and risks to nontarget organisms. Environ Toxicol Chem 2018;37:2132–2142. © 2018 SETAC DA - 2018/6/20/ PY - 2018/6/20/ DO - 10.1002/ETC.4166 VL - 37 IS - 8 SP - 2132-2142 J2 - Environ Toxicol Chem LA - en OP - SN - 0730-7268 UR - http://dx.doi.org/10.1002/ETC.4166 DB - Crossref KW - Risk assessment KW - Algae KW - Algaecides KW - Daphnia magna KW - Copper ER - TY - JOUR TI - Citation stacking in soil science articles: our response to the open letter by concerned early-career soil scientists AU - van Groenigen, Jan Willem AU - Agnelli, Alberto AU - Bai, Junhong AU - Capowiez, Yvan AU - Cayuela, Mariluz AU - Kögel-Knabner, Ingrid AU - Laird, David AU - McBratney, Alex AU - Morgan, Cristine AU - Nater, Edward A. AU - Nunan, Naoise AU - Said-Pullicino, Daniel AU - Vepraskas, Michael T2 - Geoderma DA - 2018/10// PY - 2018/10// DO - 10.1016/J.GEODERMA.2018.03.023 VL - 328 SP - 119-120 J2 - Geoderma LA - en OP - SN - 0016-7061 UR - http://dx.doi.org/10.1016/J.GEODERMA.2018.03.023 DB - Crossref ER - TY - JOUR TI - Impacts of forest-based bioenergy feedstock production on soil nitrogen cycling AU - Cacho, Julian F. AU - Youssef, Mohamed A. AU - Shi, Wei AU - Chescheir, George M. AU - Skaggs, R. Wayne AU - Tian, Shiying AU - Leggett, Zakiya H. AU - Sucre, Eric B. AU - Nettles, Jami E. AU - Arellano, Consuelo T2 - Forest Ecology and Management AB - We investigated impacts of simultaneous production of biomass for biofuel and quality timber on soil nitrogen (N) cycling in a poorly drained forest soil of eastern North Carolina, U.S.A. Treatments included traditional loblolly pine (PINE) and pine-switchgrass intercropping (PSWITCH). Treatments were replicated three times on 0.8 ha plots drained by parallel open ditches which were 1.2 m deep and spaced 100 m apart. Net N mineralization (Nm) and nitrification (Nn) rates were measured in the field using sequential in-situ technique over two years with multiple measurements in each year and laboratory by incubating soil samples for one-, two-, eight-, and thirteen weeks. Soil incubation in-situ or sample collection for laboratory incubation was conducted at nine sampling points within a 30 × 40 m subplot at each plot center and 20 cm from the soil surface. Soil samples were composited by location including near tree (NT), between two trees on the same bed (BT), and in the middle of four trees on two adjacent beds (M4T). Composite samples from NT and BT were categorized as tree-bed (BED), while those from M4T were grouped as interbed (INT). Field results showed that total soil N availability and its temporal variations over two years were not significantly affected by PSWITCH. However, it significantly reduced Nn rates, particularly in the INT. The plot-level mean Nm rates in PINE were 0.21 and 0.26 mg N·kg soil−1 d−1, while in PSWITCH they were 0.10 and 0.21 mg N kg soil−1 d−1 in 2011 and 2012, respectively. The plot-level mean Nn rates in PINE were 0.09 and 0.10 mg N kg soil−1 d−1 in 2011 and 2012, respectively, while in PSWITCH they remained at 0.03 mg N kg soil−1 d−1 across these two years. At the INT, mean Nn rates in PINE were 0.11 and 0.12 mg N kg soil−1 d−1 in 2011 and 2012, respectively, while in PSWITCH, Nn rate remained at 0.02 mg N kg soil−1 d−1 over two years. Laboratory results indicated that change in litter quality inputs (changing from mixed species to switchgrass) in the INT did not significantly affect Nm rates. Results of this study contributed to a better understanding of the changes in soil N cycling due to loblolly pine-switchgrass interactions, which is important in sustainable nutrient management of this new land use. Further, the results suggested that growing switchgrass as intercrop to managed loblolly pine has positive water quality implication since ammonium N is less mobile in soil than nitrate N. DA - 2018/7// PY - 2018/7// DO - 10.1016/J.FORECO.2018.04.002 VL - 419-420 SP - 227-239 J2 - Forest Ecology and Management LA - en OP - SN - 0378-1127 UR - http://dx.doi.org/10.1016/J.FORECO.2018.04.002 DB - Crossref KW - Loblolly pine KW - Switchgrass KW - Biomass KW - Bioenergy KW - Soil N cycling KW - Soil N dynamics ER - TY - JOUR TI - The role of citizen science in addressing grand challenges in food and agriculture research AU - Ryan, S. F. AU - Adamson, N. L. AU - Aktipis, A. AU - Andersen, L. K. AU - Austin, R. AU - Barnes, L. AU - Beasley, M. R. AU - Bedell, K. D. AU - Briggs, S. AU - Chapman, B. AU - Cooper, C. B. AU - Corn, J. O. AU - Creamer, N. G. AU - Delborne, J. A. AU - Domenico, P. AU - Driscoll, E. AU - Goodwin, J. AU - Hjarding, A. AU - Hulbert, J. M. AU - Isard, S. AU - Just, M. G. AU - Gupta, K. Kar AU - López-Uribe, M. M. AU - O'Sullivan, J. AU - Landis, E. A. AU - Madden, A. A. AU - McKenney, E. A. AU - Nichols, L. M. AU - Reading, B. J. AU - Russell, S. AU - Sengupta, N. AU - Shapiro, L. R. AU - Shell, L. K. AU - Sheard, J. K. AU - Shoemaker, D. D. AU - Sorger, D. M. AU - Starling, C. AU - Thakur, S. AU - Vatsavai, R. R. AU - Weinstein, M. AU - Winfrey, P. AU - Dunn, R. R. T2 - Proceedings of the Royal Society B: Biological Sciences AB - The power of citizen science to contribute to both science and society is gaining increased recognition, particularly in physics and biology. Although there is a long history of public engagement in agriculture and food science, the term 'citizen science' has rarely been applied to these efforts. Similarly, in the emerging field of citizen science, most new citizen science projects do not focus on food or agriculture. Here, we convened thought leaders from a broad range of fields related to citizen science, agriculture, and food science to highlight key opportunities for bridging these overlapping yet disconnected communities/fields and identify ways to leverage their respective strengths. Specifically, we show that (i) citizen science projects are addressing many grand challenges facing our food systems, as outlined by the United States National Institute of Food and Agriculture, as well as broader Sustainable Development Goals set by the United Nations Development Programme, (ii) there exist emerging opportunities and unique challenges for citizen science in agriculture/food research, and (iii) the greatest opportunities for the development of citizen science projects in agriculture and food science will be gained by using the existing infrastructure and tools of Extension programmes and through the engagement of urban communities. Further, we argue there is no better time to foster greater collaboration between these fields given the trend of shrinking Extension programmes, the increasing need to apply innovative solutions to address rising demands on agricultural systems, and the exponential growth of the field of citizen science. DA - 2018/11/21/ PY - 2018/11/21/ DO - 10.1098/rspb.2018.1977 VL - 285 IS - 1891 SP - 20181977 UR - https://doi.org/10.1098/rspb.2018.1977 KW - citizen science KW - agriculture KW - grand challenges KW - sustainable development goals KW - extension KW - food science ER - TY - JOUR TI - Weed management in sorghum cultivation AU - Bagavathiannan, M. AU - Everman, W. AU - Govindasamy, P. AU - Dille, A. AU - Jugulam, M. AU - Norsworthy, J. T2 - ACHIEVING SUSTAINABLE CULTIVATION OF SORGHUM, VOL 1: GENETICS, BREEDING AND PRODUCTION TECHNIQUES DA - 2018/// PY - 2018/// DO - 10.19103/AS.2017.0015.18 VL - 31 SP - 465-482 SN - 2059-6944 ER - TY - CONF TI - Ammonium ion selective electrode response in swine urine solutions AU - Deviney, A.V. AU - Classen, J.J. AU - Rice, J.M. AU - Hesterberg, D. AB - Abstract. Global awareness of nitrogen loss from livestock manure is driving research towards reducing ammonia emissions. The majority of manure ammonia is produced by the hydrolysis of urine urea by urease enzyme from fecal bacteria near the time of deposition. Over time, microbial activity produces additional ammonia through the metabolism of organic nitrogen in manure. An immediate and accurate field method would be a useful tool to quantify ammonia formation and loss. Standard colorimetric methods of measuring ammonia typically involve extensive sample preparation and costly equipment. Ammonium ion selective electrodes (AISEs) are a common portable tool used for water quality analysis but little literature exists for their use in manure solutions. Manure solutions contain much higher concentrations of ammonium and other ions than municipal wastewater, resulting in high ionic strength and other potential interferences in an AISE response. A method that corrects for these interferences would enable more rapid measurement of ammonium. Comparison with spectrophotometric lab analysis was used to determine the effect of sow urine on AISE response. Dilutions of sow urine with and without ammonium spikes were used to assess the effect of ionic strength and K:NH4 ratios on AISE response. Results confirm that ionic strength exerts a suppressive effect while high interfering ion ratios increase the reading. Based on these results, future work may determine how to mitigate the effects of high ionic strength and interfering ion concentrations in manure solutions. This will allow the development of a methodology for determining ammonium concentrations in these solutions. C2 - 2018/// C3 - ASABE 2018 Annual International Meeting DA - 2018/// DO - 10.13031/aim.201800208 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-85054172161&partnerID=MN8TOARS ER - TY - JOUR TI - Pasture systems for pigs AU - Pietrosemoli, Silvana AU - Green, James T. T2 - ACHIEVING SUSTAINABLE PRODUCTION OF PIG MEAT, VOL 3: ANIMAL HEALTH AND WELFARE AB - The inclusion of pastures in outdoor pig systems contributes significantly to improving the sustainability of these farming systems. This chapter examines the characteristics of pasture pig systems, including forages and pasture management as well the effects of pasture on meat quality. The chapter also provides a detailed case study of the pasture pig system developed at the Center for Environmental Farming Systems (CEFS) in the United States. Finally, the chapter looks ahead to future research in the field of sustainable pasture pig systems and provides guidance on further reading in this area. DA - 2018/// PY - 2018/// DO - 10.19103/AS.2017.0013.21 SP - 151-202 ER - TY - JOUR TI - Preventing mycotoxin contamination in groundnut cultivation AU - Jordan, David AU - Brandenburg, Rick AU - Payne, Gary AU - Hoisington, David AU - Magnan, Nick AU - Rhoads, James AU - Abudulai, Mumuni AU - Adhikari, Koushik AU - Chen, Jinru AU - Akromah, Richard AU - Appaw, William AU - Ellis, William AU - Balota, Maria AU - Mallikarjunan, Kumar AU - Boote, Kenneth AU - MacDonald, Greg AU - Bowen, Kira AU - Bravo-Ureta, Boris AU - Jelliffe, Jeremy AU - Budu, Agnes AU - Chalwe, Hendrix AU - Mweetwa, Alice AU - Ngulube, Munsanda AU - Dankyi, Awere AU - Mochia, Brandford AU - Hoffmann, Vivian AU - Muitia, Amade AU - Mwangwela, Agnes AU - Njoroge, Sam AU - Okello, David AU - Opoku, Nelson T2 - ACHIEVING SUSTAINABLE CULTIVATION OF GRAIN LEGUMES, VOL 2: IMPROVING CULTIVATION OF PARTICULAR GRAIN LEGUMES DA - 2018/// PY - 2018/// DO - 10.19103/AS.2017.0023.28 VL - 36 SP - 181-211 SN - 2059-6944 ER - TY - JOUR TI - Improving cultivation of groundnuts AU - Nigam, S. N. AU - Jordan, D. L. AU - Janila, P. T2 - ACHIEVING SUSTAINABLE CULTIVATION OF GRAIN LEGUMES, VOL 2: IMPROVING CULTIVATION OF PARTICULAR GRAIN LEGUMES AB - Groundnut (also known as peanut) (Arachis hypogaea L.), a native of South America, has often been referred to as an unpredictable legume in the past (Gregory and Gregory, 1979; Hammons, 1994). The genus Arachis contains 81 described species, categorized into nine taxonomic sections, and includes both diploids and tetraploids belonging to either annual or perennial type. The classification is based on morphology, geographical distribution and cross-compatibility among the species (Valls and Simpson, 2005). The only cultivated groundnut, Arachis hypogaea L., is further divided into two sub-species ‘hypogaea’ and ‘fastigata’ based on the branching pattern and the distribution of vegetative and reproductive axes. Although it has been known to humankind for many centuries, its commercial cultivation started only in early 1900, when it began receiving research attention... DA - 2018/// PY - 2018/// DO - 10.19103/AS.2017.0023.27 VL - 36 SP - 155-179 SN - 2059-6944 ER - TY - RPRT TI - Management of yellow nutsedge in sweetpotato AU - Beam, S.C. AU - Jennings, K.M. DA - 2018/3/12/ PY - 2018/3/12/ M1 - AG-837 SN - AG-837 ER - TY - MGZN TI - Investing in natural grass AU - Miller, G.L. T2 - SportsTurf DA - 2018/// PY - 2018/// VL - 34 SP - 50 M1 - 11 ER - TY - MGZN TI - Application conditions influence turf colorant performance AU - Pinnix, D. AU - Miller, G.L. T2 - SportsTurf DA - 2018/// PY - 2018/// VL - 34 SP - 18,20–21 M1 - 9 ER - TY - MGZN TI - Impact of fraise mowing on soil physical properties of bermudagrass surfaces AU - McCauley, R. AU - Miller, G.L. AU - Pinnix, G.D. T2 - North Carolina Turfgrass DA - 2018/// PY - 2018/// SP - 12-14,16 M3 - Cover ER - TY - MGZN TI - What are you looking for? AU - Miller, G.L. T2 - SportsTurf DA - 2018/// PY - 2018/// VL - 34 SP - 50 M1 - 9 ER - TY - MGZN TI - Using what you got AU - Miller, G.L. T2 - SportsTurf DA - 2018/// PY - 2018/// VL - 34 SP - 50 M1 - 7 ER - TY - MGZN TI - Taking it to the next level AU - Miller, G.L. T2 - SportsTurf DA - 2018/// PY - 2018/// VL - 34 SP - 50 M1 - 3 ER - TY - MGZN TI - Ryegrass slip and slide AU - Miller, G.L. T2 - SportsTurf DA - 2018/// PY - 2018/// VL - 34 SP - 58 M1 - 1 ER - TY - JOUR TI - Integrating grafting and emerging products to manage soilborne diseases of tomato AU - Louws, F. J. AU - Suchoff, D. AU - Kressin, J. AU - Panthee, D. AU - Driver, J. AU - Gunter, C. T2 - V INTERNATIONAL SYMPOSIUM ON TOMATO DISEASES: PERSPECTIVES AND FUTURE DIRECTIONS IN TOMATO PROTECTION AB - Major soilborne diseases in North Carolina and surrounding states include fusarium wilt (FW) (causal agent Fusarium oxysporum f. sp. lycopersici; all three races), verticillium wilt (VW) (Verticillium dahliae; two races), southern stem blight (SSB) (Sclerotium rolfsii), root-knot nematodes (RKN) (primarily Meloidogyne incognita) and bacterial wilt (BW) (Ralstonia solanacearum race 1), distributed across the subtropical to temperate ecosystems in the state. FW, VW, SSB, and RKN can be well managed using standard fumigants. Alternative management practices are needed in production systems where fumigants are not used or effective, and/or where heirloom tomato cultivars are grown. We are involved in a USA multi-state program to determine the viability of grafting in open-field production systems. Previously published work showed the utility of grafting to manage FW, SSB, RKN, and BW. In complementary work to manage BW, a replicated on-farm field trial demonstrates that fumigants such as Paladin (79% dimethyl disulfide + 21% chloropicrin) and PicClor60 (60% chloropicrin + 40% 1,3-dichloropropene) allow up to 80% plant death, similar to incidence in non-fumigated plots, whereas grafting to resistant rootstock (Seminis 'Cheong Gang') confers 100% control in non-fumigated plots. Another on-farm randomized complete block design experiment demonstrated that three commercially available rootstocks conferred 100% plant stand, whereas non-grafted plants had 80% plant death using a round tomato scion ('Red Mountain') or 15% plant death using a roma tomato ('Picus'). Grafted plants show economic viability in North Carolina, and additional work is needed to optimize this tool in diverse production systems. DA - 2018/// PY - 2018/// DO - 10.17660/ActaHortic.2018.1207.34 VL - 1207 SP - 249-254 SN - 2406-6168 KW - Ralstonia solanacearum KW - vegetable grafting KW - rootstock KW - on-farm-research KW - fumigation ER - TY - JOUR TI - Effect of Bicyclopyrone on Triploid Watermelon in Plasticulture AU - Bertucci, Matthew B. AU - Jennings, Katherine M. AU - Monks, David W. AU - Jordan, David L. AU - Schultheis, Jonathan R. AU - Louws, Frank J. AU - Waldschmidt, Matthew D. T2 - Weed Technology AB - Abstract Field studies were conducted to determine watermelon tolerance and yield response when treated with bicyclopyrone preplant (PREPLANT), POST, and POST-directed (POST-DIR). Treatments consisted of two rates of bicyclopyrone (37.5 and 50 g ai ha –1 ), fomesafen (175 g ai ha –1 ), S -metolachlor (802 g ai ha –1 ), and a nontreated check. Preplant treatments were applied to formed beds 1 d prior to transplanting and included bicyclopyrone (37.5 and 50 g ha –1 ) and fomesafen (175 g ha –1 ), and new polyethylene mulch was subsequently laid above treated beds. POST and POST-DIR treatments were applied 14 ± 1 d after watermelon transplanting and included bicyclopyrone (37.5 and 50 g ha –1 ) POST and POST-DIR, and S -metolachlor (802 g ai ha –1 ) POST-DIR. POST-DIR treatments were applied to row middles, ensuring that no herbicide contacted watermelon vines or polyethylene mulch. At 2 wk after transplanting (WAT), 15% foliar bleaching was observed in watermelon treated with bicyclopyrone (50 g ha –1 ) PRE. At 3 WAT, bicyclopyrone (37.5 and 50 g ha –1 ) POST caused 16% and 17% foliar bleaching and 8% and 9% crop stunting, respectively. At 4 WAT, initial injury had subsided and bicyclopyrone (37.5 and 50 g ha –1 ) POST caused 4% and 4% foliar bleaching and 4% and 8% crop stunting, respectively. No symptoms of bleaching or stunting were observed at 6- and 8-WAT ratings. Watermelon total yield, marketable yield, total fruit number, marketable fruit number, and average fruit size were unaffected by herbicide treatments. Therefore, registration of bicyclopyrone (37.5 and 50 g ha –1 ) PREPLANT, POST, and POST-DIR would offer watermelon producers a safe herbicide option and a novel mode of action for weed management. DA - 2018/6/21/ PY - 2018/6/21/ DO - 10.1017/wet.2018.36 VL - 32 IS - 4 SP - 439-443 J2 - Weed Technol LA - en OP - SN - 0890-037X 1550-2740 UR - http://dx.doi.org/10.1017/WET.2018.36 DB - Crossref KW - Crop injury KW - herbicide KW - HPPD ER - TY - JOUR TI - Interference of Palmer amaranth (Amaranthus palmeri) Density in Grafted and Nongrafted Watermelon AU - Bertucci, Matthew B. AU - Jennings, Katherine M. AU - Monks, David W. AU - Schultheis, Jonathan R. AU - Louws, Frank J. AU - Jordan, David L. T2 - Weed Science AB - Abstract Watermelon [ Citrullus lanatus (Thunb.) Matsum & Nakai] grafting is commonly used for management of diseases caused by soilborne pathogens; however, little research exists describing the effect of grafting on the weed-competitive ability of watermelon. Field experiments determined the response in yield, fruit number, and fruit quality of grafted and nongrafted watermelon exposed to increasing densities of Palmer amaranth ( Amaranthus palmeri S. Watson). Grafting treatments included ‘Exclamation’ triploid (seedless) watermelon grafted on two interspecific hybrid squash rootstocks ‘Carnivor’ and ‘Kazako’, with nongrafted Exclamation as the control. Weed treatments included A. palmeri at densities of 1, 2, 3, and 4 A. palmeri plants per watermelon planting hole (0.76-m row) and a weed-free control. Increasing A. palmeri densities caused significant reductions (P <0.05) in marketable watermelon yield and marketable fruit number. Watermelon yield reduction was described by a rectangular hyperbola model, and 4 A. palmeri plants planting hole −1 reduced marketable yield 41%, 38%, and 65% for Exclamation, Carnivor, and Kazako, respectively. Neither grafting treatment nor A. palmeri density had a biologically meaningful effect on soluble solids content or on the incidence of hollow heart in watermelon fruit. Amaranthus palmeri seed and biomass production was similar across weed population densities, but seed number per female A. palmeri decreased according to a two-parameter exponential decay equation. Thus, increasing weed population densities resulted in increased intraspecific competition among A. palmeri plants. While grafting may offer benefits for disease resistance, no benefits regarding weed-competitive ability were observed, and a consistent yield penalty was associated with grafting, even in weed-free treatments. DA - 2018/12/17/ PY - 2018/12/17/ DO - 10.1017/wsc.2018.77 VL - 67 IS - 2 SP - 229-238 J2 - Weed Sci LA - en OP - SN - 1550-2759 UR - http://dx.doi.org/10.1017/wsc.2018.77 DB - Crossref KW - Carlene Chase KW - University of Florida KW - Competition KW - Cucurbitaceae KW - seed production KW - vegetable ER - TY - JOUR TI - Weed Control and Peanut (Arachis hypogaea L.) Response to Acetochlor Alone and in Combination with Various Herbicides AU - Chaudhari, Sushila AU - Jordan, David L. AU - Grey, Timothy L. AU - Prostko, Eric P. AU - Jennings, Katherine M. T2 - Peanut Science AB - ABSTRACT Acetochlor, a chloroacetamide herbicide, is now registered for preplant (PPI), preemergence (PRE), and postemergence (POST) application in peanut. Field research was conducted during 2011 and 2012 in Georgia and North Carolina to determine peanut response and weed control by acetochlor compared with S-metolachlor alone and in programs with other herbicides. In weed-free experiments, peanut tolerance to acetochlor (1.26 and 2.52 kg ai/ha) and S-metolachlor (1.42 kg ai/ha) were evaluated when applied PPI, PRE, early postemergence (EPOST), or POST. Peanut tolerance to acetochlor was similar to S-metolachlor with no negative impact of either herbicide on peanut yield compared with non-treated peanut in absence of weed interference. When applied PRE, acetochlor controlled Palmer amaranth, pitted morningglory, sicklepod, and Texas millet similarly to S-metolachlor while control of broadleaf signalgrass was greater with S-metolachlor. Weed control programs containing EPOST and/or POST applications of herbicides following PRE herbicides provided the best overall weed control but did not affect yellow nutsedge control regardless of whether acetochlor or S-metolachlor were applied. Herbicide programs including PRE, EPOST, and POST herbicides most often resulted in the greatest yields. There was no difference in peanut yield regardless of the presence of acetochlor or S-metolachlor in a comprehensive herbicide program. DA - 2018/1// PY - 2018/1// DO - 10.3146/ps17-19.1 VL - 45 IS - 1 SP - 45-55 J2 - Peanut Science LA - en OP - SN - 0095-3679 UR - http://dx.doi.org/10.3146/PS17-19.1 DB - Crossref ER - TY - JOUR TI - Vegetation-Free Strip Width Affects Growth, Berry Composition, and Yield of Cabernet franc in Vigorous Growing Environments AU - Basinger, Nicholas T. AU - Jennings, Katherine M. AU - Monks, David W. AU - Mitchem, Wayne E. AU - Chaudhari, Sushila AU - Heitman, Joshua L. AU - Havlin, John L. AU - Howard, Adam M. AU - Spayd, Sara E. T2 - Catalyst: Discovery into Practice AB -

Summary

Goals:

In regions such as the eastern United States, excess vine vigor can be problematic. In this region, it is common to plant a perennial grass between rows, which can compete with vines for water and nutrients. The purpose of this research was to determine the effect of vegetation-free strip (VFS) width beneath the planted row on vine growth and fruit quality. The current recommendation for VFS width is 90 to 120 cm. However, modification of the VFS width can provide additional competition, limiting vine vigor. Determining the optimal width and effect of the VFS on vine size, berry composition, and yield would allow growers to optimize groundcover management in this region.

Key Findings:

Reducing VFS width decreased pruning weight/m cordon, shoot number/m cordon, lateral shoot number/cane, and summer fresh hedging weights. Narrowing the VFS width was most effective in the two of four years with the least rainfall. Yield/m cordon was reduced by narrowing VFS width, but not to below normal adjusted crop loads. Cluster weight, number of berries/cluster, and cluster number/m cordon were also reduced by narrowing VFS width. Berry soluble solids and total anthocyanins increased and TA decreased with decreasing VFS width, improving berry quality. Postveraison natural weed population growth in the VFS did not affect vine growth or fruit yield and composition.

Impact and Significance:

In the eastern United States, high rainfall and humidity promote excessive vine growth and immense pest pressure for Vitis vinifera production. Improved canopy characteristics could increase fruit quality by reducing pest pressure, by increasing soluble solids and total anthocyanin concentrations, and by improving the balance between pH and titratable acidity (TA). Increasing competition for water and nutrients during the growing season (by narrowing the VFS or allowing late-season weed competition) may be an effective way to accomplish these improvements. In this study, narrower VFS width in a tall fescue (Festuca arundinacea var. ‘Kentucky 31’) groundcover reduced vine vegetative growth and positively influenced berry composition. Vineyard weed populations that established naturally postveraison did not affect vine size, yield, or fruit quality. DA - 2018/6/18/ PY - 2018/6/18/ DO - 10.5344/catalyst.2018.17005 VL - 2 IS - 1 SP - 15-23 J2 - Catalyst: Discovery into Practice LA - en OP - SN - 2469-7974 2469-7974 UR - http://dx.doi.org/10.5344/catalyst.2018.17005 DB - Crossref ER - TY - JOUR TI - Effects of Vegetation-Free Strip Width and Irrigation on Newly Planted Peach AU - Buckelew, Juliana K. AU - Mitchem, Wayne E. AU - Monks, David W. AU - Chaudhari, Sushila AU - Jennings, Katie M. AU - Mehra, Lucky K. T2 - International Journal of Fruit Science AB - Field experiments were conducted at two locations (Clayton and Jackson Springs, NC) to determine the influence of vegetation-free strip width (VFSW) and irrigation on newly planted peach growth and yield in a low-density orchard with a volunteer weedy ground cover. The experiments included VFSW of 0, 0.6, 1.2, 2.4, 3, or 3.6 m under irrigated or nonirrigated conditions. Seasonal variation in the orchard floor vegetation was observed as different weed species reported in summer and winter. However, this difference was not apparent with respect to VFSF and irrigation. At Jackson Springs, NC, the predicted irrigated VFSW which would produce the same trunk cross-sectional area (TCSA) as the grower standard (3-m nonirrigated) was 1.5, 1.3, and 0.8 m for one-, two-, and three-year-old trees, respectively. The predicted irrigated VFSW which would produce the same yield as the grower standard was 1.16 m. At Clayton, TCSA and fruit yield were not different by irrigation, but did increase linearly with VFSW. At both locations, leaf nitrogen (N) concentration was lower in irrigated trees than nonirrigated trees. Leaf N, leaf area, and SPAD were positively related to VFSW at Jackson Springs. In contrast, leaf N concentration was not different by VFSW at Clayton. However, leaf area and SPAD were positively related to VFSW at Clayton. These results suggest that a 1.5 m VFSW combined with proper irrigation and fertilization will produce tree growth and yield in newly planted orchard with volunteer weedy vegetation similar to the current grower standard in the southeastern USA. DA - 2018/11// PY - 2018/11// DO - 10.1080/15538362.2018.1545622 VL - 19 IS - 1 SP - 75-90 KW - Competition KW - fruit tree KW - orchard KW - floor-management KW - weed-control ER - TY - JOUR TI - Critical Period for Weed Control in Grafted and Nongrafted Watermelon Grown in Plasticulture AU - Bertucci, Matthew B. AU - Jennings, Katherine M. AU - Monks, David W. AU - Schultheis, Jonathan R. AU - Louws, Frank J. AU - Jordan, David L. AU - Brownie, Cavell T2 - Weed Science AB - Abstract Field experiments determined the critical period for weed control (CPWC) in grafted and nongrafted watermelon [ Citrullus lanatus (Thumb.) Matsum. & Nakai] grown in plasticulture. Transplant types included ‘Exclamation’ seedless watermelon as the nongrafted control as well as Exclamation grafted onto two interspecific hybrid squash (ISH) rootstocks, ‘Carnivor’ and ‘Kazako’. To simulate weed emergence throughout the season, establishment treatments (EST) consisted of two seedlings each of common purslane ( Portulaca oleracea L.), large crabgrass [ Digitaria sanguinalis (L.) Scop.], and yellow nutsedge ( Cyperus esculentus L.) transplanted in a 15 by 15 cm square centered on watermelon plants at 0, 2, 3, 4, and 6 wk after watermelon transplanting (WATr) and remained until the final watermelon harvest at 11 WATr. To simulate weed control at different times in the season, removal treatments (REM) consisted of two seedlings of the same weed species transplanted in a 15 by 15 cm square centered on watermelon plants on the same day of watermelon transplanting and allowed to remain until 2, 3, 4, 6, and 11 WATr, at which time they were removed. Season-long weedy and weed-free controls were included for both EST and REM studies in both years. For all transplant types, aboveground biomass of weeds decreased as weed establishment was delayed and increased as weed removal was delayed. The predicted CPWC for nongrafted Exclamation and Carnivor required only a single weed removal between 2.3 and 2.5 WATr and 1.9 and 2.6 WATr, respectively, while predicted CPWC for Kazako rootstock occurred from 0.3 to 2.6 WATr. Our study results suggest that weed control for this mixed population of weeds would be similar between nongrafted Exclamation and Exclamation grafted onto Carnivor. But the observed CPWC of Exclamation grafted onto Kazako suggests that CPWC may vary with specific rootstock–scion combinations. DA - 2018/11/19/ PY - 2018/11/19/ DO - 10.1017/wsc.2018.76 VL - 67 IS - 2 SP - 221-228 J2 - Weed Sci LA - en OP - SN - 1550-2759 UR - http://dx.doi.org/10.1017/wsc.2018.76 DB - Crossref KW - Carlene Chase KW - University of Florida KW - Competition KW - establishment KW - interference KW - removal ER - TY - JOUR TI - Turnip Tolerance to Preplant Incorporated Trifluralin AU - Chaudhari, Sushila AU - Jennings, Katherine M. AU - Culpepper, Stanley AU - Batts, Roger B. AU - Bellinder, Robin T2 - Weed Technology AB - Abstract Field research was conducted in 2012 and 2013 in Georgia, New York, and North Carolina to evaluate the effect of trifluralin PPI on turnip root production. Treatments included trifluralin PPI at 0, 0.42, 0.56, 0.84, 1.12, 1.68, 2.24, and 3.36 kg ai ha −1 . Aboveground injury to turnip varied by location and increased from 0% to 85% as trifluralin rate increased from 0.42 to 3.36 kg ha −1 . Trifluralin at 0.42 to 0.84 kg ha −1 caused ≤7% injury, except at Clayton, NC, and Freeville, NY, where injury ≤32%. Trifluralin at 0.42 to 0.84 kg ha −1 reduced turnip root yield ≤11% at all locations, except Clinton, NC, where yield was reduced 29% and 43% by 0.56 and 0.84 kg ha −1 , respectively. Turnip roots were not injured internally by trifluralin. Our research results suggest that up to 0.84 kg ha −1 trifluralin PPI is safe to use in turnip roots. DA - 2018/12/4/ PY - 2018/12/4/ DO - 10.1017/wet.2018.66 VL - 33 IS - 1 SP - 123-127 J2 - Weed Technol LA - en OP - SN - 0890-037X 1550-2740 UR - http://dx.doi.org/10.1017/wet.2018.66 DB - Crossref KW - Trifluralin KW - turnip, Brassica rapa L. 'Purple Top White Globe' KW - Crop injury KW - herbicide KW - yield ER - TY - JOUR TI - Response of Palmer Amaranth and Sweetpotato to Flumioxazin/Pyroxasulfone AU - Beam, Shawn C. AU - Chaudhari, Sushila AU - Jennings, Katherine M. AU - Monks, David W. AU - Meyers, Stephen L. AU - Schultheis, Jonathan R. AU - Waldschmidt, Mathew AU - Main, Jeffrey L. T2 - Weed Technology AB - Abstract Studies were conducted to determine the tolerance of sweetpotato and Palmer amaranth control to a premix of flumioxazin and pyroxasulfone pretransplant (PREtr) followed by (fb) irrigation. Greenhouse studies were conducted in a factorial arrangement of four herbicide rates (flumioxazin/pyroxasulfone PREtr at 105/133 and 57/72 g ai ha –1 , S -metolachlor PREtr 803 g ai ha –1 , nontreated) by three irrigation timings [2, 5, and 14 d after transplanting (DAP)]. Field studies were conducted in a factorial arrangement of seven herbicide treatments (flumioxazin/pyroxasulfone PREtr at 40/51, 57/72, 63/80, and 105/133 g ha –1 , 107 g ha –1 flumioxazin PREtr fb 803 g ha –1 S -metolachlor 7 to 10 DAP, and season-long weedy and weed-free checks) by three 1.9-cm irrigation timings (0 to 2, 3 to 5, or 14 DAP). In greenhouse studies, flumioxazin/pyroxasulfone reduced sweetpotato vine length and shoot and storage root fresh biomass compared to the nontreated check and S -metolachlor. Irrigation timing had no influence on vine length and root fresh biomass. In field studies, Palmer amaranth control was≥91% season-long regardless of flumioxazin/pyroxasulfone rate or irrigation timing. At 38 DAP, sweetpotato injury was≤37 and≤9% at locations 1 and 2, respectively. Visual estimates of sweetpotato injury from flumioxazin/pyroxasulfone were greater when irrigation timing was delayed 3 to 5 or 14 DAP (22 and 20%, respectively) compared to 0 to 2 DAP (7%) at location 1 but similar at location 2. Irrigation timing did not influence no.1, jumbo, or marketable yields or root length-to-width ratio. With the exception of 105/133 g ha –1 , all rates of flumioxazin/pyroxasulfone resulted in marketable sweetpotato yield and root length-to-width ratio similar to flumioxazin fb S -metolachlor or the weed-free checks. In conclusion, flumioxazin/pyroxasulfone PREtr at 40/51, 57/72, and 63/80 g ha –1 has potential for use in sweetpotato for Palmer amaranth control without causing significant crop injury and yield reduction. DA - 2018/11/29/ PY - 2018/11/29/ DO - 10.1017/wet.2018.80 VL - 33 IS - 1 SP - 128-134 J2 - Weed Technol LA - en OP - SN - 0890-037X 1550-2740 UR - http://dx.doi.org/10.1017/wet.2018.80 DB - Crossref KW - Peter J. Dittmar, University of Florida KW - Flumioxazin KW - pyroxasulfone KW - S-metolachlor KW - Palmer amaranth, Amaranthus palmeri (S.) Watson AMAPA KW - sweetpotato, Ipomoea batatas (L.) Lam KW - Application rate KW - crop injury KW - herbicide efficacy KW - storage root shape KW - timing ER - TY - CHAP TI - Using soil descriptions to evaluate surface water management in the Ical Group AU - Ricker, M.C. AU - Marken, D.B. AU - Cooper, Z. T2 - Proyecto Arqueológico El Perú-Waka’ PY - 2018/// SP - 130–195 PB - Fundación de Investigación Arqueológica Waka’ ER - TY - JOUR TI - Defoliation management affects productivity, leaf/stem ratio, and tiller counts of ‘performer’ switchgrass AU - Bekewe, P.E. AU - Castillo, M.S. AU - Rivera, R. T2 - Agronomy Journal AB - Core Ideas Defoliation management resulted in a wide range of plant responses that varied by year, with deleterious responses more evident in the second year. Greater leaf/stem ratios occurred with more frequent defoliation treatments. Frequent defoliations such as every 3 wk should maintain a stubble height of at least 40 cm, defoliation frequencies ≥6 wk to 20‐cm stubble height, and ≥9 wk to 10 cm stubble height are warranted to ensure stand persistence. ‘Performer’ switchgrass ( Panicum virgatum L.) was released in 2006 by the USDA‐NCSU forage program because of its greater digestibility compared to standard cultivars grown in the southeastern United States. Forages with greater digestibility have potential to positively impact animal responses, however, defoliation management can influence its productivity and persistence. The objectives were to determine the effect of the factorial combination of four defoliation heights (DH) (clipped to 10, 20, 30, and 40‐cm) and four defoliation frequencies (DF) (clipped every 3, 6, 9, and 12 wk) on productivity, leaf/stem ratio, and tiller counts. The experiment was conducted in 2016 and 2017 at the Central Crops Research Station, Clayton, NC. The 16 treatments were allocated in a complete randomized block design replicated four times. In 2016, total dry matter (DM) yield ranged from 4.2 to 13.1 Mg ha −1 being greatest for the 9‐ and 12‐wk DF at 10‐ and 20‐cm DH and lowest for all DH at 3‐wk defoliation frequency. In 2017, the DM yield range was wider ranging from 0.5 to 14.0 Mg ha −1 with lower tiller counts for the 10‐ and 20‐cm DH, 3‐wk DF treatments. Leaf/stem ratio was greater for the more frequently defoliated treatments in both years. ‘Performer’ switchgrass is a productive forage and on the basis of total DM harvested, leaf/stem ratio, and tiller counts, frequent defoliations such as every 3 wk to 40‐cm stubble height, ≥6 wk to 20‐cm stubble height, and ≥ 9 wk to 10 cm stubble height, are warranted to ensure stand persistence. DA - 2018/// PY - 2018/// DO - 10.2134/agronj2018.01.0003 VL - 110 IS - 4 SP - 1467-1472 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-85050070546&partnerID=MN8TOARS ER - TY - JOUR TI - Field‐grown soybean transcriptome shows diurnal patterns in photosynthesis‐related processes AU - Locke, Anna M. AU - Slattery, Rebecca A. AU - Ort, Donald R. T2 - Plant Direct AB - Many plant physiological processes have diurnal patterns regulated by diurnal environmental changes and circadian rhythms, but the transcriptional underpinnings of many of these cycles have not been studied in major crop species under field conditions. Here, we monitored the transcriptome of field-grown soybean (Glycine max) during daylight hours in the middle of the growing season with RNA-seq. The analysis revealed 21% of soybean genes were differentially expressed over the course of the day. Expression of some circadian-related genes in field-grown soybean differed from previously reported expression patterns measured in controlled environments. Many genes in functional groups contributing to and/or depending on photosynthesis showed differential expression, with patterns particularly evident in the chlorophyll synthesis pathway. Gene regulatory network inference also revealed seven diurnally sensitive gene nodes involved with circadian rhythm, transcription regulation, cellular processes, and water transport. This study provides a diurnal overview of the transcriptome for an economically important field-grown crop and a basis for identifying pathways that could eventually be tailored to optimize diurnal regulation of carbon gain. DA - 2018/12// PY - 2018/12// DO - 10.1002/pld3.99 VL - 2 IS - 12 J2 - Plant Direct LA - en OP - SN - 2475-4455 2475-4455 UR - http://dx.doi.org/10.1002/pld3.99 DB - Crossref ER - TY - JOUR TI - Investigating Freezing Patterns in Plants Using Infrared Thermography AU - Livingston, David P., III T2 - SURVIVAL STRATEGIES IN EXTREME COLD AND DESICCATION: ADAPTATION MECHANISMS AND THEIR APPLICATIONS AB - Since the discovery of infrared radiation in 1800, the improvement of technology to detect and image infrared (IR) has led to numerous breakthroughs in several scientific fields of study. The principle that heat is released when water freezes and the ability to image this release of heat using IR thermography (IRT) has allowed an unprecedented understanding of freezing in plants. Since the first published report of the use of IRT to study freezing in plants, numerous informative discoveries have been reported. Examples include barriers to freezing, specific sites of ice nucleation, direction and speed of ice propagation, specific structures that supercool, and temperatures at which they finally freeze. These and other observations underscore the significance of this important technology on plant research. DA - 2018/// PY - 2018/// DO - 10.1007/978-981-13-1244-1_7 VL - 1081 SP - 117-127 SN - 2214-8019 KW - Infrared thermography KW - Plants KW - Freezing KW - Latent heat KW - Ice nucleation KW - Ice propagation KW - Barrier KW - Supercool KW - Thermocouple ER - TY - SOUND TI - Controlled Freezing Tests and QTL Mapping in Cold-acclimated and Non-acclimated Zoysiagrass AU - Brown, J.M. AU - Holloway, H.M. AU - Tuong, T. AU - Yu, X. AU - Livingston, D.P. AU - Patton, A.J. AU - Arellano, C. AU - Schwartz, B.M. AU - Milla-Lewis, S.R. DA - 2018/11/4/ PY - 2018/11/4/ ER - TY - SOUND TI - From the breeder’s corner AU - Milla-Lewis, S.R. DA - 2018/1/17/ PY - 2018/1/17/ M3 - invited presentation ER - TY - SOUND TI - From Classical to Molecular Approaches: Building a Turfgrass Breeding Program for the Transition Zone AU - Milla-Lewis, S.R. DA - 2018/4/5/ PY - 2018/4/5/ M3 - invited presentation ER - TY - SOUND TI - Analysis of St. Augustinegrass cultivars using SSR markers and testing for the presence of Sugarcane Mosaic Virus AU - Buhlman, J.L. AU - Harmon, P.F. AU - Milla-Lewis, S.R. AU - Rios, E.F. AU - Kenworthy, K.E. DA - 2018/11/4/ PY - 2018/11/4/ ER - TY - JOUR TI - Peanut residue distribution gradients and tillage practices determine patterns of nitrogen mineralization AU - Jani, Arun D. AU - Mulvaney, Michael J. AU - Enloe, Heather A. AU - Erickson, John E. AU - Leon, Ramon G. AU - Rowland, Diane L. AU - Wood, C. Wesley T2 - Nutrient Cycling in Agroecosystems DA - 2018/11// PY - 2018/11// DO - 10.1007/s10705-018-9962-2 VL - 113 IS - 1 SP - 63-76 KW - Peanut KW - Carbon KW - Nitrogen KW - Residues KW - Mineralization KW - Tillage ER - TY - JOUR TI - Metabolic and Transcriptional Profiles of Dunaliella viridis Supplemented With Ammonium Derived From Glutamine AU - Dums, Jacob AU - Murphree, Colin AU - Vasani, Naresh AU - Young, Danielle AU - Sederoff, Heike T2 - FRONTIERS IN MARINE SCIENCE AB - Algal biofuel production requires an input of synthetic nitrogen fertilizer. Fertilizer synthesized via the Haber-Bosch process produces CO2 as a waste byproduct and represents a substantial financial and energy investment. Reliance on synthetic fertilizer attenuates the environmental significance and economic viability of algae production systems. To lower fertilizer input, the waste streams of algal production systems can be recycled to provide alternative sources of nitrogen such as amino acids to the algae. The halophytic green alga Dunaliella viridis can use ammonium (NH4+) derived from the abiotic degradation of amino acids, and previously, supplementation of NH4+ from glutamine degradation was shown to support acceptable levels of growth and increased neutral lipid production compared to nitrate. To understand the effect of glutamine-released NH4+ on algae growth and physiology, metabolite levels, growth parameters, and transcript profiles of D. viridis cultures were observed in a time course after transition from media containing nitrate as a sole N source to medium containing glutamine, glutamate, or a N-depleted medium. Growth parameters were similar between glutamine (NH4+) and nitrate supplemented cultures, however, metabolite data showed that the glutamine supplemented cultures (NH4+) more closely resembled cultures under nitrogen starvation (N-depleted and glutamate supplementation). Neutral lipid accumulation was the same in nitrate and glutamine-derived NH4+ cultures. However, glutamine-derived NH4+ caused a transcriptional response in the immediate hours after inoculation of the culture. The strong initial response of cultures to NH4+ changed over the course of days to closely resemble that of nitrogen starvation. These observations suggest that release of NH4+ from glutamine was sufficient to maintain growth, but not high enough to trigger a cell transition to a nitrogen replete state. Comparative transcript profiling of the nitrogen-starved and nitrate-supplied cultures show an overall downregulation of fatty acid synthesis and a shift to starch synthesis and accumulation. The results indicate that a continuous, amino acid derived slow release of NH4+ to algae cultures could reduce the amount of synthetic nitrogen needed for growth, but optimization is needed to balance nitrogen starvation and cell division. DA - 2018/8/30/ PY - 2018/8/30/ DO - 10.3389/fmars.2018.00311 VL - 5 SP - SN - 2296-7745 KW - Dunaliella KW - nitrogen starvation KW - ammonium KW - amino acids KW - glutamine KW - biofuel KW - nitrogen recycling KW - transcriptome ER - TY - JOUR TI - Large Scale Field Inoculation and Scoring of Maize Southern Leaf Blight and Other Maize Foliar Fungal Diseases AU - Sermons, Shannon M. AU - Balint-Kurti, Peter J. T2 - BIO-PROTOCOL AB - Field-grown maize is inoculated with Cochliobolus heterostrophus, causal agent of southern leaf blight disease, by dropping sorghum grains infested with the fungus into the whorl of each maize plant at an early stage of growth. The initial lesions produce secondary inoculum that is dispersed by wind and rain, causing multiple cycles of infection that assures a high uniform disease pressure over the entire field by the time of disease scoring, which occurs after anthesis. This method, with slight modifications, can also be used to study the maize fungal diseases northern leaf blight (caused by Exserohilum turcicum) and gray leaf spot (Cercospora zeae-maydis). DA - 2018/3/5/ PY - 2018/3/5/ DO - 10.21769/BioProtoc.2745 VL - 8 IS - 5 SP - SN - 2331-8325 KW - Maize KW - Cochliobolus heterostrophus KW - Inoculation KW - Fungal disease ER - TY - JOUR TI - Evaluating weed control and response of newly planted peach trees to herbicides AU - Buckelew, Juliana K. AU - Mitchem, Wayne E. AU - Chaudhari, Sushila AU - Monks, David W. AU - Jennings, Katie M. T2 - INTERNATIONAL JOURNAL OF FRUIT SCIENCE AB - Field experiments were conducted in North Carolina to determine peach response to herbicides. Mesotrione, rimsulfuron, and sulfentrazone did not injure newly planted peach trees. However, halosulfuron at the higher rate caused injury to peach trees, but did not reduce tree cross-sectional area or winter pruning weight. Another field experiment was conducted to determine the effect of herbicide-based programs on weed control. Sulfentrazone alone controlled common lamb’s-quarters and henbit but provided poor control of large crabgrass and yellow foxtail. However, a tank mix of norflurazon or oryzalin with sulfentrazone improved control of these weeds over sulfentrazone alone. Terbacil alone or in tank mix rimsulfuron, and flumioxazin alone gave excellent control of large crabgrass and yellow foxtail. DA - 2018/// PY - 2018/// DO - 10.1080/15538362.2018.1441772 VL - 18 IS - 4 SP - 383-393 SN - 1553-8621 KW - Crop injury KW - orchard KW - weed management KW - tree fruit KW - herbicide efficacy ER - TY - JOUR TI - Biochar In Situ Decreased Bulk Density and Improved Soil-Water Relations and Indicators in Southeastern US Coastal Plain Ultisols AU - Walters, Robert D. AU - White, Jeffrey G. T2 - SOIL SCIENCE AB - Biochar may improve soil physical properties for crop growth, but multiyear, multicrop field studies are lacking. To determine the effects of biochar on soil physical properties, we applied 0, 10, 20, 40, and 80 Mg ha−1 biochar with/without NPK fertilizer to the surface 15 cm of 1 × 1 m2 plots in a single association of fine-loamy, siliceous, subactive, thermic Oxyaquic and Aquic Paleudults under a 2-year corn-winter wheat–double-crop soybean rotation. After 3 years, we sampled soil to 7.6 cm, measured bulk density and water retention, and then derived pore-size distribution and related physical and water retention model parameters. Fertilizer had little to no effect. Among the statistically significant results, biochar increased structural porosity (3- to 59-μm effective pore diameter [EPD]) but neither matrix- (0.2- to 3-μm EPD) nor macro (EPD >59 μm) porosity. Biochar ≥40 Mg ha−1 decreased bulk density 16%; 80 Mg ha−1 increased total porosity 14%. However, it also increased water content at −1,500 kPa 22.5%. Biochar ≥40 Mg ha−1 increased the drained upper limit (DUL) by 15%; relative field capacity, 3%; and total and structural plant-available water (PAW: held between the DUL and −1,500 kPa), 7 and 18%, respectively. Increases were greatest at −10 kPa and least at −33 kPa. At −10 kPa, 80 Mg ha−1 biochar increased total PAW 4.0-mm equivalent depth compared with 5.7 mm for structural PAW, approximately 0.5-day demand for actively growing corn. Modeled saturated water content increased with total porosity. Biochar improved plant-soil-water relations, but required high rates. DA - 2018/// PY - 2018/// DO - 10.1097/SS.0000000000000235 VL - 183 IS - 3 SP - 99-111 SN - 1538-9243 KW - plant-available water KW - porosity KW - soil physical quality KW - water retention model ER - TY - JOUR TI - Winter Pea Cultivar/Breeding Line Screening for Grain Crop Potential in the Southeastern United States AU - Vann, R. A. AU - Reberg-Horton, S. C. AU - Castillo, M. S. AU - Mirsky, S. B. AU - McGee, R. J. T2 - Agronomy Journal AB - Core Ideas Winter pea is desirable for grain production in the southeastern USA. Many pea cultivars/lines survive the NC winter with minimal cold damage. Regional breeding efforts are needed for disease resistance in pea cultivars. Pea grain yield was restricted by excessive heat during flowering. Pea and wheat can be grown together and harvested simultaneously. Winter pea ( Pisum sativum L.) is desirable for grain production in the southeastern United States to increase feed protein availability; however, there has not been any previous effort devoted to maximizing pea genetics for grain production in this region. Studies were conducted at six environments in North Carolina to assess pea grain potential. Nineteen pea cultivars/breeding lines were planted in monoculture and in mixture with three wheat ( Triticum aestivum L.) cultivars of differing maturities. Pea cold tolerance, biomass production, disease incidence, maturity, lodging, and pea and wheat grain yield were assessed. The growth of only one pea cultivar/breeding line was severely inhibited by cold injury. Disease incidence was influenced by pea cultivars/breeding lines but not growth in monoculture or mixture with wheat. At the environments with heavy Sclerotinia pressure, grain yield of all pea cultivars/breeding lines was severely inhibited. All wheat cultivars reached physiological maturity prior to any pea cultivar/breeding line, and both species were harvested simultaneously using a combine with minimal difficulties. Pea yield was influenced by pea cultivar/breeding line but not growth in monoculture or mixture. Pea yield was greater with early maturing varieties. Pea grain yield potential across all pea cultivars/breeding lines was likely restricted by excessive heat during flowering. Many pea cultivars/breeding lines screened in this study out‐yielded the current pea available in North Carolina. Results indicated that pea and wheat can be grown simultaneously and that regional pea cultivar recommendations will enhance pea grain yield in the southeastern United States. DA - 2018/7// PY - 2018/7// DO - 10.2134/agronj2017.10.0594 VL - 110 IS - 4 SP - 1217-1225 LA - en SN - 0002-1962 UR - https://dl.sciencesocieties.org/publications/aj/abstracts/110/4/1217 DB - dl.sciencesocieties.org Y2 - 2019/2/7/ ER - TY - JOUR TI - Extractable and Germinable Seedbank Methods Provide Different Quantifications of Weed Communities AU - Reinhardt, Theresa AU - Leon, Ramon G. T2 - Weed Science AB - Abstract Seedbank sampling and quantification methods vary in their ability to describe weed diversity and density, so proper method selection is critical for studying weed communities. The germinable seedbank (GSB) method is commonly preferred over extractable seedbank method (ESB), because the latter is more time-consuming. However, these two methods have only been compared using a few weed species and a relatively small number of samples. A total of 204 weed seedbank samples were used to compare both methods for weed density, richness, evenness, and Shannon-Weiner diversity using a split-sample approach. The two methods yielded dramatically different results. The ESB had 418% higher density and 35% more species per sample but 11% less evenness than the GSB. Diversity was estimated to be only 9% higher using the extractable compared with the germinable method. While the extractable method had higher density and richness overall, this was not true for every species, with only 7 of 14 common species detected in higher amounts by the extractable method. The results indicate the two methods are not strongly correlated, limiting the possibility of generating a conversion factor between methods. Nevertheless, evenness and Shannon-Weiner diversity might allow comparisons between both methods when the emphasis is on characterizing predominant weed species. The GSB is a practical approach to compare treatments or conditions; however, the ESB is more useful to accurately quantify weed species richness, diversity, and density. DA - 2018/11// PY - 2018/11// DO - 10.1017/wsc.2018.56 VL - 66 IS - 6 SP - 715-720 LA - en SN - 1550-2759 UR - https://www.cambridge.org/core/product/identifier/S0043174518000565/type/journal_article DB - Crossref Y2 - 2019/2/8/ KW - Agroecology KW - diversity KW - integrated weed management KW - plant ecology KW - seedbank ER - TY - JOUR TI - Managing wicked herbicide-resistance: Lessons from the field AU - Schroeder, Jill AU - Barrett, Michael AU - Shaw, David R. AU - Asmus, Amy B. AU - Coble, Harold AU - Ervin, David AU - Jussaume, Raymond A. AU - Owen, Micheal D. K. AU - Burke, Ian AU - Creech, Cody F. AU - Culpepper, A. Stanley AU - Curran, William S. AU - Dodds, Darrin M. AU - Gaines, Todd A. AU - Gunsolus, Jeffrey L. AU - Hanson, Bradley D. AU - Jha, Prashant AU - Klodd, Annie E. AU - Kniss, Andrew R. AU - Leon, Ramon G. AU - McDonald, Sandra AU - Morishita, Don W. AU - Schutte, Brian J. AU - Sprague, Christy L. AU - Stahlman, Phillip W. AU - Steckel, Larry E. AU - VanGessel, Mark J. T2 - Weed Technology AB - Abstract Herbicide resistance is ‘wicked’ in nature; therefore, results of the many educational efforts to encourage diversification of weed control practices in the United States have been mixed. It is clear that we do not sufficiently understand the totality of the grassroots obstacles, concerns, challenges, and specific solutions needed for varied crop production systems. Weed management issues and solutions vary with such variables as management styles, regions, cropping systems, and available or affordable technologies. Therefore, to help the weed science community better understand the needs and ideas of those directly dealing with herbicide resistance, seven half-day regional listening sessions were held across the United States between December 2016 and April 2017 with groups of diverse stakeholders on the issues and potential solutions for herbicide resistance management. The major goals of the sessions were to gain an understanding of stakeholders and their goals and concerns related to herbicide resistance management, to become familiar with regional differences, and to identify decision maker needs to address herbicide resistance. The messages shared by listening-session participants could be summarized by six themes: we need new herbicides; there is no need for more regulation; there is a need for more education, especially for others who were not present; diversity is hard; the agricultural economy makes it difficult to make changes; and we are aware of herbicide resistance but are managing it. The authors concluded that more work is needed to bring a community-wide, interdisciplinary approach to understanding the complexity of managing weeds within the context of the whole farm operation and for communicating the need to address herbicide resistance. DA - 2018/// PY - 2018/// DO - 10.1017/wet.2018.49 VL - 32 IS - 04 SP - 475–488 KW - Herbicide resistance KW - herbicide resistance management KW - listening sessions KW - outreach ER - TY - JOUR TI - Managing herbicide resistance: Listening to the perspective of practitioners. Procedures for conducting listening sessions and an evaluation of the process AU - Schroeder, Jill AU - Barrett, Michael AU - Shaw, David R. AU - Asmus, Amy B. AU - Coble, Harold AU - Ervin, David AU - Jussaume, Raymond A. AU - Owen, Micheal D. K. AU - Burke, Ian AU - Creech, Cody F. AU - Culpepper, A. Stanley AU - Curran, William S. AU - Dodds, Darrin M. AU - Gaines, Todd A. AU - Gunsolus, Jeffrey L. AU - Hanson, Bradley D. AU - Jha, Prashant AU - Klodd, Annie E. AU - Kniss, Andrew R. AU - Leon, Ramon G. AU - McDonald, Sandra AU - Morishita, Don W. AU - Schutte, Brian J. AU - Sprague, Christy L. AU - Stahlman, Phillip W. AU - Steckel, Larry E. AU - VanGessel, Mark J. T2 - Weed Technology AB - Abstract Seven half-day regional listening sessions were held between December 2016 and April 2017 with groups of diverse stakeholders on the issues and potential solutions for herbicide-resistance management. The objective of the listening sessions was to connect with stakeholders and hear their challenges and recommendations for addressing herbicide resistance. The coordinating team hired Strategic Conservation Solutions, LLC, to facilitate all the sessions. They and the coordinating team used in-person meetings, teleconferences, and email to communicate and coordinate the activities leading up to each regional listening session. The agenda was the same across all sessions and included small-group discussions followed by reporting to the full group for discussion. The planning process was the same across all the sessions, although the selection of venue, time of day, and stakeholder participants differed to accommodate the differences among regions. The listening-session format required a great deal of work and flexibility on the part of the coordinating team and regional coordinators. Overall, the participant evaluations from the sessions were positive, with participants expressing appreciation that they were asked for their thoughts on the subject of herbicide resistance. This paper details the methods and processes used to conduct these regional listening sessions and provides an assessment of the strengths and limitations of those processes. DA - 2018/// PY - 2018/// DO - 10.1017/wet.2018.53 VL - 32 IS - 04 SP - 489–497 KW - Herbicide resistance KW - listening sessions process ER - TY - JOUR TI - Evaluation of verticutting and herbicides for tropical signalgrass (Urochloa subquadripara) control in turf AU - Pearsaul, D.G. AU - Leon, R.G. AU - Sellers, B.A. AU - Silveira, M.L. AU - Odero, D.C. T2 - Weed Technology AB - Abstract Tropical signalgrass (TSG) is one of the most problematic weeds found on golf courses, sports fields, and sod farms in south Florida. The recent ban of monosodium methane-arsonate (MSMA), an organic arsenical herbicide, from urban areas in Florida has left turfgrass managers searching for effective management options. In an effort to avoid relying solely on POST chemical control, this research examined the effect of combining a cultural practice, verticutting, along with PRE and POST herbicides as an integrated weed management approach to controlling TSG in hybrid bermudagrass. Field experiments were conducted at multiple locations over 2 yr in south Florida to: (1) determine whether verticutting before herbicide applications increases TSG control and (2) identify herbicide programs that effectively control TSG. No interactions between verticutting and herbicide programs were detected, but verticutting consistently provided a slight reduction (8% averaged across herbicide treatments) in TSG cover. Treatments containing a PRE herbicide resulted in a significant reduction (20% to 50%) in TSG cover at 52 wk after initial treatment (WAIT), while some POST herbicide treatments reduced TSG cover to <20% at 52 WAIT. A study was conducted to determine which POST herbicide combinations were most efficacious in controlling TSG. Amicarbazone alone provided ≤35% TSG control at 8 and 12 WAIT, but synergistic responses were observed between amicarbazone and mesotrione, trifloxysulfuron, and thiencarbazone+foramsulfuron+halosulfuron. Two- and three-way combinations of amicarbazone with these POST herbicides resulted in >80% TSG control at 4, 8, and 12 WAIT, with some reaching 100% TSG control at 4 WAIT. Based on these data, verticutting may provide limited complementary control, but certain combinations of POST herbicides exhibited excellent (>95%) TSG control. DA - 2018/// PY - 2018/// DO - 10.1017/wet.2018.25 VL - 32 IS - 04 SP - 392–397 KW - Cultural practices KW - integrated weed management KW - verticutting ER - TY - JOUR TI - Conventional harvest index methods may overestimate biomass and nutrient removal from abscising crop species AU - Jani, A.D. AU - Mulvaney, M.J. AU - Leon, R.G. AU - Rowland, D.L. AU - Erickson, J.E. AU - Wood, C.W. T2 - Communications in Soil Science and Plant Analysis AB - ABSTRACT Harvest index (HI) is conventionally measured using end-of-season biomass, but leaf abscission during crop growth can represent a substantial portion of total crop biomass for several species. A field study was conducted in Florida, USA, to determine the accuracy of conventional and alternative HI methods using sesame (Sesamum indicum L.) as a model species and to assess biomass and nutrient contributions from abscised leaves. Seed and nutrient HI was determined from three cultivars using the following four methods: (1) total biomass method that included both end-of-season and seasonal abscised biomass; (2) conventional method based solely on end-of-season biomass; (3) early-bloom method in which biomass collected during early-bloom stage was used as the nonseed biomass component; (4) mid-bloom method where biomass from mid-bloom stage was used for nonseed biomass. Early- and mid-bloom methods overestimated all HI and underestimated biomass and nutrient return to the soil. Most nutrient HI based on the conventional method was higher than the values based on the total biomass method. Compared to the total biomass method, the conventional method underestimated biomass and nutrient return to soil per ha by 714.8 kg biomass, 28.5 kg nitrogen, 3.6 kg phosphorus, 34.7 potassium, 4.6 magnesium, 25.7 calcium, 3.4 kg sulfur, 26.5 g boron, 361 g zinc, 25.9 g manganese, 527.2 g iron, and 18.7 g copper. Including abscised leaves when determining HI may not be feasible in field experiments due to labor constraints but is an option when measuring HI for species under similar management at regional scales to improve estimates of nutrient cycling. DA - 2018/// PY - 2018/// DO - 10.1080/00103624.2018.1547390 VL - 49 IS - 22 SP - 2889–2893 KW - Soil fertility KW - nutrient cycling KW - macronutrients KW - micronutrients ER - TY - JOUR TI - Rootstock improves high-tunnel tomato water use efficiency AU - Suchoff, D.H. AU - Schultheis, J.R. AU - Kleinhenz, M.D. AU - Louws, F.J. AU - Gunter, C.C. T2 - HortTechnology AB - Sphagnum peat is a finite resource that is often used in the horticultural industry as a component in many substrates, especially for greenhouse production of transplants. Because peatlands are being depleted by vast amounts of mining, the horticultural industry is exploring alternative resources to use in substrates. Swine lagoon sludge (SLS) is an attractive option as it may provide nutrients needed to support plant growth, as well as using an agricultural waste product to address the peat shortage. A compost was developed using an in-vessel compost reactor to compost SLS with peanut hulls [15:85 (by volume) SLS:peanut hull] to produce a swine lagoon compost (SLC). A greenhouse transplant study was conducted with three species: basil ( Ocimum basilicum ‘Dark Opal’), chives ( Allium schoenoprasum ), and dill ( Anethum graveolens ‘Hera’) grown in three substrates: SLC, a commercially available organic potting substrate with a nutrient charge (OM), and a commercial peat-based potting substrate with a 2-week nutrient charge (PEAT). The average height for basil, chives, and dill was significantly greater at transplant harvest when produced in the SLC substrate compared with the OM and PEAT. Airspace was greatest for SLC and lowest for OM and PEAT. Although root growth was not measured in this study, more prolific root growth throughout the plug was observed with SLC compared with OM and PEAT possibly because of the greater airspace in SLC. Substrate solution pH did not change substantially over time, whereas electrical conductivity (EC) decreased from 0.24 to 0.14 mS·cm −1 . Both substrate pH and EC were within acceptable ranges for transplant production. SLC provided the physical and chemical requirements for herb transplant production without any additional fertilizers or amendments. DA - 2018/// PY - 2018/// DO - 10.21273/HORTTECH03947-17 VL - 28 SP - 337–343 KW - Ocimum basilicum KW - Allium schoenoprasum KW - Anethum graveolens KW - hog waste KW - peanut hull KW - fresh cut herbs ER - TY - JOUR TI - Arbuscular Mycorrhizal Fungi and Their Responses to Nutrient Enrichment AU - Yang, Haishui AU - Schroeder-Moreno, Michelle AU - Giri, Bhoopander AU - Hu, Shuijin T2 - ROOT BIOLOGY AB - The roots of most land plants form mycorrhizal associations with soil fungi, in which plants trade carbon for increased nutrient acquisition (e.g., N and P) under nutrient deficiency conditions. However, how nutrient enrichment affects mycorrhiza is still not well understood, in particular under future global changing scenarios such as nitrogen deposition. In this chapter, we first review the major pathways of mycorrhizal-mediated nutrient acquisition and molecular mechanisms of sensing nutrient availability for mycorrhizal fungi and roots. Next, we propose two conceptual models that may control plant C allocation to mycorrhizal fungi in response to nutrient enrichment: reciprocal reward model and root-mycorrhiza trade-off model. We also describe a plant-centric model and fungal-centric model to explain responses of the mycorrhizal fungal community to nutrient enrichment as well as examine impacts of nutrient inputs on mycorrhizas functioning. DA - 2018/// PY - 2018/// DO - 10.1007/978-3-319-75910-4_17 VL - 52 SP - 429-449 SN - 1613-3382 ER - TY - JOUR TI - Protocol for Producing Three-Dimensional Infrared Video of Freezing in Plants AU - Livingston, David P., III AU - Tuong, Tan D. AU - Hoffman, Mark AU - Fernandez, Gina T2 - JOVE-JOURNAL OF VISUALIZED EXPERIMENTS AB - Freezing in plants can be monitored using infrared (IR) thermography, because when water freezes, it gives off heat. However, problems with color contrast make 2-dimensions (2D) infrared images somewhat difficult to interpret. Viewing an IR image or the video of plants freezing in 3 dimensions (3D) would allow a more accurate identification of sites for ice nucleation as well as the progression of freezing. In this paper, we demonstrate a relatively simple means to produce a 3D infrared video of a strawberry plant freezing. Strawberry is an economically important crop that is subjected to unexpected spring freeze events in many areas of the world. An accurate understanding of the freezing in strawberry will provide both breeders and growers with more economical ways to prevent any damage to plants during freezing conditions. The technique involves a positioning of two IR cameras at slightly different angles to film the strawberry freezing. The two video streams will be precisely synchronized using a screen capture software that records both cameras simultaneously. The recordings will then be imported into the imaging software and processed using an anaglyph technique. Using red-blue glasses, the 3D video will make it easier to determine the precise site of ice nucleation on leaf surfaces. DA - 2018/9// PY - 2018/9// DO - 10.3791/58025 IS - 139 SP - SN - 1940-087X KW - Environmental Sciences KW - Issue 139 KW - Infrared thermography KW - plant freezing KW - strawberry KW - anaglyph KW - 3-dimensional video KW - convergence ER - TY - JOUR TI - A Novel Passive Sampling Technique for Collecting Adult Necrophilous Insects Arriving at Neonate Pig Carcasses AU - Cruise, Angela AU - Watson, David W. AU - Schal, Coby T2 - ENVIRONMENTAL ENTOMOLOGY AB - Neonate pigs have been used as decomposition models in experimental forensic entomology studies. Their small size, however, poses challenges to traditional sampling methods of necrophilous insects, like the sweep net, the most commonly used sampling method in forensic entomology research and practice. Previous research experimentally demonstrated the potential for sticky traps as an effective sampling method for collecting necrophilous insects from neonate pigs. While sticky traps effectively sampled fly diversity from the pigs, they shared with the sweep net low sample diversity and abundance, particularly of necrophilous beetles. Motivated by chemosensory host-finding of necrophilous insects and the architecture of carrion-mimicking thermogenic flowers, we developed a ‘vented-chamber’ method and optimized its design experimentally. In this approach, a neonate pig was transiently enclosed in a chamber. The decomposition process thermally convected the natural decomposition odors in the headspace above the pig toward a pair of sticky traps. The vented-chamber method collected significantly more necrophilous flies, representing a greater diversity, than the sweep net. Nevertheless, this approach caught few beetles, and hand collections must be used as well to most effectively sample beetle diversity. DA - 2018/12// PY - 2018/12// DO - 10.1093/ee/nvy131 VL - 47 IS - 6 SP - 1573-1581 SN - 1938-2936 KW - sampling KW - biodiversity KW - ecology & behavior KW - forensic entomology ER - TY - JOUR TI - Cr(VI) uptake and reduction by biogenic iron (oxyhydr)oxides T2 - Environmental Science: Processes and Impacts AB - The mobility and toxicity of chromium (Cr) in soil and water systems are largely controlled by its oxidation state and interactions with solid phases. Relative to abiotic minerals, biogenic iron (Fe) (oxyhydr)oxides (BIOS) may enhance Cr(vi) adsorption and reduction due to their poorly ordered structures, large surface areas, and incorporation of cell derived organic matter. To determine the extent and mechanisms of the reaction between Cr(vi) and BIOS, sorption isotherm and kinetic studies were conducted using two-line ferrihydrite, BIOS, and BIOS amended with 0.135 M ferrozine (an Fe(ii) chelator). X-ray absorption near edge structure (XANES) spectroscopy of BIOS reacted with Cr(vi) showed approximately 50% reduction of the total sorbed Cr from Cr(vi) to Cr(iii) after 14 days of exposure. Sorbed Cr(iii) was best fit with an organic carboxylate complex after 1 d of reaction, but after 7 d mineral-associated Cr(iii) was the predominant form. In the presence of ferrozine, Cr(vi) reduction by BIOS was inhibited, confirming a key role for Fe(ii) as the Cr(vi) reductant. However, the lack of a 3 : 1 reaction stoichiometry between Fe(ii) and Cr(iii) produced suggests roles for reaction with organic matter and Cr(v) autoreduction in Cr(iii) production. This study thus elucidates an unrecognized mechanism of Cr sequestration by ubiquitous natural Fe (oxyhydr)oxide deposits. Furthermore, the redox transformation of mobile Cr(vi) to less soluble Cr(iii) species observed in our study implies that biogenic Fe (oxyhydr)oxides in soils and natural waters may naturally attenuate Cr(vi) concentrations through sorption and reduction processes, thus limiting its transport to downstream environments. DA - 2018/// PY - 2018/// DO - 10.1039/c8em00149a VL - 20 IS - 7 SP - 1056-1068 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-85050571845&partnerID=MN8TOARS ER - TY - JOUR TI - Microbial Compositions and Enzymes of a Forest Ecosystem in Alabama: Initial Response to Thinning and Burning Management Selections AU - Ntoko, F.A. AU - Gardner T2 - Journal of Forestry DA - 2018/7// PY - 2018/7// UR - https://www.scirp.org/journal/PaperInformation.aspx?PaperID=86043 ER - TY - JOUR TI - ITSxpress: Software to rapidly trim internally transcribed spacer sequences with quality scores for marker gene analysis [version 1; referees: awaiting peer review] AU - Rivers, Adam R. AU - Weber, Kyle C. AU - Gardner, Terrence G. AU - Liu, Shuang AU - Armstrong, Shalamar D. T2 - F1000Research AB - The internally transcribed spacer (ITS) region between the small subunit ribosomal RNA gene and large subunit ribosomal RNA gene is a widely used phylogenetic marker for fungi and other taxa. The eukaryotic ITS contains the conserved 5.8S rRNA and is divided into the ITS1 and ITS2 hypervariable regions. These regions are variable in length and are amplified using primers complementary to the conserved regions of their flanking genes. Previous work has shown that removing the conserved regions results in more accurate taxonomic classification. An existing software program, ITSx, is capable of trimming FASTA sequences by matching hidden Markov model profiles to the ends of the conserved genes using the software suite HMMER. ITSxpress was developed to extend this technique from marker gene studies using Operational Taxonomic Units (OTU’s) to studies using exact sequence variants; a method used by the software packages Dada2, Deblur, QIIME 2, and Unoise. The sequence variant approach uses the quality scores of each read to identify sequences that are statistically likely to represent real sequences. ITSxpress enables this by processing FASTQ rather than FASTA files. The software also speeds up the trimming of reads by a factor of 14-23 times on a 4-core computer by temporarily clustering highly similar sequences that are common in amplicon data and utilizing optimized parameters for Hmmsearch. ITSxpress is available as a QIIME 2 plugin and a stand-alone application installable from the Python package index, Bioconda, and Github. DA - 2018/9/6/ PY - 2018/9/6/ DO - 10.12688/f1000research.15704.1 VL - 7 IS - 1418 SP - 1418 UR - https://f1000research.com/articles/7-1418/v1 ER - TY - JOUR TI - The ectomycorrhizal contribution to tree nutrition AU - Becquer, Adeline AU - Guerrero-Galán, Carmen AU - Eibensteiner, Janice L. AU - Houdinet, Gabriella AU - Bücking, Heike AU - Zimmermann, Sabine D. AU - Garcia, Kevin T2 - Advances in Botanical Research AB - Trees can be associated with dozens of fungi helping them to acquire resources from forest soils. The most widespread mutualistic association in boreal and temperate forests is the ectomycorrhizal symbiosis. This symbiosis involves mushroom-forming fungi of basidiomycota, ascomycota, and some zygomycota clades and the roots of woody plant species, including oaks, poplars or pines. Although the impact of this association on ecosystem production and tree nutrition is investigated for about a century, our understanding on the molecular mechanisms that control water and nutrient fluxes between plant and fungal partners is still limited. Here, we review the recent knowledge on the ectomycorrhizal contribution to tree nutrition. We specifically highlight the molecular mechanisms driving the acquisition, translocation and release of water and nutrients in ectomycorrhizal systems. We particularly focus on the transport of macronutrients, including nitrogen, phosphorus, potassium, sulphur and calcium, micronutrients, and water by the symbiotic partner. We also provide background on the evolution, diversity, and importance of this symbiosis, identify knowledge gaps, and propose future research directions. DA - 2018/// PY - 2018/// DO - 10.1016/bs.abr.2018.11.003 ER - TY - JOUR TI - The Hebeloma cylindrosporum HcPT2 Pi transporter plays a key role in ectomycorrhizal symbiosis AU - Becquer, Adeline AU - Garcia, Kevin AU - Amenc, Laurie AU - Rivard, Camille AU - Doré, Jeanne AU - Trives-Segura, Carlos AU - Szponarski, Wojciech AU - Russet, Sylvie AU - Baeza, Yoan AU - Lassalle-Kaiser, Benedikt AU - Gay, Gilles AU - Zimmermann, Sabine Dagmar AU - Plassard, Claude T2 - New Phytologist AB - Through a mutualistic relationship with woody plant roots, ectomycorrhizal fungi provide growth-limiting nutrients, including inorganic phosphate (Pi), to their host. Reciprocal trades occur at the Hartig net, which is the symbiotic interface of ectomycorrhizas where the two partners are symplasmically isolated. Fungal Pi must be exported to the symbiotic interface, but the proteins facilitating this transfer are unknown. In the present study, we combined transcriptomic, microscopy, whole plant physiology, X-ray fluorescence mapping, 32 P labeling and fungal genetic approaches to unravel the role of HcPT2, a fungal Pi transporter, during the Hebeloma cylindrosporum-Pinus pinaster ectomycorrhizal association. We localized HcPT2 in the extra-radical hyphae and the Hartig net and demonstrated its determinant role for both the establishment of ectomycorrhizas and Pi allocation towards P. pinaster. We showed that the host plant induces HcPT2 expression and that the artificial overexpression of HcPT2 is sufficient to significantly enhance Pi export towards the central cylinder. Together, our results reveal that HcPT2 plays an important role in ectomycorrhizal symbiosis, affecting both Pi influx in the mycelium and efflux towards roots under the control of P. pinaster. DA - 2018/6// PY - 2018/6// DO - 10.1111/nph.15281 VL - 6 KW - ectomycorrhizal (ECM) fungus KW - overexpression KW - P-32 labeling KW - phosphate transporter KW - Pinus pinaster KW - RNA interference KW - X-ray fluorescence mapping ER - TY - JOUR TI - Plant potassium nutrition in ectomycorrhizal symbiosis: properties and roles of the three fungal TOK potassium channels in Hebeloma cylindrosporum. AU - Guerrero-Galán, C AU - Delteil, A AU - Garcia, K AU - Houdinet, G AU - Conéjéro, G AU - Gaillard, I AU - Sentenac, H AU - Zimmermann, SD T2 - Environmental microbiology AB - Summary Ectomycorrhizal fungi play an essential role in the ecology of boreal and temperate forests through the improvement of tree mineral nutrition. Potassium (K + ) is an essential nutrient for plants and is needed in high amounts. We recently demonstrated that the ectomycorrhizal fungus Hebeloma cylindrosporum improves the K + nutrition of Pinus pinaster under shortage conditions. Part of the transport systems involved in K + uptake by the fungus has been deciphered, while the molecular players responsible for the transfer of this cation towards the plant remain totally unknown. Analysis of the genome of H. cylindrosporum revealed the presence of three putative tandem‐pore outward‐rectifying K + (TOK) channels that could contribute to this transfer. Here, we report the functional characterization of these three channels through two‐electrode voltage‐clamp experiments in oocytes and yeast complementation assays. The expression pattern and physiological role of these channels were analysed in symbiotic interaction with P. pinaster . Pine seedlings colonized by fungal transformants overexpressing two of them displayed a larger accumulation of K + in shoots. This study revealed that TOK channels have distinctive properties and functions in axenic and symbiotic conditions and suggested that Hc TOK2.2 is implicated in the symbiotic transfer of K + from the fungus towards the plant . DA - 2018/4// PY - 2018/4// DO - 10.1111/1462-2920.14122 VL - 4 UR - http://europepmc.org/abstract/med/29614209 ER - TY - JOUR TI - HcTOK1 participates in the maintenance of K+ homeostasis in the ectomycorrhizal fungus Hebeloma cylindrosporum, which is essential for the symbiotic K+ nutrition of Pinus pinaster AU - Guerrero-Galán, C. AU - Garcia, K. AU - Houdinet, G. AU - Zimmermann, S. D. T2 - Plant Signaling & Behavior AB - Most land plants rely on root symbioses to complement or improve their mineral nutrition. Recent researches have put forward that mycorrhizal fungi efficiently absorb and transfer potassium (K+) from the soil to host plant roots, but the molecular mechanisms involved are not completely elucidated yet. We have recently revealed that K+ is likely released from the fungal Hartig net to the plant by TOK channels in the ectomycorrhizal model Hebeloma cylindrosporum – Pinus pinaster. H. cylindrosporum harbours three TOK members. Herein, we report that one of them, HcTOK1, has similar features than the yeast ScTOK1. Moreover, we propose a role for this channel in the transport of K+ from the medium to ectomycorrhizal roots under K+ starvation. DA - 2018/6/3/ PY - 2018/6/3/ DO - 10.1080/15592324.2018.1480845 VL - 13 IS - 6 SP - e1480845 UR - https://doi.org/10.1080/15592324.2018.1480845 KW - ectomycorrhizal symbiosis KW - ion homeostasis KW - plant nutrition KW - potassium transport KW - subcellular localization KW - TOK channel ER - TY - JOUR TI - Nutrient demand and fungal access to resources control the carbon allocation to the symbiotic partners in tripartite interactions of Medicago truncatula AU - Kafle, Arjun AU - Garcia, Kevin AU - Wang, Xiurong AU - Pfeffer, Philip E. AU - Strahan, Gary D. AU - Bücking, Heike T2 - Plant, Cell & Environment AB - Legumes form tripartite interactions with arbuscular mycorrhizal fungi and rhizobia, and both root symbionts exchange nutrients against carbon from their host. The carbon costs of these interactions are substantial, but our current understanding of how the host controls its carbon allocation to individual root symbionts is limited. We examined nutrient uptake and carbon allocation in tripartite interactions of Medicago truncatula under different nutrient supply conditions, and when the fungal partner had access to nitrogen, and followed the gene expression of several plant transporters of the Sucrose Uptake Transporter (SUT) and Sugars Will Eventually be Exported Transporter (SWEET) family. Tripartite interactions led to synergistic growth responses and stimulated the phosphate and nitrogen uptake of the plant. Plant nutrient demand but also fungal access to nutrients played an important role for the carbon transport to different root symbionts, and the plant allocated more carbon to rhizobia under nitrogen demand, but more carbon to the fungal partner when nitrogen was available. These changes in carbon allocation were consistent with changes in the SUT and SWEET expression. Our study provides important insights into how the host plant controls its carbon allocation under different nutrient supply conditions and changes its carbon allocation to different root symbionts to maximize its symbiotic benefits. DA - 2018/6/2/ PY - 2018/6/2/ DO - 10.1111/pce.13359 VL - 6 KW - arbuscular mycorrhizal symbiosis KW - carbon transport KW - Ensifer meliloti KW - legumes KW - nitrogen uptake KW - rhizobia KW - Rhizophagus irregularis KW - sucrose transport KW - sucrose uptake transporter (SUT) KW - sugars will eventually be exported transporter (SWEET) ER - TY - CHAP TI - Sustainable Weed Control in Tobacco AU - Vann, M.C. AU - Fisher, L.R. AU - Inman, M.D. T2 - Weed Control: Sustainability, Hazards, and Risks in Cropping Systems Worldwide A2 - Korres, N.E. A2 - Burgos, N.R. A2 - Duke, S.O. PY - 2018/// SP - 367–382 PB - CRC Press-Taylor and Francis Group ER - TY - JOUR TI - Evaluation of Adapt-N and Realistic Yield Expectation Approaches for Maize Nitrogen Management in North Carolina AU - Osmond, Deanna AU - Austin, Robert AU - Shelton, Shelby AU - Es, Harold AU - Sela, Shai T2 - SOIL SCIENCE SOCIETY OF AMERICA JOURNAL AB - Core Ideas The North Carolina nitrogen database made better recommendations than Adapt‐N for plot studies. Different labs produce distinctly different soil organic matter percentages from the same soil. Farmer strip trial results demonstrated approximately 60% of the time that Grower‐25% N yielded similarly to the other treatments. Farmer strip trial results showed overall similar performance for Adapt‐N and Grower‐Consultant rates. Nitrogen decision making for maize ( Zea mays L.) is difficult because of seasonal weather fluctuations. New tools have emerged based on dynamic simulation models that account for weather variability. We evaluated the performance of the Adapt‐N tool relative to North Carolina's Realistic Yield Expectation (RYE) framework through six multi‐N rate maize plot trials in three physiographic regions and 38 strip trials on commercial farms in the coastal plain. Yield response and profit were evaluated with quadratic plateau (QP) response curves. The RYE framework generally estimated the agronomic optimum N rate (AONR) well, as did Adapt‐N after modification to account for high soil organic matter (SOM) and C/N ratio mineral‐organic coastal plain soil; there was, however, much greater site variability with Adapt‐N. Adapt‐N was sensitive to SOM content inputs, which varied based on method and laboratory. The RYE provided overall higher dollar return than Adapt‐N; Adapt‐N returns varied based on SOM and yield goal inputs, since they strongly impact N rate recommendations. In the on‐farm strip‐trials, 58% of yields were not statistically different between lower N rates and other treatments including Adapt‐N. On average, Adapt‐N performed similar to grower‐consultant practice with modest tradeoffs between reduced N rates and yield. Adapt‐N recommendations and grower rates yielded higher than RYE and required more N. Overall, the RYE approach performed better than Adapt‐N in N research farm trials; in on‐farm strip trials Adapt‐N performed similarly to grower‐consultant practices and in various cases provided economical yield increases over RYE. DA - 2018/// PY - 2018/// DO - 10.2136/sssaj2018.03.0127 VL - 82 IS - 6 SP - 1449-1458 SN - 1435-0661 ER - TY - JOUR TI - Response of Sweetpotato to Oryzalin Application Rate and Timing AU - Chaudhari, Sushila AU - Jennings, Katherine M. AU - Meyers, Stephen L. T2 - Weed Technology AB - Abstract The investigation of potential herbicides for weed control in sweetpotato is critical due to the limited number of registered herbicides and the development of populations of herbicide- resistant weeds. Therefore, field studies were conducted at the Horticultural Crops Research Station, Clinton, NC and the Pontotoc Ridge–Flatwoods Branch Experiment Station, Pontotoc, MS to determine the effect of oryzalin application rate and timing on sweetpotato tolerance. Oryzalin at 0.6, 1.1, 2.2, 3.4, and 4.5 kg ai ha –1 was applied immediately after transplanting or 14 d after sweetpotato transplanting (DAP). At Clinton, oryzalin applied immediately after transplanting resulted in ≤1% leaf distortion 4 and 6 wk after transplanting (WAP) regardless of application rate. However, when oryzalin was applied 14 DAP, greater sweetpotato leaf distortion was observed from 2.2, 3.4, and 4.5 kg ha –1 (≤8%) than 0.6 and 1.1 kg ha –1 (≤4%). At Pontotoc, oryzalin applied immediately after transplanting resulted in ≤6% leaf distortion 4 WAP regardless of application rate. However, when oryzalin was applied at 14 DAP, greater leaf distortion was reported from 3.4 and 4.5 kg ha –1 (11 to 13%) than 0.6, 1.1, and 2.2 kg ha –1 (4 to 6%). Oryzalin application rate and timing did not affect yield of no.1, jumbo, or marketable sweetpotato. Based on these results, oryzalin herbicide has potential for registration in sweetpotato. DA - 2018/12// PY - 2018/12// DO - 10.1017/wet.2018.79 VL - 32 IS - 6 SP - 722-725 J2 - Weed Technol LA - en OP - SN - 0890-037X 1550-2740 UR - http://dx.doi.org/10.1017/wet.2018.79 DB - Crossref KW - Crop injury KW - crop tolerance KW - storage root ER - TY - JOUR TI - Response to "Comment on 'A Non-Empirical Method for Computing Pore Radii and Soil Water Characteristics from Particle Size Distribution' by Arya and Heitman (2015)" AU - Arya, Lalit M. AU - Heitman, Joshua L. T2 - SOIL SCIENCE SOCIETY OF AMERICA JOURNAL AB - Soil Science Society of America JournalVolume 82, Issue 6 p. 1595-1596 Response Response to “Comment on ‘A Non-Empirical Method for Computing Pore Radii and Soil Water Characteristics from Particle Size Distribution’ by Arya and Heitman (2015)” Lalit M. Arya, Lalit M. Arya Soil consultant, Oceanside, CA, 92057Search for more papers by this authorJoshua L. Heitman, Corresponding Author Joshua L. Heitman josh_heitman@ncsu.edu Soil Science Department, North Carolina State University, Raleigh, NC, 27601Corresponding author (josh_heitman@ncsu.edu).Search for more papers by this author Lalit M. Arya, Lalit M. Arya Soil consultant, Oceanside, CA, 92057Search for more papers by this authorJoshua L. Heitman, Corresponding Author Joshua L. Heitman josh_heitman@ncsu.edu Soil Science Department, North Carolina State University, Raleigh, NC, 27601Corresponding author (josh_heitman@ncsu.edu).Search for more papers by this author First published: 25 October 2018 https://doi.org/10.2136/sssaj2018.01.0063r All Rights reserved. Read 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 No abstract is available for this article. Volume82, Issue6November-December 2018Pages 1595-1596 RelatedInformation DA - 2018/// PY - 2018/// DO - 10.2136/sssaj2018.01.0063r VL - 82 IS - 6 SP - 1595-1596 SN - 1435-0661 ER - TY - JOUR TI - Response of Sweetpotato Cultivars to Linuron Rate and Application Time AU - Beam, Shawn C. AU - Jennings, Katherine M. AU - Chaudhari, Sushila AU - Monks, David W. AU - Schultheis, Jonathan R. AU - Waldschmidt, Mathew T2 - WEED TECHNOLOGY AB - Abstract Field studies were conducted in 2015 and 2016 in North Carolina to determine the response of ‘Covington’ and ‘Murasaki-29’ sweetpotato cultivars to four rates of linuron (420, 560, 840, and 1,120 g ai ha –1 ) alone or with S -metolachlor (803 g ai ha –1 ) applied 7 or 14 d after transplanting (DAP). Injury (chlorosis/necrosis and stunting) to both cultivars was greater when linuron was applied with S -metolachlor as compared to linuron applied alone. Herbicide application at 14 DAP caused greater injury (chlorosis/necrosis and stunting) to both cultivars than when applied at 7 DAP. At 4 wk after treatment (WAT), stunting of Covington and Murasaki-29 (hereafter Murasaki) from linuron at 420 to 1,120 g ha –1 increased from 27% to 50% and 25% to 53%, respectively. At 7 or 8 WAT, crop stunting of 8% or less and 0% was observed in Covington and Murasaki, respectively, regardless of application rate and timing. Murasaki root yields were similar in the linuron alone or with S -metolachlor treatments, and were lower than the nontreated check. In 2016, no. 1 and marketable sweetpotato yields of Covington were similar for the nontreated check, linuron alone, or linuron plus S -metolachlor treatments, but not in 2015. Decreases in no. 1 and marketable root yields were observed when herbicides were applied 14 DAP compared to 7 DAP for Covington in 2015 and for Murasaki in both years. No. 1 and marketable yields of Covington were similar for 420 to 1,120 g ha –1 linuron and nontreated check except marketable root yields in 2015. No. 1 and marketable sweetpotato yields of Murasaki decreased as application rates increased. DA - 2018/12// PY - 2018/12// DO - 10.1017/wet.2018.68 VL - 32 IS - 6 SP - 665-670 SN - 1550-2740 KW - Crop injury KW - crop tolerance KW - storage root ER - TY - JOUR TI - The Role of Plant Transporters in Mycorrhizal Symbioses AU - Guerrero-Galan, Carmen AU - Houdinet, Gabriella AU - Calvo-Polanco, Monica AU - Bonaldi, Katia E. AU - Garcia, Kevin AU - Zimmermann, Sabine Dagmar T2 - MEMBRANE TRANSPORT IN PLANTS AB - Membrane transport systems are crucial elements for plant nutrition and development as they play a key role in the absorption of mineral nutrients and water at the root level but also in the translocation within the plant. Moreover, membrane transport is involved in signalling and communication e.g. to adapt and interact with the environment. Most plants live in tight contact with beneficial soil microbes, such as bacteria and mycorrhizal fungi, which contribute to plant nutrition in part through modulation of the expression and functioning of plant transporter systems, as ion channels and transporters. In addition, mycorrhizal fungi largely increase the absorption surface of roots thereby promoting plant's access to soil resources as minerals and water. In turn, plants “reward” mycorrhizal fungi with sugars and/or lipids. This “fair trade” requires specific communication and a series of exchanges between the two symbiotic partners enabled by the adaptability and plasticity of their transporters. Here, we summarize recent advances allowing molecular insight in the impact of mycorrhizal symbiosis on the plant “transportome”. We highlight results obtained in ecto- and endomycorrhizal associations for plant transporters involved in the absorption of mineral nutrients and water released by the fungus at the symbiotic interface, and molecular players responsible for carbon and lipid nutrition of the fungal partner. We focus also on plant membrane transport systems implicated in early communication between plant and fungal partners. DA - 2018/// PY - 2018/// DO - 10.1016/bs.abr.2018.09.012 VL - 87 SP - 303-342 SN - 2162-5948 ER - TY - JOUR TI - TGNap1 is required for microtubule-dependent homeostasis of a subpopulation of the plant trans-Golgi network AU - Renna, Luciana AU - Stefano, Giovanni AU - Slabaugh, Erin AU - Wormsbaecher, Clarissa AU - Sulpizio, Alan AU - Zienkiewicz, Krzysztof AU - Brandizzi, Federica T2 - NATURE COMMUNICATIONS AB - Abstract Defining convergent and divergent mechanisms underlying the biogenesis and function of endomembrane organelles is fundamentally important in cell biology. In all eukaryotes, the Trans -Golgi Network (TGN) is the hub where the exocytic and endocytic pathways converge. To gain knowledge in the mechanisms underlying TGN biogenesis and function, we characterized TGNap1, a protein encoded by a plant gene of unknown function conserved with metazoans. We demonstrate that TGNap1 is a TGN protein required for the homeostasis of biosynthetic and endocytic traffic pathways. We also show that TGNap1 binds Rab6, YIP4 and microtubules. Finally, we establish that TGNap1 contributes to microtubule-dependent biogenesis, tracking and function of a TGN subset, likely through interaction with Rab6 and YIP4. Our results identify an important trafficking determinant at the plant TGN and reveal an unexpected reliance of post-Golgi traffic homeostasis and organelle biogenesis on microtubules in plants. DA - 2018/12/14/ PY - 2018/12/14/ DO - 10.1038/s41467-018-07662-4 VL - 9 SP - SN - 2041-1723 ER - TY - JOUR TI - USE OF CSM-CROPGRO-COTTON TO DETERMINE THE AGRONOMIC AND ECONOMIC VALUE OF IRRIGATION TO UPLAND COTTON PRODUCTION IN NORTH AND SOUTH CAROLINA AU - Spivey, T. A. AU - Wilkerson, G. G. AU - Buol, G. S. AU - Edmisten, K. L. AU - Barnes, E. M. T2 - TRANSACTIONS OF THE ASABE AB - Abstract. Although prior research has shown that irrigation can increase cotton fiber yields in coastal plain soils of the Carolinas, only 2.7% of North Carolina’s and 7.8% of South Carolina’s planted hectares are irrigated, compared to 39% nationally. Little research has addressed the impact of compacted subsurface soil layers on the value of irrigation. Economic analysis of irrigation is also difficult due to the lack of long-term irrigation data for the region. The objectives of this study were to adapt the CSM-CROPGRO-Cotton simulation model to production conditions in the coastal plain of the Carolinas and use it to evaluate both the agronomic and economic value of irrigation to upland cotton production. Field data collected near Lewiston-Woodville, North Carolina, in 2015-2016 were used in model calibration and validation. Soil profiles were established using historical weather and cotton yield data for 16 cotton-producing counties in North and South Carolina from 1979 to 2015. Soil profiles were fit both with and without a root-restrictive (compacted) layer for each county. To evaluate the value of irrigation for these counties, simulations were conducted using ten irrigation levels, including non-irrigated, triggered when plant-available water (PAW) reached a maximum allowable depletion of 50%. The economic analysis made use of Cotton Incorporated’s Cotton Irrigation Decision Aid to determine the economic feasibility of irrigation using investment analysis tools such as cash flow, payback period, and net present value (NPV). Predicted agronomic and economic responses to irrigation were strongly dependent on seasonal rainfall. Fiber yield of non-irrigated cotton was reduced by more than 10% of fully irrigated cotton yield in more than 70% of the site-years simulated. This study suggests that irrigation is a feasible investment for cotton producers in North and South Carolina, as positive average cash flows and NPVs were observed over all counties and soils evaluated. Keywords: Cotton, CROPGRO, Crop simulation model, Economic analysis, Irrigation, Water use efficiency, Yield loss. DA - 2018/// PY - 2018/// DO - 10.13031/trans.12801 VL - 61 IS - 5 SP - 1627-1638 SN - 2151-0040 KW - Cotton KW - CROPGRO KW - Crop simulation model KW - Economic analysis KW - Irrigation KW - Water use efficiency KW - Yield loss ER - TY - SOUND TI - High-density genetic maps of St. Augustinegrass and applications to comparative genomic analysis and QTL mapping of turf quality traits AU - Yu, X. AU - Kimball, J.A. AU - Milla-Lewis, S.R. AB - St. Augustinegrass [Stenotaphrum secundatum (Walt.) Kuntze] is a warm-season, perennial turfgrass species well adapted for home lawns and commercial landscapes with economic and ecological value. However, a lack of genomic resources in St. Augustinegrass has hindered the full utilization of genetic variance for maximizing genetic gain and limited our understanding of the species' evolution.In this study, we constructed the first high-density linkage map for St. Augustinegrass using a genotyping by sequencing (GBS) approach. The integrated linkage map consists of 2871 single nucleotide polymorphism (SNP) and 81 simple sequence repeat (SSR) markers, spanning 1241.7 cM, with an average distance of 0.4 cM between markers, and thus represents the densest genetic map for St. Augustinegrass to date. Comparative genomic analysis revealed inter-chromosome arrangements and independent nested chromosome fusion events that occurred after St. Augustinegrass, foxtail millet, sorghum, and rice diverged from a common ancestor. Forty-eight candidate quantitative trait loci (QTL) were detected for turf quality-related traits, including overall turf quality, leaf texture, genetic color, and turf density. Three hot spot regions were identified on linkage groups LG3 and LG8, where multi-QTL for different traits overlapped. Several leaf development related genes were contained within these identified QTL regions.This study developed the first high-density genetic map and identified putative QTL related to turf quality, which provide valuable genetic resources for marker-assisted selection (MAS) in St. Augustinegrass. DA - 2018/11/4/ PY - 2018/11/4/ DO - 10.1186/s12870-018-1554-4 VL - 18 LA - en PB - Springer Nature UR - https://bmcplantbiol.biomedcentral.com/articles/10.1186/s12870-018-1554-4 DB - Crossref Y2 - 2019/2/19/ KW - St.Augustinegrass KW - Linkage map KW - Comparative genomic analysis KW - QTL ER - TY - JOUR TI - Filter paper-based spin column method for cost-efficient DNA or RNA purification AU - Shi, Rui AU - Lewis, Ramsey S. AU - Panthee, Dilip R. T2 - PLOS ONE AB - We describe herein a method of recharging used commercial spin columns or assembling homemade spin columns using filter paper as binding material for cost-effective, low throughput nucleic acid purification. The efficiency of filter paper-based spin columns was evaluated for purification of nucleic acids from various sources. Following protocols of commercial kits, we found filter paper to be a useful binding material for purification of nucleic acids, including plant genomic DNA, plant total RNA, PCR products, and DNA from agarose gels. However, filter paper has a weak binding affinity to plasmid DNA in tested miniprep protocols. Protocols for the use of filter paper recharged spin columns or homemade spin columns for low throughput purification of plant genomic DNA and total RNA with unused commercial kit buffers or less expensive homemade buffers are presented. DA - 2018/12/7/ PY - 2018/12/7/ DO - 10.1371/journal.pone.0203011 VL - 13 IS - 12 SP - SN - 1932-6203 ER - TY - JOUR TI - Cu, Pb, and Zn Sorption to Biogenic Iron (Oxyhydr)Oxides Formed in Circumneutral Environments AU - Whitaker, Andrew H. AU - Duckworth, Owen W. T2 - SOIL SYSTEMS AB - The transportation and immobilization of potentially toxic metals in near-surface environments may be partially controlled by sorption processes at the solid-water interface. Myriad studies have shown that iron (oxyhydr)oxides have large sorption capacities and form strong surface complexes with metal ions. Biogenic iron (oxyhydr)oxides (BIOS) form at redox gradients where dissolved ferrous iron encounters oxygenated conditions, allowing bacteria to outcompete abiotic Fe oxidation. This process produces biominerals with distinct surface and structural properties (incorporation of cell-derived organic matter, poor crystallinity, and small particle sizes) that may alter their metal-binding affinity and sorption processes. To better understand metal binding by BIOS, Cu, Pb, and Zn, sorption rate and isotherm studies were conducted with synthetic two-line ferrihydrite and BIOS. Additionally, X-ray absorption spectroscopy and total scattering were used to elucidate the BIOS mineral structure and metal ion surface structures. On a mass normalization basis, BIOS sorbed approximately 8, 4, and 2 times more Cu, Pb, and Zn, respectively, than 2LFh over similar dissolved concentrations. Spectroscopic analyses revealed poorly crystalline structures and small coherent scattering domain sizes for BIOS. Additionally, extended X-ray absorption fine-structure spectroscopy revealed Cu, Pb, and Zn sorbed to BIOS via inner-sphere complexes, similar to 2LFh. These results suggest that, in metal contaminated environments, BIOS are more efficient in metal binding than their synthetic counterparts. DA - 2018/6// PY - 2018/6// DO - 10.3390/soilsystems2020018 VL - 2 IS - 2 SP - SN - 2571-8789 KW - BIOS KW - ferrihydrite KW - copper KW - lead KW - zinc KW - sorption KW - X-ray absorption spectroscopy (XAS) KW - binding mechanisms ER - TY - JOUR TI - 'DT-1', a Drought-tolerant Triploid Turf Bermudagrass AU - Schwartz, Brian M. AU - Hanna, Wayne W. AU - Baxter, Lisa L. AU - Raymer, Paul L. AU - Waltz, F. Clint AU - Kowalewski, Alec R. AU - Chandra, Ambika AU - Genovesi, A. Dennis AU - Wherley, Benjamin G. AU - Miller, Grady L. AU - Milla-Lewis, Susana R. AU - Reynolds, William C. AU - Wu, Yanqi AU - Martin, Dennis L. AU - Moss, Justin Q. AU - Kenna, Michael P. AU - Unruh, J. Bryan AU - Kenworthy, Kevin E. AU - Zhang, Jing AU - Munoz, Patricio R. T2 - HORTSCIENCE DA - 2018/11// PY - 2018/11// DO - 10.21273/HORTSCI13083-18 VL - 53 IS - 11 SP - 1711-1714 SN - 2327-9834 KW - Cynodon dactylon KW - Cynodon transvaalensis KW - drought tolerance KW - Tifton KW - turfgrass quality ER - TY - JOUR TI - Rootstock Effect on Grafted Tomato Transplant Shoot and Root Responses to Drying Soils AU - Suchoff, David H. AU - Gunter, Christopher C. AU - Schultheis, Jonathan R. AU - Kleinhenz, Matthew D. AU - Louws, Frank J. T2 - HORTSCIENCE AB - Improvement of crop water use is imperative. Plants’ responses to limited water can dictate their ability to better use available resources and avoid prolonged and severe stress. The following study was conducted to determine how tomato ( Solanum lycopersicum ) rootstocks with different root system morphologies respond to drying soils. Plants were grown in pots containing an inorganic substrate composed of calcined clay and sand in a greenhouse on North Carolina State University’s campus. The heirloom tomato cultivar Cherokee Purple was used as the scion for ‘Beaufort’ and ‘Shield’ rootstocks as well as the self-grafted control. These rootstocks were assigned either normal or reduced irrigation treatments. Plants grown under the normal irrigation schedule were weighed and watered daily to maintain container capacity for one week. Those receiving reduced irrigation had all water withheld for one week, at which point strong midday wilting became evident. Shoot physiological and morphological data as well as root morphological data were collected at the end of the study. A constitutive positive increase on relative water content, leaf area, stomatal conductance ( g S ), and net CO 2 assimilation rate was observed with scions grafted on ‘Beaufort’. In addition, this rootstock had a significantly longer total root system (118.6 m) compared with ‘Shield’ (94.9 m) and the self-grafted control (104.2 m). Furthermore, 76.4% of the total root length observed in ‘Beaufort’ was composed of very thin diameter roots ( <0.5 mm), which was higher than ‘Shield’ (73.67%) and the self-grafted control (69.07%). The only significant rootstock irrigation interaction observed was for effective quantum yield of photosystem II (φ PSII ). At normal irrigation there were no differences among the rootstock treatments; however, at reduced irrigation ‘Beaufort’ had significantly higher φ PSII than both ‘Shield’ and the self-grafted control. These results may explain some of the improved production and water use efficiency observed in field trials using ‘Beaufort’ rootstock, and data secured may allow for better screening of rootstocks for improved water use efficiency in the future. DA - 2018/11// PY - 2018/11// DO - 10.21273/HORTSCI13215-18 VL - 53 IS - 11 SP - 1586-1592 SN - 2327-9834 KW - rootstock KW - herbaceous grafts KW - irrigation KW - heirloom tomato KW - root system morphology ER - TY - JOUR TI - Grafting the Indeterminate Tomato Cultivar Moneymaker onto Multifort Rootstock Improves Cold Tolerance AU - Suchoff, David H. AU - Perkins-Veazie, Penelope AU - Sederoff, Heike W. AU - Schultheis, Jonathan R. AU - Kleinhenz, Matthew D. AU - Louws, Frank J. AU - Gunter, Christopher C. T2 - HORTSCIENCE AB - Tomato ( Solanum lycopersicum L.) is a warm-season, cold-sensitive crop that shows slower growth and development at temperatures below 18 °C. Improving suboptimal temperature tolerance would allow earlier planting of field-grown tomato and a reduction in energy inputs for heating greenhouses. Grafting tomato onto high-altitude Solanum habrochaites (S. Knapp and D.M. Spooner) accessions has proven effective at improving scion suboptimal temperature tolerance in limited experiments. This study was conducted to determine whether commercially available tomato rootstocks with differing parental backgrounds and root system morphologies can improve the tolerance of scion plants to suboptimal temperature. Two controlled environment growth chambers were used and maintained at either optimal (25 °C day/20 °C night) or suboptimal (15 °C day/15 °C night) temperatures. The cold-sensitive tomato cultivar Moneymaker was used as the nongrafted and self-grafted control as well as scion grafted on ‘Multifort’ ( S. lycopersicum × S. habrochaites ), ‘Shield’ ( S. lycopersicum ), and S. habrochaites LA1777 rootstocks. Plants were grown for 10 days in 3.8 L plastic containers filled with a mixture of calcined clay and sand. ‘Multifort’ rootstock significantly reduced the amount of cold-induced stress as observed by larger leaf area and higher levels of CO 2 assimilation and photosystem II quantum efficiency. ‘Multifort’ had significantly longer roots, having 42% to 56% more fine root (diameter less than 0.5 mm) length compared with the other nongrafted and grafted treatments. Leaf starch concentration was significantly lower in ‘Multifort’-grafted plants at suboptimal temperatures compared with the self-grafted and nongrafted controls and the ‘Shield’-grafted plants at the same temperature. The ability for ‘Multifort’ to maintain root growth at suboptimal temperatures may improve root system sink strength, thereby promoting movement of photosynthate from leaf to root even under cold conditions. This work demonstrates that a commercially available rootstock can be used to improve suboptimal temperature tolerance in cold-sensitive ‘Moneymaker’ scions. DA - 2018/11// PY - 2018/11// DO - 10.21273/HORTSCI13311-18 VL - 53 IS - 11 SP - 1610-1617 SN - 2327-9834 KW - Solanum habrochaites KW - Solanum lycopersicum KW - herbaceous grafts KW - root system morphology KW - suboptimal temperature ER - TY - JOUR TI - Nitrogen Fixation Establishment during Initial Growth of Grain Legume Species AU - Pradhan, Deepti AU - Sinclair, Thomas R. AU - Alijani, Khadijeh T2 - JOURNAL OF CROP IMPROVEMENT AB - Atmospheric nitrogen fixation as a result of the symbiosis between bacteria and legume species, can result in major advantages in providing host plants with organic nitrogen. The objective of the present study was to evaluate the physiological potential during early seedling development for initiation of nodulation and nitrogen fixation activity of four grain legumes species: soybean [Glycine max (L.)], cowpea [Vigna unguiculate (L.) Walp], common bean [Phaseolus vulgaris (L.)], and peanut [Arachis hypogaea (L.)]. Seedlings were grown on a hydroponic solution so that nodule development could be readily observed until about 3 weeks after germination. Nodules developed in all cases. Acetylene reduction activity (ARA) by soybean and cowpea was also found early in seedling development. In contrast, peanut and common bean showed little or no development of ARA during seedling development. The results provided insight into differences in physiological potential among grain legumes in establishing symbiotic nitrogen fixation during crop establishment. These results indicate those species/cultivars that are candidates for readily establishing nitrogen fixation activity during the seedling stage of plant development. DA - 2018/// PY - 2018/// DO - 10.1080/15427528.2017.1393648 VL - 32 IS - 1 SP - 50-58 SN - 1542-7536 KW - Common bean KW - cowpea KW - hydroponic KW - nodulation KW - peanut KW - soybean ER - TY - JOUR TI - Inheritance of limited-transpiration trait in peanut: an update AU - Sinclair, Thomas R. AU - Pradhan, Deepti AU - Shekoofa, Avat T2 - JOURNAL OF CROP IMPROVEMENT AB - Peanut (Arachis Hypogeae L.) is commonly grown on sandy soil and in environments with intermittent rainfall, both of which can lead to soil water-deficit. Limited transpiration (LT) under elevated vapor pressure deficit (VPD) can result in water conservation, allowing sustained physiological activity later in the season during reproductive development. The objective of this study was to expand the number of progeny lines phenotyped for expression of the LT trait from the mating of Tifrunner (LT trait not expressed) × NC 3033 (LT trait expressed) to allow a preliminary examination of inheritance. Half of the 24 phenotyped lines expressed LT with their VPD threshold ranging from 2.16 to 3.38 kPa. Six of the 12 genotypes expressing LT had a threshold at 2.65 kPa or less, which is the range likely to be relevant in most peanut environments. These results, indicating epistatic inheritance, are supportive of LT expression in progeny lines at a reasonable frequency for relevant use in cultivar development for water-deficit conditions. DA - 2018/// PY - 2018/// DO - 10.1080/15427528.2017.1420000 VL - 32 IS - 2 SP - 281-286 SN - 1542-7536 KW - Drought stress KW - phenotyping KW - recombinant inbred lines KW - soil water KW - vapor pressure deficit ER - TY - JOUR TI - Dissecting Symptomatology and Fumonisin Contamination Produced by Fusarium verticillioides in Maize Ears AU - Morales, Laura AU - Marino, Thiago P. AU - Wenndt, Anthony J. AU - Fouts, Julia Q. AU - Holland, James B. AU - Nelson, Rebecca J. T2 - PHYTOPATHOLOGY AB - The fungus Fusarium verticillioides can infect maize ears, contaminating the grain with mycotoxins, including fumonisins. This global public health threat can be managed by breeding maize varieties that are resistant to colonization by F. verticillioides and by sorting grain after harvest to reduce fumonisin levels in food systems. Here, we employed two F. verticillioides inoculation techniques representing distinct infection pathways to dissect ear symptomatology and morphological resistance mechanisms in a diverse panel of maize inbred lines. The “point” method involved penetrating the ear with a spore-coated toothpick and the “inundative” method introduced a liquid spore suspension under the husk of the ear. We evaluated quantitative and qualitative indicators of external and internal symptom severity as low-cost proxies for fumonisin contamination, and found that kernel bulk density was predictive of fumonisin levels (78 to 84% sensitivity; 97 to 99% specificity). Inundative inoculation resulted in greater disease severity and fumonisin contamination than point inoculation. We also found that the two inoculation methods implicated different ear tissues in defense, with cob morphology being a more important component of resistance under point inoculation. Across both inoculation methods, traits related to cob size were positively associated with disease severity and fumonisin content. Our work demonstrates that (i) the use of diverse modes of inoculation is necessary for combining complementary mechanisms of genetic resistance, (ii) kernel bulk density can be used effectively as a proxy for fumonisin levels, and (iii) trade-offs may exist between yield potential and resistance to fumonisin contamination. DA - 2018/12// PY - 2018/12// DO - 10.1094/PHYTO-05-18-0167-R VL - 108 IS - 12 SP - 1475-1485 SN - 1943-7684 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-85057563477&partnerID=MN8TOARS ER - TY - JOUR TI - Farm to childcare: An analysis of social and economic values in local food systems AU - Rutz, Jacob C. AU - Bloom, J. Dara AU - Schroeder-Moreno, Michelle AU - Gunter, Chris T2 - JOURNAL OF AGRICULTURE FOOD SYSTEMS AND COMMUNITY DEVELOPMENT AB - Farm to institution is a component of the local food movement, representing the growing link between local producers and organizations like schools, prisons, and hospitals. These are organiza­tions that have concentrated buying power and thus a sizable influence on local food supply chains. Farm to childcare represents a next step in farm to institution, serving young children at the apex of their habit formation and biological devel­opment, and providing economic opportunities for local farmers. Using a qualitative case study meth­od­ology in one urban county in North Carolina, this paper asks the questions: (1) How do childcare centers, farmers, and distributors negotiate the tensions between social and financial values in the farm-to-childcare initiative? and (2) What strategies do these supply chain actors use to overcome bar­riers? Analyzing the perceptions of participation in a farm-to-child­care project of 11 childcare cen­ters, 11 farmers, and four distributors shows paral­lel values for children’s health and community con­nections to farmers actualized in the relation­ships and pur­chase of local foods. However, market-driven values and actions dominated the supply chain for all participants when business solvency seemed to be in opposition to central social com­mitments. Childcare centers and nonprofit distribu­tors sub­sidized local food purchases with inexpen­sive, nonlocal food and grant funding, respectively. Many farmers preferred expressing social values through noncommercial activities rather than sac­rificing economic viability to participate in socially oriented programs. This study suggests that achiev­ing the social goals of farm-to-childcare programs requires creative strategies, such as coordinating sales of smaller than Grade A produce, purchasing from multiple local sources, and aggregating demand from multiple centers. See the press release for this article.  DA - 2018/// PY - 2018/// DO - 10.5304/jafscd.2018.083.004 VL - 8 IS - 3 SP - 23-39 SN - 2152-0801 KW - Embeddedness KW - Marketness KW - Local Food Systems KW - Farm to Childcare KW - Case Study ER - TY - JOUR TI - Influence of Inoculation with Bradyrhizobia and Nitrogen Rate on Yield and Estimated Economic Return of Virginia Market-Type Peanut AU - Jordan, David L. AU - Johnson, P. Dewayne AU - Hare, Andrew T. AU - Anco, Dan AU - Chapin, Jay AU - Thomas, James AU - Monfort, Scott AU - Balota, Maria T2 - CROP FORAGE & TURFGRASS MANAGEMENT AB - Core Ideas Bradyrhizobia inoculant increases peanut yield in new peanut fields and in fields with a recent history of peanut. Applied nitrogen is less effective than inoculation with Bradyrhizobia in new peanut fields. Return on investment from Bradyrhizobia inoculant occurs regardless of field history relative to peanut production. Adequate nitrogen (N) fixation by peanut ( Arachis hypogaea L.) is essential to optimize yield. In replicated trials in North Carolina, South Carolina, and Virginia from 1998–2017, commercially available in‐furrow liquid or granular inoculant increased yield from 3460 to 4660 lb/acre in new peanut fields (52 trials) and 4280 to 4450 lb/acre in fields with a previous history of peanut plantings within the past 4 years (43 trials). The increase in economic value from inoculation treatment ($8/acre) at a peanut price of $535/ton was $318/acre and $41/acre in fields with these respective histories. In a second experiment, replicated trials were conducted from 2007–2017 in fields without a history of peanut production or fields not rotated to peanut within at least the past 20 years. Economic return based on peanut prices described previously was determined to reflect cost of N applied as ammonium sulfate ($0.28/lb ammonium sulfate) as a single application 45 to 60 days after planting when canopy foliage began to express N deficiency. A linear or quadratic response to rates of 0, 60, 90, 120, and 150 lb N/acre was noted in five trials with no response observed in the remaining four trials. When these experiments were included with five other experiments where non‐inoculated and inoculated controls were compared with one rate only (120 lb N/acre), yield and economic return were greater for inoculated peanut compared with peanut receiving N or the non‐inoculated and non‐fertilized control. Nitrogen increased peanut yield and economic return compared with the non‐fertilized control. Results from these experiments underscore the value of inoculation with Bradyrhizobia at planting regardless of field history and the limitations of applied N to correct N deficiencies in peanut. DA - 2018/10/18/ PY - 2018/10/18/ DO - 10.2134/cftm2018.01.0002 VL - 4 IS - 1 SP - SN - 2374-3832 ER - TY - JOUR TI - Summary of Variables Associated with Application of Plant Protection Products in Peanut AU - Jordan, David L. AU - Hare, Andrew T. AU - Roberson, Gary T. AU - Shew, Barbara B. AU - Brandenburg, Rick L. AU - Anco, Dan AU - Balota, Maria AU - Mehl, Hillary AU - Taylor, Sally T2 - CROP FORAGE & TURFGRASS MANAGEMENT AB - Core Ideas Peanut acreage was positively correlated with tank size, boom width, and ground speed. Peanut acreage was not correlated with peanut yield, spray volume, and spray pressure. Co‐applying three or more products in the same tank was common among growers. Flat‐fan nozzles were the most commonly used spray nozzles among peanut growers. Growers spend approximately 18% of their time applying crop protection products. DA - 2018/10/18/ PY - 2018/10/18/ DO - 10.2134/cftm2018.05.0034 VL - 4 IS - 1 SP - SN - 2374-3832 ER - TY - JOUR TI - Examples of Differences in Red Edge Reflectance and Normalized Difference Vegetative Index Caused by Stresses in Peanut AU - Carley, Danesha S. AU - Jordan, David L. AU - Dharmasri, Cecil L. AU - Shew, Barbara B. AU - Sutton, Turner B. AU - Brandenburg, Rick L. T2 - CROP FORAGE & TURFGRASS MANAGEMENT AB - Core Ideas Canopy reflectance is a potential tool for peanut management. Lesions caused by disease decreased red edge reflectance and NDVI. Leaves expressing nitrogen deficiency and drought stress decreased red edge reflectance and NDVI. DA - 2018/10/18/ PY - 2018/10/18/ DO - 10.2134/cftm2018.06.0042 VL - 4 IS - 1 SP - SN - 2374-3832 ER - TY - JOUR TI - Late-Season Nitrogen Application to Tobacco Produced in Fine-Textured Soils AU - Mason, J. Hunter AU - Vann, Matthew C. AU - Fisher, Loren R. AU - McGinnis, Michelle S. T2 - CROP FORAGE & TURFGRASS MANAGEMENT AB - Core Ideas Nitrogen is key to maximum leaf yield and quality. Nitrogen management is currently based upon expected conditions. Alternative strategies could improve N management. Alternative strategies are not suitable for fine‐textured soil types. Late‐season nitrogen (N) assimilation can greatly impact the yield and quality of flue‐cured tobacco, particularly in the fine‐textured Piedmont soils of North Carolina. Research was conducted in 2015 to 2016 to evaluate the effects of N application rate and number of N applications to the yield, quality, value, and leaf chemistry of flue‐cured tobacco. Liquid N (28% urea ammonium nitrate) was applied at 50, 70, and 90 lb N/acre. Each rate was either applied in two splits (0.5 rate 7–10 days after transplanting and 0.5 rate at layby) or three (0.5 rate 7–10 days after transplanting, a 0.25 rate at layby, and a 0.25 rate 2 weeks after layby) after transplanting. Cured leaf N concentration was similar at 50 and 70 lb N/acre (2.58 and 2.61%, respectively) but was increased in treatments receiving 90 lb N/acre (2.77%). Additionally, three N applications (2.73%) increased cured leaf N relative to two N applications (2.58%). The same treatment parameters did not impact yield or value but reduced cured leaf quality in one growing environment due to prolonged N assimilation. Results indicate that current recommendations for N application rates (50 lb/acre) and timings (split‐applied twice in equal portions) are adequate to obtain maximum yield, quality, and value on fine‐textured soils similar to those evaluated in this study. DA - 2018/7/2/ PY - 2018/7/2/ DO - 10.2134/cftm2018.02.0007 VL - 4 IS - 1 SP - SN - 2374-3832 ER - TY - JOUR TI - Nutrient Disorders of Burley and Flue-Cured Tobacco: Part 2-Micronutrient Disorders AU - Henry, Josh B. AU - Vann, Matthew AU - McCall, Ingram AU - Cockson, Paul AU - Whipker, Brian E. T2 - CROP FORAGE & TURFGRASS MANAGEMENT AB - Core Ideas Recognizing micronutrient disorders is important for commercial production. Unique, previously unobserved nutrient disorder symptoms were observed. Foliar nutrient concentrations were identified for burley and flue‐cured tobacco. Symptoms and critical values were compared with published results. Nutrient disorders often manifest unique symptoms and vary in critical nutrient ranges where visual symptoms appear depending on plant species and type. Understanding and recognizing nutrient disorders for different types of tobacco is important for maintaining yield and quality. Burley and flue‐cured tobacco ( Nicotiana tabacum L.) account for over 90% of all tobacco produced in the United States, and thus, were grown in this study to investigate the effects of micronutrient disorders. Tobacco plants were grown in silica sand culture, and control plants received a complete modified Hoagland's all‐nitrate solution, whereas nutrient‐deficient treatments were induced with a complete nutrient formula withholding a single nutrient. Boron toxicity was also induced by increasing the element tenfold higher than the complete nutrient formula. Plants were automatically irrigated, and the leached solution was captured for reuse. A complete replacement of nutrient solutions was done weekly. Plants were monitored daily to document and photograph symptoms as they developed. A description of nutrient disorder symptomology and critical tissue concentrations associated with symptomology are presented. DA - 2018/3/22/ PY - 2018/3/22/ DO - 10.2134/cftm2017.11.0077 VL - 4 IS - 1 SP - SN - 2374-3832 ER - TY - JOUR TI - Weed Species Richness and Density following Repeated Use of Glyphosate in Four Fields in North Carolina AU - Jordan, David L. AU - York, Alan C. T2 - CROP FORAGE & TURFGRASS MANAGEMENT AB - Core Ideas Long‐term use of glyphosate can reduce weed species richness. Long‐term use of glyphosate can select for resistant biotypes. Impact of continuous use of glyphosate depends on weed species. DA - 2018/4/19/ PY - 2018/4/19/ DO - 10.2134/cftm2017.12.0089 VL - 4 IS - 1 SP - SN - 2374-3832 ER - TY - JOUR TI - Nutrient Disorders o Burley and Flue-Cured Tobacco: Part 1-Macronutrient Deficiencies AU - Henry, Josh B. AU - Vann, Matthew AU - McCall, Ingram AU - Cockson, Paul AU - Whipker, Brian E. T2 - CROP FORAGE & TURFGRASS MANAGEMENT AB - Core Ideas Recognizing macronutrient disorders is important for commercial production. Foliar nutrient concentrations were identified for burley and flue‐cured tobacco. Symptoms and critical values were compared with published results. Nutrient deficiency disorders often manifest unique symptoms and vary in critical nutrient ranges depending on species and type. Understanding and recognizing nutrient disorders for different types of tobacco ( Nicotiana tabacum L.) is important for maintaining quality and yield. Burley and flue‐cured tobacco account for over 90% of all tobacco produced in the United States, and thus, were grown in this study to investigate the effects of macronutrient deficiencies. Tobacco plants were grown in silica sand culture, and control plants received a complete modified Hoagland's all‐nitrate solution, whereas nutrient‐deficient treatments were induced with a complete nutrient formula withholding a single nutrient. Plants were automatically irrigated, and the leached solution was captured for reuse. A complete replacement of nutrient solutions was done weekly. Plants were monitored daily to document and photograph symptoms as they developed. A description of nutrient disorder symptomology and critical tissue concentrations are presented. DA - 2018/3/22/ PY - 2018/3/22/ DO - 10.2134/cftm2017.11.0076 VL - 4 IS - 1 SP - SN - 2374-3832 ER - TY - JOUR TI - Air Temperature Effects on Turfgrass Colorant Transfer AU - Pinnix, Garland D. AU - McCauley, Raymond K. AU - Miller, Grady L. T2 - CROP FORAGE & TURFGRASS MANAGEMENT AB - Core Ideas Air temperature during turf colorant application can greatly affect colorant performance. Turf colorant applications that occur in colder temperatures increases the risk of colorant transfer onto absorbent materials. Turf colorant selection is imperative as certain products are able to adhere to the turfgrass canopy better than others. Turf colorants are used to provide green color to turfgrasses during times of stress and dormancy. When used to treat dormant turfgrass, proper application timing is imperative to increase functionality. The objective of this field study was to evaluate effects of air temperature on colorant transfer onto an absorbent material. Seven turfgrass colorants were applied to dormant ‘Tifway’ hybrid bermudagrass [ Cynodon dactylon (L.) Pers. × Cynodon transvaalensis Burtt‐Davy] and ‘El Toro’ zoysiagrass ( Zoysia japonica Steud.) at three air temperatures (25, 45, and 60°F). Colorant transfer for each air temperature treatment was sampled at 1, 2, 4, and 7 days after application (DAA) by dragging an absorbent cloth the length of treated turfgrass plots. When applied at 25°F, colorant transfer was 2.2 and 2.3 times greater than the amount transferred at 45 and 60°F, respectively. Regreen, Fairway, Perennial Ryegrass, and Premium all exceeded the threshold for colorant transfer (0.030 reflectance) 7 DAA when applied at 25°F. Spaint was the only product to have an acceptable measure of colorant transfer across air temperatures. Additionally, Regreen did not have an acceptable level of colorant transfer at any point during evaluations. When applied at 45 and 60°F, colorant transfer for Spaint, Green Turf Paint, and Green Dye Turf were at least 5 and 6 times lower, respectively, compared to other colorants. Data implied increased potential for colorant transfer when applied at 25°F compared to 45 or 60°F and illustrate variability in product transfer potential. DA - 2018/6/14/ PY - 2018/6/14/ DO - 10.2134/cftm2017.12.0091 VL - 4 IS - 1 SP - SN - 2374-3832 ER - TY - JOUR TI - Nitrogen Rate and Mowing Height Affect Seasonal Performance of Zoysiagrass Cultivars AU - Schwartz, Brian AU - Zhang, Jing AU - Kenworthy, Kevin AU - Miller, Grady AU - Peacock, Charles AU - Sladek, Bradley AU - Christensen, Christian T2 - AGRONOMY JOURNAL AB - Core Ideas Nitrogen rate had a greater impact on turfgrass quality of zoysiagrass when the grass was actively growing, but the effect of mowing height was only significant during spring green‐up. Nitrogen rate of 171 kg ha −1 was suitable for consistent turf performance in zoysiagrass and the effect of increasing N rate from 171 to 268 kg per ha was minimal. Japanese lawngrass and manilagrass can be successfully maintained at 2.5 or 5.0 cm and 0.6 or 1.2 cm, respectively, for equivalent performance during the majority of the year; however, during spring green‐up, the lower mowing height may deliver better turf performance. As new zoysiagrass ( Zoysia spp.) cultivars are released, field studies on N responses and mowing heights conducted over several years under different environments are needed to determine best management practices. This study was initiated to (i) characterize a general response (color, density, turf quality) to N fertilization rate, mowing height, and their interactions among zoysiagrass cultivars; and (ii) establish appropriate mowing height and N rate recommendations for each of the cultivars studied. Four Japanese lawngrass cultivars ( Z. japonica Steud.) and four manilagrass cultivars ( Z. matrella L. Merr.) were evaluated in Citra, FL, for 4 yr and in Raleigh, NC, for 2 yr under three N rates (73, 171, and 268 kg ha −1 yr −1 ) and two mowing heights (2.5 and 5.0 cm for Japanese lawngrass; 0.6 and 1.2 cm for manilagrass). Genetic differences were evident among the zoysiagrass cultivars. Nitrogen rate had a greater impact on most of the observed characteristics when the grass was actively growing, but the effect of mowing height was only significant during spring green‐up. The medium N rate was suitable for consistent turf performance throughout the year and the effect of increasing N rate from 171 kg ha −1 to 268 kg ha −1 was minimal. Japanese lawngrass and manilagrass can be successfully maintained at 2.5 or 5.0 cm and 0.6 or 1.2 cm, respectively, for equivalent performance during the majority of the year. However, during spring green‐up, the lower mowing height may deliver better turf performance. DA - 2018/// PY - 2018/// DO - 10.2134/agronj2018.01.0006 VL - 110 IS - 6 SP - 2114-2123 SN - 1435-0645 ER - TY - JOUR TI - HcPT1.2 participates in Pi acquisition in Hebeloma cylindrosporum external hyphae of ectornycorrhizas under high and low phosphate conditions AU - Becquer, Adeline AU - Garcia, Kevin AU - Plassard, Claude T2 - PLANT SIGNALING & BEHAVIOR AB - Ectomycorrhizal fungi improve tree phosphorus nutrition through transporters specifically localized at soil-hyphae and symbiotic interfaces. In the model symbiosis between the fungus Hebeloma cylindrosporum and the maritime pine (Pinus pinaster), several transporters possibly involved in phosphate fluxes were identified, including three H+:Pi transporters. Among these three, we recently unraveled the function of one of them, named HcPT2, in both pure culture and symbiotic interaction with P. pinaster. Here we investigated the transporter named HcPT1.2, by analyzing inorganic phosphate transport ability in a yeast complementation assay, assessing its expression in the fungus associated or not with the plant, and immunolocalizing the proteins in ectomycorrhizas. We also evaluated the effect of external Pi concentration on expression and localization of HcPT1.2. Our results revealed that HcPT1.2 is involved in Pi acquisition by H. cylindrosporum mycelium, irrespective of the external Pi concentrations. DA - 2018/// PY - 2018/// DO - 10.1080/15592324.2018.1525997 VL - 13 IS - 10 SP - SN - 1559-2324 UR - https://doi.org/10.1080/15592324.2018.1525997 KW - Ectomycorrhizal symbiosis KW - H+:Pi transporter KW - Immunolocalization KW - Inorganic phosphate KW - RT-qPCR KW - Yeast complementation ER - TY - JOUR TI - Nonionic Surfactant Affects Dislodgeable 2,4-D Foliar Residue from Turfgrass AU - Maxwell, Patrick J. AU - Gannon, Travis W. AU - Cooper, Richard J. T2 - WEED TECHNOLOGY AB - Abstract 2,4-dimethylamine salt (2,4-D) is a synthetic auxin herbicide used extensively in turfgrass for selective broadleaf weed control. Previous research has shown that 2,4-D can dislodge from treated turf, notably in the presence of canopy moisture. Practitioners commonly apply 2,4-D in combination with various commercially available surfactants to increase efficacy. Field research was completed to evaluate the effect of surfactant inclusion and sample collection time within a day on dislodgeable 2,4-D residue from perennial ryegrass. Research was initiated May 24, 2016 in Raleigh, NC and repeated in time to quantify dislodgeable 2,4-D following application (2.1 kg ae ha –1 ) either alone or with a nonionic surfactant (0.5% vol/vol). Sample collection occurred 1, 2, 3, 6, 12 or 24 d after treatment (DAT) at AM [7:00 AM Eastern Standard Time (EST)] and PM (2:00 PM EST) sample timings within a day. 2,4-D applied with surfactant (0.4% to 25.4% of applied) reduced dislodgeable foliar residue compared to 2,4-D applied alone (0.5% to 31.2%) from 1 through 6 DAT, whereas dislodgeable 2,4-D was not detected at 12 and 24 DAT. Regardless of surfactant inclusion or absence, samples collected in the AM resulted in a 5- to 10-fold increase in dislodgeable 2,4-D compared to samples collected in the PM from 1 through 6 DAT, suggesting that 2,4-D dislodgeability may be influenced by conditions favoring canopy moisture development. This research will improve turfgrass management practices and research designed to minimize human 2,4-D exposure. DA - 2018/10// PY - 2018/10// DO - 10.1017/wet.2018.47 VL - 32 IS - 5 SP - 557-563 SN - 1550-2740 KW - Adjuvant KW - best management practice KW - herbicide exposure KW - pesticide exposure KW - turfgrass management ER - TY - JOUR TI - Critical Period for Palmer Amaranth (Amaranthus palmeri) Control in Pickling Cucumber AU - McGowen, Samuel J. AU - Jennings, Katherine M. AU - Chaudhari, Sushila AU - Monks, David W. AU - Schultheis, Jonathan R. AU - Reberg-Horton, Chris T2 - Weed Technology AB - Abstract Field studies were conducted in North Carolina to determine the critical period for Palmer amaranth control (CPPAC) in pickling cucumber. In removal treatments (REM), emerged Palmer amaranth were allowed to compete with cucumber for 14, 21, 28, or 35 d after sowing (DAS) in 2014 and 14, 21, 35, or 42 DAS in 2015, and cucumber was kept weed-free for the remainder of the season. In the establishment treatments (EST), cucumber was maintained free of Palmer amaranth by hand removal until 14, 21, 28, or 35 DAS in 2014 and until 14, 21, 35, or 42 DAS in 2015; after this, Palmer amaranth was allowed to establish and compete with the cucumber for the remainder of the season. The beginning and end of the CPPAC, based on 5% loss of marketable yield, was determined by fitting log-logistic and Gompertz equations to the relative yield data representing REM and EST, respectively. Season-long competition by Palmer amaranth reduced pickling cucumber yield by 45% to 98% and 88% to 98% during 2014 and 2015, respectively. When cucumber was planted on April 25, 2015, the CPPAC ranged from 570 to 1,002 heat units (HU), which corresponded to 32 to 49 DAS. However, when cucumber planting was delayed 2 to 4 wk (May 7 and May 21, 2014 and May 4, 2015), the CPPAC lasted from 100 to 918 HU (7 to 44 DAS). This research suggested that planting pickling cucumber as early as possible during the season may help to reduce competition by Palmer amaranth and delay the beginning of the CPPAC. DA - 2018/10// PY - 2018/10// DO - 10.1017/wet.2018.58 VL - 32 IS - 5 SP - 586-591 LA - en SN - 0890-037X, 1550-2740 UR - https://www.cambridge.org/core/journals/weed-technology/article/critical-period-for-palmer-amaranth-amaranthus-palmeri-control-in-pickling-cucumber/4BCED15B7D9F47DAFB0DF91FC9112015 DB - Cambridge Core Y2 - 2019/2/11/ KW - Establishment KW - heat units KW - removal KW - weed competition ER - TY - JOUR TI - Field measurement in vegetable crops indicates need for reevaluation of on-farm food loss estimates in North America AU - Johnson, Lisa K. AU - Dunning, Rebecca D. AU - Gunter, Chris C. AU - Bloom, J. Dara AU - Boyette, Michael D. AU - Creamer, Nancy G. T2 - AGRICULTURAL SYSTEMS AB - Food loss and waste in the US has been estimated at 40%, a figure that does not include losses at the agricultural level. Consumer food waste is expensive and environmentally damaging as it travels the length of the supply chain and largely ends up in the landfill. Most research and campaigns emphasize the consumer level, which has resulted in the omission of data collection and development of solutions for producers of fruit and vegetable crops. The available estimates of edible produce lost in the field are based on assumptions and estimates, rather than field data. Therefore, this project aimed to measure losses in the field in order to understand if estimates are accurate. Sixty-eight fields of eight vegetable crops were evaluated on nine North Carolina farms during the 2017 production season, using a sampling and scaling method. Combining the unharvested crops of marketable quality and edible but not marketable quality (produce that does not meet appearance quality standards), the average produce volume available after the primary harvest was 5114.59 kg per hectare. Totaling an average of 42% of the marketed yield for these crops, these high figures indicate the need for a reevaluation of the food loss estimates at the agricultural level in the US, and a focus on solutions. DA - 2018/11// PY - 2018/11// DO - 10.1016/j.agsy.2018.09.008 VL - 167 SP - 136-142 SN - 1873-2267 KW - Food loss KW - Food waste KW - primary production KW - Postharvest loss KW - Vegetable crops KW - Fresh produce ER - TY - JOUR TI - THE GRAPE REMOTE SENSING ATMOSPHERIC PROFILE AND EVAPOTRANSPIRATION EXPERIMENT AU - Kustas, William P. AU - Anderson, Martha C. AU - Alfieri, Joseph G. AU - Knipper, Kyle AU - Torres-Rua, Alfonso AU - Parry, Christopher K. AU - Nieto, Hector AU - Agam, Nurit AU - White, William A. AU - Gao, Feng AU - McKee, Lynn AU - Prueger, John H. AU - Hipps, Lawrence E. AU - Los, Sebastian AU - Alsina, Maria Mar AU - Sanchez, Luis AU - Sams, Brent AU - Dokoozlian, Nick AU - McKee, Mac AU - Jones, Scott AU - Yang, Yun AU - Wilson, Tiffany G. AU - Lei, Fangni AU - McElrone, Andrew AU - Heitman, Josh L. AU - Howard, Adam M. AU - Post, Kirk AU - Melton, Forrest AU - Hain, Christopher T2 - BULLETIN OF THE AMERICAN METEOROLOGICAL SOCIETY AB - Abstract Particularly in light of California’s recent multiyear drought, there is a critical need for accurate and timely evapotranspiration (ET) and crop stress information to ensure long-term sustainability of high-value crops. Providing this information requires the development of tools applicable across the continuum from subfield scales to improve water management within individual fields up to watershed and regional scales to assess water resources at county and state levels. High-value perennial crops (vineyards and orchards) are major water users, and growers will need better tools to improve water-use efficiency to remain economically viable and sustainable during periods of prolonged drought. To develop these tools, government, university, and industry partners are evaluating a multiscale remote sensing–based modeling system for application over vineyards. During the 2013–17 growing seasons, the Grape Remote Sensing Atmospheric Profile and Evapotranspiration eXperiment (GRAPEX) project has collected micrometeorological and biophysical data within adjacent pinot noir vineyards in the Central Valley of California. Additionally, each year ground, airborne, and satellite remote sensing data were collected during intensive observation periods (IOPs) representing different vine phenological stages. An overview of the measurements and some initial results regarding the impact of vine canopy architecture on modeling ET and plant stress are presented here. Refinements to the ET modeling system based on GRAPEX are being implemented initially at the field scale for validation and then will be integrated into the regional modeling toolkit for large area assessment. DA - 2018/9// PY - 2018/9// DO - 10.1175/BAMS-D-16-0244.1 VL - 99 IS - 9 SP - 1791-1812 SN - 1520-0477 ER - TY - JOUR TI - The Accuracy of Genomic Prediction between Environments and Populations for Soft Wheat Traits AU - Huang, Mao AU - Ward, Brian AU - Griffey, Carl AU - Van Sanford, David AU - McKendry, Anne AU - Brown-Guedira, Gina AU - Tyagi, Priyanka AU - Sneller, Clay T2 - CROP SCIENCE AB - Genomic selection (GS) uses training population (TP) data to estimate the value of lines in a selection population. In breeding, the TP and selection population are often grown in different environments, which can cause low prediction accuracy when the correlation of genetic effects between the environments is low. Subsets of TP data may be more predictive than using all TP data. Our objectives were (i) to evaluate the effect of using subsets of TP data on GS accuracy between environments, and (ii) to assess the accuracy of models incorporating marker × environment interaction (MEI). Two wheat ( Triticum aestivum L.) populations were phenotyped for 11 traits in independent environments and genotyped with single‐nucleotide polymorphism markers. Within each population–trait combination, environments were clustered. Data from one cluster were used as the TP to predict the value of the same lines in the other cluster(s) of environments. Models were built using all TP data or subsets of markers selected for their effect and stability. The GS accuracy using all TP data was >0.25 for 9 of 11 traits. The between‐environment accuracy was generally greatest using a subset of stable and significant markers; accuracy increased up to 48% relative to using all TP data. We also assessed accuracy using each population as the TP and the other as the selection population. Using subsets of TP data or the MEI models did not improve accuracy between populations. Using optimized subsets of markers within a population can improve GS accuracy by reducing noise in the prediction data set. DA - 2018/// PY - 2018/// DO - 10.2135/cropsci2017.10.0638 VL - 58 IS - 6 SP - 2274-2288 SN - 1435-0653 ER - TY - JOUR TI - Identification of Virginia-Type Peanut Genotypes for Water-Deficit Conditions Based on Early Decrease in Transpiration Rate with Soil Drying AU - Sinclair, Thomas R. AU - Shekoofa, Avat AU - Isleib, Thomas G. AU - Balota, Maria AU - Zhang, Hao T2 - CROP SCIENCE AB - Early decrease in transpiration rate as soil progressively dries allows soil water conservation for sustained crop physiological activity as water deficit continues to increase. This trait is likely to be particularly useful for peanut ( Arachis hypogaea L.), which is often grown on sandy soil where water deficit can develop quickly. This study was undertaken to identify peanut genotypes that express this water conservation trait and to determine if it confers a yield advantage. Three approaches were taken. (i) Two populations of peanut were tested in controlled environments during progressive soil drying. Especially high thresholds of soil water content for initiation of decrease in transpiration rate were identified in three lines in each of the breeding populations. (ii) Nine genotypes were identified for field observation of leaf wilting under rain shelters and in the open field. There was a correspondence between the early decrease in transpiration rate with soil drying and delayed wilting. (iii) Yield trial data for three genotypes were examined to identify those lines that consistently had higher yields than the commercial check cultivar ‘Bailey’, particularly at low yield levels commonly associated with drier conditions. When expressing total seed yield in monetary return, these breeding lines had yield values that were consistently superior to Bailey below the US$2000 ha −1 threshold. Based on the three experimental approaches, N12006ol consistently expressed a desired response of early decrease in transpiration rate with soil drying, delayed wilting in the field when soil water deficit developed, and greater yield value than Bailey in low‐yield environments. DA - 2018/// PY - 2018/// DO - 10.2135/cropsci2018.05.0293 VL - 58 IS - 6 SP - 2607-2612 SN - 1435-0653 ER - TY - JOUR TI - Aquaporin Activity to Improve Crop Drought Tolerance AU - Shekoofa, Avat AU - Sinclair, Thomas R. T2 - CELLS AB - In plants, aquaporins (AQP) occur in multiple isoforms in both plasmalemma and tonoplast membranes resulting in regulation of water flow in and out of cells, and ultimately, water transfer through a series of cells in leaves and roots. Consequently, it is not surprising that physiological and molecular studies have identified AQPs as playing key roles in regulating hydraulic conductance in roots and leaves. As a result, the activity of AQPs influences a range of physiological processes including phloem loading, xylem water exit, stomatal aperture and gas exchange. The influence of AQPs on hydraulic conductance in plants is particularly important in regulating plant transpiration rate, particularly under conditions of developing soil water-deficit stress and elevated atmospheric vapor pressure deficit (VPD). In this review, we examine the impact of AQP activity and hydraulic conductance on crop water use and the identification of genotypes that express soil water conservation as a result of these traits. An important outcome of this research has been the identification and commercialization of cultivars of peanut (Arachis hypogaea L.), maize (Zea mays L.), and soybean (Glycine max (Merr) L.) for dry land production systems. DA - 2018/9// PY - 2018/9// DO - 10.3390/cells7090123 VL - 7 IS - 9 SP - SN - 2073-4409 KW - aquaporins (AQPs) KW - water deficit stress KW - high vapor pressure deficit (VPD) KW - limited-transpiration (TRlim) trait ER - TY - JOUR TI - Comparison of Root System Morphology of Cucurbit Rootstocks for Use in Watermelon Grafting AU - Bertucci, Matthew B. AU - Suchoff, David H. AU - Jennings, Katherine M. AU - Monks, David W. AU - Gunter, Christopher C. AU - Schultheis, Jonathan R. AU - Louws, Frank J. T2 - HORTTECHNOLOGY AB - Grafting of watermelon ( Citrullus lanatus ) is an established production practice that provides resistance to soilborne diseases or tolerance to abiotic stresses. Watermelon may be grafted on several cucurbit species (interspecific grafting); however, little research exists to describe root systems of these diverse rootstocks. A greenhouse study was conducted to compare root system morphology of nine commercially available cucurbit rootstocks, representing four species: pumpkin ( Cucurbita maxima ), squash ( Cucurbita pepo ), bottle gourd ( Lagenaria siceraria ), and an interspecific hybrid squash ( C. maxima × C. moschata ). Rootstocks were grafted with a triploid watermelon scion (‘Exclamation’), and root systems were compared with nongrafted (NG) and self-grafted (SG) ‘Exclamation’. Plants were harvested destructively at 1, 2, and 3 weeks after transplant (WAT), and data were collected on scion dry weight, total root length (TRL), average root diameter, root surface area, root:shoot dry-weight ratio, root diameter class proportions, and specific root length. For all response variables, the main effect of rootstock and rootstock species was significant ( P < 0.05). The main effect of harvest was significant ( P < 0.05) for all response variables, with the exception of TRL proportion in diameter class 2. ‘Ferro’ rootstock produced the largest TRL and root surface area, with observed values 122% and 120% greater than the smallest root system (‘Exclamation’ SG), respectively. Among rootstock species, pumpkin produced the largest TRL and root surface area, with observed values 100% and 82% greater than those of watermelon, respectively. These results demonstrate that substantial differences exist during the initial 3 WAT in root system morphology of rootstocks and rootstock species available for watermelon grafting and that morphologic differences of root systems can be characterized using image analysis. DA - 2018/10// PY - 2018/10// DO - 10.21273/HORTTECH04098-18 VL - 28 IS - 5 SP - 629-636 SN - 1943-7714 KW - Citrullus lanatus KW - Cucurbita maxima KW - Cucurbita moscbata KW - Cucurbita pepo KW - Lagenaria siceraria KW - scion ER - TY - JOUR TI - A Global Meta-Analysis to Predict Atrazine Sorption from Soil Properties AU - Ou, Ling AU - Gannon, Travis W. AU - Arellano, Consuelo AU - Polizzotto, Matthew L. T2 - JOURNAL OF ENVIRONMENTAL QUALITY AB - Atrazine (2‐chloro‐4‐ethylamino‐6‐isopropylamino‐1,3,5‐triazine) is one of the most widely used herbicides worldwide, and groundwater contamination is of concern, especially in heavily used regions and in edaphic conditions prone to leaching. Soil sorption plays an essential role in atrazine environmental fate, yet consistent atrazine risk prediction remains limited. A quantitative meta‐analysis was conducted to characterize the effect of soil properties on atrazine sorption, using 378 previous observations in 48 publications from 1985 to 2015 globally, which included data on soil properties and sorption parameters. A supplemental regional study was conducted to test the derived meta‐analysis models. The meta‐analysis indicated that percentage organic C (OC) was the most important parameter for estimating atrazine sorption, followed by percentage silt, soil pH, and percentage clay. Meta‐analysis and supplemental study models were developed for Freundlich sorption coefficients ( K f ) and sorption distribution coefficients ( K d ) as a function of OC. The global meta‐analysis models generated positive linear trends for OC with K f and K d ( R 2 = 0.197 and 0.205, respectively). Organic C was highly correlated with K f and K d in supplemental experimental study models ( R 2 = 0.93 and 0.92, respectively), indicating accurate prediction of sorption within the evaluated region. Continental models were investigated, which improved the goodness of fit. Models developed via meta‐analysis may be used to predict atrazine sorption over wide ranges of data, whereas more accurate and refined prediction can be achieved by specific regional models through experimental studies. However, such models could be improved if standardized agroclimatic conditions, soil classification, and other key variables were more widely reported. Core Ideas Meta‐analysis quantified soil properties governing atrazine sorption. Organic C content had the highest correlation with atrazine soil sorption. Meta‐analysis models showed similar trends to independent experimental results. Continental and supplemental models improved fit compared with global models. Standard climate and soil taxonomic data should be reported to optimize models. DA - 2018/// PY - 2018/// DO - 10.2134/jeq2017.11.0429 VL - 47 IS - 6 SP - 1389-1399 SN - 1537-2537 ER - TY - JOUR TI - "A Biometeorological Time Scale for Cereal Crop Involving Day and Night Temperatures and Photoperiod" by George W. Robertson, International Journal of Biometeorology (1968) 12:191-223 AU - Sinclair, Thomas R. T2 - CROP SCIENCE AB - 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 the 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 George Robertson published in 1968 that provided key concepts used yet today to describe the pace of plant development. Robertson developed the ideas of normalized development rates for each ontogenetic stage, multiplication of temperature and photoperiod responses, and inclusion of base temperature and photoperiod parameters in the response functions. DA - 2018/// PY - 2018/// DO - 10.2135/cropsci2018.05.0289 VL - 58 IS - 6 SP - 2229-2232 SN - 1435-0653 ER - TY - JOUR TI - Assessing Carolina Bay Wetland Restoration Risks to Downstream Water Quality by Characterizing Land Use and Stream Proximity AU - Sullivan, Dana G. AU - White, Jeffrey G. AU - Vepraskas, Michael T2 - Wetlands DA - 2018/10/26/ PY - 2018/10/26/ DO - 10.1007/S13157-018-1095-5 VL - 39 IS - 3 SP - 495-506 J2 - Wetlands LA - en OP - SN - 0277-5212 1943-6246 UR - http://dx.doi.org/10.1007/S13157-018-1095-5 DB - Crossref KW - Carolina Bay KW - Wetland KW - Restoration KW - Water quality KW - Phosphorus KW - Risk assessment ER - TY - JOUR TI - Neural Net Classification Combined With Movement Analysis to Evaluate Setaria viridis as a Model System for Time of Day of Anther Appearance AU - Desai, Jigar S. AU - Slabaugh, Erin AU - Liebelt, Donna J. AU - Fredenberg, Jacob D. AU - Gray, Benjamin N. AU - Jagadish, S. V. Krishna AU - Wilkins, Olivia AU - Doherty, Colleen J. T2 - FRONTIERS IN PLANT SCIENCE AB - In many plant species, the time of day at which flowers open to permit pollination is tightly regulated. Proper time of flower opening, or Time of Day of Anther Appearance (TAA), may coordinate flowering opening with pollinator activity or may shift temperature sensitive developmental processes to cooler times of day. The genetic mechanisms that regulate the timing of this process in cereal crops are unknown. To address this knowledge gap, it is necessary to establish a monocot model system that exhibits variation in TAA. Here, we examine the suitability of Setaria viridis, the model for C4 photosynthesis, for such a role. We developed an imaging system to monitor the temporal regulation of growth, flower opening time, and other physiological characteristics in Setaria. This system enabled us to compare Setaria varieties Ames 32254, Ames 32276, and PI 669942 variation in growth and daily flower opening time. We observed that TAA occurs primarily at night in these three Setaria accessions. However, significant variation between the accessions was observed for both the ratio of flowers that open in the day versus night and the specific time of day where the rate is maximal. Characterizing this physiological variation is a requisite step towards uncovering the genetic molecular mechanisms regulating TAA. Leveraging the regulation of TAA could provide researchers with a genetic tool to improve crop productivity in new environments. DA - 2018/10/31/ PY - 2018/10/31/ DO - 10.3389/fpls.2018.01585 VL - 9 SP - SN - 1664-462X KW - flower opening time KW - spikelet opening time KW - timing of anthesis KW - setaria KW - developmental stage KW - image analysis of plants KW - biological image classification ER - TY - JOUR TI - Winter pea genotype screening for grain crop production in the southeastern USA AU - Vann, R.A. AU - Reberg-Horton, S.C. AU - Castillo, M.S. AU - Mirsky, S.B. AU - McGee, R.J. T2 - Agronomy Journal DA - 2018/// PY - 2018/// VL - 110 SP - 1–10 ER - TY - JOUR TI - Chemical Treatment to Reduce Turbidity in Pumped Construction Site Water AU - Kang, Jihoon AU - Vetter, Joshua W. AU - McLaughlin, Richard A. T2 - JOURNAL OF ENVIRONMENTAL ENGINEERING AB - Many construction projects need to pump turbid water from borrow pits or other excavations into stilling basins or sediment filter bags prior to discharge. This study evaluated the effectiveness of these devices with polyacrylamide (PAM) injection to reduce effluent turbidity. Results from laboratory jar tests using two coastal plain sediments of North Carolina suggested that a cationic PAM was the most effective in reducing turbidity, followed by a nonionic PAM. Anionic PAM was effective in whole-soil jar tests but not when turbid supernatant was tested. A stilling basin was not effective in reducing the turbidity of the pumped water without PAM. Cationic and nonionic PAMs injected to the pumped turbid water reduced effluent turbidity from the basin by 98% and 90%, respectively. Pumping the turbid water through a sediment filter bag was also not effective for turbidity reduction unless PAM was injected into the pumping system. Our results suggested that the relatively nontoxic, nonionic PAM may be an alternative where anionic PAM is not effective in reducing turbidity in borrow pit operations. DA - 2018/12// PY - 2018/12// DO - 10.1061/(ASCE)EE.1943-7870.0001498 VL - 144 IS - 12 SP - SN - 1943-7870 KW - Baffles KW - Chemical treatment KW - Flocculation KW - Stilling basin KW - Turbidity ER - TY - JOUR TI - Summary of 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 - Soil bulk density (ρb) is a key indicator of soil compaction and soil health that relates to water infiltration, plant rooting depth, nutrient availability, and soil microbial activity. Under field conditions, ρb usually varies with time and depth because of agronomic practices, root growth, and environmental processes (e.g., rainfall events, wetting/drying, and freezing/thawing). The traditional technique (i.e., the coring method) for determining ρb has the problems of destructive sampling, labor intensive, and is unable to capture the spatial and temporal variations. In a chapter of the recent Methods of Soil Analysis book, we present a review of the theory, instrumentation, and procedures of the thermo–time domain reflectometry (thermo-TDR) technique for monitoring in situ ρb (2). A thermo-TDR sensor (Fig. 1) measures soil thermal properties and water content (θ) concurrently by integrating the functions of the heat-pulse and TDR sensors. The method employs available models that relate heat capacity (C) or thermal conductivity (λ) to soil texture, θ, and ρb. With the prior information of sand/clay fractions and specific heat of soil solids, ρb is estimated inversely from θ and C or λ measurements made with thermo-TDR sensors. Laboratory and field tests have shown that the relative errors in ρb estimates are generally within 10%. The new method provides in situ and continuous ρb measurements with no calibration requirement, thus offers the potential for studying coupled heat and water processes in deformable soils where ρb changes with time and depth. Schematic view of the configuration for the 1 thermo-TDR sensor. The drawings are not to scale. DA - 2018/// PY - 2018/// DO - 10.2136/sssaj2018.01.0053 VL - 82 IS - 4 SP - 733-733 SN - 1435-0661 ER - TY - JOUR TI - Soil-Test Biological Activity with the Flush of CO2: I.C and N Characteristics of Soils in Corn Production AU - Franzluebbers, Alan J. AU - Pershing, Mary R. AU - Crozier, Carl AU - Osmond, Deanna AU - Schroeder-Moreno, Michelle T2 - SOIL SCIENCE SOCIETY OF AMERICA JOURNAL AB - Core Ideas Soil nitrogen mineralization can be predicted with the flush of CO 2 . Soil texture does not alter the relationship between the flush of CO 2 and N mineralization. Large quantity of mineralizable N in surface soils is possible with conservation management. The flush of CO 2 is an appropriate indicator for soil‐test biological activity. The flush of CO 2 is a rapid and reliable indicator of soil N availability. Nitrogen limits crop production when insufficient and harms the environment when excessive. Tailoring N inputs to cropping systems remains a high priority to achieve production and environmental goals. We collected soils from 47 corn ( Zea mays L.) production fields in North Carolina and Virginia at depths of 0 to 10, 10 to 20, and 20 to 30 cm and evaluated soil C and N characteristics in association with soil N mineralization. Soil organic C at a depth of 0 to 10 cm varied among sites from ∼10 to 80 g kg –1 , and generally declined with depth because of many sites with no‐tillage management. Net N mineralization during 24 d of aerobic incubation (25°C, 50% water‐filled pore space) was 54 to 114 mg N kg –1 (24 d) –1 at 0 to 10 cm, 22 to 41 mg N kg –1 (24 d) –1 at 10 to 20 cm, and 12 to 22 mg N kg –1 (24 d) –1 at 20 to 30 cm (middle 50% of observations at each depth). Total soil N was positively associated with net N mineralization ( r 2 = 0.58), but the flush of CO 2 during 3 d was even more closely associated with net N mineralization ( r 2 = 0.77). Association between the flush of CO 2 and net N mineralization did not change significantly when data were sorted by different regions or soil textural classes. The flush of CO 2 is a rapid, reliable, and robust indicator of soil‐test biological activity. The strong association of the flush of CO 2 with net N mineralization also corroborated use of the flush of CO 2 as a rapid and reliable indicator of soil N availability. DA - 2018/// PY - 2018/// DO - 10.2136/sssaj2017.12.0433 VL - 82 IS - 3 SP - 685-695 SN - 1435-0661 ER - TY - JOUR TI - Soil Test Biological Activity with the Flush of CO2: II. Greenhouse Growth Bioassay from Soils in Corn Production AU - Franzluebbers, Alan J. AU - Pershing, Mary R. T2 - SOIL SCIENCE SOCIETY OF AMERICA JOURNAL AB - Core Ideas Grass growth in the greenhouse was dependent on soil nitrogen mineralization. Soil‐test biological activity was a valuable indicator of nitrogen mineralization. Biological activity, residual inorganic nitrogen, and total nitrogen were most important. Soil nitrogen (N) mineralization is variably affected by management and edaphic conditions. A routine soil test that reflects both soil biological activity and N mineralization could improve predictions for N fertilizer recommendations to cereal grains on different soil types and landscape settings. We collected soils from 47 corn production fields in North Carolina and Virginia at depths of 0 to 10, 10 to 20, and 20 to 30 cm and evaluated soil C and N characteristics in association with sorghum‐sudangrass [ Sorghum bicolor (L.) Moench ssp. Drummondii] dry matter production and N uptake during 6 to 8 wk of growth in the greenhouse. Plant dry matter and N uptake were strongly associated, as expected. Plant available N (sum of net N mineralization during 24 d of aerobic incubation + residual inorganic N) had the strongest association with plant dry matter production ( r 2 = 0.76) and N uptake ( r 2 = 0.85). However, the flush of CO 2 during a 0‐ to 3‐d period following rewetting of dried soil was nearly equally effective at r 2 = 0.74 and r 2 = 0.76, respectively. Multiple regression models with 4 ± 2 additional variables led to r 2 = 0.88 ± 0.10 among different separations of data based on depth, region, and soil textural class. We suggest the optimum combination of variables to predict soil N availability would be the flush of CO 2 , residual inorganic N, and total soil N concentration, as they balance relevant scientific information with limited soil‐testing resources (time and labor). We demonstrated that the flush of CO 2 was a rapid and reliable indicator of soil N availability. DA - 2018/// PY - 2018/// DO - 10.2136/sssaj2018.01.0024 VL - 82 IS - 3 SP - 696-707 SN - 1435-0661 ER - TY - JOUR TI - Acetosyringone treatment duration affects large T-DNA molecule transfer to rice callus AU - Xi, Jing AU - Patel, Minesh AU - Dong, Shujie AU - Que, Qiudeng AU - Qu, Rongda T2 - BMC BIOTECHNOLOGY AB - Large T-DNA fragment transfer has long been a problem for Agrobacterium-mediated transformation. Although vector systems, such as the BIBAC series, were successfully developed for the purpose, low transformation efficiencies were consistently observed. To gain insights of this problem in monocot transformation, we investigated the T-strand accumulation of various size of T-DNA in two kinds of binary vectors (one copy vs. multi-copy) upon acetosyringone (AS) induction and explored ways to improve the efficiency of the large T-DNA fragment transfer in Agrobacterium-mediated rice transformation. By performing immuno-precipitation of VirD2-T-strands and quantitative real-time PCR assays, we monitored the accumulation of the T-strands in Agrobacterium tumeficiens after AS induction. We further demonstrated that extension of AS induction time highly significantly improved large-size T-DNA transfer to rice cells. Our data provide valuable information of the T-strand dynamics and its impact on large T-DNA transfer in monocots, and likely dicots as well. DA - 2018/8/9/ PY - 2018/8/9/ DO - 10.1186/s12896-018-0459-5 VL - 18 SP - SN - 1472-6750 KW - Agrobacterium KW - BIBAC KW - Immuno-precipitation KW - Large T-DNA KW - Monocot transformation ER - TY - JOUR TI - Summary of 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 - Core Ideas Describes the method for determining near‐surface water content with heat pulse sensors. Temperature data prior to a heat‐pulse are used to reduce ambient temperature effects. The PILS–ABC model is used to minimize errors because of the soil–air interface. Surface layer soil water content is important for evaporation, surface energy balance, seed germination, residue decomposition, microbial activity, and many other biological, chemical, and physical processes. The standard method (i.e., the gravimetric method) for measuring soil water content requires destructive sampling and is unsuitable for continuous measurement. Techniques such as neutron thermalization and time domain reflectometry suffer relatively large errors in measuring soil water content near the surface. In a recent Methods of Soil Analysis article, the authors present the principles and procedures for using a heat‐pulse sensor to determine near‐surface soil water content. DA - 2018/// PY - 2018/// DO - 10.2136/sssaj2018.04.0138 VL - 82 IS - 5 SP - 1015-1015 SN - 1435-0661 ER - TY - JOUR TI - Contrasting Warming and Ozone Effects on Denitrifiers Dominate Soil N2O Emissions AU - Qu, Yunpeng AU - Jiang, Yu AU - Guo, Lijin AU - Burkey, Kent O. AU - Zobel, Richard W. AU - Shew, H. David AU - Hu, Shuijin T2 - ENVIRONMENTAL SCIENCE & TECHNOLOGY AB - Nitrous oxide (N2O) in the atmosphere is a major greenhouse gas and reacts with volatile organic compounds to create ozone (an air pollutant) in the troposphere. Climate change factors such as warming and elevated ozone (eO3) affect N2O fluxes, but the direction and magnitude of these effects are uncertain and the underlying mechanisms remain unclear. We examined the impact of simulated warming (control + 3.6 °C) and eO3 (control + 45 ppb) on soil N2O fluxes in a soybean agroecosystem. Results obtained showed that warming significantly increased soil labile C, microbial biomass, and soil N mineralization, but eO3 reduced these parameters. Warming enhanced N2O-producing denitrifers ( nirS- and nirK-type), corresponding to increases in both the rate and sum of N2O emissions. In contrast, eO3 significantly reduced both N2O-producing and N2O-consuming ( nosZ-type) denitrifiers but had no impact on N2O emissions. Further, eO3 offsets the effects of warming on soil labile C, microbial biomass, and the population size of denitrifiers but still increased N2O emissions, indicating a direct effect of temperature on N2O emissions. Together, these findings suggest that warming may promote N2O production through increasing both the abundance and activities of N2O-producing microbes, positively feeding back to the ongoing climate change. DA - 2018/10/2/ PY - 2018/10/2/ DO - 10.1021/acs.est.8b01093 VL - 52 IS - 19 SP - 10956-10966 SN - 1520-5851 ER - TY - JOUR TI - The extent and pathways of nitrogen loss in turfgrass systems: Age impacts AU - Chen, Huaihai AU - Yang, Tianyou AU - Xia, Qing AU - Bowman, Daniel AU - Williams, David AU - Walker, John T. AU - Shi, Wei T2 - SCIENCE OF THE TOTAL ENVIRONMENT AB - Nitrogen loss from fertilized turf has been a concern for decades, with most research focused on inorganic (NO3−) leaching. The present work examined both inorganic and organic N species in leachate and soil N2O emissions from intact soil cores of a bermudagrass chronosequence (1, 15, 20, and 109 years old) collected in both winter and summer. Measurements of soil N2O emissions were made daily for 3 weeks, while leachate was sampled once a week. Four treatments were established to examine the impacts of fertilization and temperature: no N, low N at 30 kg N ha−1, and high N at 60 kg N ha−1, plus a combination of high N and temperature (13 °C in winter or 33 °C in summer compared to the standard 23 °C). Total reactive N loss generally showed a “cup” pattern of turf age, being lowest for the 20 years old. Averaged across all intact soil cores sampled in winter and summer, organic N leaching accounted for 51% of total reactive N loss, followed by inorganic N leaching at 41% and N2O-N efflux at 8%. Proportional loss among the fractions varied with grass age, season, and temperature and fertilization treatments. While high temperature enhanced total reactive N loss, it had little influence on the partitioning of loss among dissolved organic N, inorganic N and N2O-N when C availability was expected to be high in summer due to rhizodeposition and root turnover. This effect of temperature was perhaps due to higher microbial turnover in response to increased C availability in summer. However when C availability was low in winter, warming might mainly affect microbial growth efficiency and therefore partitioning of N. This work provides a new insight into the interactive controls of warming and substrate availability on dissolved organic N loss from turfgrass systems. DA - 2018/10/1/ PY - 2018/10/1/ DO - 10.1016/j.scitotenv.2018.05.053 VL - 637 SP - 746-757 SN - 1879-1026 KW - Reactive N KW - Microbial activity KW - N2O KW - Leaching KW - Turfgrass KW - Chronosequence ER - TY - JOUR TI - Sowing date and mulch to improve water use and yield of wheat and barley in the Middle East environment AU - Shaaban, Ahmad Shams Aldien AU - Wahbi, Ammar AU - Sinclair, Thomas R. T2 - AGRICULTURAL SYSTEMS AB - Water is a critical limitation of crop yield in Middle East environments. Cereal production is limited to the winter months when rains occur. Options to increase the effective use of the available water to increase yield could be of direct benefit. This simulation study was undertaken for four locations in Syria that encompassed the wetter climate for wheat production in the north and the drier climate for barley production in the middle and south. Simulations were done for four sowing dates along with either the absence or presence of mulch on the soil surface. These simulations showed that sowing in early November for both barley and wheat resulted in the highest average yields among the simulated sowing dates. Surprisingly, the retention of straw mulch on the soil surface had only a small impact on yield. In most cases, yield increases were fairly modest in the range of about 4 to 9%. Since management practices to retain straw mulch in place in the field are challenging in the Syrian environment, these simulations do not indicate priority be given to developing this management practice solely for water retention. DA - 2018/9// PY - 2018/9// DO - 10.1016/j.agsy.2018.05.011 VL - 165 SP - 26-32 SN - 1873-2267 KW - Barley KW - Mulch KW - Simulation KW - Sowing date KW - Wheat ER - TY - JOUR TI - Soil-Test Biological Activity with the Flush of CO2: IV. Fall-Stockpiled Tall Fescue Yield Response to Applied Nitrogen AU - Franzluebbers, Alan J. AU - Pehim-Limbu, Smriti AU - Poore, Matt H. T2 - AGRONOMY JOURNAL AB - Core Ideas Soil biological activity is a reliable indicator of soil nitrogen availability. Nitrogen fertilization of fall stockpiled tall fescue should be adjusted based on soil testing. The flush of CO 2 is a robust indicator of soil biological activity. A new paradigm of soil testing based on soil biological activity is possible. Fall stockpiling of tall fescue ( Lolium arundinaceum ) in the southeastern United States is promoted as an ecologically favorable cattle management approach to avoid the financial and environmental burdens of winter hay feeding. We hypothesized that soil N mineralization should be an important factor controlling forage yield response to N fertilizer. We conducted 55 N fertilizer trials in combination with analyses of soil C and N fractions at multiple locations in Georgia, North Carolina, Virginia, and West Virginia during two seasons. Plant‐available N, as a combination of residual inorganic N + mineralizable N at depth of 0 to 10 cm, was significantly negatively related with extent of forage dry matter response to N fertilizer input. Large variations in economically optimum N fertilizer requirement (EONR) occurred among fields, but when several fields were averaged along a gradient of soil biological activity, a strong negative yield response with increasing soil‐test biological activity emerged. With moderate soil‐test biological activity of 200 mg CO 2 –C kg – 1 soil 3 d – 1 , EONR was 20 kg N Mg – 1 forage dry matter (a value similar to current N fertilizer recommendations). However, with progressively greater soil‐test biological activity up to 600 mg CO 2 –C kg – 1 soil 3 d – 1 , EONR declined in a nonlinear manner to near zero. These results illustrate that N fertilizer recommendations for fall stockpiled tall fescue pastures should be a function of soil‐test biological activity as an indicator of biologically active N. Greater economic and environmental sustainability would likely be attainable with a shift to recognizing soil biological activity in an ecologically oriented fertilization paradigm. DA - 2018/// PY - 2018/// DO - 10.2134/agronj2018.03.0146 VL - 110 IS - 5 SP - 2033-2049 SN - 1435-0645 ER - TY - JOUR TI - Application Methods of Organic Poultry Feather Meal to Flue-Cured Tobacco AU - Bennett, Nathan AU - Vann, Matthew AU - Fisher, Loren T2 - AGRONOMY JOURNAL AB - Core Ideas There is flexibility with poultry feather meal application methods. Broadcast application before planting initiates N release earlier. Sidedress application is more efficient in high rainfall growing seasons. Optimal application methods of organic poultry feather meal for flue‐cured tobacco ( Nicotiana tabacum L.) production are unknown. Research was conducted in 2012 and 2013 to quantify the effects of two poultry feather meal sources, 13–0–0 Nature Safe and 12–1–0 Nutrimax, applied using three different methods: 100% broadcast before transplanting, 50% broadcast before transplanting + 50% sidedress, 10 d after transplanting, and 100% sidedress 10 d after transplanting. A conventional N treatment comprised of 28% liquid urea–ammonium nitrate (UAN) was split‐applied 10 d after transplanting and at layby. Leaf yield was similar between each individual organic N treatment and UAN. Nature Safe applied 100% sidedress resulted in leaf N concentration and cured leaf quality similar to UAN. In the absence of the UAN treatment, application method typically had a greater impact on measurements than feather meal source. Leaf N concentration was generally increased with the 100% sidedress application, most likely due to closer nutrient proximity relative to roots. Increased N assimilation from 100% sidedress treatments also produced a slightly darker leaf color as quantified by Soil Plant Analysis Development (SPAD) measurements and a higher total alkaloid concentration in cured leaves. Leaf yield was similar among application methods in 2012, but was highest in the 100% sidedress treatment in 2013 due to high early season rainfall. Results from this study demonstrate the effectiveness of both feather meal sources and that 100% sidedress applications may prove ideal under a range of environmental conditions commonly encountered in North Carolina. DA - 2018/// PY - 2018/// DO - 10.2134/agronj2017.11.0678 VL - 110 IS - 5 SP - 1874-1882 SN - 1435-0645 ER - TY - JOUR TI - Biosolids Type, Rate, and Receiving Soil Affect Anaerobic Incubation Nitrogen Availability Coefficients AU - White, Jeffrey G. AU - Dodd, Ryan AU - Walters, Robert T2 - SOIL SCIENCE SOCIETY OF AMERICA JOURNAL AB - Core Ideas Potentially available N (PAN) differed greatly among biosolids, soils, and rates. Nitrogen availability coefficients (NAC) under or overestimated PAN from −140 to 181%. The effects of soil and biosolids on PAN and NAC were of similar magnitudes. Biosolids NAC might best be estimated with the receiving soil and a range of rates. Seven‐day anaerobic incubation can provide relatively quick and easy estimates of potentially available N (PAN), but has been little used to estimate N availability coefficients (NAC) of biosolids destined for land application. We hypothesized that waterlogged‐incubation estimates of PAN and NAC depend on biosolids type, application rate, and receiving soil. We applied three dissimilar biosolids at five rates to four representative southeastern US soils and measured NH 4 –N and NO 3 –N after a 7‐d laboratory waterlogged incubation. Target PAN rates were 0, 0.5, 1, 1.5, and 2× a realistic yield expectation (RYE) rate, 127 kg N ha –1 , for tall fescue ( Festuca arundinacea ), a common biosolids‐receiving grass. Biosolids application rates were based on biosolids types, associated book‐value NACs, and biosolids total N. Anaerobic incubation of soil plus biosolids yielded predominantly NH 4 –N. There were three‐way biosolids × rate × soil interactions for NH 4 –N, PAN, and NAC. The PAN differed substantially among biosolids, rates, and receiving soils, ranging from –12.1 to 146 mg kg –1 , while NAC ranged from ‐0.13 to 0.86. Negative values suggested N lost via denitrification or immobilization. The PAN trends reflected biosolids total N. At the highest application rate, soil had no detectable effect on the NAC; otherwise, soil affected NAC by as much as an order of magnitude. Presuming anaerobic incubation provides reasonable estimates of PAN, NAC of any particular biosolids might best be estimated via incubation with the receiving soil across an RYE‐based range of N application rates, rather than relying on book value NAC. DA - 2018/// PY - 2018/// DO - 10.2136/sssaj2018.06.0219 VL - 82 IS - 5 SP - 1290-1300 SN - 1435-0661 ER - TY - JOUR TI - Comparison of Partitioning and Efficacy Between Copper Algaecide Formulations: Refining the Critical Burden Concept AU - Bishop, West M. AU - Richardson, Robert J. AU - Willis, Ben E. T2 - WATER AIR AND SOIL POLLUTION DA - 2018/9// PY - 2018/9// DO - 10.1007/s11270-018-3958-z VL - 229 IS - 9 SP - SN - 1573-2932 KW - Algal management KW - Copper algaecides KW - Lyngbya wollei KW - Pithophora varia KW - Critical burden ER - TY - JOUR TI - Stem, Leaf, and Panicle Yield and Nutrient Content of Biomass and Sweet Sorghum AU - Heitman, A. J. AU - Castillo, M. S. AU - Smyth, T. J. AU - Crozier, C. R. T2 - AGRONOMY JOURNAL AB - Core Ideas Sorghum is a potential dedicated bioenergy crop both from biomass and sugar yields. Increasing rates of N fertilizer affected biomass yield and nutrient removal for sorghum cultivar ES5200 by partitioning resources primarily toward the stem component. For sorghum M81‐E, the seed head component accounted for a greater proportion of biomass, compared with sorghum ES5200, and biomass yield and nutrients were more evenly distributed among the three components. Returning the leaf and seed head components back to the field to enhance soil fertility has the potential to provide at least 45, 7, and, 26 kg ha −1 of N, P, and K, respectively. Information on biomass yield and nutrient content among leaf, stem, and head components can aid on sorghum [ Sorghum bicolor (L.) Moench] cultivar selection and harvest management practices to optimize the quality of the harvested feedstock and residue management. The objectives of this study were to characterize and to determine the effect of five N fertilization rates (0, 67, 134, 201, and 268 kg ha −1 ) on biomass yield and N, P, and K content of the stem, leaf, and panicle components of two dedicated bioenergy sorghum cultivars. Biomass sorghum Blade ES5200 and sweet sorghum M81‐E were grown in 2014 and 2015 in North Carolina. For ES5200, total biomass yield was 14.4 Mg ha −1 with 74, 25, and 2% accounted by the stem, leaf, and panicle, respectively. For M81‐E, total biomass yield was 11.5 Mg ha −1 with 62, 24, and 15% accounted by the stem, leaf, and panicle, respectively. Nutrient content by the leaf + panicle components combined were about 45, 7, and 26 kg ha −1 for N, P, and K, respectively, for both cultivars; however, for ES5200, the leaf + panicle components combined accounted for 46, 37, and 16% of total N, P, and K content, respectively, whereas for M81‐E they accounted for 62, 74, and 24% of total N, P, and K content, respectively. Addition of N fertilizer resulted in greater shifts in the stem component responses but to different extents for each cultivar. DA - 2018/// PY - 2018/// DO - 10.2134/agronj2018.03.0178 VL - 110 IS - 5 SP - 1659-1665 SN - 1435-0645 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-85052711959&partnerID=MN8TOARS ER - TY - JOUR TI - Effect of Soybean Maturity, Crimson Clover Seeding Method, and Seeding Rate on Clover Biomass and Nitrogen Content AU - Vann, R. A. AU - Reberg-Horton, S.C. AU - Crozier, C.R. AU - Place, G.T. T2 - Agronomy Journal AB - Core Ideas Crimson clover seeding following the last cultivation of soybeans in July into MG3 to MG5 soybeans did not result in any substantial crimson clover growth in both years. After harvest seeding into MG3 and MG4 soybean and aerial seeding into MG4 and MG5, soybean produced substantial clover N content ranging from 76 to 107 kg ha −1 . After harvest seeding behind MG5 soybeans reduced clover N content because late cover crop establishment restricted biomass production. Seeding rate had no effect on clover biomass, clover N content, or corn yield for both drilled and aerially‐seeded crimson clover. Timely crimson clover ( Trifolium incarnatum L.) establishment is a management challenge for producers in the southeastern United States. Aerial seeding methods and the use of early maturing soybeans may allow for earlier crimson clover establishment and potentially increase nitrogen contributions to the following crop. A soybean ( Glycine max L.)–crimson clover–corn ( Zea mays L.) rotation experiment was conducted in Goldsboro, NC from 2006 to 2008. Three crimson clover seeding methods were evaluated: aerial seeding after last soybean cultivation, aerial application before soybean leaf drop, and after‐harvest drill seeding. Each seeding method was evaluated in three soybean maturity groups (MG; 3, 4, 5) and contained three crimson clover seeding rates (22, 39, 56 kg ha −1 ). Clover biomass accumulation, clover N content, and corn yield were determined. Crimson clover seeding following the last cultivation of soybeans into MG3, MG4, and MG5 did not result in any substantial crimson clover growth. After harvest seeding into MG3 and MG4 soybean residue and aerial seeding prior to soybean leaf drop into MG4 and MG5 soybean produced substantial clover N content ranging from 76 to 107 kg ha −1 . After‐harvest seeding behind MG5 soybeans reduced clover N content likely because late cover crop establishment restricted biomass production. Seeding rate had no effect on clover biomass, clover N content, or corn yield. An independent crimson clover aerial seeding rate experiment conducted from 2006 to 2008 in Goldsboro, NC also confirmed no effect of crimson clover seeding rate on clover biomass or N content. DA - 2018/// PY - 2018/// DO - 10.2134/agronj2018.02.0118 VL - 110 IS - 5 SP - 1829–1835 SN - 1435-0645 ER - TY - JOUR TI - Biomass production of herbaceous energy crops in the United States: field trial results and yield potential maps from the multiyear regional feedstock partnership AU - Lee, Do Kyoung AU - Aberle, Ezra AU - Anderson, Eric K. AU - Anderson, William AU - Baldwin, Brian S. AU - Baltensperger, David AU - Barrett, Michael AU - Blumenthal, Jurg AU - Bonos, Stacy AU - Bouton, Joe AU - Bransby, David I. AU - Brummer, Charlie AU - Burks, Pane S. AU - Chen, Chengci AU - Daly, Christopher AU - Egenolf, Josh AU - Farris, Rodney L. AU - Fike, John H. AU - Gaussoin, Roch AU - Gill, John R. AU - Gravois, Kenneth AU - Halbleib, Michael D. AU - Hale, Anna AU - Hanna, Wayne AU - Harmoney, Keith AU - Heaton, Emily A. AU - Heiniger, Ron W. AU - Hoffman, Lindsey AU - Hong, Chang O. AU - Kakani, Gopal AU - Kallenbach, Robert AU - Macoon, Bisoondat AU - Medley, James C. AU - Missaoui, Ali AU - Mitchell, Robert AU - Moore, Ken J. AU - Morrison, Jesse I. AU - Odvody, Gary N. AU - Richwine, Jonathan D. AU - Ogoshi, Richard AU - Parrish, Jimmy Ray AU - Quinn, Lauren AU - Richard, Ed AU - Rooney, William L. AU - Rushing, J. Brett AU - Schnell, Ronnie AU - Sousek, Matt AU - Staggenborg, Scott A. AU - Tew, Thomas AU - Uehara, Goro AU - Viands, Donald R. AU - Voigt, Thomas AU - Williams, David AU - Williams, Linda AU - Wilson, Lloyd Ted AU - Wycislo, Andrew AU - Yang, Yubin AU - Owens, Vance T2 - GLOBAL CHANGE BIOLOGY BIOENERGY AB - Abstract Current knowledge of yield potential and best agronomic management practices for perennial bioenergy grasses is primarily derived from small‐scale and short‐term studies, yet these studies inform policy at the national scale. In an effort to learn more about how bioenergy grasses perform across multiple locations and years, the U.S. Department of Energy ( US DOE )/Sun Grant Initiative Regional Feedstock Partnership was initiated in 2008. The objectives of the Feedstock Partnership were to (1) provide a wide range of information for feedstock selection (species choice) and management practice options for a variety of regions and (2) develop national maps of potential feedstock yield for each of the herbaceous species evaluated. The Feedstock Partnership expands our previous understanding of the bioenergy potential of switchgrass, Miscanthus, sorghum, energycane, and prairie mixtures on Conservation Reserve Program land by conducting long‐term, replicated trials of each species at diverse environments in the U.S. Trials were initiated between 2008 and 2010 and completed between 2012 and 2015 depending on species. Field‐scale plots were utilized for switchgrass and Conservation Reserve Program trials to use traditional agricultural machinery. This is important as we know that the smaller scale studies often overestimated yield potential of some of these species. Insufficient vegetative propagules of energycane and Miscanthus prohibited farm‐scale trials of these species. The Feedstock Partnership studies also confirmed that environmental differences across years and across sites had a large impact on biomass production. Nitrogen application had variable effects across feedstocks, but some nitrogen fertilizer generally had a positive effect. National yield potential maps were developed using PRISM ‐ ELM for each species in the Feedstock Partnership. This manuscript, with the accompanying supplemental data, will be useful in making decisions about feedstock selection as well as agronomic practices across a wide region of the country. DA - 2018/10// PY - 2018/10// DO - 10.1111/gcbb.12493 VL - 10 IS - 10 SP - 698-716 SN - 1757-1707 KW - bioenergy KW - biomass KW - Conservation Reserve Program KW - energycane KW - feedstock KW - Miscanthus KW - sorghum KW - switchgrass ER - TY - JOUR TI - Registration of Two Wheat Germplasm Lines Fixed for Pm58 AU - Wiersma, Andrew T. AU - Whetten, Rebecca B. AU - Zhang, Guorong AU - Sehgal, Sunish K. AU - Kolb, Frederic L. AU - Poland, Jesse A. AU - Mason, R. Esten AU - Carter, Arron H. AU - Cowger, Christina AU - Olson, Eric L. T2 - JOURNAL OF PLANT REGISTRATIONS AB - Powdery mildew is a persistent threat to global wheat ( Triticum aestivum L.) production. To broaden the genetic base for resistance to powdery mildew in wheat, germplasm lines U6714‐A‐011 (Reg. No. GP‐1023, PI 682090) and U6714‐B‐056 (Reg. No. GP‐1022, PI 682089) were developed at Michigan State University and are fixed for the novel powdery mildew resistance gene Pm58 . This gene was identified in Aegilops tauschii Coss. accession TA1662, introgressed, and mapped to wheat chromosome 2DS. The two germplasm lines described are BC 2 F 4 –derived inbred backcrossed lines from a direct cross between TA1662 and the recurrent wheat parent KS05HW14, a hard white winter wheat line adapted to western Kansas. In addition to exhibiting resistant reactions to multiple Bgt isolates with broad virulence profiles, both lines have moderate yield potential and good agronomic characteristics, making them suitable as breeding germplasm. The availability of these lines will enable the incorporation of Pm58 into wheat breeding programs, providing additional genetic variation for resistance to powdery mildew. DA - 2018/5// PY - 2018/5// DO - 10.3198/jpr2017.06.0036crg VL - 12 IS - 2 SP - 270-273 SN - 1940-3496 ER - TY - JOUR TI - Critical Next Steps in Combating Herbicide Resistance: Our View AU - Shaw, David R. AU - Barrett, Michael AU - Schroeder, Jill AU - Asmus, Amy B. AU - Ervin, David AU - Jussaume, Raymond A., Jr. AU - Coble, Harold T2 - WEED SCIENCE AB - An abstract is not available for this content. As you have access to this content, full HTML content is provided on this page. A PDF of this content is also available in through the ‘Save PDF’ action button. DA - 2018/9// PY - 2018/9// DO - 10.1017/wsc.2018.42 VL - 66 IS - 5 SP - 559-561 SN - 1550-2759 KW - William Vencill KW - University of Georgia ER - TY - JOUR TI - Mapping adult plant stem rust resistance in barley accessions Hietpas-5 and GAW-79 AU - Case, Austin J. AU - Bhavani, Sridhar AU - Macharia, Godwin AU - Pretorius, Zacharias AU - Coetzee, Vicky AU - Kloppers, Frederik AU - Tyagi, Priyanka AU - Brown-Guedira, Gina AU - Steffenson, Brian J. T2 - THEORETICAL AND APPLIED GENETICS DA - 2018/10// PY - 2018/10// DO - 10.1007/s00122-018-3149-8 VL - 131 IS - 10 SP - 2245-2266 SN - 1432-2242 ER - TY - JOUR TI - Mapping adult plant stem rust resistance in barley accessions Hietpas-5 and GAW-79 (vol 131, pg 2245, 2018) AU - Case, Austin J. AU - Bhavani, Sridhar AU - Macharia, Godwin AU - Pretorius, Zacharias AU - Coetzee, Vicky AU - Kloppers, Frederik AU - Tyagi, Priyanka AU - Brown-Guedira, Gina AU - Steffenson, Brian J. T2 - THEORETICAL AND APPLIED GENETICS AB - Unfortunately, one co-author name was incorrectly published in the original publication. The complete correct name should read as follows. DA - 2018/10// PY - 2018/10// DO - 10.1007/s00122-018-3170-y VL - 131 IS - 10 SP - 2267-2267 SN - 1432-2242 ER - TY - JOUR TI - Single nucleotide polymorphisms in a regulatory site of VRN-A1 first intron are associated with differences in vernalization requirement in winter wheat AU - Kippes, Nestor AU - Guedira, Mohammed AU - Lin, Lijuan AU - Alvarez, Maria A. AU - Brown-Guedira, Gina L. AU - Dubcovsky, Jorge T2 - MOLECULAR GENETICS AND GENOMICS AB - Winter wheats require a long exposure to cold temperatures (vernalization) to accelerate flowering. However, varieties differ in the length of the period of cold required to saturate the vernalization response. Here we show that single nucleotide polymorphisms (SNP) at the binding site of the GRP2 protein in the VRN-A1 first intron (henceforth, RIP3) are associated with significant differences in heading time after a partial vernalization treatment. The ancestral winter VRN-A1 allele in 'Triple Dirk C' has one SNP in the RIP3 region (1_SNP) relative to the canonical RIP3 sequence, whereas the derived 'Jagger' allele has three SNPs (3_SNPs). Both varieties have a single VRN-A1 copy encoding identical proteins. In an F2 population generated from a cross between these two varieties, plants with the 3_SNPs haplotype headed significantly earlier (P < 0.001) than those with the 1_SNP haplotype, both in the absence of vernalization (17 days difference) and after 3-weeks of vernalization (11 days difference). Plants with the 3_SNPs haplotype showed higher VRN-A1 transcript levels than those with the 1_SNP haplotype. The 3_SNPs haplotype was also associated with early heading in a panel of 127 winter wheat varieties grown in three separate controlled-environment experiments under partial vernalization (36 to 54 days, P < 0.001) and one experiment under field conditions (21 d, P < 0.0001). The RIP3 polymorphisms can be used by wheat breeders to develop winter wheat varieties adapted to regions with different duration or intensity of the cold season. DA - 2018/10// PY - 2018/10// DO - 10.1007/s00438-018-1455-0 VL - 293 IS - 5 SP - 1231-1243 SN - 1617-4623 KW - Wheat KW - Flowering KW - Vernalization KW - VRN1 KW - RIP3 KW - GRP2 ER - TY - JOUR TI - The E3 ligase BRUTUS facilitates degradation of VOZ1/2 transcription factors AU - Selote, Devarshi AU - Matthiadis, Anna AU - Gillikin, Jeffrey W. AU - Sato, Masa H. AU - Long, Terri A. T2 - PLANT CELL AND ENVIRONMENT AB - BRUTUS (BTS) is an iron binding E3 ligase that has been shown to bind to and influence the accumulation of target basic helix-loop-helix transcription factors through 26S proteasome-mediated degradation in Arabidopsis thaliana. Vascular Plant One-Zinc finger 1 (VOZ1) and Vascular plant One-Zinc finger 2 (VOZ2) are NAM, ATAF1/2 and CUC2 (NAC) domain transcription factors that negatively regulate drought and cold stress responses in plants and have previously been shown to be degraded via the 26S proteasome. However, the mechanism that initializes this degradation is unknown. Here, we show that BTS interacts with VOZ1 and VOZ2 and that the presence of the BTS RING domain is essential for these interactions. Through cell-free degradation and immunodetection analyses, we demonstrate that BTS facilitates the degradation of Vascular plant One-Zinc finger 1/2 (VOZ1/2) protein in the nucleus particularly under drought and cold stress conditions. In addition to its known role in controlling the iron-deficiency response in plants, here, we report that BTS may play a role in drought and possibly other abiotic stress responses by facilitating the degradation of transcription factors, VOZ1/2. DA - 2018/10// PY - 2018/10// DO - 10.1111/pce.13363 VL - 41 IS - 10 SP - 2463-2474 SN - 1365-3040 KW - abiotic stress KW - Arabidopsis thaliana KW - BRUTUS KW - ubiquitin-proteasome system KW - VOZ1/2 ER - TY - JOUR TI - Approaches for Estimating Soil Water Retention Curves at Various Bulk Densities With the Extended Van Genuchten Model AU - Tian, Zhengchao AU - Gao, Weida AU - Kool, Dilia AU - Ren, Tusheng AU - Horton, Robert AU - Heitman, Joshua L. T2 - WATER RESOURCES RESEARCH AB - Abstract Soil bulk density (ρ b ) variations influence soil hydraulic properties, such as the water retention curve (WRC), but they are usually ignored in soil water simulation models. We extend the van Genuchten WRC model parameters to account for ρ b variations using a series of empirical expressions. WRC measurements made on eight soils with various ρ b , and textures are used to calibrate these ρ b ‐related empirical equations. Accordingly, two approaches are developed to estimate WRCs of soils at various ρ b . Another eight soils with a wide range of ρ b and textures are used to evaluate the accuracy of the new approaches. Approach 1 estimates WRCs for each soil at various ρ b using a WRC measurement made at a reference ρ b and the soil texture fractions. This approach gives reasonable WRC estimates for the eight validation soils, with an average root‐mean‐square error (RMSE) of 0.025 m 3 /m 3 and an average determination coefficient ( R 2 ) of 0.94. For Approach 2, a WRC measurement made at a reference ρ b and one additional water content‐matric potential value measured at a different ρ b value are used, which produces WRC estimates with an average RMSE of 0.017 m 3 /m 3 and an average R 2 of 0.97. The methodology used in Approach 2 is also applied to the Brooks and Corey WRC model to obtain accurate and precise WRC estimates. The proposed approaches have the potential to be incorporated into simulation models for estimating soil hydraulic properties that are affected by transient and variable ρ b . DA - 2018/8// PY - 2018/8// DO - 10.1029/2018WR022871 VL - 54 IS - 8 SP - 5584-5601 SN - 1944-7973 KW - soil water retention curve KW - van Genuchten model KW - bulk density ER - TY - JOUR TI - Early Season Growth, Yield, and Fruit Quality of Standard and Mini Watermelon Grafted onto Several Commercially Available Cucurbit Rootstocks AU - Bertucci, Matthew B. AU - Jennings, Katherine M. AU - Monks, David W. AU - Schultheis, Jonathan R. AU - Perkins-Veazie, Penelope AU - Louws, Frank J. AU - Jordan, David L. T2 - HORTTECHNOLOGY AB - Grafting watermelon ( Citrullus lanatus ) is a common practice in many parts of the world and has recently received increased interest in the United States. The present study was designed to evaluate early season growth, yield, and fruit quality of watermelon in response to grafting and in the absence of known disease pressure in a fumigated system. Field experiments were conducted using standard and mini watermelons (cv. Exclamation and Extazy, respectively) grafted onto 20 commercially available cucurbit rootstocks representing four species: giant pumpkin ( Cucurbita maxima ), summer squash ( Cucurbita pepo ), bottle gourd ( Lagenaria siceraria ), and interspecific hybrid squash [ISH ( C. maxima × Cucurbita moschata )]. Nongrafted ‘Exclamation’ and ‘Extazy’ were included as controls. To determine early season growth, leaf area was measured at 1, 2, and 3 weeks after transplant (WAT). At 1 WAT, nongrafted ‘Exclamation’ produced the smallest leaf area; however, at 3 WAT, nongrafted ‘Exclamation’ produced the largest leaf area in 2015, and no differences were observed in 2016. Leaf area was very similar among rootstocks in the ‘Extazy’ study, with minimal differences observed. Marketable yield included fruit weighing ≥9 and ≥3 lb for ‘Exclamation’ and ‘Extazy’, respectively. In the ‘Exclamation’ study, highest marketable yields were observed in nongrafted ‘Exclamation’, and ‘Exclamation’ grafted to ‘Pelops’, ‘TZ148’, and ‘Coloso’, and lowest marketable yields were observed when using ‘Marvel’ and ‘Kazako’ rootstocks, which produced 47% and 32% of nongrafted ‘Exclamation’ yield, respectively. In the ‘Extazy’ study, the highest marketable yield was observed in nongrafted ‘Extazy’, and ‘Kazako’ produced the lowest yields (48% of nongrafted ‘Extazy’). Fruit quality was determined by measuring fruit acidity (pH), soluble solids concentration (SSC), lycopene content, and flesh firmness from a sample of two fruit from each plot from the initial two harvests of each year. Across both studies, rootstock had no effect on SSC or lycopene content. As reported in previous studies, flesh firmness was increased as a result of grafting, and nongrafted ‘Exclamation’ and ‘Extazy’ had the lowest flesh firmness among standard and mini watermelons, respectively. The present study evaluated two scions with a selection of 20 cucurbit rootstocks and observed no benefits in early season growth, yield, or phytonutrient content. Only three of 20 rootstocks in each study produced marketable yields similar to the nongrafted treatments, and no grafted treatment produced higher yields than nongrafted ‘Exclamation’ or ‘Extazy’. Because grafted seedlings have an associated increase in cost and do not produce increased yields, grafting in these optimized farming systems and using fumigated soils does not offer an advantage in the absence of soilborne pathogens or other stressors that interfere with watermelon production. DA - 2018/8// PY - 2018/8// DO - 10.21273/HORTTECH04051-18 VL - 28 IS - 4 SP - 459-469 SN - 1943-7714 KW - Citrullus lanatus KW - Cucurbita maxima KW - Cucurbita moschata KW - Cucurbitn pepo KW - Lagenaria siceraria KW - scion ER - TY - JOUR TI - Determining in-situ unsaturated soil hydraulic conductivity at a fine depth scale with heat pulse and water potential sensors AU - Tian, Zhengchao AU - Kool, Dilia AU - Ren, Tusheng AU - Horton, Robert AU - Heitman, Joshua L. T2 - JOURNAL OF HYDROLOGY AB - Abstract Unsaturated hydraulic conductivity (K) of surface soil changes substantially with space and time, and it is of great importance for many ecological, agricultural, and hydrological applications. In general, K is measured in the laboratory, or more commonly, predicted using soil water retention curve and saturated hydraulic conductivity. In the field, K can be determined through infiltration experiments. However, none of these approaches are capable of continuously monitoring K in-situ at fine depth scales. In this study, we propose and investigate an approach to continuously estimate fine depth-scale K dynamics under field conditions. Evaporation rate and change in water storage in a near-surface soil layer are measured with the heat pulse method. Then, water flux density at the lower boundary of the soil layer is estimated from evaporation rate, change in water storage, and rainfall or irrigation rate using a simple water balance approach. Finally, K values at different soil depths are derived using the Buckingham-Darcy equation from water flux densities and measured water potential gradients. A field experiment is performed to evaluate the performance of the proposed approach. K values at 2-, 4-, 7.5-, and 12.5-cm depths are estimated with the new approach. The results show that in-situ K estimates vary with time following changes in soil water content, and the K-water content relationship changes with depth due to the difference in bulk density. In-situ estimated K-matric potential curves agree well with those measured in the laboratory. In-situ K estimates also show good agreement with the Mualem-van Genuchten model predictions, with an average root mean square error in log10 (K, mm h−1) of 0.54 and an average bias of 0.17. The new approach provides reasonable in-situ K estimates and has potential to reveal the influences of natural soil conditions on hydraulic properties as they change with depth and time. DA - 2018/9// PY - 2018/9// DO - 10.1016/j.jhydrol.2018.07.052 VL - 564 SP - 802-810 SN - 1879-2707 KW - In-situ unsaturated soil hydraulic conductivity KW - Heat pulse KW - Water potential gradient ER - TY - JOUR TI - Plant Genetics: Two Steps on the Path to Maize Adaptation AU - Holland, James B. T2 - CURRENT BIOLOGY AB - Two distinct variations in the promoter of a key flowering time gene were selected during the spread of maize from its tropical origin to northern North America. DA - 2018/9/24/ PY - 2018/9/24/ DO - 10.1016/j.cub.2018.07.049 VL - 28 IS - 18 SP - R1098-R1101 SN - 1879-0445 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-85053555135&partnerID=MN8TOARS ER - TY - JOUR TI - Effective Water Use Required for Improving Crop Growth Rather Than Transpiration Efficiency AU - Sinclair, Thomas R. T2 - FRONTIERS IN PLANT SCIENCE AB - The phenomenological expression showing crop yield to be directly dependent on crop transpiration use efficiency (TE) has encouraged continued focus on TE as a viable approach to increasing crop yields. The difficulty in the phenomenological perspective is that research tends not to match up with the underlying mechanistic variables defining TE. Experimental evidence and the mechanistic derivation of TE by Tanner and Sinclair showed that the common focus on increasing the intrinsic ratio of leaf CO2/H2O exchange has limited opportunities for improvement. On the other hand, the derivation showed that daily vapor pressure deficit (VPD) weighted for the daily cycle of transpiration rate has a large, direct impact on TE. While VPD is often viewed as an environmental variable, daily weighted VPD can be under plant control as a result of partial stomatal closure during the midday. A critical feature of the partial stomatal closure is that transpiration rate is decreased resulting in conservation of soil water. The conserved soil water allows late-season, sustained physiological activity during subsequent periods of developing water deficits, which can be especially beneficial during reproductive development. The shift in the temporal dynamics of water use by water conservations traits has been shown in simulation studies to result in substantial yield increases. It is suggested from this analysis that effective water use through the growing season is more important for increasing crop yield than attempts focused on improving the static, intrinsic TE ratio. DA - 2018/9/28/ PY - 2018/9/28/ DO - 10.3389/fpls.2018.01442 VL - 9 SP - SN - 1664-462X KW - crop growth KW - effective water use KW - stomatal conductance KW - transpiration KW - vapor pressure deficit ER - TY - JOUR TI - Screening Germplasm and Quantification of Components Contributing to Thrips Resistance in Cotton AU - Kaur, Baljinder AU - Kuraparthy, Vasu AU - Bacheler, Jack AU - Fang, Hui AU - Bowman, Daryl T. T2 - JOURNAL OF ECONOMIC ENTOMOLOGY AB - Three hundred and ninety-one Gossypium hirsutum and 34 Gossypium barbadense accessions were screened for thrips resistance under field conditions at the Upper Coastal Plain Research Station in Rocky Mount, North Carolina in years 2014 and 2015. Visual damage ratings, thrips counts, and seedling dry weights were recorded at 2.5, 3.5, and 4.5 wk after planting, respectively. Population density and thrips arrival times varied between years. Data from the three separate damage scoring dates provided a better estimate of resistance or susceptibility to thrips than ratings from the individual dates over the season. Tobacco thrips [Frankliniella fusca (Hinds) (Thysanoptera: Thripidae)], followed by western flower thrips [Frankliniella occidentalis (Pergande) (Thysanoptera: Thripidae)], were the dominant thrips species observed in the study. Five resistant G. barbadense accessions and five moderately resistant upland cotton accessions were identified from field evaluations. Greenhouse experiments were conducted in Fall 2015 and Spring 2016 to determine if plant height, growth rate, leaf pubescence, and leaf area were significantly different in resistant and susceptible groups of G. hirsutum and G. barbadense accessions identified from the field screenings. Leaf pubescence and relative growth rate were significantly higher in resistant accessions compared with susceptible accessions in absence of thrips. There was no difference for plant height and leaf area between resistant and susceptible groups. Results suggest thrips-resistant plants have a possible competitive advantage through faster growth and higher trichome density, which limits thrips movement. DA - 2018/10// PY - 2018/10// DO - 10.1093/jee/toy201 VL - 111 IS - 5 SP - 2426-2434 SN - 1938-291X UR - https://publons.com/wos-op/publon/31419923/ KW - cotton KW - thrips KW - field screening KW - resistance KW - leaf pubescence ER - TY - JOUR TI - Partitioning between evaporation and transpiration from Agrostis stolonifera L. during light and dark periods AU - Rosas-Anderson, Pablo AU - Taggart, Matthew J. AU - Heitman, Joshua L. AU - Miller, Grady L. AU - Sinclair, Thomas R. AU - Rufty, Thomas W. T2 - AGRICULTURAL AND FOREST METEOROLOGY AB - Pressures on water availability for irrigation of turfgrasses continue in many parts of the United States as climate and weather patterns shift and populations increase. It is essential to understand underlying factors controlling water loss to more precisely predict irrigation requirements and develop new strategies for improving effective use of water. In this study, we investigate two key components of potential water loss from a bentgrass (Agrostis stolonifera L.) system that have not previously been examined in detail: 1) water loss in darkness, and 2) water loss through evaporation directly from the soil. The experiments were conducted in controlled environment chambers with intact cores from the field. An automated gravimetric system and soil moisture probes allowed precise measurements of water loss over ranges of vapor pressure deficits (VPD). The gravimetric and soil probe results indicated that substantial evapotranspiration occurred in darkness, at rates 40 to 60% of that in the light across VPDs. Simulations using field weather data from dry and humid environments indicated nighttime water loss rates would be expected to be 30 to 40% of that in the light. Using cores treated with a fast-acting, desiccating herbicide that eliminated transpiration but kept core resistances intact, evaporation directly from the soil surface was estimated to account for 40% of total water loss in the light and 60 to 70% in the dark. The results, collectively, indicated that water loss in darkness must be separately accounted for to accurately estimate daily evapotranspiration totals and irrigation requirements. Furthermore, because of the very high potential for evaporative water loss in the light and dark, efforts to improve water use efficiencies in the turfgrass system should include strategies that regulate both transpiration by the plant and evaporation from the soil surface. DA - 2018/10/15/ PY - 2018/10/15/ DO - 10.1016/j.agrformet.2018.05.018 VL - 260 SP - 73-79 SN - 1873-2240 KW - Evapotranspiration KW - Soil evaporation KW - Nighttime transpiration KW - Stomatal conductance KW - Turfgrass KW - Epidermal conductance ER - TY - JOUR TI - Long-term cryopreservation of non-spore-forming fungi in Microbank (TM) beads for plant pathological investigations AU - Lakshman, Dilip K. AU - Singh, Vimla AU - Camacho, Manuel E. T2 - JOURNAL OF MICROBIOLOGICAL METHODS AB - Long-term preservation of experimental fungi without genetic, morphological, and pathogenic changes is of paramount importance in mycological and plant pathological investigations. Several cryogenic and non-cryogenic methods are available for the preservation of fungi, but the methods can be cumbersome, hazardous, expensive, and often not suitable for long-term storage of non-spore-forming (sterile) fungi. A method of preservation of spore-forming fungi in commercially available porous beads (Micrbank™) under cryogenic condition was successfully tested for three non-spore-forming basidiomycetes genera: Rhizoctonia solani (teleomorph: Thanatephorus cucumeris) (n = 19), Ceratobasidium species (n = 1), and Waitea circinata (n = 3), and a non-spore forming ascomycetes, Sclerotinia sclerotiorum (n = 1). For comparison, spore-forming ascomycetous fungi, Alternaria alternata (n = 1), Bauveria basiana (n = 2), Botrytis cinerea (n = 1), Fusarium oxysporum f.sp. gladiolii (n = 1), Trichoderma spp. (n = 3), and Thielaviopsis basicola (n = 2) were also cryopreserved in Microbank beads. Viable fungal isolates of all test species were retrieved after five years of storage at −80 °C, which was longer than the viabilities of the corresponding isolates cryopreserved in agar plugs or colonized wheat seeds. Fungi revived from the Microbank beads maintained identical morphology and cultural characteristics of the parent isolates. Randomly selected Rhizoctonia isolates revived from the Microbank beads maintained respective pathological properties of the parent isolates; also, no mutation was detected in the internal transcribed spacer (ITS) ribosomal DNA when compared with respective cultures maintained at ambient temperature. This finding demonstrated the utility of cryopreservation in Microbank beads as a convenient alternative to conventional long-term preservation of a wide group of fungal cultures for plant pathological investigations and serves as the first report of using porous beads under cryogenic conditions for long-term storage of sterile fungi. DA - 2018/5// PY - 2018/5// DO - 10.1016/j.mimet.2018.04.007 VL - 148 SP - 120-126 SN - 1872-8359 KW - Rhizoctonia solani KW - Non-spore-forming fungi KW - Long-term preservation KW - Cryopreservation KW - Microbank beads ER - TY - JOUR TI - Cellulose synthase "class specific regions' are intrinsically disordered and functionally undifferentiated AU - Scavuzzo-Duggan, Tess R. AU - Chaves, Arielle M. AU - Singh, Abhishek AU - Sethaphong, Latsavongsakda AU - Slabaugh, Erin AU - Yingling, Yaroslava G. AU - Haigler, Candace H. AU - Roberts, Alison W. T2 - JOURNAL OF INTEGRATIVE PLANT BIOLOGY AB - Cellulose synthases (CESAs) are glycosyltransferases that catalyze formation of cellulose microfibrils in plant cell walls. Seed plant CESA isoforms cluster in six phylogenetic clades, whose non-interchangeable members play distinct roles within cellulose synthesis complexes (CSCs). A 'class specific region' (CSR), with higher sequence similarity within versus between functional CESA classes, has been suggested to contribute to specific activities or interactions of different isoforms. We investigated CESA isoform specificity in the moss, Physcomitrella patens (Hedw.) B. S. G. to gain evolutionary insights into CESA structure/function relationships. Like seed plants, P. patens has oligomeric rosette-type CSCs, but the PpCESAs diverged independently and form a separate CESA clade. We showed that P. patens has two functionally distinct CESAs classes, based on the ability to complement the gametophore-negative phenotype of a ppcesa5 knockout line. Thus, non-interchangeable CESA classes evolved separately in mosses and seed plants. However, testing of chimeric moss CESA genes for complementation demonstrated that functional class-specificity is not determined by the CSR. Sequence analysis and computational modeling showed that the CSR is intrinsically disordered and contains predicted molecular recognition features, consistent with a possible role in CESA oligomerization and explaining the evolution of class-specific sequences without selection for class-specific function. DA - 2018/6// PY - 2018/6// DO - 10.1111/jipb.12637 VL - 60 IS - 6 SP - 481-497 SN - 1744-7909 ER - TY - JOUR TI - Topological Data Analysis as a Morphometric Method: Using Persistent Homology to Demarcate a Leaf Morphospace AU - Li, Mao AU - An, Hong AU - Angelovici, Ruthie AU - Bagaza, Clement AU - Batushansky, Albert AU - Clark, Lynn AU - Coneva, Viktoriya AU - Donoghue, Michael J. AU - Edwards, Erika AU - Fajardo, Diego AU - Fang, Hui AU - Frank, Margaret H. AU - Gallaher, Timothy AU - Gebken, Sarah AU - Hill, Theresa AU - Jansky, Shelley AU - Kaur, Baljinder AU - Klahs, Phillip C. AU - Klein, Laura L. AU - Kuraparthy, Vasu AU - Londo, Jason AU - Migicovsky, Zoe AU - Miller, Allison AU - Mohn, Rebekah AU - Myles, Sean AU - Otoni, Wagner C. AU - Pires, J. C. AU - Rieffer, Edmond AU - Schmerler, Sam AU - Spriggs, Elizabeth AU - Topp, Christopher N. AU - Van Deynze, Allen AU - Zhang, Kuang AU - Zhu, Linglong AU - Zink, Braden M. AU - Chitwood, Daniel H. T2 - FRONTIERS IN PLANT SCIENCE AB - Current morphometric methods that comprehensively measure shape cannot compare the disparate leaf shapes found in seed plants and are sensitive to processing artifacts. We explore the use of persistent homology, a topological method applied as a filtration across simplicial complexes (or more simply, a method to measure topological features of spaces across different spatial resolutions), to overcome these limitations. The described method isolates subsets of shape features and measures the spatial relationship of neighboring pixel densities in a shape. We apply the method to the analysis of 182,707 leaves, both published and unpublished, representing 141 plant families collected from 75 sites throughout the world. By measuring leaves from throughout the seed plants using persistent homology, a defined morphospace comparing all leaves is demarcated. Clear differences in shape between major phylogenetic groups are detected and estimates of leaf shape diversity within plant families are made. The approach predicts plant family above chance. The application of a persistent homology method, using topological features, to measure leaf shape allows for a unified morphometric framework to measure plant form, including shapes, textures, patterns, and branching architectures. DA - 2018/4/25/ PY - 2018/4/25/ DO - 10.3389/fpls.2018.00553 VL - 9 SP - SN - 1664-462X UR - https://publons.com/wos-op/publon/12063358/ KW - leaf shape KW - leaves KW - morphology KW - shape KW - topology KW - topological data analysis KW - persistent homology KW - morphometrics ER - TY - JOUR TI - Selection of host-plant genotype: the next step to increase grain legume N-2 fixation activity AU - Sinclair, Thomas R. AU - Nogueira, Marco A. T2 - JOURNAL OF EXPERIMENTAL BOTANY AB - Symbiotic N2 fixation research thus far has been primarily focused on selection of bacteria. However, little progress in impacting crop yields has resulted from this approach. Bacteria introduced in field soils rarely compete well with indigenous bacteria, including mutated lines selected for high nitrogen fixation capacity. Consequently, introduction of ‘elite’ bacteria in fields commonly does not result in crop yield increase. This review highlights that the primary regulation of N2 fixation is a result of response of integrated physiological activity at the plant level. Nitrogen feedback from the host plant plays an important role in regulating the N2 fixation rate. Rapid sequestration of fixed nitrogen by the plant is especially important for high N2 fixation activity. In addition, water cycling in the plant between the shoot and nodules plays a key role in sustaining high N2 fixation activity. Therefore, attention in selecting the host-plant genotype is suggested to be the next step to increasing N2 fixation activity of grain legumes. DA - 2018/7/10/ PY - 2018/7/10/ DO - 10.1093/jxb/ery115 VL - 69 IS - 15 SP - 3523-3530 SN - 1460-2431 KW - Grain legume KW - N-2-fixing bacteria KW - nodules KW - soil inoculation KW - symbiotic nitrogen fixation KW - water flux ER - TY - JOUR TI - Near‐infrared spectroscopic models for analysis of winter pea (Pisum sativum L.) quality constituents AU - Saha, U. AU - Vann, R. A. AU - Reberg-Horton, S. C. AU - Castillo, M. AU - Mirsky, S. AU - McGee, R. AU - Sonon, L. T2 - Journal of the Science of Food and Agriculture AB - Abstract BACKGROUND Winter pea ( Pisum sativum L.) grows well in a wide geographic region, both as a forage and cover crop. Understanding the quality constituents of this crop is important for both end uses; however, analysis of quality constituents by conventional wet chemistry methods is laborious, slow and costly. Near infrared reflectance spectroscopy (NIRS) is a precise, accurate, rapid and cheap alternative to using wet chemistry for estimating quality constituents. We developed and validated NIRS calibration models for constituent analysis of this crop. RESULTS Of the 11 constituent models developed, nine constituents including moisture, dry‐matter, total‐nitrogen, crude protein, acid detergent fiber, neutral detergent fiber, AD‐lignin, cellulose and non‐fibrous carbohydrate had low standard errors and a high coefficient of determination ( R 2 = 0.88–0.98; 1 – VR, which is the coefficient of determination during cross‐validation = 0.77–0.92) for both calibration and cross‐validation, indicating their potential for quantitative predictability. The calibration models for ash ( R 2 = 0.65; 1 – VR = 0.46) and hemicellulose ( R 2 = 0.75; 1 – VR = 0.50) also appeared to be adequate for qualitative screening. Predictions of an independent validation set yielded reliable agreement between the NIRS predicted values and the reference values with low standard error of prediction (SEP), low bias, high coefficient of determination ( r 2 = 0.82‐0.95), high ratios of performance to deviation (RPD = SD/SEP; 2.30–3.85) and high ratios of performance to interquartile distance (RPIQ = IQ/SEP; 2.57–7.59) for all 11 constituents. CONCLUSION Precise, accurate and rapid analysis of winter pea for major forage and cover crop quality constituents can be performed at a low cost using the NIRS calibration models developed. © 2018 Society of Chemical Industry DA - 2018/// PY - 2018/// DO - 10.1002/jsfa.8947 VL - 98 IS - 11 SP - 4253–4267 SN - 1097-0010 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-85049802740&partnerID=MN8TOARS KW - winter pea KW - calibration KW - cover crop quality KW - forage quality KW - near-infrared spectroscopy ER - TY - JOUR TI - Linkage analysis and identification of quantitative trait loci associated with freeze tolerance and turf quality traits in St. Augustinegrass AU - Kimball, Jennifer A. AU - Tuong, Tanduy D. AU - Arellano, Consuelo AU - Livingston, David P. AU - Milla-Lewis, Susana R. T2 - Molecular Breeding DA - 2018/5// PY - 2018/5// DO - 10.1007/s11032-018-0817-y VL - 38 IS - 5 SP - 67 LA - en SN - 1380-3743, 1572-9788 UR - http://link.springer.com/10.1007/s11032-018-0817-y DB - Crossref Y2 - 2019/2/19/ KW - St. Augustinegrass KW - Linkage map KW - QTL KW - Freeze tolerance KW - Turf quality ER - TY - JOUR TI - Inheritance of resistance to papaya ringspot virus-watermelon strain in watermelon AU - Guner, N. AU - Pesic-VanEsbroeck, Z. AU - Rivera-Burgos, L. A. AU - Wehner, T. C. T2 - HortScience AB - Sources of resistance to the watermelon strain of papaya ringspot virus-watermelon strain (PRSV-W) have been identified within the watermelon ( Citrullus lanatus ) germplasm collection. Inheritance of the resistance to PRSV-W was studied in three Citrullus amarus (formerly C. lanatus var. citroides ) PI accessions: PI 244017, PI 244019, and PI 485583. Three susceptible parent lines, ‘Allsweet’, ‘Calhoun Gray’, and ‘New Hampshire Midget’, were crossed with resistant PI accessions to develop F 1 , F 2 , and BC 1 progenies in six families. A single recessive gene was found to control the resistance to PRSV-W in all three resistant PI accessions. Allelism tests indicated that the three PI accessions carry the same resistance allele to PRSV-W. The gene symbol ‘ prv ’ is proposed for PRSV-W resistance in PI 244017, PI 244019, and PI 485583 in watermelon. DA - 2018/// PY - 2018/// DO - 10.21273/hortsci12944-18 VL - 53 IS - 5 SP - 624-627 ER - TY - JOUR TI - Identification and functional characterization of a novel BEL1-LIKE homeobox transcription factor GmBLH4 in soybean AU - Tao, Yuan AU - Chen, Ming AU - Shu, Yingjie AU - Zhu, Yajing AU - Wang, Shuang AU - Huang, Liyan AU - Yu, Xingwang AU - Wang, Zhankui AU - Qian, Peipei AU - Gu, Weihong AU - Ma, Hao T2 - PLANT CELL TISSUE AND ORGAN CULTURE DA - 2018/8// PY - 2018/8// DO - 10.1007/s11240-018-1419-4 VL - 134 IS - 2 SP - 331-344 SN - 1573-5044 KW - Soybean growth and development KW - High temperature and humidity stress KW - Leaf phenotype KW - GmBLH4 KW - Shoot apical meristem KW - Interaction ER - TY - JOUR TI - Herbicidal and Seed Dormancy Induction Activity of Fermentation Residual Vinasse AU - Leon, Ramon G. AU - Laat, Rocio T2 - WEED SCIENCE AB - Abstract Vinasse, a liquid fermentation residual of bio-ethanol production that also contains solid particles in suspension, is commonly used as a soil amendment. Previous studies reported vinasse reduced seed germination and seedling establishment, suggesting herbicidal activity. Laboratory experiments were conducted to determine whether vinasse herbicidal activity is present in the liquid or solid phase, and whether it affects plants during seed early germination (i.e., imbibition), late germination (i.e., embryo growth and radicle protrusion), or seedling growth. Most of the herbicidal activity was associated with the liquid phase, and for most species, seed viability was predominantly affected after the imbibition phase. Susceptibility to vinasse was species dependent. Lettuce ( Lactuca sativa L.) germination was <8% when seeds were imbibed and germinated in vinasse solutions or imbibed in water and germinated in vinasse. Conversely, imbibing lettuce seeds in vinasse solutions and germinating them in water did not change their germination in comparison with seeds imbibed and germinated in water (>80% germination). Wheat ( Triticum aestivum L.) and sicklepod [ Senna obtusifolia (L.) H. S. Irwin & Barneby] germination decreased 10% and 35% when seeds were imbibed and germinated in vinasse, respectively, while Palmer amaranth ( Amaranthus palmeri S. Watson) and southern crabgrass [ Digitaria ciliaris (Retz.) Koeler] germination decreased >90%. All evaluated species reduced radicle growth as vinasse concentration increased. Filtered liquid vinasse with reduced concentration of salt and ionic compounds inhibited radicle growth similarly to unfiltered vinasse, indicating that the herbicidal activity was not due to osmotic effects and was likely present in the organic liquid phase. Amaranthus palmeri , S. obtusifolia , and D. ciliaris increased the proportion of dormant seed more than 2-fold when they were imbibed or imbibed and germinated in vinasse solutions. Vinasse might be useful for weed management to reduce germinable weed seedbanks by increasing seedling mortality and seed dormancy either by properly timing of its application as a soil amendment or by purifying herbicidal compounds and using them directly for weed control. DA - 2018/// PY - 2018/// DO - 10.1017/wsc.2017.84 VL - 66 IS - 3 SP - 317-323 SN - 1550-2759 KW - Allelopathy KW - cultural practices KW - dormancy KW - germination KW - integrated weed management KW - natural herbicides KW - seed KW - seedbanks ER - TY - JOUR TI - Evaluation of seven mulch treatments for erosion control and vegetation establishment on steep slopes AU - Lee, G. AU - McLaughlin, R. A. AU - Whitely, K. D. AU - Brown, V. K. T2 - JOURNAL OF SOIL AND WATER CONSERVATION AB - Soil erosion and sediment pollution in and around construction sites can result from land disturbing activities that leave areas of unprotected soil during construction. This study evaluated different types of hydromulch for erosion control and grass establishment in comparison to straw alone or straw plus an application of polyacrylamide (PAM) on steep slopes at five construction sites in North Carolina. One site was located in the Coastal Plain (CP) region, and another in the Mountain (M) region, with the remaining three in the Piedmont (P1 through P3). At each site, 20 plots (3 m [10 ft] wide by 6 to 9 m [20 to 30 ft] long) were established on a contiguous area. After applying grass seed, the erosion control treatments were as follows: wheat straw (Triticum aestivum) and wheat straw + 22.4 kg ha−1 (20 lb ac−1) of granular, linear, anionic PAM on all five sites; and hydromulches including flexible growth medium (FGM), stabilized mulch matrix (SMM), bonded fiber matrix (BFM), wood fiber/cellulosic blend (WCB), and wood fiber mulch (WFM) applied at three sites each. Runoff volumes, turbidity, eroded sediment, and nutrient concentration data were collected after natural rain events; grass growth and cover were also evaluated. At both the CP and M sites, there were no differences between treatments, most likely due to the sandy soil texture at CP and a combination of sandy soil texture and relatively light rainfall events at M. At P1, there was a trend of straw cover producing higher runoff volume, turbidity, total suspended solids (TSS), and in general higher concentrations and amount of nutrient loss compared to all hydromulch treatments. In contrast, at P2 and P3, hydromulches tended to have greater runoff volumes, turbidity, and TSS compared to straw. Also, on these sites, straw + PAM treatment had lower concentrations of total phosphorus (P) in runoff compared to WCB. The addition of PAM did not have an effect on runoff volumes at any site, but it reduced average turbidity on P2. Overall, there was no clear pattern of hydromulch advantages over straw as a mulch for reducing erosion or establishing grass on steep slopes. DA - 2018/// PY - 2018/// DO - 10.2489/jswc.73.4.434 VL - 73 IS - 4 SP - 434-442 SN - 1941-3300 KW - erosion KW - hydromulch KW - polyacrylamide KW - turbidity ER - TY - JOUR TI - Establishing the relationship of soil nitrogen immobilization to cereal rye residues in a mulched system AU - Williams, Alwyn AU - Wells, M. Scott AU - Dickey, David A. AU - Hu, Shuijin AU - Maul, Jude AU - Raskin, Daniel T. AU - Reberg-Horton, S. Chris AU - Mirsky, Steven B. T2 - PLANT AND SOIL AB - Soil nitrogen (N) immobilization from cover crop residues may help suppress weeds. We established a gradient of cereal rye shoot biomass to determine the extent that soil N can be immobilized and its effect on redroot pigweed (Amaranthus retroflexus L.). A microplot study was conducted in no-till cereal rye (Secale cereale L.)—soybean (Glycine max L. (Merr.)) systems at two sites in eastern USA. Microplots received 0, 2000, 5000, 8000, 12,000 or 15,000 kg ha−1 of cereal rye shoot biomass, and were injected with two mg 15N kg−1 soil 5 cm below the soil surface. Pigweeds were sown and allowed to germinate. Maximum rates of cereal rye shoot decomposition were observed at ≥5000 kg ha−1. Although cereal rye shoot N declined, shoots became enriched with 15N, indicating fungal transfer of soil N to shoots. Soil inorganic N declined by an average of 5 kg N ha−1. Pigweed tissue N and biomass were reduced in the presence of cereal rye. The magnitude of pigweed N reduction was similar across all shoot application rates. We found weak evidence for a cereal rye shoot-based N immobilization mechanism of weed suppression. Our results indicate N immobilization may be primarily due to root residues. DA - 2018/5// PY - 2018/5// DO - 10.1007/s11104-018-3566-0 VL - 426 IS - 1-2 SP - 95-107 SN - 1573-5036 KW - Secale cereale L. KW - Weed suppression KW - Cover crop mulch KW - N-15 stable isotope KW - N immobilization KW - Residue decomposition ER - TY - JOUR TI - Effects of Turbidity, Sediment, and Polyacrylamide on Native Freshwater Mussels AU - Buczek, Sean B. AU - Cope, W. Gregory AU - McLaughlin, Richard A. AU - Kwak, Thomas J. T2 - JOURNAL OF THE AMERICAN WATER RESOURCES ASSOCIATION AB - Abstract Turbidity is a ubiquitous pollutant adversely affecting water quality and aquatic life in waterways globally. Anionic polyacrylamide (PAM) is widely used as an effective chemical flocculent to reduce suspended sediment (SS) and turbidity. However, no information exists on the toxicity of PAM‐flocculated sediments to imperiled, but ecologically important, freshwater mussels (Unionidae). Thus, we conducted acute (96 h) and chronic (24 day) laboratory tests with juvenile fatmucket ( Lampsilis siliquoidea ) and three exposure conditions (nonflocculated settled sediment, SS, and PAM‐flocculated settled sediment) over a range of turbidity levels (50, 250, 1,250, and 3,500 nephelometric turbidity units). Survival and sublethal endpoints of protein oxidation, adenosine triphosphate (ATP) production, and protein concentration were used as measures of toxicity. We found no effect of turbidity levels or exposure condition on mussel survival in acute or chronic tests. However, we found significant reductions in protein concentration, ATP production, and oxidized proteins in mussels acutely exposed to the SS condition, which required water movement to maintain sediment in suspension, indicating responses that are symptoms of physiological stress. Our results suggest anionic PAM applied to reduce SS may minimize adverse effects of short‐term turbidity exposure on juvenile freshwater mussels without eliciting additional lethal or sublethal toxicity. DA - 2018/6// PY - 2018/6// DO - 10.1111/1752-1688.12639 VL - 54 IS - 3 SP - 631-643 SN - 1752-1688 KW - turbidity KW - invertebrates KW - toxicology KW - erosion KW - best management practices (BMPs) KW - environmental impacts ER - TY - JOUR TI - Effect of Cultivar, Ethephon, Flooding, and Storage Duration on Sweetpotato Internal Necrosis AU - Dittmar, Peter J. AU - Schultheis, Jonathan R. AU - Jennings, Katherine M. AU - Monks, David W. AU - Chaudhari, Sushila AU - Meyers, Stephen AU - Jiang, Chen T2 - HORTTECHNOLOGY AB - The reason for internal necrosis occurrences in sweetpotato ( Ipomoea batatas ) storage roots is not well understood. This disorder begins internally in the storage roots as small light brown spots near the proximal end of the root that eventually can become more enlarged as brown/black regions in the cortex. The objective of this study was to determine the effect of ethephon and flooding on the development of internal necrosis in the sweetpotato cultivars Beauregard, Carolina Ruby, and Covington over storage durations from 9 to 150 days after harvest (DAH) when roots had been cured. Soil moisture treatments were no-flooding, and simulated flooding that was created by applying 10 inches of overhead irrigation during 2 weeks before harvest. Ethephon was applied at 0, 0.75, and 0.98 lb/acre 2 weeks before harvest. Overall, ‘Covington’ and ‘Carolina Ruby’ had greater internal necrosis incidence (22% to 65% and 32% to 51%, respectively) followed by ‘Beauregard’ (9% to 22%) during storage duration from 9 to 150 DAH at both soil moistures. No significant change was observed for either internal necrosis incidence or severity for ‘Beauregard’ and ‘Carolina Ruby’ over the storage duration of 9–150 DAH. However, there was an increase of internal necrosis incidence and severity 9–30 DAH in ‘Covington’, with incidence and severity remaining similar 30–150 DAH. Storage roots in treatments sprayed with 0.75 or 0.98 lb/acre ethephon had higher internal necrosis incidence and severity compared with the nontreated, regardless of cultivars at both soil moistures. This research confirms that sweetpotato cultivars differ in their susceptibility to internal necrosis (incidence and severity), ethephon applied to foliage can contribute to internal necrosis development in storage roots, and internal necrosis incidence reaches a maximum by 30 DAH in ‘Covington’ and 9 DAH in ‘Carolina Ruby’ and ‘Beauregard’. DA - 2018/6// PY - 2018/6// DO - 10.21273/horttech03917-17 VL - 28 IS - 3 SP - 246-251 SN - 1943-7714 KW - Ipomoea batatas KW - postharvest KW - ethylene ER - TY - JOUR TI - Cholesterol accumulation by suppression of SMT1 leads to dwarfism and improved drought tolerance in herbaceous plants AU - Chen, Miao AU - Chen, Jingjing AU - Luo, Na AU - Qu, Rongda AU - Guo, Zhenfei AU - Lu, Shaoyun T2 - PLANT CELL AND ENVIRONMENT AB - Dwarfism and drought tolerance are 2 valuable traits in breeding of many crops. In this study, we report the novel physiological roles of cholesterol in regulation of plant growth and drought tolerance. Compared with the wild type, sterol-C24-methyltransferase 1 (SMT1) gene transcript was greatly reduced in a bermudagrass mutant with dwarfism and enhanced drought tolerance, accompanied with cholesterol accumulation, elevated transcript levels of a small group of genes including SAMDC, and increased concentrations of putrescine (Put), spermidine (Spd), and spermine (Spm). Knock-down of OsSMT1 expression by RNA interference resulted in similar phenotypic changes in transgenic rice. Moreover, exogenously applied cholesterol also led to elevated transcripts of a similar set of genes, higher levels of Put, Spd, and Spm, improved drought tolerance, and reduced plant height in both bermudagrass and rice. We revealed that it is Spm, but not Spd, that is responsible for the height reduction in bermudagrass and rice. In conclusion, we suggest that cholesterol induces expression of SAMDC and leads to dwarfism and elevated drought tolerance in plants as a result of the promoted Spd and Spm synthesis. DA - 2018/6// PY - 2018/6// DO - 10.1111/pce.13168 VL - 41 IS - 6 SP - 1417-1426 SN - 1365-3040 KW - cholesterol KW - drought tolerance KW - plant growth KW - polyamine synthesis KW - sterol-C24-methyltransferase 1 ER - TY - JOUR TI - Characterization of Nicotiana tabacum genotypes possessing deletion mutations that affect potyvirus resistance and the production of trichome exudates AU - Dluge, Kurtis L. AU - Song, Zhongbang AU - Wang, Bingwu AU - Steede, W. Tyler AU - Xiao, Bingguang AU - Liu, Yong AU - Dewey, Ralph E. T2 - BMC GENOMICS AB - Advances in genomics technologies are making it increasingly feasible to characterize breeding lines that carry traits of agronomic interest. Tobacco germplasm lines that carry loci designated VAM and va have been extensively investigated due to their association with potyvirus resistance (both VAM and va) and defects in leaf surface compounds originating from glandular trichomes (VAM only). Molecular studies and classical genetic analyses are consistent with the model that VAM and va represent deletion mutations in the same chromosomal region. In this study, we used RNA-seq analysis, together with emerging tobacco reference genome sequence information to characterize the genomic regions deleted in tobacco lines containing VAM and va. Tobacco genotypes TI 1406 (VAM), K326-va and K326 (wild type) were analyzed using RNA-seq to generate a list of genes differentially expressed in TI 1406 and K326-va, versus the K326 control. Candidate genes were localized onto tobacco genome scaffolds and validated as being absent in only VAM, or missing in both VAM and va, through PCR analysis. These results enabled the construction of a map that predicted the relative extent of the VAM and va mutations on the distal end of chromosome 21. The RNA-seq analyses lead to the discovery that members of the cembratrienol synthase gene family are deleted in TI 1406. Transformation of TI 1406 with a cembratrienol synthase cDNA, however, did not recover the leaf chemistry phenotype. Common to both TI 1406 and K326-va was the absence of a gene encoding a specific isoform of a eukaryotic translation initiation factor (eiF4E1.S). Transformation experiments showed that ectopic expression of eiF4E1.S is sufficient to restore potyvirus susceptibility in plants possessing either the va or VAM mutant loci. We have demonstrated the feasibility of using RNA-seq and emerging whole genome sequence resources in tobacco to characterize the VAM and va deletion mutants. These results lead to the discovery of genes underlying some of the phenotypic traits associated with these historically important loci. Additionally, initial size estimations were made for the deleted regions, and dominant markers were developed that are very close to one of the deletion junctions that defines va. DA - 2018/6/20/ PY - 2018/6/20/ DO - 10.1186/s12864-018-4839-y VL - 19 SP - SN - 1471-2164 KW - Nicotiana tabacum KW - VAM KW - Va KW - Trichome exudate ER - TY - JOUR TI - Atmospheric CO2 Enrichment and Reactive Nitrogen Inputs Interactively Stimulate Soil Cation Losses and Acidification AU - Zhang, Li AU - Qiu, Yunpeng AU - Cheng, Lei AU - Wang, Yi AU - Liu, Lingli AU - Tu, Cong AU - Bowman, Dan C. AU - Burkey, Kent O. AU - Bian, Xinmin AU - Zhang, Weijian AU - Hu, Shuijin T2 - ENVIRONMENTAL SCIENCE & TECHNOLOGY AB - Reactive N inputs (Nr) may alleviate N-limitation of plant growth and are assumed to help sustain plant responses to the rising atmospheric CO2 (eCO2). However, Nr and eCO2 may elicit a cascade reaction that alters soil chemistry and nutrient availability, shifting the limiting factors of plant growth, particularly in acidic tropical and subtropical croplands with low organic matter and low nutrient cations. Yet, few have so far examined the interactive effects of Nr and eCO2 on the dynamics of soil cation nutrients and soil acidity. We investigated the cation dynamics in the plant–soil system with exposure to eCO2 and different N sources in a subtropical, acidic agricultural soil. eCO2 and Nr, alone and interactively, increased Ca2+ and Mg2+ in soil solutions or leachates in aerobic agroecosystems. eCO2 significantly reduced soil pH, and NH4+-N inputs amplified this effect, suggesting that eCO2-induced plant preference of NH4+-N and plant growth may facilitate soil acidification. This is, to our knowledge, the first direct demonstration of eCO2 enhancement of soil acidity, although other studies have previously shown that eCO2 can increase cation release into soil solutions. Together, these findings provide new insights into the dynamics of cation nutrients and soil acidity under future climatic scenarios, highlighting the urgency for more studies on plant–soil responses to climate change in acidic tropical and subtropical ecosystems. DA - 2018/6/19/ PY - 2018/6/19/ DO - 10.1021/acs.est.8b00495 VL - 52 IS - 12 SP - 6895-6902 SN - 1520-5851 ER - TY - JOUR TI - Two types of cellulose synthesis complex knit the plant cell wall together AU - Haigler, Candace H. T2 - Proceedings of the National Academy of Sciences AB - Plant secondary cell walls (SCWs) compose most of Earth’s renewable fibers and biomass (1), and they have irreplaceable roles in the plant lifestyle, ecosystem cycles, carbon sequestration, and human industry. Nonetheless, much remains unknown about how these strong, cellulose-rich polymer networks are synthesized and assembled. Watanabe et al. (2) generate key insights into the dynamic regulation of the cellulose synthase (CESA) enzyme family during the transition between the synthesis of the primary cell wall (PCW), which surrounds all expanding plant cells, and the SCW, which confers specialized functions to some cells. The PCW and SCW become unified despite being successively synthesized and having different matrix polymers and cellulose content. This structural coherency is related to the little-explored “transition period” of cell wall synthesis (3⇓⇓–6), the focus of Watanabe et al.’s research (2). Their results provide clues about how differences in SCW properties of diverse plants may arise and point to the isomer-specific regulation of intracellular membrane protein trafficking, leading to important future research directions. Based on in silico structural comparison with a bacterial enzyme (7), each CESA synthesizes one β-1,4-glucan chain while simultaneously exporting the polymer into the cell wall space. The individual CESAs are organized within a cellulose synthesis complex (CSC), which has six lobes and an average 21.4-nm hexagonal diameter as measured where the transmembrane helices cross the plasma membrane (8) (Fig. 1). Eighteen CESAs are predicted to exist within one CSC (8), which facilitates the coalescence of multiple glucan chains into a microfibril. Each CSC moves within the plasma membrane as it spins a strong, partially crystalline, cellulose microfibril in its wake (9). The locations of CSCs in the membrane and their direction of movement are affected by, but not entirely dependent on, cortical microtubules (6, 9, 10). For example, cortical … [↵][1]1Email: candace_haigler{at}ncsu.edu. [1]: #xref-corresp-1-1 DA - 2018/6/18/ PY - 2018/6/18/ DO - 10.1073/pnas.1808423115 VL - 115 IS - 27 SP - 6882-6884 J2 - Proc Natl Acad Sci USA LA - en OP - SN - 0027-8424 1091-6490 UR - http://dx.doi.org/10.1073/pnas.1808423115 DB - Crossref ER - TY - JOUR TI - Testing ontogenetic patterns of sexual size dimorphism against expectations of the expensive tissue hypothesis, an intraspecific example using oyster toadfish (Opsanus tau) AU - Dornburg, Alex AU - Warren, Dan L. AU - Zapfe, Katerina L. AU - Morris, Richard AU - Iglesias, Teresa L. AU - Lamb, April AU - Hogue, Gabriela AU - Lukas, Laura AU - Wong, Richard T2 - ECOLOGY AND EVOLUTION AB - Abstract Trade‐offs associated with sexual size dimorphism ( SSD ) are well documented across the Tree of Life. However, studies of SSD often do not consider potential investment trade‐offs between metabolically expensive structures under sexual selection and other morphological modules. Based on the expectations of the expensive tissue hypothesis, investment in one metabolically expensive structure should come at the direct cost of investment in another. Here, we examine allometric trends in the ontogeny of oyster toadfish ( Opsanus tau ) to test whether investment in structures known to have been influenced by strong sexual selection conform to these expectations. Despite recovering clear changes in the ontogeny of a sexually selected trait between males and females, we find no evidence for predicted ontogenetic trade‐offs with metabolically expensive organs. Our results are part of a growing body of work demonstrating that increased investment in one structure does not necessarily drive a wholesale loss of mass in one or more organs. DA - 2018/4// PY - 2018/4// DO - 10.1002/ece3.3835 VL - 8 IS - 7 SP - 3609-3616 SN - 2045-7758 KW - evolutionary ecology KW - fishes KW - life history trade-offs KW - phenotypic evolution KW - reproductive physiology KW - swim bladder ER - TY - JOUR TI - Recurrent Changes of Weed Seed Bank Density and Diversity in Crop-Livestock Systems AU - Leon, Ramon G. AU - Wright, David L. T2 - AGRONOMY JOURNAL AB - Core Ideas Crop phase can be used to modify weed diversity. Grazing in sod‐based rotations decreased Palmer amaranth seed bank. Weed seed banks respond rapidly to crop phase within diverse rotations. Weeds are important biodiversity components in agroecosystems, but weed competition with cash crops requires farmers to manage weeds, limiting biodiversity within agricultural fields. Crop rotation increases weed diversity, but weeds are still managed in all cash crop phases so yields are not negatively affected. In our research, a bahiagrass ( Paspalum notatum Flüggé)–bahiagrass–peanut ( Arachis hypogaea L)–cotton ( Gossypium hirsutum L.) rotation exhibited recurrent changes in weed seed banks. The bahiagrass crop phases increased, whereas peanut and cotton phases decreased weed density and diversity. Increasing weed seed banks in bahiagrass did not negatively impact the cash crops peanut and cotton. Furthermore, including grazing in the rotation did not affect overall weed seed banks, but caused a 75% reduction in Palmer amaranth ( Amaranthus palmeri S. Watson) populations, the most problematic weed species in peanut and cotton. Our results indicate that grazing bahiagrass will promote weed diversity and suppress Palmer amaranth, resulting in better weed management in the peanut and cotton rotation crops. DA - 2018/// PY - 2018/// DO - 10.2134/agronj2017.11.0662 VL - 110 IS - 3 SP - 1068-1078 SN - 1435-0645 ER - TY - JOUR TI - Peanut (Arachis hypogaea) response to weed and disease management in northern Ghana AU - Abudulai, Mumuni AU - Naab, Jesse AU - Seini, Shaibu Seidu AU - Dzomeku, Israel AU - Boote, Kenneth AU - Brandenburg, Rick AU - Jordan, David T2 - INTERNATIONAL JOURNAL OF PEST MANAGEMENT AB - Weeds and diseases can reduce peanut (Arachis hypogaea L.) yield or increase cost of production to maintain acceptable yield. While herbicides and fungicides have limited availability in many areas of Ghana and currently are too expensive for resource-poor farmers, control by these pesticides can have a major positive impact on peanut yield. Field experiments were conducted during the rainy seasons of 2009 and 2010 in northern Ghana to determine the effects of herbicide and hand weeding in combination with fungicides on pest management and peanut yield. Peanut pod yield was often more highly correlated with disease severity and canopy defoliation resulting from early leaf spot (caused by Cercospora arachidicola Hori) and late leaf spot (caused by Cercosporidium personatum (Berk. & M.A. Curtis) Deighton) than weed biomass. In some instances, less disease and canopy defoliation were observed when weeds were not controlled effectively compared with increased weed management through hand weeding or herbicide. Two hand weedings or applying pendimethalin preemergence with one hand weeding in combination with 4 applications of triadimefon and chlorothalonil resulted in the lowest weed density and canopy defoliation and often resulted in the highest peanut yield. DA - 2018/// PY - 2018/// DO - 10.1080/09670874.2017.1371806 VL - 64 IS - 3 SP - 204-209 SN - 1366-5863 KW - Disease control KW - fungicides KW - groundnut KW - herbicides KW - integrated pest management KW - weed control ER - TY - JOUR TI - Legume Cover Crops and Tillage Impact Nitrogen Dynamics in Organic Corn Production AU - Liebman, Alexander M. AU - Grossman, Julie AU - Brown, Matthew AU - Wells, M. Scott AU - Reberg-Horton, S. C. AU - Shi, Wei T2 - AGRONOMY JOURNAL AB - Core Ideas Reduced tillage of legume cover crops releases significant amount of N coupled with corn N uptake. Roller crimper termination of legumes releases nitrogen at similar total amounts to disking. Increased experimentation needed to improve corn population and yields in roller crimped stands. Cover cropping and reduced tillage are two management practices that increase ecosystem services in agroecosystems. However, their interactive effects on N dynamics and cash crop yield are underexplored. In this study, four different termination approaches, employing no‐till and tillage, and organic and conventional techniques were used with four winter annual leguminous cover crop species to investigate the combined effect on plant‐available nitrogen (PAN) and subsequent organic corn ( Zea mays L.) yield. Termination treatments included roller‐crimping, flail‐mowing, disking, and herbicide application with cover crops of Austrian winter pea ( Pisum sativum L. subs. arvense, AWP), hairy vetch ( Vicia villosa var. AU Early Cover, HV), balansa clover [ Trifolium michelianum Savi ssp. balansae (Boiss.) Ponert, BC] and crimson clover ( Trifolium incarnatum var. Dixie, CC). Plant‐available N (NO 3 − and NH 4 + ) was determined using biweekly soil inorganic N extractions and resin probes. Cover crop biomass, cover crop C/N ratio, and cover crop total N were measured prior to termination. Nitrogen was most available from AWP and HV across termination methods at 6 to 10 wk after termination. Disked HV contributed highest levels of N across all 16 cropping by termination combinations. Highest biomass N was found in HV (226 kg ha −1 ), followed by AWP (189 kg ha −1 ) and CC (181 kg ha −1 ). Corn yield ranged widely, from 0.23 Mg ha −1 in 0 N control to >9 Mg ha −1 in HV and AWP treatments. Cover crop species plays an important role in N dynamics, frequently influencing soil processes to a more significant degree than termination approach. DA - 2018/// PY - 2018/// DO - 10.2134/agronj2017.08.0474 VL - 110 IS - 3 SP - 1046-1057 SN - 1435-0645 ER - TY - JOUR TI - Improving wood properties for wood utilization through multi-omics integration in lignin biosynthesis AU - Wang, Jack P. AU - Matthews, Megan L. AU - Williams, Cranos M. AU - Shi, Rui AU - Yang, Chenmin AU - Tunlaya-Anukit, Sermsawat AU - Chen, Hsi-Chuan AU - Li, Quanzi AU - Liu, Jie AU - Lin, Chien-Yuan AU - Naik, Punith AU - Sun, Ying-Hsuan AU - Loziuk, Philip L. AU - Yeh, Ting-Feng AU - Kim, Hoon AU - Gjersing, Erica AU - Shollenberger, Todd AU - Shuford, Christopher M. AU - Song, Jina AU - Miller, Zachary AU - Huang, Yung-Yun AU - Edmunds, Charles W. AU - Liu, Baoguang AU - Sun, Yi AU - Lin, Ying-Chung Jimmy AU - Li, Wei AU - Chen, Hao AU - Peszlen, Ilona AU - Ducoste, Joel J. AU - Ralph, John AU - Chang, Hou-Min AU - Muddiman, David C. AU - Davis, Mark F. AU - Smith, Chris AU - Isik, Fikret AU - Sederoff, Ronald AU - Chiang, Vincent L. T2 - NATURE COMMUNICATIONS AB - A multi-omics quantitative integrative analysis of lignin biosynthesis can advance the strategic engineering of wood for timber, pulp, and biofuels. Lignin is polymerized from three monomers (monolignols) produced by a grid-like pathway. The pathway in wood formation of Populus trichocarpa has at least 21 genes, encoding enzymes that mediate 37 reactions on 24 metabolites, leading to lignin and affecting wood properties. We perturb these 21 pathway genes and integrate transcriptomic, proteomic, fluxomic and phenomic data from 221 lines selected from ~2000 transgenics (6-month-old). The integrative analysis estimates how changing expression of pathway gene or gene combination affects protein abundance, metabolic-flux, metabolite concentrations, and 25 wood traits, including lignin, tree-growth, density, strength, and saccharification. The analysis then predicts improvements in any of these 25 traits individually or in combinations, through engineering expression of specific monolignol genes. The analysis may lead to greater understanding of other pathways for improved growth and adaptation. DA - 2018/4/20/ PY - 2018/4/20/ DO - 10.1038/s41467-018-03863-z VL - 9 SP - SN - 2041-1723 ER - TY - JOUR TI - High throughput phenotyping of morpho-anatomical stem properties using X-ray computed tomography in sorghum AU - Gomez, Francisco E. AU - Carvalho, Geraldo, Jr. AU - Shi, Fuhao AU - Muliana, Anastasia H. AU - Rooney, William L. T2 - PLANT METHODS AB - In bioenergy/forage sorghum, morpho-anatomical stem properties are major components affecting standability and juice yield. However, phenotyping these traits is low-throughput, and has been restricted by the lack of a high-throughput phenotyping platforms that can collect both morphological and anatomical stem properties. X-ray computed tomography (CT) offers a potential solution, but studies using this technology in plants have evaluated limited numbers of genotypes with limited throughput. Here we suggest that using a medical CT might overcome sample size limitations when higher resolution is not needed. Thus, the aim of this study was to develop a practical high-throughput phenotyping and image data processing pipeline that extracts stem morpho-anatomical traits faster, more efficiently and on a larger number of samples. A medical CT was used to image morpho-anatomical stem properties in sorghum. The platform and image analysis pipeline revealed extensive phenotypic variation for important morpho-anatomical traits in well-characterized sorghum genotypes at suitable repeatability rates. CT estimates were highly predictive of morphological traits and moderately predictive of anatomical traits. The image analysis pipeline also identified genotypes with superior morpho-anatomical traits that were consistent with ground-truth based classification in previous studies. In addition, stem cross section intensity measured by the CT was highly correlated with stem dry-weight density, and can potentially serve as a high-throughput approach to measure stem density in grass stems. The use of CT on a diverse set of sorghum genotypes with a defined platform and image analysis pipeline was effective at predicting traits such as stem length, diameter, and pithiness ratio at the internode level. High-throughput phenotyping of stem traits using CT appears to be useful and feasible for use in an applied breeding program. DA - 2018/7/13/ PY - 2018/7/13/ DO - 10.1186/s13007-018-0326-3 VL - 14 SP - SN - 1746-4811 KW - X-ray computed tomography KW - Sorghum KW - High-throughput phenotyping KW - Stem morphology KW - Stem anatomy KW - Stem biomechanics KW - Computer vision ER - TY - JOUR TI - Expected value of crossbred dairy cattle artificial insemination breeding strategies in virgin heifers and lactating cows AU - Barrientos-Blanco, Jorge A. AU - Thompson, Nathanael M. AU - Widmar, Nicole J. Olynk AU - Wolf, Christopher A. AU - Snyder, Lori Unruh T2 - LIVESTOCK SCIENCE AB - Research on sexed semen breeding techniques has largely focused on purebred cattle production systems and little work has been done evaluating sexed semen use in crossbred dairy cattle. Complementing a crossbreeding reproduction strategy with sexed semen artificial insemination (AI) has the potential to increase profit potential of sexed semen technology in the short and long run. The objective of this project was to estimate and compare the expected net present value (NPV) of reproduction management programs considering several conventional and sexed semen breeding strategies, cow ages, and breed compositions. While the potential benefits of sexed semen are varied, it is important to note that the focus of this study is on the economic returns to the breeding program. This is not a life-cycle analysis, and therefore, only the sexed semen costs and returns that directly impact the returns to the breeding program are considered. Specifically, a NPV model that incorporates dystocia and stillbirth costs, in addition to improved fertility of crossbred cattle (over purebred cattle), directly into the expected NPV calculation is developed. Increased use of crossbred dairy cattle in the United States make this research particularly timely and relevant. Consistent with previous research, results indicate that pure conventional semen AI and a mixed strategy with one sexed semen AI followed by conventional semen were generally the preferred breeding strategies in terms of expected NPV across all breeds and dam ages evaluated. Similarly, our results also support previous findings that the expected NPV of breeding programs for virgin heifers were consistently higher than lactating cows. In terms of breeds, the crossbreed scenarios generally produced higher expected NPV than scenarios for purebred Holsteins. The most influential factors resulting in these higher returns were the higher cumulative pregnancy rates associated with the crossbreds. Reproductive benefits of crossbred dairy cattle may be able to alleviate some economic pressure currently associated with poor dairy reproduction with AI breeding strategies (especially those incorporating sexed semen). However, it is important to note the likely tradeoffs associated with improvements in fertility (e.g., reduced milk production), the consideration of which is necessary to maximize whole farm profitability. DA - 2018/5// PY - 2018/5// DO - 10.1016/j.livsci.2018.03.005 VL - 211 SP - 66-74 SN - 1878-0490 KW - Artificial insemination KW - Crossbreed KW - Net present value KW - Sexed semen ER - TY - JOUR TI - Adaptability and stability of corn inbred lines regarding resistance to gray leaf spot and northern leaf blight AU - Saito, Belisa Cristina AU - Silva, Leonardo Queiroz AU - Costa Andrade, Joao Antonio AU - Goodman, Major M. T2 - CROP BREEDING AND APPLIED BIOTECHNOLOGY AB - The objectives of this study were to identify resistant and susceptible corn inbred lines based on their stability and adaptability for resistance to disease symptoms of gray leaf spot and northern leaf blight, suggest resistant inbred lines aimed at producing synthetics, and identify the sowing dates with higher occurrence of diseases to use these dates for identification of genetic resistance. We evaluated 41 corn inbred lines in randomized block designs with three replications and 11 sowing dates. Evaluations were performed 30 days after silking. Stability and adaptability analyses were performed by the regression method. The highest severities of disease occurred in sowing from June to September. On average, all the inbred lines were classified as resistant; however, considering adaptability and stability, five inbred lines were found suitable to produce dent synthetics resistant to both diseases. For flint synthetics resistant to both diseases, inbred lines IVF1-7, IVF1-10, 2F, 9F, and 10F are most suitable. DA - 2018/// PY - 2018/// DO - 10.1590/1984-70332018v18n2a21 VL - 18 IS - 2 SP - 148-154 SN - 1984-7033 KW - Leaf diseases KW - disease resistance KW - synthetic ER - TY - JOUR TI - Accounting for Genotype-by-Environment Interactions and Residual Genetic Variation in Genomic Selection for Water-Soluble Carbohydrate Concentration in Wheat AU - Ovenden, Ben AU - Milgate, Andrew AU - Wade, Len J. AU - Rebetzke, Greg J. AU - Holland, James B. T2 - G3-GENES GENOMES GENETICS AB - Abiotic stress tolerance traits are often complex and recalcitrant targets for conventional breeding improvement in many crop species. This study evaluated the potential of genomic selection to predict water-soluble carbohydrate concentration (WSCC), an important drought tolerance trait, in wheat under field conditions. A panel of 358 varieties and breeding lines constrained for maturity was evaluated under rainfed and irrigated treatments across two locations and two years. Whole-genome marker profiles and factor analytic mixed models were used to generate genomic estimated breeding values (GEBVs) for specific environments and environment groups. Additive genetic variance was smaller than residual genetic variance for WSCC, such that genotypic values were dominated by residual genetic effects rather than additive breeding values. As a result, GEBVs were not accurate predictors of genotypic values of the extant lines, but GEBVs should be reliable selection criteria to choose parents for intermating to produce new populations. The accuracy of GEBVs for untested lines was sufficient to increase predicted genetic gain from genomic selection per unit time compared to phenotypic selection if the breeding cycle is reduced by half by the use of GEBVs in off-season generations. Further, genomic prediction accuracy depended on having phenotypic data from environments with strong correlations with target production environments to build prediction models. By combining high-density marker genotypes, stress-managed field evaluations, and mixed models that model simultaneously covariances among genotypes and covariances of complex trait performance between pairs of environments, we were able to train models with good accuracy to facilitate genetic gain from genomic selection. DA - 2018/6// PY - 2018/6// DO - 10.1534/g3.118.200038 VL - 8 IS - 6 SP - 1909-1919 SN - 2160-1836 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-85047875467&partnerID=MN8TOARS KW - Genomic Selection KW - residual genetic variation KW - genotype-by-environment interaction KW - factor analytic model KW - relative accuracy KW - GenPred KW - Shared Data Resources ER - TY - JOUR TI - Vertically distinct microbial communities in the Mariana and Kermadec trenches AU - Peoples, Logan M. AU - Donaldson, Sierra AU - Osuntokun, Oladayo AU - Xia, Qing AU - Nelson, Alex AU - Blanton, Jessica AU - Allen, Eric E. AU - Church, Matthew J. AU - Bartlett, Douglas H. T2 - PLOS ONE AB - Hadal trenches, oceanic locations deeper than 6,000 m, are thought to have distinct microbial communities compared to those at shallower depths due to high hydrostatic pressures, topographical funneling of organic matter, and biogeographical isolation. Here we evaluate the hypothesis that hadal trenches contain unique microbial biodiversity through analyses of the communities present in the bottom waters of the Kermadec and Mariana trenches. Estimates of microbial protein production indicate active populations under in situ hydrostatic pressures and increasing adaptation to pressure with depth. Depth, trench of collection, and size fraction are important drivers of microbial community structure. Many putative hadal bathytypes, such as members related to the Marinimicrobia, Rhodobacteraceae, Rhodospirilliceae, and Aquibacter, are similar to members identified in other trenches. Most of the differences between the two trench microbiomes consists of taxa belonging to the Gammaproteobacteria whose distributions extend throughout the water column. Growth and survival estimates of representative isolates of these taxa under deep-sea conditions suggest that some members may descend from shallower depths and exist as a potentially inactive fraction of the hadal zone. We conclude that the distinct pelagic communities residing in these two trenches, and perhaps by extension other trenches, reflect both cosmopolitan hadal bathytypes and ubiquitous genera found throughout the water column. DA - 2018/4/5/ PY - 2018/4/5/ DO - 10.1371/journal.pone.0195102 VL - 13 IS - 4 SP - SN - 1932-6203 ER - TY - JOUR TI - Sensitivity analysis of temperature changes for determining thermal properties of partially frozen soil with a dual probe heat pulse sensor AU - Kojima, Yuki AU - Heitman, Joshua L. AU - Noborio, Kosuke AU - Ren, Tusheng AU - Horton, Robert T2 - COLD REGIONS SCIENCE AND TECHNOLOGY AB - Determining thermal conductivity (λ) and volumetric heat capacity (C) of partially frozen soils with a dual probe heat pulse (DPHP) sensor is challenging because an applied heat pulse melts ice surrounding the heater probe. Examining DPHP temperature changes with a commonly-used analytical solution that only accounts for heat conduction leads to inaccurate λ and C estimates for partially frozen soils at temperatures between −5 °C and 0 °C. In order to determine λ and C accurately and simultaneously, it is necessary to understand how various properties of partially frozen soil influence the temperature changes produced by DPHP sensors. The objective of this study is to determine the sensitivity of DPHP temperature changes to soil conditions and soil thermal properties. A numerical solution for radial heat conduction with soil freezing and thawing is developed. A series of simulations are performed, in which various errors are imposed onto a selected model parameter while other model parameters are held constant, and sensitivity coefficient values (φ) of the time of maximum probe temperature (tm) and of the maximum probe temperature rise (Tm) for each parameter are calculated. Temperature changes at the measurement probe are quite sensitive to initial soil temperature (φ values for tm and for Tm are −0.99 and 0.99, respectively), λ (φ value for tm is −0.93), and parameters determining the shape of the soil freezing characteristic (FC) curve, i.e., saturated water content θs (φ values for tm and for Tm are 0.59 and −0.73, respectively) and n (φ values for tm and for Tm are −2.7 and 2.4, respectively). Temperature changes are not very sensitive to C (φ values for tm and for Tm are 0.034 and −0.15, respectively). Although previous investigations tried to determine C by inverse analysis, this sensitivity analysis shows that the influence of C on temperature response to a heat pulse is masked by that of the FC. Thus, λ and FC parameters are the best candidate parameters to be determined by inverse analysis of DPHP data. This new result will guide further testing of DPHP sensors in partially frozen soils. DA - 2018/7// PY - 2018/7// DO - 10.1016/j.coldregions.2018.03.022 VL - 151 SP - 188-195 SN - 1872-7441 KW - Partially frozen soil KW - Thermal conductivity KW - Volumetric heat capacity KW - Dual probe heat pulse KW - Freezing characteristic ER - TY - JOUR TI - Bulk density effects on soil hydrologic and thermal characteristics: A numerical investigation AU - Kojima, Yuki AU - Heitman, Joshua L. AU - Sakai, Masaru AU - Kato, Chihiro AU - Horton, Robert T2 - HYDROLOGICAL PROCESSES AB - Abstract Soil bulk density (ρ b ) is commonly treated as static in studies of land surface dynamics. Magnitudes of errors associated with this assumption are largely unknown. Our objectives were to (a) quantify ρ b effects on soil hydrologic and thermal properties and (b) evaluate effects of ρ b on surface energy balance and heat and water transfer. We evaluated 6 soil properties, volumetric heat capacity, thermal conductivity, soil thermal diffusivity, water retention characteristics, hydraulic conductivity, and vapour diffusivity, over a range of ρ b , using a combination of 6 models. Thermal conductivity, water retention, hydraulic conductivity, and vapour diffusivity were most sensitive to ρ b , each changing by fractions greater than the associated fractional changes in ρ b . A 10% change in ρ b led to 10–11% change in thermal conductivity, 6–11% change in saturated and residual water content, 49–54% change in saturated hydraulic conductivity, and 80% change in vapour diffusivity. Subsequently, 3 field seasons were simulated with a numerical model (HYDRUS‐1D) for a range of ρ b values. When ρ b increased 25% (from 1.2 to 1.5 Mg m −3 ), soil temperature variation decreased by 2.1 °C in shallow layers and increased by 1 °C in subsurface layers. Surface water content differed by 0.02 m 3 m −3 for various ρ b values during drying events but differences mostly disappeared in the subsurface. Matric potential varied by >100 m of water. Surface energy balance showed clear trends with ρ b . Latent heat flux decreased 6%, sensible heat flux increased 9%, and magnitude of ground heat flux varied by 18% (with a 25% ρ b increase). Transient ρ b impacted surface conditions and fluxes, and clearly, it warrants consideration in field and modelling investigations. DA - 2018/7/1/ PY - 2018/7/1/ DO - 10.1002/hyp.13152 VL - 32 IS - 14 SP - 2203-2216 SN - 1099-1085 KW - coupled soil heat and water transfer KW - soil bulk density KW - soil hydraulic properties KW - soil thermal properties KW - surface energy balance ER - TY - JOUR TI - Bayesian Spectral Modeling for Multivariate Spatial Distributions of Elemental Concentrations in Soil AU - Terres, Maria A. AU - Fuentes, Montserrat AU - Hesterberg, Dean AU - Polizzotto, Matthew T2 - BAYESIAN ANALYSIS AB - Recent technological advances have enabled researchers in a variety of fields to collect accurately geocoded data for several variables simultaneously. In many cases it may be most appropriate to jointly model these multivariate spatial processes without constraints on their conditional relationships. When data have been collected on a regular lattice, the multivariate conditionally autoregressive (MCAR) models are a common choice. However, inference from these MCAR models relies heavily on the pre-specified neighborhood structure and often assumes a separable covariance structure. Here, we present a multivariate spatial model using a spectral analysis approach that enables inference on the conditional relationships between the variables that does not rely on a pre-specified neighborhood structure, is non-separable, and is computationally efficient. Covariance and cross-covariance functions are defined in the spectral domain to obtain computational efficiency. The resulting pseudo posterior inference on the correlation matrix allows for quantification of the conditional dependencies. A comparison is made with an MCAR model that is shown to be highly sensitive to the choice of neighborhood. The approaches are illustrated for the toxic element arsenic and four other soil elements whose relative concentrations were measured on a microscale spatial lattice. Understanding conditional relationships between arsenic and other soil elements provides insights for mitigating pervasive arsenic poisoning in drinking water in southern Asia and elsewhere. DA - 2018/3// PY - 2018/3// DO - 10.1214/16-ba1034 VL - 13 IS - 1 SP - 1-28 SN - 1936-0975 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-85039854529&partnerID=MN8TOARS KW - conditional dependence KW - lattice KW - non-separable covariance KW - quasi-matern spectral density KW - spatial modeling ER - TY - JOUR TI - A case for comprehensive analyses demonstrated by evaluating the yield benefits of neonicotinoid seed treatment in maize (Zea mays L.) AU - Del Pozo-Valdivia, Alejandro I. AU - Reisig, Dominic D. AU - Arellano, Consuelo AU - Heiniger, Ron W. T2 - CROP PROTECTION AB - With increased scrutiny of the neonicotinoid class of chemistry and its negative impact on the pollinator community, ecological cost/benefit analyses of agronomic crops that use these insecticides are increasingly important. This study initially sought to address the question of yield benefit due to neonicotinoid seed treatment in maize (Zea mays L.), using North Carolina yield contest data from 2002 to 2006, the time period from initial neonicotinoid seed treatment adoption to nearly ubiquitous adoption. However, we recognized that several agronomic practices, including planting date, hybrid selection, and fertilization, could affect the yield of this crop; moreover, they could be collinear with one another and the analysis could be skewed by early adopters of new technology. Hence, we used all available data to compare among traditional approaches and a data-mining approach for analyzing the impact of neonicotinoid seed treatment on maize yield. At-planting insecticide treatment was not an important predictor of maize yield. When analyzed using the traditional approach (T-test), yields were significantly higher for fields planted with neonicotinoid treated seed compared to seed without neonicotinoid; however, data-mining approach (Decision tree analysis) that took into account other factors contributing to yield did not identify seed treatments as important. The contrast in these results highlights the need for future carefully designed studies that target to minimize inter- and intra-site variation; and include measurements of additional factors that may influence yield, such as seeding rate, tillage, and herbicide applications, as input variables that are largely lacking in current approaches on the subject. DA - 2018/8// PY - 2018/8// DO - 10.1016/j.cropro.2017.10.021 VL - 110 SP - 171-182 SN - 1873-6904 KW - Agronomic practice KW - Clothianidin KW - Corn KW - Decision tree analysis KW - Imidacloprid KW - PROC GLMSELECT KW - SAS enterprise miner work station KW - Thiamethoxam ER - TY - JOUR TI - Virulence Differences in Blumeria graminis f. sp tritici from the Central and Eastern United States AU - Cowger, Christina AU - Mehra, Lucky AU - Arellano, Consuelo AU - Meyers, Emily AU - Murphy, J. Paul T2 - PHYTOPATHOLOGY AB - Wheat powdery mildew is a disease of global importance that occurs across a wide geographic area in the United States. A virulence survey of Blumeria graminis f. sp. tritici, the causal agent, was conducted by sampling 36 wheat fields in 15 U.S. states in the years 2013 and 2014. Using a hierarchical sampling protocol, isolates were derived from three separated plants at each of five separated sites within each field in order to assess the spatial distribution of pathotypes. In total, 1,017 isolates from those fields were tested individually on single-gene differential cultivars containing a total of 21 powdery mildew resistance (Pm) genes. Several recently introgressed mildew resistance genes from wild wheat relatives (Pm37, Pm53, MlAG12, NCAG13, and MlUM15) exhibited complete or nearly complete resistance to all local B. graminis f. sp. tritici populations from across the sampled area. One older gene, Pm4b, also retained at least some efficacy across the sampled area. The B. graminis f. sp. tritici population sampled from Arkansas and Missouri, on the western edge of the eastern soft red winter wheat region, had virulence profiles more similar to other soft wheat mildew populations than to the geographically closer population from hard wheat fields in the Plains states of Oklahoma, Nebraska, and Kansas. The Plains population differed in that it was avirulent to several Pm genes long defeated in the soft-wheat-growing areas. Virulence complexity was greatest east of the Mississippi River, and diminished toward the west. Several recently introgressed Pm genes (Pm25, Pm34, Pm35, and NCA6) that are highly effective against mildew in the field in North Carolina were unexpectedly susceptible to eastern-U.S. B. graminis f. sp. tritici populations in detached-leaf tests. Sampled fields displayed a wide range of pathotype diversity and spatial distribution, suggesting that epidemics are caused by varying numbers of pathotypes in all regions. The research confirmed that most long-used Pm genes are defeated in the eastern United States, and the U.S. B. graminis f. sp. tritici population has different virulence profiles in the hard- and soft-wheat regions, which are likely maintained by host selection, isolation by distance, and west-to-east gene flow. DA - 2018/3// PY - 2018/3// DO - 10.1094/phyto-06-17-0211-r VL - 108 IS - 3 SP - 402-411 SN - 1943-7684 ER - TY - JOUR TI - Rice SUB1A constrains remodelling of the transcriptome and metabolome during submergence to facilitate post-submergence recovery AU - Locke, Anna M. AU - Barding, Gregory A., Jr AU - Sathnur, Sumukh AU - Larive, Cynthia K. AU - Bailey‐Serres, Julia T2 - Plant, Cell & Environment AB - Abstract The rice ( Oryza sativa L.) ethylene‐responsive transcription factor gene SUB1A‐1 confers tolerance to prolonged, complete submergence by limiting underwater elongation growth. Upon desubmergence, SUB1A‐1 genotypes rapidly recover photosynthetic function and recommence development towards flowering. The underpinnings of the transition from stress amelioration to the return to homeostasis are not well known. Here, transcriptomic and metabolomic analyses were conducted to identify mechanisms by which SUB1A improves physiological function over the 24 hr following a sublethal submergence event. Evaluation of near‐isogenic genotypes after submergence and over a day of reaeration demonstrated that SUB1A transiently constrains the remodelling of cellular activities associated with growth. SUB1A influenced the abundance of ca. 1,400 transcripts and had a continued impact on metabolite content, particularly free amino acids, glucose, and sucrose, throughout the recovery period. SUB1A promoted recovery of metabolic homeostasis but had limited influence on mRNAs associated with growth processes and photosynthesis. The involvement of low energy sensing during submergence and recovery was supported by dynamics in trehalose‐6‐phosphate and mRNAs encoding key enzymes and signalling proteins, which were modulated by SUB1A . This study provides new evidence of convergent signalling pathways critical to the rapidly reversible management of carbon and nitrogen metabolism in submergence resilient rice. DA - 2018/4// PY - 2018/4// DO - 10.1111/pce.13094 VL - 41 IS - 4 SP - 721–736 SN - 0140-7791 1365-3040 UR - http://dx.doi.org/10.1111/pce.13094 KW - abiotic stress KW - energy sensing KW - ethylene-responsive transcription factor KW - hypoxia KW - metabolism KW - SUBMERGENCE1A KW - trehalose-6-phosphate ER - TY - JOUR TI - Reference quality assembly of the 3.5-Gb genome of Capsicum annuum from a single linked-read library AU - Hulse-Kemp, Amanda M. AU - Maheshwari, Shamoni AU - Stoffel, Kevin AU - Hill, Theresa A. AU - Jaffe, David AU - Williams, Stephen R. AU - Weisenfeld, Neil AU - Ramakrishnan, Srividya AU - Kumar, Vijay AU - Shah, Preyas AU - Schatz, Michael C. AU - Church, Deanna M. AU - Van Deynze, Allen T2 - HORTICULTURE RESEARCH AB - Linked-Read sequencing technology has recently been employed successfully for de novo assembly of human genomes, however, the utility of this technology for complex plant genomes is unproven. We evaluated the technology for this purpose by sequencing the 3.5-gigabase (Gb) diploid pepper (Capsicum annuum) genome with a single Linked-Read library. Plant genomes, including pepper, are characterized by long, highly similar repetitive sequences. Accordingly, significant effort is used to ensure that the sequenced plant is highly homozygous and the resulting assembly is a haploid consensus. With a phased assembly approach, we targeted a heterozygous F1 derived from a wide cross to assess the ability to derive both haplotypes and characterize a pungency gene with a large insertion/deletion. The Supernova software generated a highly ordered, more contiguous sequence assembly than all currently available C. annuum reference genomes. Over 83% of the final assembly was anchored and oriented using four publicly available de novo linkage maps. A comparison of the annotation of conserved eukaryotic genes indicated the completeness of assembly. The validity of the phased assembly is further demonstrated with the complete recovery of both 2.5-Kb insertion/deletion haplotypes of the PUN1 locus in the F1 sample that represents pungent and nonpungent peppers, as well as nearly full recovery of the BUSCO2 gene set within each of the two haplotypes. The most contiguous pepper genome assembly to date has been generated which demonstrates that Linked-Read library technology provides a tool to de novo assemble complex highly repetitive heterozygous plant genomes. This technology can provide an opportunity to cost-effectively develop high-quality genome assemblies for other complex plants and compare structural and gene differences through accurate haplotype reconstruction. DA - 2018/1/12/ PY - 2018/1/12/ DO - 10.1038/s41438-017-0011-0 VL - 5 SP - SN - 2052-7276 ER - TY - JOUR TI - Harvest regimen changes sericea lespedeza condensed tannin, fiber and protein concentrations AU - Muir, James P. AU - Terrill, Thomas H. AU - Mosjidis, Jorge A. AU - Luginbuhl, Jean-Marie AU - Miller, James E. AU - Burke, Joan M. AU - Coleman, Samuel W. T2 - GRASSLAND SCIENCE AB - Abstract Sericea lespedeza ( Lespedeza cuneata [Dumont de Courset] G. Don.; SL ) is a perennial, warm‐season legume containing condensed tannins ( CT ) that can play important roles in ruminant ecosystems. Our research objective was to determine season‐long average herbage CT fractions, crude protein ( CP ) and fiber concentrations under three harvest regimens for SL cv. AU G razer at five locations within the southeastern USA during 2010. Harvest regimens were regrowth every 35 days (35‐day), previously uncut plots every 35 days ( ACCUM ), or regrowth when height reached 40 cm (40 cm). We found harvest regimen by location interactions ( P ≤ 0.05) for all dependent variables. The ACCUM plants usually had greater ( P ≤ 0.05) fiber concentrations where there were differences, except for the Louisiana location. The lowest (114 g kg −1 ; P ≤ 0.05) CP concentrations were measured in ACCUM plants at the driest location (Texas) while the highest (181 g kg −1 for North Carolina plants) came from the 35‐day regimen. Total CT ( TCT ) concentration varied ( P ≤ 0.05) from a low of 61.1 g kg −1 for ACCUM plants in Louisiana to 100.7 g kg −1 for Texas plants harvested from 35‐day plots. In summary, harvest regimen influenced SL nutrient and CT concentrations. Fiber concentration was better correlated (−0.621 for acid detergent fiber; P ≤ 0.05) with TCT than CP (−0.014; P = 0.82). Sericea lespedeza regrowth harvested every 35 days had higher season‐long average TCT concentrations in two of five locations along with greater CP and less fiber concentrations in four of five locations compared to the ACCUM regimen. DA - 2018/4// PY - 2018/4// DO - 10.1111/grs.12186 VL - 64 IS - 2 SP - 137-144 SN - 1744-697X KW - Acid detergent fiber KW - Lespedeza cuneata KW - neutral detergent fiber KW - nitrogen ER - TY - JOUR TI - Reduced Translocation Is Associated with Antagonism of Glyphosate by Glufosinate in Giant Foxtail (Setaria faberi) and Velvetleaf (Abutilon theophrasti) AU - Besancon, Thierry E. AU - Penner, Donald AU - Everman, Wesley J. T2 - WEED SCIENCE AB - Previous reports have underscored antagonism that may result from mixing glyphosate and glufosinate across a wide range of application rates and for various broadleaf and grass weed species, but no investigation has been conducted to characterize glyphosate absorption and translocation when combined with glufosinate. The objectives of this study were to evaluate herbicide efficacy and assess herbicide interaction and physiological response with combinations of glyphosate and glufosinate on common lambsquarters, velvetleaf, and giant foxtail. Greenhouse studies to determine interaction resulted in strong and persistent antagonism between glyphosate at 110 and 220 g ae ha −1 and glufosinate at 20 or 40 g ae ha −1 in giant foxtail, whereas only transient and reduced antagonism was noted for velvetleaf and common lambsquarters. Combining glyphosate and glufosinate increased the maximum absorption of glyphosate by 9% and 23% in velvetleaf and giant foxtail, respectively, compared with glyphosate alone. In velvetleaf, averaged over time, only 2.6% of the applied radioactivity translocated out of the treated leaf when glufosinate was mixed with glyphosate compared with 9.9% when glyphosate was applied alone. In giant foxtail, 21.6% of the [ 14 C]glyphosate translocated out of the treated leaf when glufosinate was mixed with glyphosate compared with 52.4% when glyphosate was applied alone. Conversely, no change in the radioactive pattern of translocation was noted for common lambsquarters. These results suggest that reduced translocation of glyphosate is the physiological mechanism responsible for the antagonism observed between glyphosate and glufosinate in giant foxtail and, to a lesser extent, in velvetleaf. DA - 2018/// PY - 2018/// DO - 10.1017/wsc.2017.72 VL - 66 IS - 2 SP - 159-167 SN - 1550-2759 KW - Absorption KW - herbicide interaction ER - TY - JOUR TI - Influence of PhoslockA (R) on legacy phosphorus, nutrient ratios, and algal assemblage composition in hypereutrophic water resources AU - Bishop, W. M. AU - Richardson, Robert T2 - Environmental Science and Pollution Research DA - 2018/// PY - 2018/// DO - 10.1007/s11356-017-0832-2 VL - 25 IS - 5 SP - 4544–4557 ER - TY - JOUR TI - Improved thermo-time domain reflectometry method for continuous in-situ determination of soil bulk density AU - Tian, Zhengchao AU - Lu, Yili AU - Ren, Tusheng AU - Horton, Robert AU - Heitman, Joshua L. T2 - SOIL & TILLAGE RESEARCH AB - Quantifying the dynamics of surface soil bulk density (ρb) is important for characterizing water, heat, and gas exchanges in agricultural and environmental applications. Unfortunately, very few approaches are available for continuous in-situ monitoring of ρb. The soil heat capacity-based (C-based) thermo-time domain reflectometry (thermo-TDR) approach has been used to measure ρb in-situ, but this approach gives ρb estimates with relatively large errors. In this study, we present a new soil thermal conductivity-based (λ-based) thermo-TDR approach for continuous and automatic determination of ρb variation in-situ. An error analysis, literature data, and field experiments were used to evaluate the performance of the C-based and λ-based approaches. The error analysis undertaken on hypothetical soils indicated that the new λ-based approach was less sensitive to errors in the measurement inputs than was the C-based approach when the same relative errors occurred, except on very dry soils. Thermo-TDR measurements reported in the literature on seven soils showed that the new λ-based approach provided more accurate and precise ρb estimates, with coefficient of determination (R2) of 0.70 and root mean square error (RMSE) of 0.103 Mg m−3, than did the C-based approach which gave ρb with R2 of 0.32 and RMSE of 0.178 Mg m−3. Two field experiments were conducted to test the performance of the new λ-based thermo-TDR approach for monitoring ρb dynamics. The results showed that following tillage surface ρb increased by about 35% within 40 days. The ρb obtained by the λ-based thermo-TDR approach agreed well with independent core sampling measurements, with an average RMSE of 0.122 Mg m−3. The C-based approach failed to give acceptable ρb estimates in most cases because of probe deflection and environmental factors. We conclude that the new λ-based thermo-TDR approach is a promising method for continuous in situ measurements of ρb. DA - 2018/5// PY - 2018/5// DO - 10.1016/j.still.2017.12.021 VL - 178 SP - 118-129 SN - 1879-3444 KW - Thermo-TDR probe KW - Soil bulk density KW - Heat capacity-based approach KW - Thermal conductivity-based approach ER - TY - JOUR TI - Identification of M-Type Gametophyte Factors in Maize Genetic Resources AU - Jones, Zachary G. AU - Goodman, Major M. T2 - CROP SCIENCE AB - Maize ( Zea mays L.) gametophyte factors are the basis of dent sterile popcorns, where they are used to prevent pollen contamination from dent corns and have been proposed as useful for protection of other specialty types. Current gametophytic systems rely entirely on the strong allele of Gametophyte Factor 1 ( Ga1‐s ) to impart the selective barrier needed in these hybrids. This allele, however, is naturally overcome by another allele at the same locus ( Ga1‐m ), which is only detectable by specific evaluation, allowing it to go undetected in breeding lines, thus creating a scenario with substantial risk to Ga1‐s hybrids. Other gametophytic systems exist but have parallel allelic structure with possibly parallel risks, especially from m‐ type alleles. By screening a set of maize genetic resources, we assessed the risk posed by the Ga1‐m allele. We identified the allele in several populations readily useful for expanding the genetic base of commercial maize, including several Germplasm Enhancement of Maize lines. To examine the possible distribution of m‐ type alleles at other key gametophytic loci, we screened the maize nested association mapping population founder lines for the presence of m‐ type gametophytic alleles, identifying 19 previously unreported m‐ type gametophytic alleles in these lines. Our results also highlight the frequent concomitancy of gametophytic alleles at different loci, the full interactions of which are ignored by standard phenotyping methods that consider individual loci, confounding allele status determination. We provide a method for determining allele status at multiple gametophytic loci and highlight the implications of concomitant alleles, especially Ga1‐m and Tcb1‐m , on the possible deployment of new barrier systems. DA - 2018/// PY - 2018/// DO - 10.2135/cropsci2017.09.0560 VL - 58 IS - 2 SP - 719-727 SN - 1435-0653 ER - TY - JOUR TI - Evolutionary Adaptations of Palmer Amaranth (Amaranthus palmeri) to Nitrogen Fertilization and Crop Rotation History Affect Morphology and Nutrient-Use Efficiency AU - Bravo, Washington AU - Leon, Ramon G. AU - Ferrell, Jason A. AU - Mulvaney, Michael J. AU - Wood, C. Wesley T2 - WEED SCIENCE AB - Palmer amaranth control has become a major challenge for multiple cropping systems across the southeastern and midwestern United States. Despite extensive research on herbicide-resistance evolution, little research has been done exploring how Palmer amaranth might also be evolving other adaptive traits in response to different selection forces present in agricultural fields and the enrichment of soils with nutrients such as nitrogen. The objective of the present study was to determine whether Palmer amaranth populations have evolved different morphology and growth patterns in response to glyphosate use and fertilization history. Ten Palmer amaranth populations, including glyphosate-resistant (GR) and glyphosate-susceptible (GS) populations, were collected from different cropping systems with histories of high and low nitrogen fertilization in the states of Florida and Georgia. All populations were grown in pots filled with soil fertilized with either 0 or 40 kgNha −1 , and their response to nitrogen was compared for morphological, growth, and nutrient-use traits. Populations differed in how they modified their morphology and growth in response to N, with major differences in traits such as foliar area, branch production, leaf shape, and canopy architecture. Populations with high nitrogen-fertilization histories had higher (>43%) nutrient-use efficiency (NUE) than populations with low nitrogen-fertilization histories. Similarly, GR populations have evolved higher NUE (>47%) and changed canopy architecture more than GS populations in response to nitrogen fertilization. The results of the present study highlight the importance of paying more attention to adaptations to cultural practices that might increase weediness and how genetic changes in traits involved in morphology and metabolism might favor compensatory mechanisms increasing the fitness of the population carrying herbicide-resistant traits. DA - 2018/// PY - 2018/// DO - 10.1017/wsc.2017.73 VL - 66 IS - 2 SP - 180-189 SN - 1550-2759 KW - Crop rotation KW - evolution KW - fitness KW - integrated weed management KW - nutrient content KW - resistance ER - TY - JOUR TI - Ecogeography of teosinte AU - Sanchez Gonzalez, Jose de Jesus AU - Ruiz Corral, Jose Ariel AU - Medina Garcia, Guillermo AU - Ramirez Ojeda, Gabriela AU - Cruz Larios, Lino AU - Holland, James Brendan AU - Miranda Medrano, Roberto AU - Garcia Romero, Giovanni Emmanuel T2 - PLOS ONE AB - Adaptation of crops to climate change has motivated an increasing interest in the potential value of novel traits from wild species; maize wild relatives, the teosintes, harbor traits that may be useful to maize breeding. To study the ecogeographic distribution of teosinte we constructed a robust database of 2363 teosinte occurrences from published sources for the period 1842–2016. A geographical information system integrating 216 environmental variables was created for Mexico and Central America and was used to characterize the environment of each teosinte occurrence site. The natural geographic distribution of teosinte extends from the Western Sierra Madre of the State of Chihuahua, Mexico to the Pacific coast of Nicaragua and Costa Rica, including practically the entire western part of Mesoamerica. The Mexican annuals Zea mays ssp. parviglumis and Zea mays ssp. mexicana show a wide distribution in Mexico, while Zea diploperennis, Zea luxurians, Zea perennis, Zea mays ssp. huehuetenangensis, Zea vespertilio and Zea nicaraguensis had more restricted and distinct ranges, representing less than 20% of the total occurrences. Only 11.2% of teosinte populations are found in Protected Natural Areas in Mexico and Central America. Ecogeographical analysis showed that teosinte can cope with extreme levels of precipitation and temperatures during growing season. Modelling teosinte geographic distribution demonstrated congruence between actual and potential distributions; however, some areas with no occurrences appear to be within the range of adaptation of teosintes. Field surveys should be prioritized to such regions to accelerate the discovery of unknown populations. Potential areas for teosintes Zea mays ssp. mexicana races Chalco, Nobogame, and Durango, Zea mays ssp. huehuetenangensis, Zea luxurians, Zea diploperennis and Zea nicaraguensis are geographically separated; however, partial overlapping occurs between Zea mays ssp. parviglumis and Zea perennis, between Zea mays ssp. parviglumis and Zea diploperennis, and between Zea mays ssp. mexicana race Chalco and Zea mays ssp. mexicana race Central Plateau. Assessing priority of collecting for conservation showed that permanent monitoring programs and in-situ conservation projects with participation of local farmer communities are critically needed; Zea mays ssp. mexicana (races Durango and Nobogame), Zea luxurians, Zea diploperennis, Zea perennis and Zea vespertilio should be considered as the highest priority taxa. DA - 2018/2/16/ PY - 2018/2/16/ DO - 10.1371/journal.pone.0192676 VL - 13 IS - 2 SP - SN - 1932-6203 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-85042214920&partnerID=MN8TOARS ER - TY - JOUR TI - EFFECT OF DRAINAGE WATER MANAGEMENT ON NITRATE NITROGEN LOSS TO TILE DRAINS IN NORTH CAROLINA AU - Poole, C. A. AU - Skaggs, R. W. AU - Youssef, M. A. AU - Chescheir, G. M. AU - Crozier, C. R. T2 - TRANSACTIONS OF THE ASABE AB - Abstract. Short-term studies have demonstrated that drainage water management (DWM), or controlled drainage (CD), can be used to substantially reduce the loss of nitrogen (N) from drained lands for a wide range of soils, crops, locations, and climates. Long-term studies on the effects of the practice are limited. This article presents results on the effects of CD on nitrate-N (NO 3 -N) losses for three crops, corn ( L.), wheat ( L.), and soybean ( [L.] Merr.), in a two-year rotation in North Carolina. Nitrate losses were measured on replicated plots under CD and conventional, or free drainage (FD), treatments for nine years between 1992 and 2012 on a tile-drained site near Plymouth, North Carolina. The site is on a Portsmouth sandy loam soil with parallel drains 22.9 m apart and 1.15 m deep. The subsurface drainage characteristics under FD were drainage intensity (DI) = 8 mm d -1 , drainage coefficient (DC) = 14 mm d -1 , and Kirkham coefficient (KC) = 18 mm d -1 . Compared to FD, CD reduced annual drainage outflow by 33% and NO 3 -N export by 30%, with an average annual reduction of 6.3 kg ha -1 year -1 . CD increased average NO 3 -N concentrations by 0.9 mg L -1 , but the difference was not significant. The reduction in NO 3 -N export observed in the CD treatment was equal to the increase in N removed by the harvested grain. The results document the effects of CD on NO 3 -N export over a wide range of weather conditions during the nine-year study. While the average 30% reduction in NO 3 -N losses in drainage water is in the midrange of that reported by previous studies for different soils and climates, this is believed to be the first time such a reduction has been attributed to the effect of CD on increasing yields and N removed in the harvested grain. Keywords: Controlled drainage (CD), Corn, Drainage water, Drainage water management (DWM), Nitrate, Nitrogen, Soybean, Water quality, Wheat. DA - 2018/// PY - 2018/// DO - 10.13031/trans.12296 VL - 61 IS - 1 SP - 233-244 SN - 2151-0040 KW - Controlled drainage (CD) KW - Corn KW - Drainage water KW - Drainage water management (DWM) KW - Nitrate KW - Nitrogen KW - Soybean KW - Water quality KW - Wheat ER - TY - JOUR TI - Bacterial and fungal communities, fermentation, and aerobic stability of conventional hybrids and brown midrib hybrids ensiled at low moisture with or without a homo- and heterofermentative inoculant AU - Romero, J. J. AU - Joo, Y. AU - Park, J. AU - Tiezzi, F. AU - Gutierrez-Rodriguez, E. AU - Castillo, M. S. T2 - JOURNAL OF DAIRY SCIENCE AB - We evaluated the effects of adding a combination inoculant to 4 corn (Zea mays L.) hybrids harvested at low moisture on the nutritive value, fermentation profile, aerobic stability, bacterial and fungal populations, and community structure. The treatment design was the factorial combination of 4 corn hybrids ensiled with (INO) and without (CON) inoculant. The hybrids were TMF2R737 (MCN), F2F817 (MBR), P2089YHR (PCN), and PI144XR (PBR), ensiled at 44.0, 38.1, 42.0, and 41.3% of dry matter, respectively; MBR and PBR were brown midrib mutants. The inoculant contained Lactobacillus buchneri and Pediococcus pentosaceus (4 × 105 and 1 × 105 cfu/g of fresh corn). The experimental design was a complete randomized design with treatments replicated 6 times. Corn was chopped, treated or not with inoculant, packed into 7.6-L bucket silos, and stored for 100 d. At d 0, we found higher bacterial observed operational taxonomic units in the brown midrib mutants (MBR and PBR) relative to MCN and PCN (654 and 534 vs. 434 and 444 ± 15.5, respectively). The bacterial and fungal families with the highest relative abundance (RA) were Enterobacteriaceae (61.4%) and incertae sedis Tremellales (12.5%). At silo opening, we observed no effects of INO treatment on dry matter recovery (∼94.3 ± 1.07%), but aerobic stability was extended for all INO-treated hybrids (∼217 vs. ∼34.7 h), except for MBR (∼49 ± 38 h), due to a decreased yeast population (3.78 vs. 5.13 ± 0.440 log cfu/g of fresh corn) and increased acetic acid concentration (1.69 vs. 0.51 ± 0.132%) compared with the control. Furthermore, INO treatment reduced bacterial (61.2 vs. 276 ± 8.70) and increased fungal (59.8 vs. 43.6 ± 2.95) observed operational taxonomic units compared with CON. We observed that INO treatment increased the RA of Lactobacillaceae across all hybrids (∼99.1 vs. ∼58.9), and to larger extent MBR (98.3 vs. 34.3 ± 5.29), and decreased Enterobacteriaceae (0.614 vs. 23.5 ± 2.825%) among 4 other bacterial families relative to CON. For fungi, INO treatment increased the RA of Debaryomycetaceae (63.1 vs. 17.3 ± 8.55) and 5 other fungal families and decreased the RA of Pichiaceae (6.47 vs. 47.3 ± 10.95) and incertae sedis Saccharomycetales (8.47 vs. 25.9 ± 5.748) compared with CON. The bacterial and fungal community structures changed, due to ensiling, to a distinct and more stable community dominated by Lactobacillaceae and Debaryomycetaceae, respectively, when INO treatment was applied relative to CON. In conclusion, the INO treatment used in this study improved low-moisture whole-crop corn silage quality because of a shift in the bacterial and fungal community composition during ensiling. DA - 2018/4// PY - 2018/4// DO - 10.3168/jds.2017-13754 VL - 101 IS - 4 SP - 3057-3076 SN - 1525-3198 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-85041241637&partnerID=MN8TOARS KW - silage KW - inoculant KW - hybrid KW - next-generation sequencing ER - TY - JOUR TI - Application of monitoring to inform policy and programs and achieve water quality goals AU - Duriancik, Lisa F. AU - Flahive, Katie AU - Osmond, Deanna T2 - JOURNAL OF SOIL AND WATER CONSERVATION AB - Water quality monitoring is used throughout the world to assess the quality of water resources. Data and analyses from assessments can be used to inform policy as well as program design, delivery approaches, practice design, and adaptive management to enhance outcomes. Many of these assessments have demonstrated problems associated with nutrient enrichment and sedimentation of water resources (Chapman 1996; Dubrovsky and Hamilton 2010; Scott and Gemmell 2013). Not surprisingly, because of its land area and necessary inputs to support food production services, agriculture can be a major source of nutrients and sediment (USEPA 2008), contributing to the impairment of water resources across the globe. Key water quality monitoring programs to document large-scale water quality status or trends exist. These are useful for tracking changes in water resource condition and trends over time in basins or large water bodies, but are often not fine enough resolution alone to attribute effects to specific actions or understand the processes occurring or being influenced by management. DA - 2018/// PY - 2018/// DO - 10.2489/jswc.73.1.11a VL - 73 IS - 1 SP - 11A-15A SN - 1941-3300 ER - TY - JOUR TI - A SNP-based high-density linkage map of zoysiagrass (Zoysia japonica Steud.) and its use for the identification of QTL associated with winter hardiness AU - McCamy, H. AU - Holloway, P. AU - Yu, Xingwang AU - Dunne, Jeffrey C. AU - Schwartz, Brian M. AU - Patton, Aaron J. AU - Arellano, Consuelo AU - Milla-Lewis, Susana R. T2 - MOLECULAR BREEDING DA - 2018/1// PY - 2018/1// DO - 10.1007/s11032-017-0763-0 VL - 38 IS - 1 SP - SN - 1572-9788 KW - Freeze tolerance KW - Genetic map KW - QTL KW - SNP KW - Winter survival KW - Zoysiagrass ER - TY - JOUR TI - Yield and Nitrogen Removal of Bioenergy Grasses as Influenced by Nitrogen Rate and Harvest Management in the Coastal Plain Region of North Carolina AU - Wang, Zan AU - Jot Smyth, T. AU - Crozier, Carl R. AU - Gehl, Ronald J. AU - Heitman, Adam J. T2 - BioEnergy Research DA - 2018/3// PY - 2018/3// DO - 10.1007/s12155-017-9876-x VL - 11 IS - 1 SP - 44–53 SN - 1939-1234 1939-1242 UR - http://dx.doi.org/10.1007/S12155-017-9876-X KW - Biomass yield KW - Harvest frequency KW - Switchgrass KW - Miscanthus ER - TY - JOUR TI - The impact of relative individual ecosystem demand on stacking ecosystem credit markets AU - Motallebi, Marzieh AU - Hoag, Dana L. AU - Tasdighi, Ali AU - Arabi, Mazdak AU - Osmond, Deanna L. AU - Boone, Randall B. T2 - ECOSYSTEM SERVICES AB - A blended actual and hypothetical vertical ecosystem services stacking scenario is developed for a water quality trading (WQT) program in North Carolina. Demand is estimated for total nitrogen reduction and simulated for total phosphorous reduction. Nitrogen and phosphorus are complementary pollutants jointly produced by a single conservation practice, riparian buffers. The supply of reduction is based on the amount of riparian buffers that would be implemented by farmers at a given offering price for WQT credits. Nitrogen reduction is the primary ecosystem service that already has a market in the form of a WQT program. Phosphorus reduction is a hypothetical, secondary ecosystem service that we introduce to evaluate ecosystem stacking. We specifically evaluate stacking in thin markets, where there are few buyers and/or sellers. Our detailed analysis shows that the relative size of demand for different services plays a profound role in the success of stacking when markets are thin; and many if not most ecosystem markets are thin. A secondary service with relatively low demand will either be too small (insufficient) to generate any new credits, or, in a non-competitive market with few sellers, produce no additionality of the secondary service (double dipping). In these two cases, sponsors of the secondary market should not make payments since they will receive no additional benefits above what would have been achieved under conservation practices implemented for the primary ecosystem service. We find that ecosystem stacking is most likely to generate more revenue to producers and to reduce pollution emissions when demand for the secondary service is comparable in magnitude to the primary service. Accurate assessment of relative demand can help policy makers determine where stacking might work, and help purchasers avoid paying for services without results, especially where markets are thin. DA - 2018/2// PY - 2018/2// DO - 10.1016/j.ecoser.2017.12.010 VL - 29 SP - 137-144 SN - 2212-0416 KW - Additionality KW - Credit stacking KW - Double dipping KW - Riparian buffers KW - Water quality trading KW - Jordan Lake Watershed ER - TY - JOUR TI - Periphyton and abiotic factors influencing arsenic speciation in aquatic environments AU - Lopez, Adeline R. AU - Silva, Silmara Costa AU - Webb, Samuel M. AU - Hesterberg, Dean AU - Buchwalter, David B. T2 - ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY AB - Abstract Benthic periphytic biofilms are important food sources at the base of aquatic ecosystems. These biofilms also sit at the interface of oxic waters and hypoxic sediments, and can be influenced by or influence trace element speciation. In the present study, we compared arsenic (As) enrichment in periphyton exposed to arsenate (As[V]) or arsenite (As[III]) (20 μg/L, static renewal, 7 d), and we found similar accumulation patterns of total As (101 ± 27 and 88 ± 22 mg kg −1 dry wt, respectively). Periphyton As was 6281‐ and 6684‐fold higher than their aqueous exposures and occurred primarily as As(V). When these biofilms were fed to larval mayflies, similar total As tissue concentrations (13.9 and 14.6 mg kg −1 dry wt, respectively) were observed, revealing significant biodilution (∼ 10% of their dietary concentrations). Finally, we investigated the influence of aeration and periphyton presence on As speciation in solutions and solid phases treated with As(III). Predominantly As(III) solutions were slowly oxidized over a 7‐d time period, in the absence of periphyton, and aeration did not strongly affect oxidation rates. However, in the presence of periphyton, solution and solid‐phase analyses (by microscale x‐ray absorption spectroscopy) showed rapid As(III) oxidation to As(V) and an increasing proportion of organo‐As forming over time. Thus periphyton plays several roles in As environmental behavior: 1) decreasing total dissolved As concentrations via abiotic and biotic accumulation, 2) rapidly oxidizing As(III) to As(V), 3) effluxing organo‐As forms into solution, and 4) limiting trophic transfer to aquatic grazers. Environ Toxicol Chem 2018;37:903–913. © 2017 SETAC DA - 2018/3// PY - 2018/3// DO - 10.1002/etc.4025 VL - 37 IS - 3 SP - 903-913 SN - 1552-8618 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-85039735474&partnerID=MN8TOARS KW - Abiotic transformation KW - Aquatic plants KW - Bioconcentration KW - Biotransformation KW - Metal speciation KW - Arsenic ER - TY - JOUR TI - Mapping Late Leaf Spot Resistance in Peanut (Arachis hypogaea) Using QTL-seq Reveals Markers for Marker-Assisted Selection AU - Clevenger, Josh AU - Chu, Ye AU - Chavarro, Carolina AU - Botton, Stephanie AU - Culbreath, Albert AU - Isleib, Thomas G. AU - Holbrook, C. C. AU - Ozias-Akins, Peggy T2 - FRONTIERS IN PLANT SCIENCE AB - Late leaf spot (Cercosporidium personatum) is a major fungal disease of cultivated peanut (Arachis hypogaea). A recombinant inbred line (RIL) population segregating for quantitative field resistance was used to identify quantitative trait loci (QTL) using QTL-seq. High rates of false positive SNP calls using established methods in this allotetraploid crop obscured significant QTL. To resolve this problem, robust parental SNPs were first identified using polyploid-specific SNP identification pipelines, leading to discovery of significant QTL for late leaf spot resistance. These QTL were confirmed over four years of field data. Selection with markers linked to these QTL resulted in a significant increase in resistance, showing that these markers can be immediately applied in breeding programs. This study demonstrates that QTL-seq can be used to rapidly identify QTLs controlling highly quantitative traits in polyploid crops with complex genomes. Markers identified can then be deployed in breeding programs, increasing the efficiency of selection using molecular tools. DA - 2018/2/5/ PY - 2018/2/5/ DO - 10.3389/fpls.2018.00083 VL - 9 SP - SN - 1664-462X KW - Arachis KW - QTL-seq KW - late leaf spot KW - polyploidy KW - resistance ER - TY - JOUR TI - In-row Vegetation-free Strip Width Effect on Established 'Navaho' Blackberry AU - Basinger, Nicholas T. AU - Jennings, Katherine M. AU - Monks, David W. AU - Mitchem, Wayne E. AU - Perkins-Veazie, Penelope M. AU - Chaudhari, Sushila T2 - WEED TECHNOLOGY AB - Abstract A field study was conducted in 2014 and 2015 in an established 5-yr old commercial blackberry planting to determine the effect of vegetation-free strip width (VFSW) on ‘Navaho’ blackberry vegetative growth, yield and fruit quality parameters, identify the optimum VFSW for blackberry plantings in the southeastern USA, and provide practical groundcover management recommendations that can increase the productivity of blackberry plantings. In Fall 2013, tall fescue was seeded in-row and allowed to establish. In Spring 2014, VFSW treatments (0, 0.6, 0.9, 1.2, and 1.8 m) were established in a randomized complete block statistical design with four replications. Blackberry growth measurements included primocane and floricane number, cane diam, individual fruit weight and yield. Fruit quality measurements included, soluble solids concentration (SSC), titratable acidity (TA) and pH. Primocane number increased with increasing VFSW in both years. Floricane number increased with increasing VFSW in 2014. Primocane diam decreased with increasing VFSW in 2014 but had a quadratic response in 2015. Berry weight and cumulative yield increased with increasing VFSW in both years. The only berry quality component affected by VFSW was pH, which decreased as VFSW increased. Results indicate that widening the VFSW in blackberry from the current recommendation of 1.2 m to 1.8 m could provide growers a means to increase plant growth, berry weight, and cumulative yield blackberry of a planting. DA - 2018/// PY - 2018/// DO - 10.1017/wet.2017.85 VL - 32 IS - 1 SP - 85-89 SN - 1550-2740 KW - Cover crop KW - groundcover KW - herbicide strip KW - orchard floor management weed interference ER - TY - JOUR TI - Implications of cereal rye/crimson clover management for conventional and organic cotton producers AU - Vann, R.A. AU - Reberg-Horton, S.C. AU - Edmisten, K.L. AU - York, A.C. T2 - Agronomy Journal AB - Core Ideas Cereal rye/crimson clover cover crop mixtures can be used for weed suppression and soil moisture conservation in cotton production. Cover crop management at cotton planting can influence cotton emergence, weed suppression, and soil moisture dynamics. Cotton emergence declined when cotton was planted directly into standing cover crop and without row cleaners engaged, but this reduction did not affect cotton lint yield. Soil temperature was reduced and soil moisture was increased by the presence of a cover crop mulch regardless of cover crop residue management strategy at cotton planting. Cover crop residue management did not affect cotton lint yield when herbicides were used, indicating that conventional producers have flexibility in terminating cover crops and residue management at cotton planting. Cover crop residue management can affect performance of the subsequent crop. This experiment was conducted in five environments in North Carolina from 2014 to 2016 to determine the effect of a cereal rye ( Secale cereale )/crimson clover ( Trifolium incarnatum) mulch on cotton ( Gossypium hirsutum L.) emergence, soil temperature, soil moisture, weed suppression, and cotton yield under a conventional and organic weed control context. The cereal rye and crimson clover mixture was planted in mid‐October and terminated 1 wk prior to cotton planting using a roller‐crimper or herbicide application. Cover crop residue management included fertilized, rolled cover crop with row cleaners engaged at planting (Roll+F+RC), rolled cover crop with row cleaners engaged at planting (Roll+RC), rolled cover crop (Roll), standing cover crop with row cleaners engaged at planting (Stand+RC), and no cover crop (BARE). Weed treatments included with and without herbicides. Cover crop dry biomass ranged from 3820 to 6610 kg ha −1 across environments. Fertilizing the cover crop enhanced cover crop dry biomass production by 250 to 1860 kg ha −1 . Cotton emergence declined when cotton was planted directly into standing cover crop and without row cleaners engaged. Soil temperature was reduced and soil moisture was increased by the presence of a cover crop. Cover crop residue management did not affect late‐season weed biomass at four of the five environments. Cover crop residue management did not affect cotton lint yield when herbicides were used, indicating that conventional producers have flexibility in terminating cover crops and residue management at cotton planting. DA - 2018/// PY - 2018/// DO - 10.2134/agronj2017.06.0246 VL - 110 IS - 2 SP - 621–631 SN - 1435-0645 ER - TY - JOUR TI - Identification of Soybean Host Plant Resistance to Brown Marmorated Stink Bugs in Maturity Group III Plant Introductions AU - La Mantia, Jonathan M. AU - Mian, M. A. Rouf AU - Redinbaugh, Margaret G. T2 - JOURNAL OF ECONOMIC ENTOMOLOGY AB - Halyomorpha halys (Stål; Hemiptera: Pentatomidae), brown marmorated stink bug (BMSB), is a polyphagous nonnative insect first found in the United States in 1996. As of 2017, BMSB has been detected in 43 states and is a severe agricultural pest in mid-Atlantic states. On soybean, Glycine max (L.) Merr (Fabales: Fabaceae), damage from BMSB infestation ranges from puncture marks with seed discoloration and deformities to seed and pod abortion. Host plant resistance has been used for managing pest populations and mitigating soybean yield losses caused by neotropical stink bugs (Eushistus heros, Nezara viridula, and Piezodorus guildinii) in Brazil and on the U.S. Gulf Coast. We evaluated maturity group III plant introductions (PIs) for resistance to BMSB damage. In 2014, field cage choice tests of 106 PIs revealed a range of both BMSB damage incidence and severity. In field choice tests, PIs 085665 and 097139 showed the lowest incidence of BMSB damage and seed weight loss due to BMSB, while PIs 243532, 243540, and 567252 had the highest. In whole plant no-choice tests, PIs 085665 and 097139 also had high levels of resistance. However, PI 085665 had a higher incidence of damage but lower seed weight loss than PI 097139, which may suggest bimodal resistance. Moreover, PIs 085665 and 097139 are from Japan and North Korea, respectively, two geographically isolated countries where BMSB is native. Thus, further characterization of host plant resistance to BMSB in each of these lines may elucidate distinct mechanisms that could be synergistic if stacked in breeding lines. DA - 2018/2// PY - 2018/2// DO - 10.1093/jee/tox295 VL - 111 IS - 1 SP - 428-434 SN - 1938-291X KW - soybeans KW - host plant resistance KW - stink bug KW - Halyomorpha KW - halys ER - TY - JOUR TI - Genome-Wide Analysis of Grain Yield Stability and Environmental Interactions in a Multiparental Soybean Population AU - Xavier, Alencar AU - Jarquin, Diego AU - Howard, Reka AU - Ramasubramanian, Vishnu AU - Specht, James E. AU - Graef, George L. AU - Beavis, William D. AU - Diers, Brian W. AU - Song, Qijian AU - Cregan, Perry B. AU - Nelson, Randall AU - Mian, Rouf AU - Shannon, J. Grover AU - McHale, Leah AU - Wang, Dechun AU - Schapaugh, William AU - Lorenz, Aaron J. AU - Xu, Shizhong AU - Muir, William M. AU - Rainey, Katy M. T2 - G3-GENES GENOMES GENETICS AB - Abstract Genetic improvement toward optimized and stable agronomic performance of soybean genotypes is desirable for food security. Understanding how genotypes perform in different environmental conditions helps breeders develop sustainable cultivars adapted to target regions. Complex traits of importance are known to be controlled by a large number of genomic regions with small effects whose magnitude and direction are modulated by environmental factors. Knowledge of the constraints and undesirable effects resulting from genotype by environmental interactions is a key objective in improving selection procedures in soybean breeding programs. In this study, the genetic basis of soybean grain yield responsiveness to environmental factors was examined in a large soybean nested association population. For this, a genome-wide association to performance stability estimates generated from a Finlay-Wilkinson analysis and the inclusion of the interaction between marker genotypes and environmental factors was implemented. Genomic footprints were investigated by analysis and meta-analysis using a recently published multiparent model. Results indicated that specific soybean genomic regions were associated with stability, and that multiplicative interactions were present between environments and genetic background. Seven genomic regions in six chromosomes were identified as being associated with genotype-by-environment interactions. This study provides insight into genomic assisted breeding aimed at achieving a more stable agronomic performance of soybean, and documented opportunities to exploit genomic regions that were specifically associated with interactions involving environments and subpopulations. DA - 2018/2// PY - 2018/2// DO - 10.1534/g3.117.300300 VL - 8 IS - 2 SP - 519-529 SN - 2160-1836 KW - Finlay-Wilkinson index KW - GGE KW - association mapping KW - meta-analysis KW - SoyNAM KW - Multiparent Advanced Generation Inter-Cross (MAGIC) KW - multiparental populations KW - MPP ER - TY - JOUR TI - Expression of Drought-Tolerant N-2 Fixation in Heterogeneous Inbred Families derived from PI471938 and Hutcheson Soybean AU - Riar, Mandeep K. AU - Cerezini, Paula AU - Manandhar, Anju AU - Sinclair, Thomas R. AU - Li, Zenglu AU - Carter, Thomas E. T2 - CROP SCIENCE AB - ABSTRACT Nitrogen fixation of soybean [ Glycine max (L.) Merr.] is particularly vulnerable to drought, since, in most genotypes, N 2 fixation activity decreases very early in the soil drying cycle. Although a few soybean genotypes, including ‘PI 471938’, have been identified that express N 2 fixation tolerance of drought, it is unknown how readily this trait is transferred to progeny. Unfortunately, the techniques used to phenotype for the tolerance trait are either too crude or too labor‐intensive to allow the acquisition of data required for a classical inheritance assessment. In this study, a heterogeneous inbred family (HIF) population derived from PI 471938 × ‘Hutcheson’ was studied for its N 2 fixation drought tolerance to obtain a preliminary indication of the expression of this trait in progeny genotypes. An in situ flow‐through acetylene reduction assay was used to track the N 2 fixation rates of 13 HIFs over dry‐down periods lasting about 2 wk. There was a distinct segregation among the HIFs, with nine exhibiting tolerance equivalent to PI 471938 and four exhibiting sensitivity equal to or greater than Hutcheson. These results indicate that N 2 fixation drought tolerance might be transferred to progeny lines fairly readily, or at least retained in a selected population such as these HIFs. DA - 2018/// PY - 2018/// DO - 10.2135/cropsci2017.02.0089 VL - 58 IS - 1 SP - 364-369 SN - 1435-0653 ER - TY - JOUR TI - Diagnostic Markers for Vernalization and Photoperiod Loci Improve Genomic Selection for Grain Yield and Spectral Reflectance in Wheat AU - Mason, R. Esten AU - Addison, Christopher K. AU - Babar, Ali AU - Acuna, Andrea AU - Lozada, Dennis AU - Subramanian, Nithya AU - Arguello, Maria Nelly AU - Miller, Randall G. AU - Brown-Guedira, Gina AU - Guedira, Mohammed AU - Johnson, Jerry T2 - CROP SCIENCE AB - ABSTRACT The objective of this study was to identify quantitative trait loci (QTL) associated with normalized difference vegetation index (NDVI) measured across different growth stages in a wheat ( Triticum aestivum L.) recombinant inbred line (RIL) population and to determine the predictability of NDVI and grain yield (GY) using a genomic selection (GS) approach. The RILs were grown over three seasons in 12 total site‐years and NDVI was measured in seven site‐years. Measurements of NDVI from tillering to physiological maturity showed low to moderate heritability ( h 2 = 0.06–0.68). Positive correlations were observed among NDVI, GY, and biomass, particularly in low‐yielding site‐years. Quantitative trait loci analysis found 18 genomic regions associated with NDVI, with most pleiotropic across multiple growth stages. The QTL were detected near markers for Ppd‐B1 , Ppd‐D1 , vrn‐A1 , and vrn‐B1 , with Ppd‐D1 having the largest effect. Multiple QTL models showed that epistatic interactions between Ppd and Vrn loci also significantly influenced NDVI. Genomic selection accuracy ranged from r = −0.10 to 0.54 for NDVI across growth stages. However, the inclusion of Vrn and Ppd loci as fixed effect covariates increased GS accuracy for NDVI and GY in site‐year groupings with the lowest heritability. The highest accuracy for GY ( r = 0.58–0.59) was observed in the site‐year grouping with the highest heritability ( h 2 = 0.85). Overall, these results will aid in future selection of optimal plant growth for target environments using both phenotypic and GS approaches. DA - 2018/// PY - 2018/// DO - 10.2135/cropsci2017.06.0348 VL - 58 IS - 1 SP - 242-252 SN - 1435-0653 ER - TY - JOUR TI - Defining the Role of the MADS-Box Gene, Zea Agamous-like1, a Target of Selection During Maize Domestication AU - Wills, David M. AU - Fang, Zhou AU - York, Alessandra M. AU - Holland, James B. AU - Doebley, John F. T2 - JOURNAL OF HEREDITY AB - Abstract Genomic scans for genes that show the signature of past selection have been widely applied to a number of species and have identified a large number of selection candidate genes. In cultivated maize (Zea mays ssp. mays) selection scans have identified several hundred candidate domestication genes by comparing nucleotide diversity and differentiation between maize and its progenitor, teosinte (Z. mays ssp. parviglumis). One of these is a gene called zea agamous-like1 (zagl1), a MADS-box transcription factor, that is known for its function in the control of flowering time. To determine the trait(s) controlled by zagl1 that was (were) the target(s) of selection during maize domestication, we created a set of recombinant chromosome isogenic lines that differ for the maize versus teosinte alleles of zagl1 and which carry cross-overs between zagl1 and its neighbor genes. These lines were grown in a randomized trial and scored for flowering time and domestication related traits. The results indicated that the maize versus teosinte alleles of zagl1 affect flowering time as expected, as well as multiple traits related to ear size with the maize allele conferring larger ears with more kernels. Our results suggest that zagl1 may have been under selection during domestication to increase the size of the maize ear. DA - 2018/5// PY - 2018/5// DO - 10.1093/jhered/esx073 VL - 109 IS - 3 SP - 333-338 SN - 1465-7333 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-85044226393&partnerID=MN8TOARS KW - flowering time KW - kernel row number KW - selection scan ER - TY - JOUR TI - Characterization of Phytophthora nicotianae Resistance Conferred by the Introgressed Nicotiana rustica Region, Wz, in Flue-Cured Tobacco AU - McCorkle, Kestrel L. AU - Drake-Stowe, Katherine AU - Lewis, Ramsey S. AU - Shew, David T2 - PLANT DISEASE AB - Black shank, caused by Phytophthora nicotianae, is one of the most important diseases affecting tobacco worldwide and is primarily managed through use of host resistance. An additional source of resistance to P. nicotianae, designated as Wz, has been introgressed into Nicotiana tabacum from N. rustica. The Wz gene region confers high levels of resistance to all races, but has not been characterized. Our study found Wz-mediated resistance is most highly expressed in the roots, with only a slight reduction in stem-lesion size in Wz genotypes compared with susceptible controls. No substantial relationships were observed between initial inoculum levels and disease development on Wz genotypes, which is generally consistent with qualitative or complete resistance. Isolates of P. nicotianae adapted for five host generations on plants with the Wz gene caused higher disease severity than isolates adapted on Wz plants for only one host generation. Wz-adapted isolates did not exhibit increased aggressiveness on genotypes with other sources of partial resistance, suggesting pathogen adaptation was specific to the Wz gene. To reduce potential for pathogen population shifts with virulence on Wz genotypes, Wz should be combined with other resistance sources and rotation of varying black shank resistance mechanisms is also recommended. DA - 2018/2// PY - 2018/2// DO - 10.1094/pdis-03-17-0339-re VL - 102 IS - 2 SP - 309-317 SN - 1943-7692 ER - TY - JOUR TI - Strengths and Limitations of Nitrogen Rate Recommendations for Corn and Opportunities for Improvement AU - Morris, Thomas F. AU - Murrell, T. Scott AU - Beegle, Douglas B. AU - Camberato, James J. AU - Ferguson, Richard B. AU - Grove, John AU - Ketterings, Quirine AU - Kyveryga, Peter M. AU - Laboski, Carrie A. M. AU - McGrath, Joshua M. AU - Meisinger, John J. AU - Melkonian, Jeff AU - Moebius-Clune, Bianca N. AU - Nafziger, Emerson D. AU - Osmond, Deanna AU - Sawyer, John E. AU - Scharf, Peter C. AU - Smith, Walter AU - Spargo, John T. AU - Es, Harold M. AU - Yang, Haishun T2 - AGRONOMY JOURNAL AB - Core Ideas Nitrogen recommendations for individual corn fields are less accurate than desired. Nitrogen recommendations need improvement for economic and environmental reasons. A review of fundamental concepts will improve understanding about N recommendations. Examination of N recommendation systems, tests, and models will improve recommendations. Nitrogen fixation by the Haber–Bosch process has more than doubled the amount of fixed N on Earth, significantly influencing the global N cycle. Much of this fixed N is made into N fertilizer that is used to produce nearly half of the world's food. Too much of the N fertilizer pollutes air and water when it is lost from agroecosystems through volatilization, denitrification, leaching, and runoff. Most of the N fertilizer used in the United States is applied to corn ( Zea mays L.), and the profitability and environmental footprint of corn production is directly tied to N fertilizer applications. Accurately predicting the amount of N needed by corn, however, has proven to be challenging because of the effects of rainfall, temperature, and interactions with soil properties on the N cycle. For this reason, improving N recommendations is critical for profitable corn production and for reducing N losses to the environment. The objectives of this paper were to review current methods for estimating N needs of corn by: (i) reviewing fundamental background information about how N recommendations are created; (ii) evaluating the performance, strengths, and limitations of systems and tools used for making N fertilizer recommendations; (iii) discussing how adaptive management principles and methods can improve recommendations; and (iv) providing a framework for improving N fertilizer rate recommendations. DA - 2018/// PY - 2018/// DO - 10.2134/agronj2017.02.0112 VL - 110 IS - 1 SP - 1-37 SN - 1435-0645 ER - TY - JOUR TI - Color, Transfer, and Application Parameters of Turfgrass Colorants AU - Pinnix, Garland D. AU - Miller, Grady L. AU - Bowman, Daniel C. AU - Grabow, Garry L. T2 - AGRONOMY JOURNAL AB - Core Ideas Turf colorants can be used as an alternative to winter overseeding, therefore saving turf managers resources. Multidimensional scaling analysis can be used to separate turf colorants into groups, allowing turf managers to better select products based on color parameters. Turf colorant transfer varies greatly among products and can result in severe staining. Turfgrass colorants are primarily used as an alternative to winter overseeding. Information on colorants is limited in the scientific literature. The primary objective of this field study was to evaluate the effect turfgrass colorants had on color parameters (colorant intensity, color, and hue angle) of dormant bermudagrass ( Cynodon sp.). Secondary objectives were to examine colorant transfer (wipe off) from the turfgrass surface to an absorbent material and to measure product viscosities. Twenty‐five colorants were applied at two spray volumes (75 and 112 mL m –2 ) on dormant bermudagrass at two heights of cut (0.3 and 1.5 cm). Multidimensional scaling and cluster analysis were used to separate colorants based on measured color parameters. Group 1 colorants maintained colorant intensity the longest, but colorant color was reduced at application due to the appearance of bright blue (e.g., Munsell 5BG/6/6) and bright green (e.g., Munsell 7.5GY/7/10) colors. Group 2 colorants provided the darkest green (e.g., Munsell 5GY/4/4) color, while Group 3 colorants provided minimal color change of dormant turfgrass. Among the Group 2 colorants, Green Lawnger, Lesco Green, Ultradwarf Super, Southwest Green, and Endurant provided a natural green color. Measurements of colorant transfer showed that Blue, Regreen, SprayMax, Green Dye Turf, Titan Green Turf, Solarogen, and Endurant have the highest propensity to disassociate from treated turfgrass. The use of multidimensional scaling and cluster analysis provided new information regarding a number of turf colorants. Grouping products by measured parameters indicated that products within Group 2 provided superior performance. DA - 2018/// PY - 2018/// DO - 10.2134/agronj2017.03.0164 VL - 110 IS - 1 SP - 66-76 SN - 1435-0645 ER -