TY - JOUR TI - Heat waves imposed during early pod development in soybean (Glycine max) cause significant yield loss despite a rapid recovery from oxidative stress AU - Siebers, Matthew H. AU - Yendrek, Craig R. AU - Drag, David AU - Locke, Anna M. AU - Rios Acosta, Lorena AU - Leakey, Andrew D. B. AU - Ainsworth, Elizabeth A. AU - Bernacchi, Carl J. AU - Ort, Donald R. T2 - Global Change Biology AB - Abstract Heat waves already have a large impact on crops and are predicted to become more intense and more frequent in the future. In this study, heat waves were imposed on soybean using infrared heating technology in a fully open‐air field experiment. Five separate heat waves were applied to field‐grown soybean ( Glycine max ) in central Illinois, three in 2010 and two in 2011. Thirty years of historical weather data from Illinois were analyzed to determine the length and intensity of a regionally realistic heat wave resulting in experimental heat wave treatments during which day and night canopy temperatures were elevated 6 °C above ambient for 3 days. Heat waves were applied during early or late reproductive stages to determine whether and when heat waves had an impact on carbon metabolism and seed yield. By the third day of each heat wave, net photosynthesis ( A ), specific leaf weight ( SLW ), and leaf total nonstructural carbohydrate concentration ( TNC ) were decreased, while leaf oxidative stress was increased. However, A , SLW , TNC , and measures of oxidative stress were no different than the control ca. 12 h after the heat waves ended, indicating rapid physiological recovery from the high‐temperature stress. That end of season seed yield was reduced (~10%) only when heat waves were applied during early pod developmental stages indicates the yield loss had more to do with direct impacts of the heat waves on reproductive process than on photosynthesis. Soybean was unable to mitigate yield loss after heat waves given during late reproductive stages. This study shows that short high‐temperature stress events that reduce photosynthesis and increase oxidative stress resulted in significant losses to soybean production in the Midwest, U.S. The study also suggests that to mitigate heat wave‐induced yield loss, soybean needs improved reproductive and photosynthetic tolerance to high but increasingly common temperatures. DA - 2015/5/19/ PY - 2015/5/19/ DO - 10.1111/gcb.12935 VL - 21 IS - 8 SP - 3114-3125 J2 - Global Change Biology LA - en OP - SN - 1354-1013 1365-2486 UR - http://dx.doi.org/10.1111/gcb.12935 DB - Crossref ER - TY - JOUR TI - Phosphorus fractions and organic matter chemistry under different land use on Humic Cambisols in Southern Brazil AU - De Oliveira, C.M.B. AU - Erich, M.S. AU - Gatiboni, L.C. AU - Ohno, T. T2 - Geoderma Regional AB - The Araucaria moist forest was once widespread in southern Atlantic Brazil but today, due to agriculture and timber harvesting, only remnants remain, mainly in mountainous regions of southern Brazil. This study combines Hedley sequential extraction to determine phosphorus (P) fractionation with 31P NMR, fluorescence spectroscopy, and ESI-FT-ICR-MS to examine soil P and organic matter chemistry at five different Araucaria moist forest sites, including two natural sites, grassland and native forest, and three altered sites, two apple orchard sites (fertilized apple rows and unfertilized soil between apple rows) and a pine plantation site without fertilization. This study examined how land use change has altered soil chemistry compared to native vegetation, focusing specifically on P and C fractions. Although the native grassland site contained the highest amount of soil C, the sites were similar in total P. The largest extractable fraction at all sites was NaOH-extractable organic P (Po), and the quantity of Po (0.1 M plus 0.5 M extractions) did not differ significantly among the soils. The 31P NMR analysis revealed that the majority of NaOH-extractable P was present as either inorganic P (Pi) orthophosphate (49%) or Po monoesters (34%). Pi orthophosphate was highest in pine plantation and apple orchard in the row sites (66 and 67% of P detected, respectively) and lowest in native grassland (20% of P detected), while Po was highest in the native grassland soil (75% of P detected). In our samples ~ 1% or fewer of labile C compounds contained P, while 5–6% of adsorbed C compounds contained both N and P. Using 31P NMR and ESI-FT-ICR-MS approaches, we found evidence of chemical changes in native soil P and organic matter due to land use change, specifically loss of organic forms of P and increased organic matter aromaticity in apple soils compared to native soils. This research shows that the conversion of native grasslands to apple orchards led to a decrease in organic matter quality and Po depletion while conversion to pine plantations has a low impact on these parameters. These analytical techniques are promising approaches to improving our understanding of both P and C chemistry and the effects of land use changes on coupled biogeochemical cycles. DA - 2015/// PY - 2015/// DO - 10.1016/j.geodrs.2015.06.001 VL - 5 SP - 140-149 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-84933510755&partnerID=MN8TOARS ER - TY - JOUR TI - Phosphorus availability and microbial immobilization in a Nitisol with the application of mineral and organo-mineral fertilizers AU - Morais, F.A. AU - Gatiboni, L.C. T2 - Anais da Academia Brasileira de Ciencias AB - The aim of this study was to evaluate P availability, P and C contained in the microbial biomass, and enzymatic activity (acid phosphatases and β-glucosidases) in a Nitisol with the application of mineral and organo-mineral fertilizers. The experiment was performed in a protected environment with control over air temperature and soil moisture. The experimental design was organized in a "5 x 4" factorial arrangement with five sources of P and four times of soil incubation. The sources were: control (without P), triple superphosphate, diammonium phosphate, natural Arad reactive rock phosphate, and organo-mineral fertilizer. The experimental units consisted of PVC columns filled with agricultural soil. The columns were incubated and broken down for analysis at 1, 20, 40, and 60 days after application of the fertilizers. In each column, samples were taken at the layers of 0-2.5, 2.5-5.0, and 5.0-15.0 cm below the zone of the fertilizers. The application of soluble phosphates and organo-mineral fertilizer temporarily increased P availability in the zone near the fertilizers (0-2.5 cm), with maximum availability occurring at approximately 32 days. Microbial immobilization showed behavior similar to P availability, and the greatest immobilizations occurred at approximately 30 days. The organo-mineral fertilizer was not different from soluble phosphates. DA - 2015/// PY - 2015/// DO - 10.1590/0001-3765201520140008 VL - 87 IS - 4 SP - 2289-2299 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-84949942986&partnerID=MN8TOARS ER - TY - JOUR TI - Mineralization and nitrification of nitrogen from poultry litter applied to soil,Mineralização e nitrificação do nitrogênio proveniente da cama de aves aplicada ao solo AU - Rogeri, D.A. AU - Ernani, P.R. AU - Louren?o, K.S. AU - Cassol, P.C. AU - Gatiboni, L.C. T2 - Revista Brasileira de Engenharia Agricola e Ambiental AB - RESUMO A eficiência fertilizante da cama de aves depende da capacidade de mineralização de seus nutrientes que se encontram na forma orgânica. O potencial poluente deste resíduo, por outro lado, depende, dentre outros fatores, da rapidez da nitrificação dos compostos nitrogenados. O presente estudo objetivou quantificar a mineralização líquida e a nitrificação do N presente na cama de aves após sua aplicação em um Cambissolo Húmico álico. Os tratamentos consistiram na incubação com o solo de doses de cama (equivalente a 0; 4; 8; 16 Mg ha-1) e uma dose de ureia (204 kg ha-1 de N), todas incorporadas ou aplicadas sobre a superfície do solo. Determinaram-se os teores de amônio e nitrato no solo aos 2, 6, 12, 19, 26, 32 e 48 dias após o início da incubação. Os teores de amônio diminuíram e os de nitrato aumentaram com o tempo de incubação em função do processo de nitrificação; esta conversão foi mais rápida quando a cama de aves foi incorporada ao solo em relação à aplicação na superfície. A recuperação do N da cama de aves na forma mineral foi pequena, independentemente da forma de aplicação ao solo, com valores que decresceram em função da dose de 22,0 para 15,7% para as doses 4 e 16 Mg ha-1, respectivamente, aos 48 dias de incubação. DA - 2015/// PY - 2015/// DO - 10.1590/1807-1929/agriambi.v19n6p534-540 VL - 19 IS - 6 SP - 534-540 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-84931337591&partnerID=MN8TOARS ER - TY - JOUR TI - Relative efficiency of rock phosphates in fertilization of planting seedlings eucalyptus dunnii maiden and eucalyptus benthamii maiden etcambagem in soil with and without liming,EficiÊncia relativa de fosfatos naturais na adubaÇÃo de plantio de mudas de eucalyptus dunnii maiden e eucalyptus benthamii maiden etcambagem em solo sem e com calagem AU - Dias, L.P.R. AU - Gatiboni, L.C. AU - Brunetto, G. AU - Simonete, M.A. AU - Bicaratto, B. T2 - Ciencia Florestal DA - 2015/// PY - 2015/// VL - 25 IS - 1 SP - 37-48 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-84926443556&partnerID=MN8TOARS ER - TY - JOUR TI - Loss of soil nitrogen and peach yield with the addition of organic compost,Perdas de nitrogênio do solo e resposta do pessegueiro à adição de composto orgânico AU - Sete, P.B. AU - De Melo, G.W.B. AU - Oliveira, B.S. AU - Freitas, R.F. AU - Dal Magro, R. AU - Ambrosini, V.G. AU - Trapp, T. AU - Comin, J.J. AU - Gatiboni, L.C. AU - Brunetto, G. T2 - Ciencia Rural AB - A aplicação de composto orgânico no solo pode incrementar a produção de pêssego, porém parte do N pode ser perdido por lixiviação e volatilização. O trabalho objetivou avaliar o estado nutricional das plantas, a produção de pêssego, a lixiviação de formas de N no solo e a volatilização de N-NH3 em um pomar de pessegueiro com a adição de composto orgânico produzido a partir de resíduos de agroindústrias de suco, resíduos de abatedouro de aves e serragem. O pomar foi implantado em 2009 e, em julho de 2010, 2011 e 2012, foram aplicados 0, 3, 6, 12 e 24L de composto por m2 e avaliaram-se os teores totais de nutrientes nas folhas e a produção. Em 2012, usando lisímetros instalados a 20 e a 40cm de profundidade, avaliaram-se as formas de N lixiviadas na solução percolada nos tratamentos 0 e 24L de composto. Usando câmeras coletoras, foi avaliada a volatilização de N-NH3 em todos os tratamentos até 478h depois da deposição do composto no solo. A aplicação de composto na superfície do solo incrementou o teor de K e N nas folhas completas, aumentando a produção de frutos. A aplicação de composto no florescimento aumentou a concentração de nitrato na solução do solo, somente na profundidade de 20cm. A emissão de amônia aumentou com o incremento da dose de composto aplicado, especialmente e nos períodos de maior temperatura DA - 2015/// PY - 2015/// DO - 10.1590/0103-8478cr20131232 VL - 45 IS - 4 SP - 651-657 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-84926378810&partnerID=MN8TOARS ER - TY - JOUR TI - Environmental vulnerability and phosphorus fractions of areas with pig slurry applied to the soil AU - Couto, R.R. AU - Santos, M. AU - Comin, J.J. AU - Martini, L.C.P. AU - Gatiboni, L.C. AU - Martins, S.R. AU - Filho, P.B. AU - Brunetto, G. T2 - Journal of Environmental Quality AB - The application of pig slurry as a fertilizer can cause soil and water contamination. Intrinsic characteristics of the environment may enhance this effect and influence the vulnerability of the agricultural system. The goal of this study was to evaluate the accumulation of soil P fractions in areas treated with pig slurry and in forest areas and to propose an evaluation of the areas’ vulnerability to P contamination. Soil samples were collected from 10 areas with pig slurry applied to the soil and one in forest without a history of pig slurry application, all located in the Coruja and Bonito rivers microbasin at Braço do Norte, Santa Catarina, southern Brazil. Samples were prepared and subjected to P chemical fractionation. Two versions of the P index method, based on soil P forms or only on P extracted by Mehlich-1, were used to evaluate the environmental risk of the studied areas. Estimated soil losses were lower for the forest and natural pasture and highest in areas with black oat (Avena strigosa Schreb.)–corn (Zea mays L.) crop cultivation. Concentrations of P fractions, especially of organic and inorganic P extracted by 0.1 and 0.5 mol L−1 NaOH and NaHCO3 and of inorganic P extracted by anion exchange resin and HCl, were higher in areas with a longer history and higher frequency of pig slurry applications. Vulnerability to P contamination was mainly influenced by soil P concentrations and soil losses in the studied areas. The P index based on Hedley's fractionation P forms resulted in a more accurate risk scoring of the studied areas than the P index based on the concentration of available P extracted by Mehlich-1. DA - 2015/// PY - 2015/// DO - 10.2134/jeq2014.08.0359 VL - 44 IS - 1 SP - 162-173 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-84920993351&partnerID=MN8TOARS ER - TY - JOUR TI - Effectiveness of chemical methods in predicting phosphorus availability to flood irrigated rice in Soils of Santa Catarina State, Brazil,Eficiência de métodos analíticos na predição da disponibilidade de fósforo para arroz irrigado em solos catarinenses AU - Simonete, M.A. AU - Ernani, P.R. AU - Moro, L. AU - Teixeira-Gandra, C.F.A. AU - Gatiboni, L.C. T2 - Revista Brasileira de Ciencia do Solo AB - Os solos cultivados com arroz irrigado no Estado de Santa Catarina apresentam características mineralógicas e químicas distintas dos solos utilizados nos estudos de calibração do extrator Mehlich-1, para estimar a disponibilidade de fósforo do solo para as plantas. Desse modo, o objetivo deste trabalho foi avaliar a eficiência dos extratores Mehlich-1, Mehlich-3, Resina em lâminas, Olsen e EDTA na predição da disponibilidade P para plantas de arroz cultivadas em sistema de alagamento em solos representativos de lavouras orizícolas do Estado de Santa Catarina. O experimento foi conduzido em casa de vegetação, com cinco solos oriundos de várias lavouras orizícolas, em 2014. Foram adicionados aos solos quatro concentrações de P, correspondendo a 0, ¼, ½ e 1,0 vez a quantidade de P para atingir 0,2 mg L-1 de P na solução do solo (com base na capacidade de adsorção de cada solo). Foram usadas três repetições por tratamento, dispostas no delineamento completamente casualizado. Após cinco dias da adição dos níveis de P, as unidades experimentais constituídas por vasos de 8 L contendo 3,5 kg de solo seco foram amostradas para determinar o P disponível do solo por cinco métodos químicos. Na sequência, essas foram alagadas e cultivadas com seis plantas de arroz por 46 dias, quando se quantificaram a massa de matéria seca e o P absorvido pela parte aérea das plantas. A eficácia dos métodos Mehlich-1, Mehlich-3, Resina em lâminas, Olsen e EDTA foi avaliada por correlação linear entre a quantidade de P extraída dos solos e a quantidade absorvida pelas plantas. A quantidade de P absorvida pelas plantas de arroz aumentou com o acréscimo das doses de P aplicadas, variando com o tipo de solo. A maior recuperação do P adicionado aos solos foi obtida pelo extrator EDTA, seguido pelo Olsen. O P extraído pelo EDTA e Mehlich-3 evidenciou melhor correlação com quantidade de P absorvida pelo arroz. O agrupamento dos solos segundo características relacionadas à adsorção de P no solo melhora a eficiência de todos os métodos em predizer a disponibilidade de P em solos cultivados com arroz no sistema de inundação. DA - 2015/// PY - 2015/// DO - 10.1590/01000683rbcs20140797 VL - 39 IS - 4 SP - 1151-1160 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-84943222989&partnerID=MN8TOARS ER - TY - JOUR TI - Accumulation of copper and zinc fractions in vineyard soil in the mid-western region of Santa Catarina, Brazil AU - Rosa Couto, R. AU - Benedet, L. AU - Comin, J.J. AU - Filho, P.B. AU - Martins, S.R. AU - Gatiboni, L.C. AU - Radetski, M. AU - Valois, C.M. AU - Ambrosini, V.G. AU - Brunetto, G. T2 - Environmental Earth Sciences DA - 2015/// PY - 2015/// DO - 10.1007/s12665-014-3861-x VL - 73 IS - 10 SP - 6379-6386 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-84939991941&partnerID=MN8TOARS ER - TY - JOUR TI - Seed imbibition and germination of Plothymenia reticulata Benth. (Fabaceae) affected by mercury: Possible role of aquaporins AU - Cardoso, Amanda Avila AU - Borges, Eduardo Euclydes AU - Souza, Genaina Aparecida AU - Silva, Cristiane Jovelina AU - Oliveira Pires, Raquel Maria AU - Santos Dias, Denise Cunha T2 - Acta Botanica Brasilica AB - Studies that evaluate the physiological and biochemical mechanisms of germination within forest species are needed in order to improve our understanding of such processes. Mercury and dithiothreitol are indicated as important tools in studies that assess the activity of aquaporins during imbibition and germination of seeds. To investigate the alterations caused by mercury inPlathymenia reticulata seedsdifferent doses of mercury were used in the presence and absence of dithiothreitol. Mercury had a dose-dependent effect on the seeds; in the most dilute solutions mercury partially inhibited the imbibition process, whereas in the most concentrated solutions it caused the death of the embryos. A delay in the hydration of the seeds may have caused decreased germination as a result of the reduced functionality of the aquaporins that were oxidized by mercury. In the presence of the reducing agent dithiothreitol, the activity of these proteins was restored and the germination process was re-established. These findings indicate the importance of aquaporins in the imbibition and germination stages of P. reticulataseeds, and they provide a better understanding of these important developmental events in plants. DA - 2015/// PY - 2015/// DO - 10.1590/0102-33062014abb0038 VL - 29 IS - 3 SP - 285-291 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-84942324027&partnerID=MN8TOARS KW - aquaporins KW - dithiothreitol KW - forest species KW - mercury KW - seed ER - TY - JOUR TI - Environmental factors on seed germination, seedling survival and initial growth of sacha inchi (Plukenetia volubilis l.),Fatores ambientais na germinação de sementes e na sobrevivência e crescimento inicial de plântulas de sacha inchi (Plukenetia volubilis L.) AU - Cardoso, A. A. AU - Obolari, A. de M. M. AU - Borges, E. E. de AU - Silva, C. J. da AU - Rodrigues, H. S. AU - M. M. Obolari, A. AU - Borges, E. E. AU - Silva, C. J. T2 - Journal of Seed Science AB - Abstract: Sacha inchi (Plukenetia volubilis L.) is an Amazon species of elevated agro-industrial potential due the high content of omega-3 and omega-6 in its seeds. Despite of it, little information about its propagation by seeds is currently available. Thus, the aim of this study was to assess seed germination, seedling survival and growth of this species under different conditions of substrate (on paper, between papers and paper roll), light (continuous darkness, 12-h photoperiod and continuous light) and temperature (continuous temperature at 20, 25, 30, 35 and 40 °C). Germination is stimulated by substrates with increased surface contact with the seeds, presence of light and temperatures between 25 and 35 °C. Survival and initial growth of seedlings are favored by vermiculite, continuous light and 30 °C temperature. These conditions allow rapid and uniform germination of seeds and better establishment and development of seedlings. We encourage the propagation of sacha inchi by seeds, since we consider it a feasible technique. DA - 2015/// PY - 2015/// DO - 10.1590/2317-1545v37n2145054 VL - 37 IS - 2 SP - 111-116 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-84937002825&partnerID=MN8TOARS KW - Plukenetia volubilis KW - substrate KW - light KW - temperature KW - seedling production ER - TY - JOUR TI - Changes in Macrophage Gene Expression Associated with Leishmania (Viannia) braziliensis Infection T2 - PLOS ONE AB - Different Leishmania species cause distinct clinical manifestations of the infectious disease leishmaniasis. It is fundamentally important to understand the mechanisms governing the interaction between Leishmania and its host cell. Little is known about this interaction between Leishmania (Viannia) braziliensis and human macrophages. In this study, we aimed to identify differential gene expression between non-infected and L. (V) braziliensis-infected U937-derived macrophages. We deployed a whole human transcriptome microarray analysis using 72 hours post-infection samples and compared those samples with their non-infected counterparts. We found that 218 genes were differentially expressed between infected and non-infected macrophages. A total of 71.6% of these genes were down-regulated in the infected macrophages. Functional enrichment analyses identified the steroid and sterol/cholesterol biosynthetic processes between regulatory networks down-regulated in infected macrophages. RT-qPCR further confirmed this down-regulation in genes belonging to these pathways. These findings contrast with those from studies involving other Leishmania species at earlier infection stages, where gene up-regulation for this metabolic pathway has been reported. Sterol biosynthesis could be an important biological process associated with the expression profile of macrophages infected by L. (V.) braziliensis. Differential transcriptional results suggest a negative regulation of the genetic regulatory network involved in cholesterol biosynthesis. DA - 2015/6/8/ PY - 2015/6/8/ DO - 10.1371/journal.pone.0128934 UR - http://dx.doi.org/10.1371/journal.pone.0128934 ER - TY - SOUND TI - Turfgrass training for county agents AU - Miller, Grady DA - 2015/12/9/ PY - 2015/12/9/ ER - TY - RPRT TI - Sod Shortages AU - Miller, G.L. A3 - North Carolina State University DA - 2015/1/16/ PY - 2015/1/16/ PB - North Carolina State University ER - TY - SOUND TI - NC State Turfgrass Report AU - Miller, Grady DA - 2015/6/3/ PY - 2015/6/3/ ER - TY - SOUND TI - Beyond the Fertilizer: Advanced Nutrition for Turfgrasses AU - Miller, Grady DA - 2015/10/1/ PY - 2015/10/1/ ER - TY - RPRT TI - 2015 Winter damage of warm-season grasses AU - Yelverton, F. AU - Miller, G. A3 - North Carolina State University DA - 2015/2/24/ PY - 2015/2/24/ PB - North Carolina State University ER - TY - SOUND TI - Potassium Fertilization AU - Miller, Grady DA - 2015/8/27/ PY - 2015/8/27/ ER - TY - SOUND TI - Establishment of Turfgrasses AU - Miller, Grady DA - 2015/2/11/ PY - 2015/2/11/ ER - TY - SOUND TI - Turfgrass Fertilization Programs for Golf Courses AU - Miller, Grady DA - 2015/10/1/ PY - 2015/10/1/ ER - TY - SOUND TI - NC’s Role in Developing Drought Tolerant Warm-Season Turfgrasses for the Southeast AU - Miller, Grady DA - 2015/6/4/ PY - 2015/6/4/ ER - TY - SOUND TI - Mowing, Aerification, and Other Cultural Practices AU - Miller, Grady DA - 2015/2/11/ PY - 2015/2/11/ ER - TY - SOUND TI - Colorant Use on golf courses AU - Miller, Grady DA - 2015/11/16/ PY - 2015/11/16/ ER - TY - RPRT TI - Spring cleanup of tall fescue damage AU - Miller, G.L. A3 - North Carolina State University DA - 2015/4/21/ PY - 2015/4/21/ PB - North Carolina State University ER - TY - CONF TI - Overseeding Athletic Fields AU - Miller, Grady T2 - NC Sports Turf Managers Association Meeting C2 - 2015/5/27/ CY - Durham, NC DA - 2015/5/27/ PY - 2015/5/27/ ER - TY - SOUND TI - Turfgrass Selection for NC AU - Miller, Grady DA - 2015/1/27/ PY - 2015/1/27/ ER - TY - JOUR TI - Turf colorants for aesthetic and/or as an alternative to overseeding AU - Miller, G.L. AU - Pinnix, D. T2 - Golfdom DA - 2015/4// PY - 2015/4// VL - 71 IS - 4 SP - 34-37 ER - TY - CONF TI - What is Your Pest Control Program? AU - Miller, Grady T2 - NC Sports Turf Managers Association Meeting C2 - 2015/4/14/ CY - Charlotte, NC DA - 2015/4/14/ PY - 2015/4/14/ ER - TY - SOUND TI - Water Requirements of NC Turfgrasses AU - Miller, Grady DA - 2015/5/21/ PY - 2015/5/21/ ER - TY - RPRT TI - Pest Control for Professional Turfgrass Managers AU - Brandenburg, R. AU - Butler, L. AU - Gannon, T. AU - Martin, M. AU - Miller, G. AU - Peacock, C. AU - Richardson, R. AU - Warren, L. AU - Yelverton, F. A3 - North Carolina State University DA - 2015/// PY - 2015/// M1 - AG-408 PB - North Carolina State University SN - AG-408 ER - TY - RPRT TI - 2015 Turfgrass Pest Management Manual AU - Bowman, D.C. AU - Brandenburg, R.L. AU - Gannon, T.W. AU - Kerns, J.P. AU - Peacock, C.H. AU - Richardson, R.J. AU - Rufty, T.W. AU - Warren, L.S. AU - Yelverton, F.H. A3 - North Carolina State University DA - 2015/6// PY - 2015/6// M1 - AG-348 PB - North Carolina State University SN - AG-348 ER - TY - JOUR TI - Sequencing of allotetraploid cotton (Gossypium hirsutum L. acc. TM-1) provides a resource for fiber improvement. AU - Zhang, T AU - Hu, Y AU - Jiang, W AU - Fang, L AU - Guan, X AU - Chen, J AU - Zhang, J AU - Saski, CA AU - Scheffler, BE AU - Stelly, DM AU - Hulse-Kemp, AM AU - Wan, Q AU - Liu, B AU - Liu, C AU - Wang, S AU - Pan, M AU - Wang, Y AU - Wang, D AU - Ye, W AU - Chen, ZJ T2 - Nature biotechnology AB - Upland cotton is a model for polyploid crop domestication and transgenic improvement. Here we sequenced the allotetraploid Gossypium hirsutum L. acc. TM-1 genome by integrating whole-genome shotgun reads, bacterial artificial chromosome (BAC)-end sequences and genotype-by-sequencing genetic maps. We assembled and annotated 32,032 A-subgenome genes and 34,402 D-subgenome genes. Structural rearrangements, gene loss, disrupted genes and sequence divergence were more common in the A subgenome than in the D subgenome, suggesting asymmetric evolution. However, no genome-wide expression dominance was found between the subgenomes. Genomic signatures of selection and domestication are associated with positively selected genes (PSGs) for fiber improvement in the A subgenome and for stress tolerance in the D subgenome. This draft genome sequence provides a resource for engineering superior cotton lines. DA - 2015/5// PY - 2015/5// DO - 10.1038/nbt.3207 VL - 33 IS - 5 SP - 531–537, UR - http://europepmc.org/abstract/med/25893781 ER - TY - JOUR TI - Development of a 63K SNP Array for Cotton and High-Density Mapping of Intraspecific and Interspecific Populations of Gossypium spp. AU - Hulse-Kemp, AM AU - Lemm, J AU - Plieske, J AU - Ashrafi, H AU - Buyyarapu, R AU - Fang, DD AU - Frelichowski, J AU - Giband, M AU - Hague, S AU - Hinze, LL AU - Kochan, KJ AU - Riggs, PK AU - Scheffler, JA AU - Udall, JA AU - Ulloa, M AU - Wang, SS AU - Zhu, QH AU - Bag, SK AU - Bhardwaj, A AU - Stelly, DM AB - High-throughput genotyping arrays provide a standardized resource for plant breeding communities that are useful for a breadth of applications including high-density genetic mapping, genome-wide association studies (GWAS), genomic selection (GS), complex trait dissection, and studying patterns of genomic diversity among cultivars and wild accessions. We have developed the CottonSNP63K, an Illumina Infinium array containing assays for 45,104 putative intraspecific single nucleotide polymorphism (SNP) markers for use within the cultivated cotton species Gossypium hirsutum L. and 17,954 putative interspecific SNP markers for use with crosses of other cotton species with G. hirsutum. The SNPs on the array were developed from 13 different discovery sets that represent a diverse range of G. hirsutum germplasm and five other species: G. barbadense L., G. tomentosum Nuttal × Seemann, G. mustelinum Miers × Watt, G. armourianum Kearny, and G. longicalyx J.B. Hutchinson and Lee. The array was validated with 1,156 samples to generate cluster positions to facilitate automated analysis of 38,822 polymorphic markers. Two high-density genetic maps containing a total of 22,829 SNPs were generated for two F2 mapping populations, one intraspecific and one interspecific, and 3,533 SNP markers were co-occurring in both maps. The produced intraspecific genetic map is the first saturated map that associates into 26 linkage groups corresponding to the number of cotton chromosomes for a cross between two G. hirsutum lines. The linkage maps were shown to have high levels of collinearity to the JGI G. raimondii Ulbrich reference genome sequence. The CottonSNP63K array, cluster file and associated marker sequences constitute a major new resource for the global cotton research community. DA - 2015/4// PY - 2015/4// DO - 10.1534/g3.115.018416 VL - 5 IS - 6 SP - 1187–1209, UR - http://europepmc.org/abstract/med/25908569 KW - linkage analysis KW - recombination KW - interspecific SNPs KW - intraspecific SNPs KW - breeding ER - TY - JOUR TI - BAC-End Sequence-Based SNP Mining in Allotetraploid Cotton (Gossypium) Utilizing Resequencing Data, Phylogenetic Inferences, and Perspectives for Genetic Mapping. AU - Hulse-Kemp, A.M. AU - Ashrafi, H. AU - Stoffel, K. AU - Zheng, X. AU - Saski, C.A. AU - Scheffler, B.E. AU - Fang, D.D. AU - Chen, Z.J. AU - Van Deynze, A. AU - Stelly, D.M. AU - G3 AB - Abstract A bacterial artificial chromosome library and BAC-end sequences for cultivated cotton (Gossypium hirsutum L.) have recently been developed. This report presents genome-wide single nucleotide polymorphism (SNP) mining utilizing resequencing data with BAC-end sequences as a reference by alignment of 12 G. hirsutum L. lines, one G. barbadense L. line, and one G. longicalyx Hutch and Lee line. A total of 132,262 intraspecific SNPs have been developed for G. hirsutum, whereas 223,138 and 470,631 interspecific SNPs have been developed for G. barbadense and G. longicalyx, respectively. Using a set of interspecific SNPs, 11 randomly selected and 77 SNPs that are putatively associated with the homeologous chromosome pair 12 and 26, we mapped 77 SNPs into two linkage groups representing these chromosomes, spanning a total of 236.2 cM in an interspecific F2 population (G. barbadense 3-79 × G. hirsutum TM-1). The mapping results validated the approach for reliably producing large numbers of both intraspecific and interspecific SNPs aligned to BAC-ends. This will allow for future construction of high-density integrated physical and genetic maps for cotton and other complex polyploid genomes. The methods developed will allow for future Gossypium resequencing data to be automatically genotyped for identified SNPs along the BAC-end sequence reference for anchoring sequence assemblies and comparative studies. DA - 2015/6// PY - 2015/6// DO - 10.1534/g3.115.017749 VL - 5 IS - 6 SP - 1095–1105, UR - http://europepmc.org/abstract/med/25858960 KW - SNP genotyping KW - cotton genomics KW - resequencing KW - BAC-derived SNPs KW - intraspecific ER - TY - CONF TI - Using Colorants on Golf Courses AU - Miller, Grady T2 - Southeast Turfgrass Conference C2 - 2015/3/30/ CY - Wilmington, NC DA - 2015/3/30/ PY - 2015/3/30/ ER - TY - SOUND TI - Evaluation and Preparation for High-Use Athletic Fields AU - Miller, Grady DA - 2015/3/24/ PY - 2015/3/24/ ER - TY - RPRT TI - 2015 Sod Producers’ Report for North Carolina AU - Miller, G.L. A3 - North Carolina State University Extension Publications DA - 2015/5/6/ PY - 2015/5/6/ M1 - AG-809 M3 - North Carolina State University Extension Publications PB - North Carolina State University Extension Publications SN - AG-809 ER - TY - SOUND TI - Fine Fescue and Creeping Bentgrass NTEP Trial Results AU - Miller, Grady DA - 2015/8/12/ PY - 2015/8/12/ ER - TY - SOUND TI - Developing Drought Tolerant Warm-Season Turfgrasses for the Southeast AU - Miller, Grady DA - 2015/6/10/ PY - 2015/6/10/ ER - TY - SOUND TI - Colorant Use on Golf Courses AU - Miller, Grady DA - 2015/3/24/ PY - 2015/3/24/ ER - TY - SOUND TI - Sod Production Survey Outlined AU - Miller, Grady DA - 2015/1/7/ PY - 2015/1/7/ ER - TY - SOUND TI - Turfgrass Trials in NC AU - Miller, Grady DA - 2015/1/7/ PY - 2015/1/7/ ER - TY - SOUND TI - Replicated Field Trials for Warm-Season Grasses in SCRI program AU - Miller, Grady AU - Milla-Lewis, Susana DA - 2015/8/12/ PY - 2015/8/12/ ER - TY - SOUND TI - Water Requirements of NC Turfgrasses AU - Miller, Grady AU - Pinnix, Drew DA - 2015/8/12/ PY - 2015/8/12/ ER - TY - MGZN TI - 2015 sod producers’ report for North Carolina AU - Miller, G.L. T2 - North Carolina Turfgrass DA - 2015/7// PY - 2015/7// SP - 12–15 ER - TY - MGZN TI - Recommended bluegrass and tall fescue cultivars for North Carolina AU - Miller, G.L. T2 - North Carolina Turfgrass DA - 2015/11// PY - 2015/11// SP - 10–12 ER - TY - MGZN TI - Athletic field priorities: When the budget get cuts AU - Miller, G.L. T2 - North Carolina Turfgrass DA - 2015/1// PY - 2015/1// SP - 11–13 ER - TY - JOUR TI - When regulations can be good AU - Miller, G.L. T2 - SportsTurf DA - 2015/// PY - 2015/// VL - 31 IS - 3 SP - 50 ER - TY - JOUR TI - Overtaken with crabiness AU - Miller, G.L. T2 - SportsTurf DA - 2015/// PY - 2015/// VL - 31 IS - 9 SP - 50 ER - TY - JOUR TI - Too late? AU - Miller, G.L. T2 - SportsTurf DA - 2015/// PY - 2015/// VL - 31 IS - 11 SP - 50 ER - TY - JOUR TI - To fertilize. Or not. AU - Miller, G.L. T2 - SportsTurf DA - 2015/// PY - 2015/// VL - 31 IS - 1 SP - 49 ER - TY - JOUR TI - When regulation can be good AU - Miller, G.L. T2 - SportsTurf DA - 2015/// PY - 2015/// VL - 31 IS - 3 SP - 50 ER - TY - JOUR TI - Punching holes AU - Miller, G.L. T2 - SportsTurf DA - 2015/// PY - 2015/// VL - 31 IS - 5 SP - 50 ER - TY - JOUR TI - Writing the Q&A AU - Miller, G.L. T2 - SportsTurf DA - 2015/// PY - 2015/// VL - 31 IS - 7 SP - 50 ER - TY - SOUND TI - Why Athletic Fields Sometimes Fail AU - Miller, Grady DA - 2015/1/23/ PY - 2015/1/23/ ER - TY - SOUND TI - Evaluation and Preparation for Heavy Use Athletic Fields AU - Miller, Grady DA - 2015/1/22/ PY - 2015/1/22/ ER - TY - JOUR TI - The valine and lysine residues in the conserved FxVTxK motif are important for the function of phylogenetically distant plant cellulose synthases AU - Slabaugh, Erin AU - Scavuzzo-Duggan, Tess AU - Chaves, Arielle AU - Wilson, Liza AU - Wilson, Carmen AU - Davis, Jonathan K AU - Cosgrove, Daniel J AU - Anderson, Charles T AU - Roberts, Alison W AU - Haigler, Candace H T2 - Glycobiology AB - Cellulose synthases (CESAs) synthesize the β-1,4-glucan chains that coalesce to form cellulose microfibrils in plant cell walls. In addition to a large cytosolic (catalytic) domain, CESAs have eight predicted transmembrane helices (TMHs). However, analogous to the structure of BcsA, a bacterial CESA, predicted TMH5 in CESA may instead be an interfacial helix. This would place the conserved FxVTxK motif in the plant cell cytosol where it could function as a substrate-gating loop as occurs in BcsA. To define the functional importance of the CESA region containing FxVTxK, we tested five parallel mutations in Arabidopsis thaliana CESA1 and Physcomitrella patens CESA5 in complementation assays of the relevant cesa mutants. In both organisms, the substitution of the valine or lysine residues in FxVTxK severely affected CESA function. In Arabidopsis roots, both changes were correlated with lower cellulose anisotropy, as revealed by Pontamine Fast Scarlet. Analysis of hypocotyl inner cell wall layers by atomic force microscopy showed that two altered versions of Atcesa1 could rescue cell wall phenotypes observed in the mutant background line. Overall, the data show that the FxVTxK motif is functionally important in two phylogenetically distant plant CESAs. The results show that Physcomitrella provides an efficient model for assessing the effects of engineered CESA mutations affecting primary cell wall synthesis and that diverse testing systems can lead to nuanced insights into CESA structure–function relationships. Although CESA membrane topology needs to be experimentally determined, the results support the possibility that the FxVTxK region functions similarly in CESA and BcsA. DA - 2015/12/8/ PY - 2015/12/8/ DO - 10.1093/glycob/cwv118 VL - 26 IS - 5 SP - 509-519 J2 - Glycobiology LA - en OP - SN - 0959-6658 1460-2423 UR - http://dx.doi.org/10.1093/glycob/cwv118 DB - Crossref KW - cellulose synthesis KW - gametophore formation KW - phenotypic complementation KW - root elongation KW - site-directed mutagenesis ER - TY - JOUR TI - Identifying Key Characteristics for Student Farm Successes through a National Delphi Study AU - Ratasky, S. AU - Schroeder-Moreno, M. AU - Jayaratne, J. AU - Bradley, L.K. AU - Grossman, J. AU - Orr, D. T2 - NACTA Journal DA - 2015/6// PY - 2015/6// VL - 59 IS - 2 SP - 96-103 ER - TY - RPRT TI - Metribuzin AU - Goodale, D. AU - Neal, J. AU - Jennings, K. AU - Mitchem, W. A3 - North Carolina State University DA - 2015/12/11/ PY - 2015/12/11/ M3 - NC State Extension Publication PB - North Carolina State University UR - http://content.ces.ncsu.edu/metribuzin ER - TY - RPRT TI - Protoporphyrinogen oxidase (PPO) inhibitors AU - Goodale, D. AU - Neal, J. AU - Jennings, K. AU - Mitchem, W. A3 - North Carolina State University DA - 2015/12/11/ PY - 2015/12/11/ M3 - NC State Extension Publication PB - North Carolina State University UR - https://content.ces.ncsu.edu/protoporphyrinogen-oxidase-inhibitors ER - TY - BOOK TI - Charles W. Stuber: Maize Geneticist and Pioneer of Marker-Assisted Selection AU - Holland, J.B. AU - Graham, G.I. AU - Murphy, J.P. AU - Senior, M.L. AB - This chapter contains sections titled: BIOGRAPHICAL SKETCH SCIENTIFIC ACHIEVEMENTS LEADERSHIP BEFORE AND AFTER RETIREMENT AWARDS AND HONORS IMPACT ON BREEDING PARADIGMS IN THE PRIVATE SECTOR IMPACT ON STUDENTS AND POSTDOCS DA - 2015/// PY - 2015/// DO - 10.1002/9781119107743.ch01 VL - 39 SE - 1-22 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-84977447531&partnerID=MN8TOARS ER - TY - CONF TI - Amending Soils for Enhanced Infiltration of Stormwater AU - Kays, Barrett L. AU - McLaughlin, Richard AU - Heitman, Joshua AU - Mohammadshirazi, Fatemeh AU - Brown, Virginia T2 - International Low Impact Development 2015 AB - Rainfall events on urban compacted soils increase the volume and rate of stormwater runoff. A research study was conducted recently in North Carolina to investigate soil amendments to enhance infiltration into compacted soils. Sites were located in the coastal plain, piedmont, and mountain regions, and the sites had sand, sandy clay, and sandy clay loam textured subsoils, respectively. The soil profiles were exhumed into the subsoils and compacted to simulate urban disturbed conditions. Physical treatments/amendments included compacted (control), shallow tillage (15 cm), and deep tillage (30 cm). Fertility amendments included agricultural lime and fertilizer according to soil test results. Triplicate plots were randomized on each of the sites. Fescue grass was seeded, mulched, and covered with jute matting. Steady-state infiltration rate, bulk density, cone penetrometer, grass shoot biomass, and grass root biomass measurements were taken over the study period. Runoff from natural rainfall events was measured for 12 storm events at the two piedmont sites. Tillage greatly increased infiltration rates, and the effect remained after three years. Evidence showed some decline in infiltration rates at the mountain site, but none at the other sites, even though the bulk densities tended to increase over time at all sites. Doubling recommended lime rates, or adding compost, or water-absorbing polyacrylamide usually had no effect on infiltration rates. The initial infiltration rates for compacted soils were usually < 1 cm hr-1, but the rates improved over several years to up to 10 cm hr-1. This was somewhat surprising, but the trend was evident at all sites. The tilled soils had infiltration rates of 20 to 35 cm hr-1 at the end of at least two years. Because this far exceeds the expected rainfall of 3 to 6 cm hr-1 for 2- to 10-year recurrence storms, the results suggest that treated areas may be able to accept significant amounts of runoff from impervious areas. C2 - 2015/1/12/ C3 - International Low Impact Development Conference 2015 DA - 2015/1/12/ DO - 10.1061/9780784479025.012 PB - American Society of Civil Engineers SN - 9780784479025 UR - http://dx.doi.org/10.1061/9780784479025.012 DB - Crossref ER - TY - RPRT TI - Shoot inhibitors herbicide injury AU - Neal, J. AU - Goodale, D. AU - Jennings, K. AU - Mitchem, W. A3 - NC Cooperative Extension DA - 2015/// PY - 2015/// PB - NC Cooperative Extension UR - http://content.ces.ncsu.edu/shoot-inhibitors ER - TY - RPRT TI - Synthetic auxins herbicide injury AU - Goodale, D. AU - Neal, J. AU - Jennings, K. A3 - NC Cooperative Extension DA - 2015/// PY - 2015/// PB - NC Cooperative Extension UR - http://content.ces.ncsu.edu/synthetic-auxins ER - TY - RPRT TI - Natural oils and acids herbicide injury AU - Goodale, D. AU - Neal, J. AU - Jennings, K. AU - Mitchem, W. A3 - NC Cooperative Extension DA - 2015/// PY - 2015/// PB - NC Cooperative Extension UR - http://content.ces.ncsu.edu/natural-oils-and-acids ER - TY - RPRT TI - Glyphosate herbicide injury AU - Neal, J. AU - Goodale, D. AU - Jennings, K. A3 - NC Cooperative Extension DA - 2015/// PY - 2015/// PB - NC Cooperative Extension UR - http://content.ces.ncsu.edu/glyphosate ER - TY - RPRT TI - Photosystem I, bipyridillium herbicides herbicide injury AU - Goodale, D. AU - Neal, J. AU - Jennings, K. AU - Mitchem, W. A3 - NC Cooperative Extension DA - 2015/// PY - 2015/// PB - NC Cooperative Extension UR - http://content.ces.ncsu.edu/photosystem-i-bipyridillium-herbicides ER - TY - RPRT TI - Carotenoid pigments herbicide injury AU - Neal, J. AU - Goodale, D. AU - Jennings, K. AU - Mitchem, W. A3 - NC Cooperative Extension DA - 2015/// PY - 2015/// PB - NC Cooperative Extension UR - http://content.ces.ncsu.edu/carotenoid-pigments ER - TY - RPRT TI - Cellulose inhibitors, indaziflam and isoxaben herbicide injury AU - Neal, J. AU - Goodale, D. AU - Jennings, K. AU - Mitchem, W. A3 - NC Cooperative Extension DA - 2015/// PY - 2015/// PB - NC Cooperative Extension UR - http://content.ces.ncsu.edu/cellulose-inhibitors-indaziflam-and-isoxaben ER - TY - RPRT TI - Acetolactate synthase (ALS) inhibitors herbicide injury AU - Neal, J. AU - Goodale, D. AU - Jennings, K. AU - Mitchem, W. A3 - NC Cooperative Extension DA - 2015/// PY - 2015/// PB - NC Cooperative Extension UR - http://content.ces.ncsu.edu/acetolactate-synthase-als-inhibitors ER - TY - RPRT TI - Photosystem II –triazine herbicides herbicide injury AU - Neal, J. AU - Goodale, D. AU - Jennings, K. AU - Mitchem, W. A3 - NC Cooperative Extension DA - 2015/// PY - 2015/// PB - NC Cooperative Extension UR - http://content.ces.ncsu.edu/photosystem-ii-triazine-herbicides ER - TY - JOUR TI - Herbicide-Based Weed Management Programs in Erect, Thornless Blackberry AU - Meyers, Stephen L. AU - Jennings, Katherine M. AU - Monks, David W. AU - Mitchem, Wayne E. T2 - International Journal of Fruit Science AB - Field studies were conducted in 2009/2010 and 2011 in North Carolina to determine the influence of herbicide-based weed management programs on weed control and blackberry tolerance. Treatments consisted of five programs with a late fall-early winter herbicide application followed by (fb) an early spring herbicide application: flumioxazin fb flumioxazin, simazine fb terbacil, terbacil fb oryzalin plus simazine, norflurazon fb oryzalin plus simazine, and terbacil fb S-metolachlor plus simazine. A sixth program consisted of winter-applied dichlobenil. Crop tolerance and weed control were recorded at the physiological crop stages of budbreak, flowering, and harvest. DA - 2015/8/5/ PY - 2015/8/5/ DO - 10.1080/15538362.2015.1044694 VL - 15 IS - 4 SP - 456-464 KW - crop injury KW - crop tolerance KW - orchard floor management ER - TY - SOUND TI - Colorant Use for Athletic Fields AU - Miller, Grady DA - 2015/5/13/ PY - 2015/5/13/ ER - TY - SOUND TI - Sports Turf Research at NCSU AU - Miller, Grady DA - 2015/6/25/ PY - 2015/6/25/ ER - TY - SOUND TI - Sports Turf AU - Miller, Grady DA - 2015/3/12/ PY - 2015/3/12/ ER - TY - SOUND TI - Why Research is Important AU - Miller, Grady DA - 2015/3/12/ PY - 2015/3/12/ ER - TY - SOUND TI - Trends in Sports Turf Management AU - Miller, Grady DA - 2015/11/17/ PY - 2015/11/17/ ER - TY - RPRT TI - 2015 Spring green-up of warm-season grasses AU - Miller, G.L. DA - 2015/4/21/ PY - 2015/4/21/ ER - TY - JOUR TI - Diurnal depression in leaf hydraulic conductance at ambient and elevated [CO2] reveals anisohydric water management in field-grown soybean and possible involvement of aquaporins AU - Locke, Anna M. AU - Ort, Donald R. T2 - Environmental and Experimental Botany AB - Diurnal cycles of photosynthesis and water use in field-grown soybean (Glycine max) are tied to light intensity and vapor pressure deficit (VPD). At high mid-day VPD, transpiration rates can lead to a decline in leaf water potential (Ψleaf) if leaf hydraulic conductance (Kleaf) is insufficient to supply water to intercellular airspaces in pace with demand. Kleaf is determined by leaf xylem conductivity to water, as well as extra-xylem pathways that are likely mediated by aquaporin water transport proteins. When transpiration demand exceeds the maximum capacity of Kleaf to supply water, high tension in the water column can cause cavitation in xylem, and these emboli-blocked xylem vessels reduce water transport and thus lower Kleaf. Stomatal conductance typically remains high at mid-day for soybean, suggesting either a mid-day increase in Kleaf or that photosynthesis may be maintained at the cost of leaf water status, indicative of an anisohydric water management strategy in soybean. This study examined diurnal fluctuations in Kleaf and Ψleaf, showing a mid-day depression in Kleaf in a pattern closely reflecting that of Ψleaf, indicating that Kleaf depression is the result of cavitation in leaf xylem. The diurnal depression of Kleaf was not prevented by growth at elevated [CO2], which lowered stomatal conductance. Diurnal transcription patterns of aquaporin genes showed that a total of 34 genes belonging to 4 aquaporin families were expressed in soybean leaves, of which 22 were differentially expressed between at least two time points. These data suggest that mid-day Kleaf depression was driven primarily by cavitation at increasing xylem water tensions, but that aquaporins are also likely involved in diurnal regulation of soybean leaf water status. It is further concluded that because soybean photosynthesis is typically sustained at mid-day, Kleaf even at the depressed level was in excess of that needed to sustain a stomatal conductance sufficient to prevent depression of photosynthesis in soybean. DA - 2015/8// PY - 2015/8// DO - 10.1016/j.envexpbot.2015.03.006 VL - 116 SP - 39-46 J2 - Environmental and Experimental Botany LA - en OP - SN - 0098-8472 UR - http://dx.doi.org/10.1016/j.envexpbot.2015.03.006 DB - Crossref ER - TY - CONF TI - Release of ‘Emery’ high-oleic large-seeded virginia-type peanut AU - Copeland, S.C. AU - Isleib, T.G. AU - Pattee, H.E. AU - Milla-Lewis, S.R. AU - Hollowell, J.E. AU - Hancock, W.G. AU - Shew, B.B. AU - Sanders, T.H. AU - Dean, L.O. AU - Hendrix, K.W. AU - Balota, M. AU - Chapin, J.W. C2 - 2015/// C3 - Proc. Am. Peanut Res. Educ. Soc. DA - 2015/// VL - 47 SP - 107 ER - TY - CONF TI - Quantitative trait loci (QTL) for seed head characteristics in bermudagrass AU - Dunne, J.C. AU - Khanal, S. AU - Schwartz, B.M. AU - Milla-Lewis, S.R. AU - Paterson, A. C2 - 2015/11/15/ C3 - Proc. Amer. Soc. Agron. Intl. Ann. Mtg. DA - 2015/11/15/ ER - TY - CONF TI - Quantitative trait loci (QTL) analysis of freezing tolerance in zoysiagrass AU - Pruitt, H.M. AU - Schwartz, B.M. AU - Patton, A.J. AU - Arellano, C. AU - Milla-Lewis, S.R. C2 - 2015/11/15/ C3 - Proc. Amer. Soc. Agron. Intl. Ann. Mtg. DA - 2015/11/15/ ER - TY - CONF TI - Outreach education achievements from a 2011-2015 project focused on improving drought and salinity tolerance in warm-season turfgrasses AU - Martin, D.L. AU - Miller, G.L. AU - Chandra, A. AU - Unruh, J.B. AU - Moss, J.Q. AU - Milla-Lewis, S.R. AU - Waltz, F.C. AU - Reynolds, W.C. AU - Schwartz, B.M. AU - Kenworthy, K.E. AU - Boyer, T. AU - Raymer, P.L. AU - Wu, Y.Q. C2 - 2015/11/15/ C3 - Proc. Amer. Soc. Agron. Intl. Ann DA - 2015/11/15/ ER - TY - SOUND TI - Mapping quantitative trait loci (QTL) for flowering and seed-head characteristics in a hybrid bermudagrass population AU - Dunne, J.C. AU - Khanal, S. AU - Milla-Lewis, S.R. AU - Schwartz, B.M. AU - Hanna, W.W. AU - Paterson, A.H. DA - 2015/10/19/ PY - 2015/10/19/ ER - TY - SOUND TI - Shade Response of Bermudagrass accessions under varying management practices AU - Dunne, J.C. AU - Arellano, C. AU - Miller, G.L. AU - Milla-Lewis, S.R. DA - 2015/11/15/ PY - 2015/11/15/ ER - TY - SOUND TI - Developing improved turfgrass cultivars for the transition zone AU - Milla-Lewis, S.R. DA - 2015/1/7/ PY - 2015/1/7/ M3 - invited presentation ER - TY - SOUND TI - Developing improved bermudagrass cultivars for the transition zone AU - Milla-Lewis, S.R. AU - Dunne, J.C. DA - 2015/3/30/ PY - 2015/3/30/ M3 - invited presentation ER - TY - CONF TI - Comparison of Bailey virginia-type cultivar with high-oleic backcross derivatives AU - Isleib, T.G. AU - Copeland, S.C. AU - Hollowell, J.E. AU - Pattee, H.E. AU - Milla-Lewis, S.R. AU - Shew, B.B. C2 - 2015/// C3 - Proceedings of the American Peanut Research and Education Society DA - 2015/// VL - 47 SP - 106 ER - TY - SOUND TI - Breeding for cold tolerance in NC. AU - Milla-Lewis, S.R. DA - 2015/6/2/ PY - 2015/6/2/ M3 - invited presentation ER - TY - CONF TI - Genetic gain in reduction of four peanut diseases in the North Carolina State University peanut breeding program AU - Hancock, W.G. AU - Isleib, T.G. AU - Copeland, S.C. AU - Hollowell, J.W. AU - Milla-Lewis, S.R. AU - Shew, B.B. C2 - 2015/// C3 - Proceedings of the American Peanut Research and Education Society DA - 2015/// VL - 47 SP - 103 ER - TY - SOUND TI - Genetic components associated with cold tolerance and turf quality-related traits in St. Augustinegrass AU - Kimball, J.A. AU - Milla-Lewis, S.R. AU - Zuleta, M.C. AU - Mulkey, S.E. AU - Arellano, C. AU - Tuong, T.D. AU - Livingston, D.P. DA - 2015/11/15/ PY - 2015/11/15/ ER - TY - SOUND TI - Freeze tests in St. Augustinegrass : evaluation of acclimation effects AU - Kimball, J.A. AU - Milla-Lewis, S.R. AU - Tuong, T.D. AU - Livingston, D.P. AU - Arellano, C. DA - 2015/11/15/ PY - 2015/11/15/ ER - TY - SOUND TI - Effect of drought on genotype-by-environment interaction on warm-season turfgrasses AU - Muñoz, P. AU - Kenworthy, K.E. AU - Chandra, A. AU - Wu, Y.Q. AU - Martin, D.L. AU - Schwartz, B.M. AU - Raymer, P.L. AU - Milla-Lewis, S.R. DA - 2015/11/15/ PY - 2015/11/15/ ER - TY - JOUR TI - Drought tolerance in both pasture and turf types of perennial ryegrass by overexpressing its ubiquitin-like modifier LpHUB1 gene AU - Patel, M. AU - Milla-Lewis, S.R. AU - Zhang, W.J. AU - Templeton, K. AU - Reynolds, W.C. AU - Richardson, K. AU - Biswas, M. AU - Zuleta, M.C. AU - Dewey, R.E. AU - Qu, R. AU - Sathish, P. T2 - Plant Biotechnology Journal DA - 2015/// PY - 2015/// VL - 13 IS - 5 SP - 689-699 ER - TY - SOUND TI - Development of colchicine-induced tetraploid St. Augustinegrass AU - Milla-Lewis, S.R. AU - Carbajal, E.M. AU - Zuleta, M.C. AU - Schwartz, B.M. AU - Chavarro, C. AU - Ballen-Taborda, A.C. DA - 2015/11/15/ PY - 2015/11/15/ ER - TY - JOUR TI - Soil Organic Carbon Stocks in a Large Eutrophic Floodplain Forest of the Southeastern Atlantic Coastal Plain, USA AU - Ricker, Matthew C. AU - Lockaby, B. Graeme T2 - Wetlands DA - 2015/1/22/ PY - 2015/1/22/ DO - 10.1007/s13157-014-0618-y VL - 35 IS - 2 SP - 291-301 J2 - Wetlands LA - en OP - SN - 0277-5212 1943-6246 UR - http://dx.doi.org/10.1007/s13157-014-0618-y DB - Crossref KW - Floodplain KW - Soil carbon KW - Fluvial processes KW - Riparian forest ER - TY - JOUR TI - Evaluating a campus nitrogen budget for Auburn University, Alabama, USA AU - Brodbeck, A. Beau AU - LeCompte, Judson S. AU - Meder, Amanda L. AU - Ricker, Matthew C. AU - Wedge, Madeline AU - Schurman, Hanna AU - Anderson, Christopher J. T2 - Urban Ecosystems DA - 2015/4/14/ PY - 2015/4/14/ DO - 10.1007/s11252-015-0458-4 VL - 18 IS - 4 SP - 1187-1211 J2 - Urban Ecosyst LA - en OP - SN - 1083-8155 1573-1642 UR - http://dx.doi.org/10.1007/s11252-015-0458-4 DB - Crossref KW - Campus KW - Sustainability KW - Nitrogen KW - Nutrient cycle KW - Urban ecology ER - TY - SOUND TI - Cover crop mixture proportion and starter fertilizer effects on weed competition and yield in organic rotational no-till maize production AU - Atwell, R.A. AU - Mirsky, S.B. AU - Poffenbarger, H. AU - Reberg-Horton, S.C. DA - 2015/// PY - 2015/// ER - TY - JOUR TI - Survey of Glyphosate- and Imazapic-Resistant Palmer Amaranth (Amaranthus palmeri) in Florida AU - Berger, Sarah T. AU - Ferrell, Jason A. AU - Dittmar, Peter J. AU - Leon, Ramon T2 - Crop, Forage & Turfgrass Management AB - Herbicide‐resistant Palmer amaranth ( Amaranthus palmeri S. Wats.) is the most troublesome weed in Florida cotton ( Gossypium hirsutum L.) and peanut ( Arachis hypogaea L.) production. In 2012, Palmer amaranth populations were surveyed to document the extent and level of resistance to glyphosate and imazapic. Mature seedheads were sampled at 31 locations in the northwest region of Florida where cotton and peanut are predominantly produced, and in the north‐central region of Florida that mainly consists of peanut production. Palmer amaranth plants were grown from field‐collected seed in the greenhouse and treated with glyphosate and imazapic to establish a dose response for each population. Glyphosate‐resistant Palmer amaranth was found in 11 populations that were located primarily in the northwest region, with some populations having up to 30‐fold resistance. Imazapic resistance was much more widespread, being found in 29 of the 30 populations tested. Since peanut production in Florida has historically relied on successive imazapic applications, it is not surprising that widespread resistance to imazapic has developed. Resistance to both herbicides was found in 10 populations. Results from this survey reveal the magnitude of herbicide resistance in Florida and the need for growers to diversify management strategies in the future. DA - 2015/// PY - 2015/// DO - 10.2134/cftm2015.0122 VL - 1 IS - 1 SP - 0 LA - en SN - 2374-3832 UR - https://dl.sciencesocieties.org/publications/cftm/abstracts/1/1/cftm2015.0122 DB - Crossref Y2 - 2019/2/8/ ER - TY - JOUR TI - Weed seed banks are more dynamic in a sod-based than a conventional peanut-cotton rotation AU - Leon, R.G. AU - Wright, D.L. AU - Marois, J.J. T2 - Weed Science AB - Crop rotation promotes productivity, nutrient cycling, and effective pest management. However, in row-crop systems, rotation is frequently limited to two crops. Adding a third crop, especially a perennial crop, might increase crop-rotation benefits, but concerns about disruption of agricultural and ecological processes preclude grower adoption of a three-crop rotation. The objective of the present research was to determine whether weed seed banks differ between a sod-based rotation (bahiagrass–bahiagrass–peanut–cotton) and a conventional peanut–cotton rotation (peanut–cotton–cotton) and the importance of crop phase in weed seed-bank dynamics in a long-term experiment initiated in 1999 in Florida. Extractable (ESB) and germinable (GSB) seed banks were evaluated at the end of each crop phase in 2012 and 2013, and total weed seed or seedling number, Shannon-Weiner's diversity ( H ′), richness, and evenness were determined. ESB increased in H ′ (36%), richness (29%), and total number of weed seeds (40%) for sod-based compared with conventional rotation, whereas GSB increased 32% in H ′, 27% in richness, and 177% in total number of weed seedlings. Crop phase was a determinant factor in the differences between crop rotations. The first year of bahiagrass (B1) exhibited increases in weed seed and seedling number, H ′, and richness and had the highest values observed in the sod-based rotation. These increases were transient, and in the second year of bahiagrass (B2), weed numbers and H ′ decreased and reached levels equivalent to those in the conventional peanut–cotton rotation. The B1 phase increased the germinable fraction of the seed bank, compared with the other crop phases, but not the total number of weed seeds as determined by ESB. The increases in H ′ and richness in bahiagrass phases were mainly due to grass weed species. However, these grass weed species were not associated with peanut and cotton phases of the sod-based rotation. The results of the present study demonstrated that including bahiagrass as a third crop in a peanut–cotton rotation could increase weed community diversity, mainly by favoring increases in richness and diversity, but the structure and characteristics of the rotation would prevent continuous increases in the weed seed bank that could affect the peanut and cotton phases. DA - 2015/// PY - 2015/// DO - 10.1614/ws-d-15-00003.1 VL - 63 IS - 04 SP - 877–887 KW - Community KW - dormancy KW - germination KW - integrated weed management KW - long-term research KW - populations ER - TY - JOUR TI - Postemergence herbicide tolerance variation in peanut germplasm AU - Leon, R.G. AU - Tillman, B.L. T2 - Weed Science AB - Although herbicide tolerance is not usually evaluated until the final stages of breeding programs, this trait is very important for grower adoption of new peanut cultivars. Understanding herbicide tolerance of breeding lines could help breeders develop selection strategies that maximize herbicide tolerance in new commercial cultivars. However, little is known about herbicide tolerance variability in peanut germplasm. Thirty-five randomly selected breeding lines from the peanut mini-core collection and cultivars ‘Florida-07’ and ‘Georgia-06G’ were evaluated for tolerance to 11 herbicides under greenhouse conditions. Variation among peanut lines in herbicide tolerance, measured as dry weight reductions (DWR), was similar across herbicides and was normally distributed. Florida-07 and Georgia-06G were in the lower two quartiles of injury and DWR among the evaluated peanut lines. Dose–response experiments showed that the most tolerant breeding lines had I 50 (the rate required to cause 50% injury) and GR 50 (the rate required to reduce dry weight 50%) values 0.4 to 2.5 times higher than the most susceptible lines, depending on the herbicide. A breeding line had a dicamba GR 50 13 times higher than the most susceptible line and 2.8 and 4.7 times higher than Florida-07 and Georgia-06G, respectively. The most tolerant lines were consistently tolerant to herbicides with different mechanisms of action, suggesting that nontarget site mechanisms are more likely to be responsible for the tolerance than target-site mutations. These results confirmed peanut-breeding programs would greatly benefit from screening breeding lines for tolerance to key herbicides and developing an herbicide-tolerance catalog. This information can be used when designing new crosses to reduce the risk of developing cultivars with low herbicide tolerance especially considering that one-half of the breeding lines exhibited lower tolerance than the commercial cultivars. DA - 2015/// PY - 2015/// DO - 10.1614/ws-d-14-00128.1 VL - 63 IS - 02 SP - 546–554 KW - Breeding KW - crop improvement KW - genetic diversity KW - selection KW - selectivity ER - TY - JOUR TI - Post-dispersal weed seed predation and invertebrate activity-density in three tillage regimes AU - Laat R, Van Der AU - Owen, M.D.K. AU - Liebman, M. AU - Leon, R.G. T2 - Weed Science AB - Field experiments were conducted near Boone, IA, to quantify postdispersal seed predation of common lambsquarters and common waterhemp in corn (2003) and soybean (2004) managed with conventional, reduced, and zero-tillage systems. Seed predation in each tillage regime was quantified using selective exclusion treatments during July through September 2003 and June through October 2004. In addition, the activity density of ground-dwelling invertebrates was estimated with pitfall traps. Choice and no-choice feeding trials were conducted in the laboratory using the most abundant weed seed predators found in the field to determine seed preferences of the potential predator organisms. The greatest seed loss occurred during July and August. In 2003, seed predation was lower in zero tillage than in conventional and reduced tillages, but no differences in seed predation between tillage regimes were observed in 2004. Maximum seed predation for common lambsquarters was 53% in 2003 and 64% in 2004. Common waterhemp seed predation reached 80% in 2003 and 85% in 2004. The majority of seed predation was by invertebrate organisms. The most common invertebrate species captured with pitfall traps were field crickets ( Gryllus pennsylvanicus De Geer [Gryllidae, Orthoptera]) and ground beetles ( Harpalus pensylvanicus Burmeister [Coleoptera, Carabidae]). In 2003, field crickets were relatively more abundant in conventional and reduced tillage than in zero-tillage plots. In 2004, field crickets were more abundant in the reduced tillage than in the other two tillage regimes. No differences were detected for ground beetles among tillage regimes (P = 0.57). Choice and no-choice feeding experiments confirmed the preferences of field crickets and ground beetles for common lambsquarters and common waterhemp seeds over the larger seeds of giant foxtail and velvetleaf. Under field conditions, the activity density of field crickets was a significant predictor of common lambsquarters ( r 2 = 0.47) and common waterhemp ( r 2 = 0.53) seed predation. Positive relationships were also detected between the activity density of ground beetles and common lambsquarters ( r 2 = 0.30) and common waterhemp ( r 2 = 0.30) seed predation. This research demonstrated that weed seed predation is an important component affecting weed seedbanks and that crop management practices that favor the activity of predators such as field crickets or ground beetles could influence weed populations. Also, the results suggested that tillage is more important in determining the number of weed seeds available on the soil surface to predators than directly affecting predator activity density. DA - 2015/// PY - 2015/// DO - 10.1614/ws-d-15-00030.1 VL - 63 IS - 04 SP - 828–838 KW - Biological control KW - field crickets KW - ground beetles KW - integrated weed management KW - seedbank ER - TY - JOUR TI - Energycane (Saccharum spp. × S. spontaneum) biomass production, reproduction and weed risk assessment scoring in the humid tropics and subtropics AU - Leon, R.G. AU - Gilbert, R.A. AU - Comstock, J.C. T2 - Agronomy Journal AB - There is growing interest in biofuel production, and energycane ( Saccharum spp. × S. spontaneum L.) has been proposed as an important biofuel and biomass crop. However, little is known about the growth and ecology of this new crop, especially in the tropics. The present study evaluated the performance of 14 energycane clones, elephantgrass ( Pennisetum purpureum Schumach.), and two sugarcane ( S. officinarum L.) varieties in the humid tropics of Costa Rica, and eight energycane clones in the subtropics of Florida. In the tropics, energycane's growth and biomass production were highly variable when comparing clones. However, the best performing clones US85‐1006, US88‐1006, and US78‐1014 produced almost twice the dry biomass (>64 Mg ha −1 ) compared with sugarcane varieties Pindar and Q‐132 (21–39 Mg ha −1 ). In the subtropics, energycane fresh (52–79 Mg ha −1 ) and dry (20–30 Mg ha −1 ) weights were less than half of those in the tropics. Energycane clones flowered in both environments, but pollen viability was three to four times higher (>40%) in the tropics than in the subtropics, although viable seeds were found only in the tropics. Weed risk assessment (WRA) scores were higher in the tropics than in the subtropics and varied among clones. The results confirmed that energycane is a promising feedstock for biomass production and could play an important role as a bioenergy crop when grown in the tropics and subtropics, but due to genotype × environment interactions, the tradeoff between biomass production and weedy and invasive risk must be assessed for each individual clone and environment. DA - 2015/// PY - 2015/// DO - 10.2134/agronj14.0388 VL - 107 IS - 1 SP - 323–329 ER - TY - JOUR TI - Characterization and modelling of itchgrass (Rottboellia cochinchinensis) biphasic seedling emergence patterns in the tropics AU - Leon, R.G. AU - Izquierdo, J. AU - González-Andújar, J.L. T2 - Weed Science AB - Itchgrass is an aggressive weed species in tropical agroecosystems. Because of phytosanitary restrictions to exports, pineapple producers must use a zero tolerance level for this species. An understanding of itchgrass seedling emergence would help producers to better time POST control. The objective of the present study was to characterize itchgrass seedling emergence patterns and develop a predictive model. Multiple field experiments were conducted in four agricultural fields in Costa Rica between 2010 and 2011 for a total of 9 site-years. Itchgrass consistently showed a biphasic emergence pattern, with a first emergence phase that was faster and more consistent across site-years than the second one. Weibull + logistic models based on chronological time ( R 2 adj = 0.92) and thermal time with T base = 20 C ( R 2 adj = 0.92) provided the best fit for the combined emergence data for two experimental locations in 2010. Both models predicted itchgrass seedling emergence adequately for most site-years, but the thermal-time model was more accurate ( R 2 adj = 0.64 to 0.86) than the chronological model ( R 2 adj = 0.31 to 0.74), especially when temperatures were high. Both models showed high accuracy in the first emergence phase but tended to underestimate emergence rate during the second phase. The models predicted 50% emergence at 14 d or 80 growing degree days and the stabilization of the first emergence phase at approximately 25 d or 200 growing degree days. Thus, these models can be used to properly time itchgrass POST control. More research is needed to understand the regulatory mechanisms responsible for the variability of the second emergence phase. DA - 2015/// PY - 2015/// DO - 10.1614/ws-d-14-00172.1 VL - 63 IS - 03 SP - 623–630 KW - Control KW - dormancy KW - germination KW - growing degree days KW - integrated management KW - seed bank KW - thermal-time KW - tillage ER - TY - JOUR TI - Biochar decreases atrazine and pendimethalin preemergence herbicidal activity AU - Soni, N. AU - Leon, R.G. AU - Erickson, J.E. AU - Ferrell, J.A. AU - Silveira, M.L. T2 - Weed Technology AB - Biochar and vinasse are by-products of biofuel production that can be used as soil amendments. However, their addition to the soil might affect PRE herbicide activity. Although studies have shown that biochar has a high herbicide adsorption capacity, there is little information available about biochar effect on weed control especially under field conditions. Therefore, the objective of this study was to determine the influence of biochar and vinasse application on atrazine and pendimethalin availability and herbicide activity under in vitro and field conditions. In vitro atrazine and pendimethalin herbicidal activities were not influenced by vinasse addition, but biochar application reduced atrazine and pendimethalin injury for all evaluated species. A sorption experiment confirmed high affinity of biochar for atrazine and pendimethalin. Linear regression analysis showed that the slope for atrazine and pendimethalin adsorption was 16 and 4 times higher in soil with biochar than in soil alone. Under field conditions, biochar at 0.5 kg m −2 reduced atrazine and pendimethalin weed control 75% and 60%, respectively. These results suggested that the use of biochar as a soil amendment in cropping system could decrease PRE herbicide efficacy. Therefore, mitigating practices such as the use of higher rates or reliance on POST herbicides and cultivation might be necessary to ensure proper weed control. DA - 2015/// PY - 2015/// DO - 10.1614/wt-d-14-00142.1 VL - 29 IS - 03 SP - 359–366 KW - Charcoal KW - injury KW - soil amendments KW - stillage KW - weed control ER - TY - SOUND TI - Yield enhancement and nitrogen use efficiency in grafted watermelon: Fact or fiction AU - Suchoff, D.H. AU - Schultheis, J.R. AU - Gunter, C.C. AU - Hassell, R.L. AU - Louws, F.J. AU - Jackson, B.E. DA - 2015/1/8/ PY - 2015/1/8/ M3 - poster ER - TY - SOUND TI - Response of Grafted Watermelon to Nitrogen AU - Suchoff, D.H. AU - Schultheis, J.R. AU - Gunter, C.C. AU - Hassell, R.L. AU - Louws, F.J. AU - Jackson, B.E. DA - 2015/1/31/ PY - 2015/1/31/ ER - TY - SOUND TI - Response of Grafted Tomatoes to Nitrogen AU - Suchoff, D.H. AU - Gunter, C.C. AU - Schultheis, J.R. AU - Hassell, R.L. AU - Louws, F.J. AU - Jackson, B.E. DA - 2015/8/5/ PY - 2015/8/5/ ER - TY - SOUND TI - Characterization of Root Systems in Tomato and Tomato Rootstocks Through the Use of Mini-Horhizotron Technology AU - Suchoff, D.H. AU - Gunter, C.C. AU - Schultheis, J.R. AU - Jackson, B.E. AU - Hassell, R.L. AU - Louws, F.J. DA - 2015/8/4/ PY - 2015/8/4/ M3 - poster ER - TY - JOUR TI - Settling of suspended particles by flocculation can reduce the size of sediment basin AU - Kang, J. AU - King, S.E. AU - McLaughlin, R.A. T2 - Journal of Environmental Management AB - Due to stringent water quality regulations on stormwater discharges, there is increasing interest in chemically-assisted settling of suspended sediments at construction sites. This study investigated settling characteristics of flocculated sediment by polyacrylamide (PAM) in a top-loading settling tube. Studied sediment materials were obtained from construction sites in North Carolina, USA: Coastal Plain loamy sand (CPLS), Piedmont sandy clay loam (PSCL), Piedmont silt loam (PSL), and Mountain clay loam (MCL). The four different sediment suspensions mixed with and without dissolved PAM were introduced to the top of the column individually. During a 1-h settling period, samples were taken at 1-m depth from surface at various times and analyzed for total suspended solids (TSS). Flocculated sediment by PAM greatly increased its settled TSS fraction up to 95-97% only in 1-min settling period compared to those of unflocculated sediment (16-72%). The settling improvement by PAM was profound in the finer-textured soils (PSL and MCL) by increasing their median particle settling velocity (>2 cm s(-1)) compared to unflocculated counterparts (<1.1 cm s(-1)). Estimated surface area requirement of sediment basin suggested that the basins receiving flocculated sediment could be reduced in size (surface area) by 2- to 4-times compared to those receiving unflocculated sediment. Our results suggests that current sediment basin design could be modified when chemically-assisted settling is implemented, taking up less space and cost in construction sites. DA - 2015/// PY - 2015/// DO - 10.1016/j.jenvman.2015.10.049 VL - 166 SP - 450–456 KW - Flocculation KW - Polyacrylamide KW - Sediment basin KW - Settling velocity KW - Total suspended solids ER - TY - JOUR TI - Soil Pollution Due to Irrigation with Arsenic-Contaminated Groundwater: Current State of Science AU - Gillispie, E.C. AU - Sowers, T.D. AU - Duckworth, O.W. AU - Polizzotto, M.L. T2 - Current Pollution Reports AB - Food with elevated arsenic concentrations is becoming widely recognized as a global threat to human health. This review describes the current state of knowledge of soil pollution derived from irrigation with arsenic-contaminated groundwater, highlighting processes controlling arsenic cycling in soils and resulting arsenic impacts on crop and human health. Irrigation practices utilized for both flooded and upland crops have the potential to load arsenic to soils, with a host of environmental and anthropogenic factors ultimately determining the fate of arsenic. Continual use of contaminated groundwater for irrigation may result in soils with concentrations sufficient to create dangerous arsenic concentrations in the edible portions of crops. Recent advances in low-cost water and soil management options show promise for mitigating arsenic impacts of polluted soils. Better understanding of arsenic transfer from soil to crops and the controls on long-term soil arsenic accumulation is needed to establish effective arsenic mitigation strategies within vulnerable agronomic systems. DA - 2015/// PY - 2015/// DO - 10.1007/s40726-015-0001-5 VL - 1 IS - 1 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-85039931557&partnerID=MN8TOARS KW - Arsenic KW - Soil KW - Irrigation KW - Crops KW - Human health KW - Mitigation ER - TY - JOUR TI - Molecular signals required for the establishment and maintenance of ectomycorrhizal symbioses AU - Garcia, Kevin AU - Delaux, Pierre-Marc AU - Cope, Kevin R. AU - Ané, Jean-Michel T2 - New Phytologist AB - Ectomycorrhizal (ECM) symbioses are among the most widespread associations between roots of woody plants and soil fungi in forest ecosystems. These associations contribute significantly to the sustainability and sustainagility of these ecosystems through nutrient cycling and carbon sequestration. Unfortunately, the molecular mechanisms controlling the mutual recognition between both partners are still poorly understood. Elegant work has demonstrated that effector proteins from ECM and arbuscular mycorrhizal (AM) fungi regulate host defenses by manipulating plant hormonal pathways. In parallel, genetic and evolutionary studies in legumes showed that a 'common symbiosis pathway' is required for the establishment of the ancient AM symbiosis and has been recruited for the rhizobia-legume association. Given that genes of this pathway are present in many angiosperm trees that develop ectomycorrhizas, we propose their potential involvement in some but not all ECM associations. The maintenance of a successful long-term relationship seems strongly regulated by resource allocation between symbiotic partners, suggesting that nutrients themselves may serve as signals. This review summarizes our current knowledge on the early and late signal exchanges between woody plants and ECM fungi, and we suggest future directions for decoding the molecular basis of the underground dance between trees and their favorite fungal partners. DA - 2015/4// PY - 2015/4// DO - 10.1111/nph.13423 VL - 208 IS - 1 SP - 79-87 KW - arbuscular mycorrhiza KW - common symbiosis pathway KW - ectomycorrhiza KW - effectors KW - nitrogen (N) KW - nutrient exchange KW - phosphorus (P) KW - signaling ER - TY - JOUR TI - NITROGEN APPLICATION RATE INFLUENCE ON YIELD, QUALITY, AND CHEMICAL CONSTITUENTS OF FLUE-CURED TOBACCO, PART I: APPLICATION TIMING AU - Drake, M.P. AU - Vann, M.C. AU - Fisher, L.R. T2 - Tobacco Science AB - Research was conducted at 5 locations between 2012 and 2013 to determine the effect of nitrogen application rate and timing on yield, quality, and leaf chemistry of flue-cured tobacco. Urea–ammoniu... DA - 2015/1// PY - 2015/1// DO - 10.3381/14-041r.1 VL - 52 SP - 11-17 ER - TY - JOUR TI - INFLUENCE OF NITROGEN APPLICATION RATE ON THE YIELD, QUALITY, AND CHEMICAL COMPONENTS OF FLUE-CURED TOBACCO, PART II: APPLICATION METHOD AU - Drake, M.P AU - Vann, M.C AU - Fisher, L.R T2 - Tobacco Science AB - Research was conducted in 2012 and 2013 to determine the effect of nitrogen application timing and method on the yield, quality, and leaf chemistry of flue-cured tobacco. Liquid urea–ammonium–nitrate supplied 100% of the total nitrogen and was applied in differing combinations of rates, timings, and methods. Nitrogen rates above, at, and below recommendation for specific locations were split into two, three, or four application timings depending on treatment. Nitrogen application was initiated at transplanting and concluded before or at topping. Applications of nitrogen were either soil applied at each interval or were soil applied until topping where application occurred over top to promote stalk rundown. Leaf tissue samples were collected at layby and topping to evaluate total nitrogen content throughout the growing season. Composite cured leaf tissue samples from all four stalk positions were analyzed for total alkaloid and reducing-sugar content. Yield data were collected and leaf quality was determin... DA - 2015/1// PY - 2015/1// DO - 10.3381/14-043 VL - 52 SP - 26-34 ER - TY - JOUR TI - Charles W. Stuber: Maize Geneticist and Pioneer of Marker-Assisted Selection AU - Holland, James AU - Graham, G. I. AU - Murphy, J. P. AU - Lynn, M. T2 - Plant breeding reviews, vol 39 DA - 2015/// PY - 2015/// DO - 10.1002/9781119107743.ch1 VL - 39 SP - 1–22 ER - TY - JOUR TI - On-Farm Grafted Tomato Trial to Manage Bacterial Wilt AU - Suchoff, D. AU - Gunter, C. AU - Schultheis, J. AU - Louws, F. J. T2 - I INTERNATIONAL SYMPOSIUM ON VEGETABLE GRAFTING AB - Grossing over $33.7 million in annual sales, North Carolina ranks 7th in the US for the production of tomatoes (Solanum lycopersicum). A replicated on-farm trial was conducted in Rowan County, NC. On May 30th, 2013, 8.1 ha of two bacterial wilt (BW; R. solanacearum (race 1)) resistant rootstocks were planted. The objective of this trial was to evaluate disease susceptibility and production in fields with BW history. In addition, plant spacing and training systems were compared. Two experimental sites, one fumigated and one non-fumigated, were arranged in a randomized complete block design with four replications, each consisting of 91.4 m-rows in a commercial plasticulture system. Each row contained 13 10-plant treatment plots (2A—2A—3 Factorial + Control): two rootstocks (‘801’, ‘802’; Rijk Zwaan), two training systems (single-leader, double-leaders), three between-plant spacings (45.7, 61.0, and 76.2 cm) with ‘Mountain Fresh’ as the scion and a non-grafted ‘Mountain Fresh’ control spaced at 45.7 cm. Wilt incidence was collected during the two harvests. Fruit were harvested twice at 69 and 84 days after transplanting. Wilt incidence was lower in the non-fumigated field and no differences in yield between the grafted and non-grafted plants were observed. In the fumigated field, the main effect of grafting tended to increase yield. Both the main effect of training system and spacing significantly affected yield in the grafted treatments. BW incidence was significantly higher in the non-grafted treatment (29.08%) than ‘801’ and ‘802’ rootstocks (0.909 and 0.183%, respectively) (P<.0001). Single-leader grafted plants had 2.54% more BW incidence than double-leader plants (P=0.0007). Grafted tomatoes offered an alternative method to fumigation as a means to reduce BW loss and sustain marketable yield. DA - 2015/// PY - 2015/// DO - 10.17660/actahortic.2015.1086.14 VL - 1086 SP - 119-127 SN - 0567-7572 KW - grafted tomato KW - on-farm KW - bacterial wilt ER - TY - JOUR TI - Methods for RNA Profiling of Gravi-Responding Plant Tissues AU - Dalal, Jyoti AU - Land, Eric AU - Vasani, Naresh AU - He, Luyan AU - Smith, Caroline AU - Rodriguez-Welsh, Maria AU - Perera, Imara Y. AU - Sederoff, Heike T2 - PLANT GRAVITROPISM: METHODS AND PROTOCOLS AB - Plant transcriptional responses to gravity stimulation by reorientation are among the fastest measured in any tissue or species. Upon reorientation, changes in abundance of specific mRNAs can be measured within seconds or minutes, for plastid or nuclear encoded genes, respectively. Identifying fast gravity-induced transcripts has been made possible by the development of high-throughput technology for qualitative and quantitative RNA analysis. RNA profiling has undergone further rapid development due to its enormous potential in basic sciences and medical applications. We describe here the current and most widely used methods to profile the changes in an entire transcriptome by high-throughput sequencing of RNA fractions (RNAseq) and single gene transcript analysis using real-time quantitative reverse-transcriptase polymerase chain reaction (qRT-PCR). DA - 2015/// PY - 2015/// DO - 10.1007/978-1-4939-2697-8_9 VL - 1309 SP - 91-117 SN - 1940-6029 KW - RNA KW - Transcript KW - Transcriptome KW - Sequencing KW - PCR KW - RNAseq KW - sRNA KW - miRNA ER - TY - JOUR TI - Identification of resistance to the Ga1-m gametophyte factor in maize AU - Jones, Zachary G. AU - Goodman, Major M. AU - Krakowsky, Matthew D. T2 - EUPHYTICA DA - 2015/12// PY - 2015/12// DO - 10.1007/s10681-015-1518-9 VL - 206 IS - 3 SP - 785-791 SN - 1573-5060 KW - Gametophyte Factors KW - Ga1 KW - Maize KW - Popcorn ER - TY - JOUR TI - Gut bacteria mediate aggregation in the German cockroach AU - Wada-Katsumata, A. AU - Zurek, L. AU - Nalyanya, G. AU - Roelofs, W. L. AU - Zhang, A. J. AU - Schal, C. T2 - Proceedings of the National Academy of Sciences of the United States of America AB - Aggregation of the German cockroach, Blattella germanica, is regulated by fecal aggregation agents (pheromones), including volatile carboxylic acids (VCAs). We demonstrate that the gut microbial community contributes to production of these semiochemicals. Chemical analysis of the fecal extract of B. germanica revealed 40 VCAs. Feces from axenic cockroaches (no microorganisms in the alimentary tract) lacked 12 major fecal VCAs, and 24 of the remaining compounds were represented at extremely low amounts. Olfactory and aggregation bioassays demonstrated that nymphs strongly preferred the extract of control feces over the fecal extract of axenic cockroaches. Additionally, nymphs preferred a synthetic blend of 6 fecal VCAs over a solvent control or a previously identified VCA blend. To test whether gut bacteria contribute to the production of fecal aggregation agents, fecal aerobic bacteria were cultured, isolated, and identified. Inoculation of axenic cockroaches with individual bacterial taxa significantly rescued the aggregation response to the fecal extract, and inoculation with a mix of six bacterial isolates was more effective than with single isolates. The results indicate that the commensal gut microbiota contributes to production of VCAs that act as fecal aggregation agents and that cockroaches discriminate among the complex odors that emanate from a diverse microbial community. Our results highlight the pivotal role of gut bacteria in mediating insect-insect communication. Moreover, because the gut microbial community reflects the local environment, local plasticity in fecal aggregation pheromones enables colony-specific odors and fidelity to persistent aggregation sites. DA - 2015/// PY - 2015/// DO - 10.1073/pnas.1504031112 VL - 112 IS - 51 SP - 15678-15683 ER - TY - JOUR TI - Short-term nitrogen mineralization from warm-season cover crops in organic farming systems AU - S. O'Connell, AU - Shi, W. AU - Grossman, J. M. AU - Hoyt, G. D. AU - Fager, K. L. AU - Creamer, N. G. T2 - PLANT AND SOIL DA - 2015/11// PY - 2015/11// DO - 10.1007/s11104-015-2594-2 VL - 396 IS - 1-2 SP - 353-367 SN - 1573-5036 KW - Residue decomposition KW - Nitrogen mineralization KW - Green manure KW - Carbon use efficiency KW - Organic farming KW - Drought ER - TY - JOUR TI - Limited-Transpiration Trait May Increase Maize Drought Tolerance in the US Corn Belt AU - Messina, Carlos D. AU - Sinclair, Thomas R. AU - Hammer, Graeme L. AU - Curan, Dian AU - Thompson, Jason AU - Oler, Zac AU - Gho, Carla AU - Cooper, Mark T2 - AGRONOMY JOURNAL AB - Yield loss due to water deficit is ubiquitous in maize ( Zea mays L.) production environments in the United States. The impact of water deficits on yield depends on the cropping system management and physiological characteristics of the hybrid. Genotypic diversity among maize hybrids in the transpiration response to vapor pressure deficit (VPD) indicates that a limited‐transpiration trait may contribute to improved drought tolerance and yield in maize. By limiting transpiration at VPD above a VPD threshold, this trait can increase both daily transpiration efficiency and water availability for late‐season use. Reduced water use, however, may compromise yield potential. The complexity associated with genotype × environment × management interactions can be explored in a quantitative assessment using a simulation model. A simulation study was conducted to assess the likely effect of genotypic variation in limited‐transpiration rate on yield performance of maize at a regional scale in the United States. We demonstrated that the limited‐transpiration trait can result in improved maize performance in drought‐prone environments and that the impact of the trait on maize productivity varies with geography, environment type, expression of the trait, and plant density. The largest average yield increase was simulated for drought‐prone environments (135 g m −2 ), while a small yield penalty was simulated for environments where water was not limiting (–33 g m −2 ). Outcomes from this simulation study help interpret the ubiquitous nature of variation for the limited‐transpiration trait in maize germplasm and provide insights into the plausible role of the trait in past and future maize genetic improvement. DA - 2015/// PY - 2015/// DO - 10.2134/agronj15.0016 VL - 107 IS - 6 SP - 1978-1986 SN - 1435-0645 ER - TY - JOUR TI - Lentil Variation in Phenology and Yield Evaluated with a Model AU - Ghanem, Michel Edmond AU - Marrou, Helene AU - Soltani, Afshin AU - Kumar, Shiv AU - Sinclair, Thomas R. T2 - AGRONOMY JOURNAL AB - Lentil ( Lens culinaris Medik.) is a major crop highly valued in the food and nutritional security of millions of people, as well as a rotation crop. Lentil is grown in areas facing many environmental constraints from low moisture availability and high temperatures to winter cold at high elevations. The use of an appropriate and robust crop model can offer mechanistic bases for exploring and extrapolating the impact of a given plant trait or crop management across a range of environments. First, we used the generic SSM‐Legumes model to develop a simple and transparent lentil model. The SSM‐Legumes model had a robust predictive capability to assess variation in the phenological development and yield of lentil in three locations in the Middle East (Lebanon and Syria) with large differences in rainfall. The agreement between simulated and observed days to flowering or maturity and yield showed the robustness of the model in predicting lentil growth and yield. Second, we incorporated into SSM‐legumes a submodel allowing a more realistic accounting of crop survival at very low soil water content, resulting in more realistic predictions of lentil growth and yield. Third, we used the model to test the potential for increasing lentil yields by the retention of crop residue on the soil surface to decrease soil evaporation. Our results showed yield increases of up to 25% in all three locations from the retention of previous crop residues. DA - 2015/// PY - 2015/// DO - 10.2134/agronj15.0061 VL - 107 IS - 6 SP - 1967-1977 SN - 1435-0645 ER - TY - JOUR TI - Combining hydroacoustic and point-intercept survey methods to assess aquatic plant species abundance patterns and community dominance AU - Valley, R. D. AU - Johnson, M. B. AU - Dustin, D. L. AU - Jones, K. D. AU - Lauenstein, M. R. AU - Nawrocki, J. T2 - Journal of Aquatic Plant Management DA - 2015/// PY - 2015/// VL - 53 SP - 121-129 ER - TY - JOUR TI - Arsenic Distribution and Speciation in a Managed Turfgrass System Following Monosodium Methylarsenate Application AU - Mahoney, Denis J. AU - Gannon, Travis W. AU - Jeffries, Matthew D. AU - Polizzotto, Matthew L. T2 - CROP SCIENCE AB - ABSTRACT Monosodium methylarsenate (MSMA) is an organic arsenical herbicide commonly used in certain warm‐season turfgrasses. Recently, concerns about MSMA use have arisen because of the release of As into the environment, although the fate of applied As is not well quantified for realistic management scenarios. Greenhouse lysimeter experiments were conducted to determine As distribution and speciation over time following an MSMA application to established bermudagrass [ Cynodon dactylon (L.) Pers.]. At 1 wk after treatment (WAT), up to 65% of As from MSMA was detected in bermudagrass clippings and the remaining aboveground vegetation. Elevated soil and porewater As concentrations were detected to 5 cm depth but increases were not observed below this depth. Mass balance calculations revealed that As partitioned into the soil over time, with 91% of the applied As residing in the upper 5 cm of soil solids by 8 WAT. Arsenate was the dominant As species by 2 WAT and thereafter in porewater and soil. Results indicate that turfgrass management plans could be altered to minimize potential off‐target contamination from MSMA by returning clippings following mowing events and using MSMA in a herbicide rotation. DA - 2015/// PY - 2015/// DO - 10.2135/cropsci2015.03.0163 VL - 55 IS - 6 SP - 2877-2885 SN - 1435-0653 ER - TY - JOUR TI - A Non-Empirical Method for Computing Pore Radii and Soil Water Characteristics from Particle-Size Distribution AU - Arya, Lalit M. AU - Heitman, Joshua L. T2 - SOIL SCIENCE SOCIETY OF AMERICA JOURNAL AB - Soil water characteristics (SWC) is a common requirement in studies of soil physics and hydrology, and modeling this property is preferred because experimental measurements are error-prone, time-consuming, and costly. However, unknown empirical parameters in SWC models remain a source of uncertainty. This study proposes a formulation for computing pore radii and SWCs from routinely available particle-size distribution (PSD), bulk density, and particle density data, without the need for incorporating unknown empirical parameters. The proposed model emerged from combining attributes of natural-packed soil structure with those of a counterpart hypothetical structure consisting of spherical particles, and has the form where rin is the pore radius for a given fraction of particles on the PSD curve, Φ is the porosity, wi is the fraction solid mass, ρb is the bulk density, ni is the number of spherical particles that can be formed using the fraction solid mass, and Ri is the mean particle radius for the fraction. The model was applied to calculate SWC for 41 soils consisting of loam, clay, sandy loam, and sand textures. Root mean square residuals (RMSRs) of log-transformed pressure heads were calculated to assess goodness of agreement between experimental pressure heads and those predicted by the non-empirical model of this study and the empirical model of Arya et al. The distribution of RMSR values (log10|h|, cm) showed a range from 0.021 to 1.309. When viewed in conjunction with plotted SWC curves, results showed reasonable to excellent agreement with experimental data in about 75% of the cases. Barring a few exceptions, predictions of the proposed model also agreed well with predictions of the empirical model of Arya et al. DA - 2015/// PY - 2015/// DO - 10.2136/sssaj2015.04.0145 VL - 79 IS - 6 SP - 1537-1544 SN - 1435-0661 ER - TY - JOUR TI - Vertical blocking in cotton cultivar performance trials in North Carolina AU - Bowman, D. T. AU - Kuraparthy, V. T2 - Journal of Cotton Science DA - 2015/// PY - 2015/// VL - 19 IS - 2 SP - 250-257 ER - TY - JOUR TI - Using precipitation forecasts to irrigate cotton AU - Christ, E. H. AU - Webster, P. J. AU - Collins, G. D. AU - Toma, V. E. AU - Byrd, S. A. T2 - Journal of Cotton Science DA - 2015/// PY - 2015/// VL - 19 IS - 3 SP - 351-358 ER - TY - JOUR TI - Sequential and co-application of glyphosate and glufosinate in cotton AU - Cahoon, C. W. AU - York, A. C. AU - Jordan, D. L. AU - Seagroves, R. W. AU - Everman, W. J. AU - Jennings, K. M. T2 - Journal of Cotton Science DA - 2015/// PY - 2015/// VL - 19 IS - 2 SP - 337-350 ER - TY - JOUR TI - QTL Mapping Using High-Throughput Sequencing AU - Jamann, Tiffany M. AU - Balint-Kurti, Peter J. AU - Holland, James B. T2 - PLANT FUNCTIONAL GENOMICS: METHODS AND PROTOCOLS, 2ND EDITION AB - Quantitative trait locus (QTL) mapping in plants dates to the 1980s (Stuber et al. Crop Sci 27: 639–648, 1987; Paterson et al. Nature 335: 721–726, 1988), but earlier studies were often hindered by the expense and time required to identify large numbers of polymorphic genetic markers that differentiated the parental genotypes and then to genotype them on large segregating mapping populations. High-throughput sequencing has provided an efficient means to discover single nucleotide polymorphisms (SNPs) that can then be assayed rapidly on large populations with array-based techniques (Gupta et al. Heredity 101: 5–18, 2008). Alternatively, high-throughput sequencing methods such as restriction site-associated DNA sequencing (RAD-Seq) (Davey et al. Nat Rev Genet 12: 499–510, 2011; Baird et al. PloS ONE 3: e3376, 2008) and genotyping-by-sequencing (GBS) (Elshire et al. PLoS One 6: 2011; Glaubitz et al. PLoS One 9: e90346, 2014) can be used to identify and genotype polymorphic markers directly. Linkage disequilibrium (LD) between markers and causal variants is needed to detect QTL. The earliest QTL mapping methods used backcross and F2 generations of crosses between inbred lines, which have high levels of linkage disequilibrium (dependent entirely on the recombination frequency between chromosomal positions), to ensure that QTL would have sufficiently high linkage disequilibrium with one or more markers on sparse genetic linkage maps. The downside of this approach is that resolution of QTL positions is poor. The sequencing technology revolution, by facilitating genotyping of vastly more markers than was previously feasible, has allowed researchers to map QTL in situations of lower linkage disequilibrium, and consequently, at higher resolution. We provide a review of methods to identify QTL with higher precision than was previously possible. We discuss modifications of the traditional biparental mapping population that provide higher resolution of QTL positions, QTL fine-mapping procedures, and genome-wide association studies, all of which are greatly facilitated by high-throughput sequencing methods. Each of these procedures has many variants, and consequently many details to consider; we focus our chapter on the consequences of practical decisions that researchers make when designing QTL mapping studies and when analyzing the resulting data. The ultimate goal of many of these studies is to resolve a QTL to its causal sequence variation. DA - 2015/// PY - 2015/// DO - 10.1007/978-1-4939-2444-8_13 VL - 1284 SP - 257-285 SN - 1940-6029 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-84924917656&partnerID=MN8TOARS KW - Fine-mapping KW - Map-based cloning KW - Genome-wide association study ER - TY - JOUR TI - Fluridone carryover to rotational crops following application to cotton AU - Cahoon, C. W. AU - York, A. C. AU - Jordan, D. L. AU - Seagroves, R. W. AU - Everman, W. J. AU - Jennings, K. M. T2 - Journal of Cotton Science DA - 2015/// PY - 2015/// VL - 19 IS - 3 SP - 631-640 ER - TY - JOUR TI - Effect of diuron and fluometuron on grain sorghum and soybean as replacement crops following a cotton stand failure AU - Braswell, L. R. AU - York, A. C. AU - Jordan, D. L. AU - Seagroves, R. W. T2 - Journal of Cotton Science DA - 2015/// PY - 2015/// VL - 19 IS - 3 SP - 613-621 ER - TY - JOUR TI - Defoliant effects on cover crop germination, cover crop growth, and subsequent cotton (Gossypium hirsutum) development AU - Foote, W. AU - Edmisten, K. AU - Wells, R. AU - Jordan, D. T2 - Journal of Cotton Science DA - 2015/// PY - 2015/// VL - 19 IS - 2 SP - 258-267 ER - TY - JOUR TI - Cotton response and Palmer amaranth control with mixtures of glufosinate and residual herbicides AU - Cahoon, C. W. AU - York, A. C. AU - Jordan, D. L. AU - Seagroves, R. W. T2 - Journal of Cotton Science DA - 2015/// PY - 2015/// VL - 19 IS - 3 SP - 622-630 ER - TY - JOUR TI - Sensitivity of freshwater molluscs to hydrilla-targeting herbicides: providing context for invasive aquatic weed control in diverse ecosystems AU - Archambault, Jennifer M. AU - Bergeron, Christine M. AU - Cope, W. Gregory AU - Richardson, Robert J. AU - Heilman, Mark A. AU - Corey, J. Edward, III AU - Netherland, Michael D. AU - Heise, Ryan J. T2 - JOURNAL OF FRESHWATER ECOLOGY AB - Hydrilla (Hydrilla verticillata) is an invasive aquatic weed that has spread rapidly throughout the USA, especially in the southeast. A common control method is the application of aquatic herbicides, such as fluridone and endothall. However, there is limited documentation on the effects of herbicides commonly used to control hydrilla and other aquatic weeds on many non-target freshwater species and no published information exists on the toxicity of these herbicides to freshwater molluscs. We exposed juveniles (96 h) and glochidia (48 h) of the unionid mussel Lampsilis siliquoidea and adults (28 d) of Lampsilis fullerkati to a formulation of fluridone (Sonar – PR®) in laboratory toxicity tests. The early life stages of L. siliquoidea were also exposed to a formulation of the dipotassium salt of endothall (Aquathol – K®) in separate tests. Juveniles of the freshwater gastropod snail, Somatogyrus viriginicus (Lithoglyphidae), were exposed (96 h) to the Sonar – Genesis® fluridone formulation. Endpoints were survival (all species and life stages) as well as siphoning behavior and foot protrusion (adult mussels). Median lethal fluridone concentrations (LC50s) were 865 μg/L (95% CI, 729–1,026 μg/L) for glochidia (24 h), 511 μg/L (309–843 μg/L) for juvenile L. siliquoidea (96 h), and 500 μg/L (452–553 μg/L) for juvenile S. viriginicus (96 h). No mortality occurred in the 28-d exposure of adult L. fullerkati and we found no statistically significant effect of fluridone concentration on foot protrusion (p = 0.06) or siphoning behavior (p = 0.08). The 24-h LC50 for glochidia exposed to the dipotassium salt of endothall was 31.2 mg/L (30.3–32.2 mg/L) and the 96-h LC50 for juvenile mussels was 34.4 mg/L (29.3–40.5 mg/L). Freshwater molluscs were more sensitive to fluridone and endothall than most other species previously tested. Fluridone and endothall concentrations typically recommended for hydrilla treatment (5–15 μg/L and 1–5 mg/L, respectively) were not acutely toxic to the molluscs we tested and a 28-d exposure to fluridone was not lethal to adult mussels even at the highest concentration (300 μg/L), indicating minimal risk of short-term exposure effects. DA - 2015/// PY - 2015/// DO - 10.1080/02705060.2014.945104 VL - 30 IS - 3 SP - 335-348 SN - 2156-6941 KW - fluridone (Sonar) KW - endothall (Aquathol) KW - unionid mussels KW - snails KW - LC50 KW - toxicity KW - invasive species ER - TY - JOUR TI - Management of Aquatic Vegetation in the Southeastern United States AU - Stallings, Kevin D. AU - Seth-Carley, Danesha AU - Richardson, Robert J. T2 - JOURNAL OF INTEGRATED PEST MANAGEMENT AB - Aquatic vegetation is managed throughout the southeastern United States with the guidance of state and federal aquatic plant management plans. These plans often suggest ways to promote the growth of beneficial aquatic plants while attempting to guide the reduction and elimination of unwanted “weedy species.” Aquatic species are divided into the categories of algae, submersed, emergent, and floating species and this classification is based on the morphology and growth habit of the identified species. These species are surveyed using multiple research techniques designed to identify and manage the resource based on the needs of the stakeholder. Management practices can be subdivided into physical, mechanical, biological, and chemical control to reduce or eliminate an undesirable weed species. This document reviews current literature related to management of aquatic plants and provides an overview of problematic aquatic weeds in the southeastern United States. DA - 2015/1// PY - 2015/1// DO - 10.1093/jipm/pmv002 VL - 6 IS - 1 SP - SN - 2155-7470 KW - aquatic KW - management plan KW - control practice KW - weed KW - integrated pest management ER - TY - JOUR TI - Cotton as a World Crop: Origin, History, and Current Status AU - Lee, Joshua A. AU - Fang, David D. T2 - COTTON, 2ND EDITION AB - Archaeological evidence indicates that cotton has been used by humans for more than 4000 yr. The history of cotton cultivation is at least 3000 yr old. There are four cultivated cotton species, two diploid species and two tetraploid species. In this chapter, the origin and history of these four species as a crop were discussed based on theoretical consideration and archaeological evidence. Domestication of wild tetraploid cotton as an annual day-neutral crop was a big step toward cotton agriculture. Spread of cotton to the United States and its wide cultivation in this country facilitated cotton becoming a world crop. Technology advancements in cultivation, ginning, and spinning solidified the important role of cotton in the world economy. New technologies such as transgenic varieties are revolutionizing the cotton industry. This chapter provides a historical view of how cotton has become as a world crop. DA - 2015/// PY - 2015/// DO - 10.2134/agronmonogr57.2013.0019 VL - 57 SP - 1-23 SN - 2156-3276 ER - TY - CHAP TI - Virus-Induced Gene Silencing of Fiber-Related Genes in Cotton AU - Tuttle, John R. AU - Haigler, Candace H. AU - Robertson, Dominique T2 - Methods in Molecular Biology AB - Virus-Induced Gene Silencing (VIGS) is a useful method for transient downregulation of gene expression in crop plants. The geminivirus Cotton leaf crumple virus (CLCrV) has been modified to serve as a VIGS vector for persistent gene silencing in cotton. Here the use of Green Fluorescent Protein (GFP) is described as a marker for identifying silenced tissues in reproductive tissues, a procedure that requires the use of transgenic plants. Suggestions are given for isolating and cloning combinations of target and marker sequences so that the total length of inserted foreign DNA is between 500 and 750 bp. Using this strategy, extensive silencing is achieved with only 200–400 bp of sequence homologous to an endogenous gene, reducing the possibility of off-target silencing. Cotyledons can be inoculated using either the gene gun or Agrobacterium and will continue to show silencing throughout fruit and fiber development. CLCrV is not transmitted through seed, and VIGS is limited to genes expressed in the maternally derived seed coat and fiber in the developing seed. This complicates the use of GFP as a marker for VIGS because cotton fibers must be separated from unsilenced tissue in the seed to determine if they are silenced. Nevertheless, fibers from a large number of seeds can be rapidly screened following placement into 96-well plates. Methods for quantifying the extent of silencing using semiquantitative RT-PCR are given. PY - 2015/// DO - 10.1007/978-1-4939-2453-0_16 VL - 1287 SP - 219-234 OP - PB - Springer New York SN - 9781493924523 9781493924530 UR - http://dx.doi.org/10.1007/978-1-4939-2453-0_16 DB - Crossref KW - Virus-induced gene silencing KW - VIGS KW - Cotton fiber KW - GFP KW - Silencing KW - Semiquantitative RT-PCR ER - TY - JOUR TI - Variation among Cowpea Genotypes in Sensitivity of Transpiration Rate and Symbiotic Nitrogen Fixation to Soil Drying AU - Sinclair, Thomas R. AU - Manandhar, Anju AU - Belko, Nouhoun AU - Riar, Mandeep AU - Vadez, Vincent AU - Roberts, Philip A. T2 - CROP SCIENCE AB - ABSTRACT Cowpea ( Vigna unguiculata L. Walp.) is often considered a crop species appropriate for drier environments. However, little or no information exists on two key physiological traits for drought conditions: early decrease in transpiration rate in the soil drying cycle and sustained N fixation activity under low soil‐water conditions. In this study, the responses of these two traits to soil drying were compared among 10 genotypes. The fraction of transpirable soil water at which transpiration rate began to decline varied from 0.59 to 0.24. The genotypes with the higher thresholds for the transpiration decrease offer a conservative water use strategy during soil drying and, hence, may be especially appropriate for very dry areas. The fraction of transpirable soil water at which N fixation rate began to decline ranged from 0.33 in one line to another line in which there was no decline in N fixation rate. Five lines had especially low thresholds for the decline in N fixation rate, which would be highly desirable in arid areas. In fact, N fixation tolerance to drought in these five lines is superior to any responses observed in other grain legumes. There was no correlation between the thresholds for decline in transpiration and N fixation. DA - 2015/// PY - 2015/// DO - 10.2135/cropsci2014.12.0816 VL - 55 IS - 5 SP - 2270-2275 SN - 1435-0653 ER - TY - JOUR TI - Quantifying the effects of wheat residue on severity of Stagonospora nodorum blotch and yield in winter wheat AU - Mehra, L. K. AU - Cowger, C. AU - Weisz, R. AU - Ojiambo, P. S. T2 - Phytopathology AB - Stagonospora nodorum blotch (SNB), caused by the fungus Parastagonospora nodorum, is a major disease of wheat (Triticum aestivum). Residue from a previously infected wheat crop can be an important source of initial inoculum, but the effects of infected residue on disease severity and yield have not previously been quantified. Experiments were conducted in Raleigh and Salisbury, North Carolina, in 2012, 2013, and 2014 using the moderately susceptible winter wheat cultivar DG Shirley. In 2014, the highly susceptible cultivar DG 9012 was added to the experiment and the study was conducted at an additional site in Tyner, North Carolina. Four (2012) or six (2013 and 2014) wheat residue treatments were applied in the field in a randomized complete block design with five replicates. Treatments in 2012 were 0, 30, 60, and 90% residue coverage of the soil surface, while 10 and 20% residue treatments were added in 2013 and 2014. Across site-years, disease severity ranged from 0 to 50% and increased nonlinearly (P < 0.05) as residue level increased, with a rapid rise to an upper limit and showing little change in severity above 20 to 30% soil surface coverage. Residue coverage had a significant (P < 0.05) effect on disease severity in all site-years. The effect of residue coverage on yield was only significant (P < 0.05) for DG Shirley at Raleigh and Salisbury in 2012 and for DG 9012 at Salisbury in 2014. Similarly, residue coverage significantly (P < 0.05) affected thousand-kernel weight only of DG 9012 in 2014 at Raleigh and Salisbury. Our results showed that when wheat residue was sparse, small additions to residue density produced greater increases in SNB than when residue was abundant. SNB only led to effects on yield and test weight in the most disease-conducive environments, suggesting that the economic threshold for the disease may be higher than previously assumed and warrants review. DA - 2015/// PY - 2015/// DO - 10.1094/phyto-03-15-0080-r VL - 105 IS - 11 SP - 1417-1426 ER - TY - JOUR TI - Phylogenomics of polyploid Fothergilla (Hamamelidaceae) by RAD-tag based GBS-insights into species origin and effects of software pipelines AU - Qi, Zhe-Chen AU - Yu, Yi AU - Liu, Xiang AU - Pais, Andrew AU - Ranney, Thomas AU - Whetten, Ross AU - Xiang, Qiu-Yun T2 - JOURNAL OF SYSTEMATICS AND EVOLUTION AB - Abstract Fothergilla (Hamamelidaceae) consists of Fothergilla gardenii (4 x ) from the coastal plains of the southeastern USA, F. major (6 x ) from the piedmont and mountains of the same region, and a few allopatric diploid populations of unknown taxonomic status. The objective of this study was to explore the relationships of the polyploid species with the diploid plants. Genotyping by sequencing (GBS) was applied to generate genome‐wide molecular markers for phylogenetic and genetic structure analyses of 36 accessions of Fothergilla . Sanger sequencing of three plastid and one nuclear regions provided data for comparison with GBS‐based results. Phylogenetic outcomes were compared using data from different sequencing runs and different software workflows. The different data sets showed substantial differences in inferred phylogenies, but all supported a genetically distinct 6 x F. major and two lineages of the diploid populations closely associated with the 4 x F. gardenii . We hypothesize that the 4 x F. gardenii originated through hybridization between the Gulf coastal 2 x and an extinct (or undiscovered) 2 x lineage, followed by backcrosses to the Atlantic coastal 2 x before chromosome doubling, and the 6 x F. major also originated from the “extinct” 2 x lineage. Alternative scenarios are possible but are not as well supported. The origins and divergence of the polyploid species likely occurred during the Pleistocene cycles of glaciation, although fossil evidence indicates the genus might have existed for a much longer time with a wider past distribution. Our study demonstrates the power of combining GBS data with Sanger sequencing in reconstructing the evolutionary network of polyploid lineages. DA - 2015/9// PY - 2015/9// DO - 10.1111/jse.12176 VL - 53 IS - 5 SP - 432-447 SN - 1759-6831 KW - Fothergilla KW - hybridization KW - illumina sequencing KW - phylogenomics KW - RAD-tag-based GBS KW - polyploidy ER - TY - JOUR TI - Nitrogen recovery by cover crops in relation to time of planting and growth termination AU - Komatsuzaki, M. AU - Wagger, M. G. T2 - JOURNAL OF SOIL AND WATER CONSERVATION AB - Residual fertilizer nitrogen (N) in soil represents a potential environmental contaminant because of the risk of nitrate (NO3) leaching into ground water. Winter annual grass cover crops can conserve residual soil N; however, their ability to recover N greatly varies with management. A two-year field experiment in the North Carolina Coastal Plain on a State fine sandy loam (fine-loamy, mixed, thermic Typic Hapludult) compared dry matter (DM), N accumulation, and soil inorganic N following rye (Secale cereale L.), winter wheat (Triticum aestivum L.), triticale (Triticum secale L.), black oats (Avena strigosa L.), and fallow (native weeds) in relation to planting (October, November, and December) and growth termination (early March, early April, and late April/early May) dates and levels of residual soil N. Cover crop DM and N accumulations decreased with successive planting date delays (November and December) for each growth termination date in the following spring. In 2000, cumulative DM yields of October- and November-planted cover crops were 3.17 Mg ha−1 (1.41 tn ac−1) and 3.74 Mg ha−1 (1.66 tn ac−1), respectively, which were significantly greater than those of December-planted cover crops (1.90 Mg ha−1 [0.84 tn ac−1]) at the second growth termination date (early April). Cover crop N accumulation increased with a delay in growth termination, although the interaction between cover crop species and the planting date varied. October planting of rye and triticale showed greater N accumulation at a March growth termination date, averaging 37.8 kg N ha−1 (33.7 lb N ac−1) for rye and 37.6 kg N ha−1 (33.5 lb N ac−1) for triticale; these values were 7.8% and 14.1% higher than those of black oat and wheat, respectively, at the same planting and growth termination dates. November-planted wheat showed in the highest N accumulation (average, 57.9 kg N ha−1 [51.7 lb N ac−1]) at the late April/early May termination date; this was 3.8% to 7.9% higher than that of other species. In contrast, black oat showed a greater ability to scavenge soil residual N with a late planting and growth termination date combination (average, 58.7 kg N ha−1 [52.4 lb N ac−1]). The cover crop planting date affected soil inorganic N distribution at each termination date, with an October planting date resulting in lower soil profile inorganic N levels than November and December planting dates. Lower soil inorganic N concentrations were strongly associated with increases in cover crop DM and N accumulation for each growth termination date. These results should help growers identify the best niche for a cover crop with respect to recovering residual soil N in their various rotations. DA - 2015/// PY - 2015/// DO - 10.2489/jswc.70.6.385 VL - 70 IS - 6 SP - 385-398 SN - 1941-3300 KW - black oat KW - nitrogen leaching KW - planting time KW - rye KW - triticale KW - wheat ER - TY - JOUR TI - Grazing management strategies affect year-after establishment performance of a legume strip-planted into warm-season grass pasture AU - Castillo, M.S. AU - Sollenberger, L.E. AU - Mullenix, M.K. AU - Blount, A.R. AU - Williams, M.J. AU - Mackowiak, C.L. T2 - Crop Sci AB - ABSTRACT Establishing rhizoma peanut ( Arachis glabrata Benth.; RP) in strips into existing bahiagrass ( Paspalum notatum Flüggé) pastures has potential to increase forage nutritive value, decrease N fertilizer use, and improve N cycling. Grazing the grass–legume mixture in the year after planting may be possible, but appropriate grazing management strategies have not been defined. The objectives were to determine (i) the effect of year‐after‐planting (Y2) grazing management on ‘Florigraze’ RP performance when strip planted in bahiagrass swards, and (ii) the interaction of Y2 defoliation strategies with those imposed in the year of planting (Y1). Treatments were the factorial combinations of four Y1 defoliation strategies (no defoliation, hay production, simulated continuous stocking, and rotational stocking every 28 d) and three Y2 grazing frequencies (simulated continuous, 28 d, and 42 d to a 15‐cm bahiagrass stubble height). Grazing pastures in Y2 reduced RP contribution relative to that at the end of Y1. Canopy cover and frequency decreased from 30 to 10% and 80 to 50%, respectively, due to Y2 grazing for both Y1 no defoliation and hay production treatments. Cover remained below 10% in Y2 for both Y1 simulated continuous and rotational stocking treatments. Spread of RP into adjacent bahiagrass was greater in Y2 plots that in Y1 were not defoliated or were used for hay production (∼27 cm) than grazed (∼0 cm) plots. Results indicate that grazing during Y2 negatively affects RP establishment regardless of grazing frequency or RP cover at the beginning of Y2. Cattle preference for RP resulted in overgrazing; thus, if grazing occurs during RP establishment, target endpoints should be based on RP strips not the surrounding bahiagrass. DA - 2015/// PY - 2015/// DO - 10.2135/cropsci2015.02.0090 VL - 55 IS - 5 SP - 2384–2389 SN - 1435-0653 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-84939534093&partnerID=MN8TOARS ER - TY - JOUR TI - Determining Soil Ice Contents during Freezing and Thawing with Thermo-Time Domain Reflectometry AU - Tian, Zhengchao AU - Heitman, Joshua AU - Horton, Robert AU - Ren, Tusheng T2 - Vadose Zone Journal AB - Core Ideas An optimum heat application strategy was established for measuring thermal properties with the heat pulse method in partially frozen soils. At temperatures ≤ −5°C, T‐TDR probes were able to measure soil ice content changes with acceptable accuracy. At temperatures between −5 and 0°C, soil ice contents could be estimated from water content before freezing, TDR measured unfrozen water content, and T‐TDR measured total water content at temperatures below −5°C. Determining soil ice content during freezing and thawing is important and challenging for both engineering and environmental issues. The thermo‐time domain reflectometry (T‐TDR) probe, which can monitor unfrozen soil water content and soil thermal properties simultaneously, has the potential to measure ice content in partially frozen soils. The objective of this study was to identify an optimum heat application strategy for measuring soil thermal properties with T‐TDR probes in partially frozen soil while minimizing ice melting during the process. The optimized heating schemes were then applied for monitoring soil ice content dynamics during freezing and thawing. The results indicated that the heat pulse method failed at temperatures between −5 and 0°C because of temperature field disturbances from latent heat of fusion. When soil temperatures were ≤ −5°C, ice melting during heat pulse applications could be limited effectively with a combination of 60‐s heat‐pulse duration and 450 J m −1 heating strength, or a 90‐s heat‐pulse duration and heating strength of 450 to 900 J m −1 . With the optimized heating scheme, T‐TDR probes were able to measure soil ice content changes at ≤ −5°C during freezing and thawing, and the errors were within ±0.05 m 3 m −3 in sandy loams and within ±0.1 m 3 m −3 in soils with high clay content. At temperatures between −5 and 0°C, soil ice contents could not be measured accurately with the heat‐pulse method directly, but they could be estimated coarsely from water content before freezing, TDR measured unfrozen water content, and T‐TDR measured total water content at temperatures below −5°C. DA - 2015/8// PY - 2015/8// DO - 10.2136/vzj2014.12.0179 VL - 14 IS - 8 SP - vzj2014.12.0179 J2 - Vadose Zone Journal LA - en OP - SN - 1539-1663 UR - http://dx.doi.org/10.2136/vzj2014.12.0179 DB - Crossref ER - TY - JOUR TI - Comparisons of the Effects of Elevated Vapor Pressure Deficit on Gene Expression in Leaves among Two Fast-Wilting and a Slow-Wilting Soybean AU - Devi, Mura Jyostna AU - Sinclair, Thomas R. AU - Taliercio, Earl T2 - PLOS ONE AB - Limiting the transpiration rate (TR) of a plant under high vapor pressure deficit (VPD) has the potential to improve crop yield under drought conditions. The effects of elevated VPD on the expression of genes in the leaves of three soybean accessions, Plant Introduction (PI) 416937, PI 471938 and Hutcheson (PI 518664) were investigated because these accessions have contrasting responses to VPD changes. Hutcheson, a fast-wilting soybean, and PI 471938, a slow-wilting soybean, respond to increased VPD with a linear increase in TR. TR of the slow-wilting PI 416937 is limited when VPD increases to greater than about 2 kPa. The objective of this study was to identify the response of the transcriptome of these accessions to elevated VPD under well-watered conditions and identify responses that are unique to the slow-wilting accessions. Gene expression analysis in leaves of genotypes PI 471938 and Hutcheson showed that 22 and 1 genes, respectively, were differentially expressed under high VPD. In contrast, there were 944 genes differentially expressed in PI 416937 with the same increase in VPD. The increased alteration of the transcriptome of PI 416937 in response to elevated VPD clearly distinguished it from the other slow-wilting PI 471938 and the fast-wilting Hutcheson. The inventory and analysis of differentially expressed genes in PI 416937 in response to VPD is a foundation for further investigation to extend the current understanding of plant hydraulic conductivity in drought environments. DA - 2015/10/1/ PY - 2015/10/1/ DO - 10.1371/journal.pone.0139134 VL - 10 IS - 10 SP - SN - 1932-6203 ER - TY - JOUR TI - Comparison of Surface Water Quality and Yields from Organically and Conventionally Produced Sweet Corn Plots with Conservation and Conventional Tillage AU - Edgell, Joshua AU - Osmond, D. L. AU - Line, D. E. AU - Hoyt, G. D. AU - Grossman, J. M. AU - Larsen, E. M. T2 - JOURNAL OF ENVIRONMENTAL QUALITY AB - Organic agricultural systems are often assumed to be more sustainable than conventional farming, yet there has been little work comparing surface water quality from organic and conventional production, especially under the same cropping sequence. Our objective was to compare nutrient and sediment losses, as well as sweet corn (Zea mays L. var. saccharata) yield, from organic and conventional production with conventional and conservation tillage. The experiment was located in the Appalachian Mountains of North Carolina. Four treatments, replicated four times, had been in place for over 18 yr and consisted of conventional tillage (chisel plow and disk) with conventional production (CT/Conven), conservation no-till with conventional production (NT/Conven), conventional tillage with organic production (CT/Org), and conservation no-till with organic production (NT/Org). Water quality (surface flow volume; nitrogen, phosphorus, and sediment concentrations) and sweet corn yield data were collected in 2011 and 2012. Sediment and sediment-attached nutrient losses were influenced by tillage and cropping system in 2011, due to higher rainfall, and tillage in 2012. Soluble nutrients were affected by the nutrient source and rate, which are a function of the cropping system. Sweet corn marketable yields were greater in conventional systems due to high weed competition and reduced total nitrogen availability in organic treatments. When comparing treatment efficiency (yield kg ha −1/nutrient loss kg ha −1), the NT/Conven treatment had the greatest sweet corn yield per unit of nutrient and sediment loss. Other treatment ratios were similar to each other; thus, it appears the most sustainably productive treatment was NT/Conven. Core Ideas Conservation no-till limits nutrient loss to surface waters. The sustainability of production methods is dependent on nutrient inputs. ACE: a new measure to quantify the losses as well as the gains from production. DA - 2015/// PY - 2015/// DO - 10.2134/jeq2015.02.0074 VL - 44 IS - 6 SP - 1861-1870 SN - 1537-2537 ER - TY - JOUR TI - Characterization of Stripe Rust Resistance in Wheat Lines with Resistance Gene Yr17 and Implications for Evaluating Resistance and Virulence AU - Milus, Eugene A. AU - Lee, Kevin D. AU - Brown-Guedira, Gina T2 - PHYTOPATHOLOGY AB - Stripe rust, caused by Puccinia striiformis f. sp. tritici, has been the most important foliar wheat disease in south central United States since 2000 when a new strain of the pathogen emerged. The resistance gene Yr17 was used by many breeding programs to develop resistant cultivars. Although Yr17 was classified as a seedling (all-stage) resistance gene conferring a low infection type, seedlings with Yr17 frequently had intermediate to high infection types when inoculated with isolates that caused little or no disease on adult plants of the same wheat lines. The objectives of this study were to determine how to best evaluate Yr17 resistance in wheat lines and to determine which factors made seedling tests involving Yr17 so variable. Stripe rust reactions on wheat seedlings with Yr17 were influenced by temperature, wheat genotype, pathogen isolate, and the leaf (first or second) used to assess the seedling reaction. The most critical factors for accurately evaluating Yr17 reactions at the seedling stage were to avoid night temperatures below 12°C, to use the first leaf to assess the seedling reaction, to use multiple differentials with Yr17 and known avirulent, partially virulent and virulent isolates as controls, and to recognize that intermediate infection types likely represent a level of partial virulence in the pathogen that is insufficient to cause disease on adult plants in the field. DA - 2015/8// PY - 2015/8// DO - 10.1094/phyto-11-14-0304-r VL - 105 IS - 8 SP - 1123-1130 SN - 1943-7684 ER - TY - JOUR TI - A survey of cover crop practices and perceptions of sustainable farmers in North Carolina and the surrounding region AU - O'Connell, S. AU - Grossman, J. M. AU - Hoyt, G. D. AU - Shi, Wei AU - Bowen, S. AU - Marticorena, D. C. AU - Fager, K. L. AU - Creamer, N. G. T2 - Renewable Agriculture and Food Systems AB - Abstract The environmental benefits of cover cropping are widely recognized but there is a general consensus that adoption levels are still quite low among US farmers. A survey was developed and distributed to more than 200 farmers engaged in two sustainable farming organizations in NC and the surrounding region to determine their level of utilization, current practices and perceptions related to cover cropping. The majority of farms surveyed had diverse crop production, production areas <8 ha, and total gross farm incomes <US$50,000. Approximately one-third of the survey population had an organic production component. Eighty-nine percent of participants had a crop rotation plan and 79% of the total survey population utilized cover cropping. More than 25 different cool- and warm-season cover crops were reported. The statements that generated the strongest agreement about cover crop benefits were that cover crops: increase soil organic matter, decrease soil erosion, increase soil moisture, contribute nitrogen to subsequent cash crops, suppress weeds, provide beneficial insect habitat and break hard pans with their roots. Economic costs associated with cover cropping were not viewed as an obstacle to implementation. A factor analysis was conducted to identify underlying themes from a series of positive and negative statements about cover crops. Pre- and post-management challenges were able to explain the most variability (30%) among participant responses. Overall, participants indicated that the incorporation of residues was their greatest challenge and that a lack of equipment, especially for no-till systems, influenced their decisions about cover cropping. Farmers did not always appear to implement practices that would maximize potential benefits from cover crops. DA - 2015/// PY - 2015/// DO - 10.1017/s1742170514000398 VL - 30 IS - 6 SP - 550–562 ER - TY - JOUR TI - Shelf life and changes in phenolic compounds of organically grown blackberries during refrigerated storage AU - Kim, Moo Jung AU - Perkins-Veazie, Penelope AU - Ma, Guoying AU - Fernandez, Gina T2 - POSTHARVEST BIOLOGY AND TECHNOLOGY AB - Fruit of organically grown fresh market blackberry cultivars ‘Natchez’, ‘Ouachita’, and ‘Navaho’ harvested at shiny black and dull black ripeness stages were stored at 1 °C for 15 d or at 1 °C for 13 d plus 20 °C for 2 d. Berries were subjectively rated and anthocyanins and phenolic compounds were analyzed by high performance liquid chromatography (HPLC) to determine storage effects on berry postharvest quality and phenolic compounds. Berries harvested at the shiny black ripeness stage or those stored constantly at 1 °C had lower leakage, decay, and softness and a higher overall rating. ‘Navaho’ fruit had generally better storability compared to the other cultivars. Total anthocyanin content was generally higher in ‘Natchez’ and ‘Navaho’ than in ‘Ouachita’, and increased with storage at 20 °C for 2 d, while shiny black and dull black fruit were similar in anthocyanin content. Cyanidin 3-glucoside was found to represent 87–96% of the total anthocyanin content, and cyanidin 3-rutinoside, cyanidin 3-xyloside, and pelargonidin 3-glucoside were also detected. Total phenolic content increased during storage for all cultivars, especially when berries were stored at 20 °C for 2 d. Hydroxybenzoic acids were the primary phenolic compounds identified in fruit tissues of the three cultivars. Content and proportion of cyanidin 3-xyloside and vanillic acid in ‘Natchez’ were significantly lower than in ‘Ouachita’ or ‘Navaho’ fruit. Results indicate that the fruit of blackberry fruit of these cultivars, when grown organically, could be held with acceptable results when harvested at the shiny black stage of ripeness and stored at 1 °C. Transferring fruit to room temperature for as little as 2 d, even after cold storage, decreased marketability. In contrast, phenolic composition differed among cultivars and generally increased with storage. DA - 2015/12// PY - 2015/12// DO - 10.1016/j.postharvbio.2015.08.020 VL - 110 SP - 257-263 SN - 1873-2356 KW - Anthocyanins KW - Blackberries KW - Flavonols KW - Phenolic compounds KW - Postharvest KW - Storage ER - TY - JOUR TI - Rooting Front and Water Uptake: What You See and Get May Differ AU - Hall, Antonio J. AU - Sinclair, Thomas R. T2 - AGRONOMY JOURNAL AB - Soil water extraction is a key function of plant roots, and in drought‐stressed plants the differentiation in the location of roots in the soil and the location of water extraction has usually not been considered. In this experiment with maize ( Zea mays L.) grown in columns of drying sand, there was a clear lag in the depth of the water extraction front with respect to the depth of rooting. Under water‐deficit stress at least 10 cm to as much as 30 cm of the terminal segment of maize roots could not extract substrate water at measurable rates. These results showing a large difference in rooting and water extraction‐front depths indicate caution is needed in extrapolating between root position and water extraction. DA - 2015/// PY - 2015/// DO - 10.2134/agronj14.0551 VL - 107 IS - 5 SP - 1766-1770 SN - 1435-0645 ER - TY - JOUR TI - Identification of milling and baking quality QTL in multiple soft wheat mapping populations AU - Cabrera, Antonio AU - Guttieri, Mary AU - Smith, Nathan AU - Souza, Edward AU - Sturbaum, Anne AU - Hua, Duc AU - Griffey, Carl AU - Barnett, Marla AU - Murphy, Paul AU - Ohm, Herb AU - Uphaus, Jim AU - Sorrells, Mark AU - Heffner, Elliot AU - Brown-Guedira, Gina AU - Van Sanford, David AU - Sneller, Clay T2 - THEORETICAL AND APPLIED GENETICS DA - 2015/11// PY - 2015/11// DO - 10.1007/s00122-015-2580-3 VL - 128 IS - 11 SP - 2227-2242 SN - 1432-2242 ER - TY - JOUR TI - Identification of maternal haploids of Nicotiana tabacum aided by transgenic expression of green fluorescent protein: evidence for chromosome elimination in the N-tabacum x N-africana interspecific cross AU - Hancock, Wesley G. AU - Kuraparthy, Vasu AU - Kernodle, Sheri P. AU - Lewis, Ramsey S. T2 - MOLECULAR BREEDING DA - 2015/9// PY - 2015/9// DO - 10.1007/s11032-015-0372-8 VL - 35 IS - 9 SP - SN - 1572-9788 KW - Nicotiana KW - Haploids KW - Hybrid lethality KW - Tobacco KW - Chromosome elimination KW - Parthenogenesis ER - TY - JOUR TI - Field evaluation and improvement of the plate method for measuring soil heat flux density AU - Peng, Xiaoyang AU - Heitman, Joshua AU - Horton, Robert AU - Ren, Tusheng T2 - AGRICULTURAL AND FOREST METEOROLOGY AB - Soil heat flux is an important component of the energy balance at the land surface. Heat flux plates have been used widely to measure soil heat flux, but suffer from errors such as heat flow distortion and soil–plate contact resistance. The Philip correction and self-calibrating heat flux plates have been applied to minimize measurement errors. The objectives of this study were to evaluate the effectiveness of heat flux plate correction methods and to introduce improved approaches for applying these methods under field conditions. Soil heat flux at a depth (z) below the surface (Gz) was measured with conventional and self-calibrating plates buried at 2, 6, and 10 cm in a bare soil. Adjacent to the soil heat flux plates, soil thermal conductivity (λs) and temperature gradients were measured simultaneously with heat-pulse sensors, allowing Gz to be determined with the gradient method. The gradient method values were used as a standard to evaluate the performance of the heat flux plates. Temporal λs values were also estimated from soil sand content, bulk density and water content using a thermal conductivity model. At the 6- and 10-cm depths, the conventional plates underestimated Gz by 4.3–10.2 W m−2 due to heat flow distortion errors resulting from a mismatch between λs and plate thermal conductivity (λp). When the Philip correction was applied, both the measured and modeled λs values improved the accuracy of conventional heat flux plates. However, the modeling approach simplified the procedure for obtaining λs. The self-calibrating plate effectively corrected Gz errors associated with heat flow distortion (accurate to within 6.4 W m−2) at the 6 cm and 10 cm depths. At the 2 cm depth, both types of plates produced erroneous Gz data, which were attributed to alterations in the thermal field and heat flux pattern around the plates due to blocking convective heat and water transfer. We also demonstrated that the heating process of the self-calibrating plate could bias Gz data by disturbing the heat flow field around the plate. Voltage signals during and shortly after self-calibration should be discarded from data analysis. With these corrections, heat flux plates can provide an effective method for measuring soil heat flux. DA - 2015/12/15/ PY - 2015/12/15/ DO - 10.1016/j.agrformet.2015.09.001 VL - 214 SP - 341-349 SN - 1873-2240 KW - Soil heat flux KW - Soil heat flux plate method KW - Heat flow distortion error KW - Self calibrating heat flux plate KW - Philip correction KW - Surface energy balance ER - TY - JOUR TI - A novel gateway-compatible binary vector series (PC-GW) for flexible cloning of multiple genes for genetic transformation of plants AU - Dalal, Jyoti AU - Yalamanchili, Roopa AU - La Hovary, Christophe AU - Ji, Mikyoung AU - Rodriguez-Welsh, Maria AU - Aslett, Denise AU - Ganapathy, Sowmya AU - Grunden, Amy AU - Sederoff, Heike AU - Qu, Rongda T2 - PLASMID AB - The rapidly advancing field of plant synthetic biology requires transforming plants with multiple genes. This has sparked a growing interest in flexible plant transformation vectors, which can be used for multi-gene transformations. We have developed a novel binary vector series, named the PC-GW series (GenBank: KP826769-KP826773), for Agrobacterium-mediated plant transformation. The PC-GW vectors use the pCAMBIA vector backbone, and contain NPTII, hpt, bar, mCherry or egfp genes as selectable markers for plant transformation. In a modified multiple cloning site (MCS) of the T-DNA region, we have placed the attR1, attR2 and ccdB sequences for rapid cloning of one to four genes by Gateway™-assisted recombination. In addition, we have introduced four meganuclease sites, and other restriction sites for multi-gene vector construction. Finally, we have placed a CaMV 35S promoter and a 35S terminator on the 5' and 3' ends of the MCS. The CaMV 35S promoter is flanked by PstI restriction sites that can be used to replace it with another promoter sequence if needed. The PC-GW vectors provide choices for selectable markers, cloning methods, and can accommodate up to eight gene constructs in a single T-DNA, thereby significantly reducing the number of transformations or crosses needed to generate multi-transgene expressing plants. DA - 2015/9// PY - 2015/9// DO - 10.1016/j.plasmid.2015.06.003 VL - 81 SP - 55-62 SN - 1095-9890 KW - Gateway KW - Plant transformation KW - Agrobacterium KW - Gene stacking ER - TY - JOUR TI - Simple sequence repeat marker analysis of genetic diversity among progeny of a biparental mapping population of sweetpotato AU - Yada, B. AU - Brown-Guedira, G. AU - Alajo, A. AU - Ssemakula, G. N. AU - Mwanga, R. O. M. AU - Yeneho, G. C. T2 - HortScience DA - 2015/// PY - 2015/// VL - 50 IS - 8 SP - 1143-1147 ER - TY - JOUR TI - Nitrogen Rate, Cover Crop, and Tillage Practice Alter Soil Chemical Properties AU - Ritchey, Edwin L. AU - Tyler, Donald D. AU - Essington, Michael E. AU - Mullen, Michael D. AU - Saxton, Arnold M. T2 - AGRONOMY JOURNAL AB - Long‐term management practices can influence many physical and chemical soil properties. This study investigated the influence of 14 yr of continuous cotton ( Gossypium hirsutum L.) management systems on soil pH, soil organic C (SOC), and exchangeable cations. Management practices consisted of varying N rate, tillage (no‐tillage [NT] or disk tillage [DT]), and cover crop on a Lexington silt loam soil (Ultic Hapludalf) in the absence of lime additions. Lower soil pH was present in NT, hairy vetch ( Vicia villosa L.) cover treatments and with increasing N rate but similar between 0‐ to 7.5‐ and 0‐ to 15‐cm sample depths. Soil pH decreased between 0.23 to 0.37 units for each 34 kg N ha −1 added and 0.46 units with hairy vetch cover. Hairy vetch cover and 101 kg N ha −1 resulted in pH <5 and increased SOC and exchangeable Mn. Exchangeable Al values were >0.30 cmol c kg −1 with 101 kg N ha −1 and hairy vetch cover and with 101 kg N ha −1 under NT, but they were ≤0.13 cmol c kg −1 for all other treatments. Exchangeable Al increased at pH <5 for NT with hairy vetch cover, while changes were insignificant for all other treatments. The hairy vetch cover contributed acidity equivalent to 42 to 68 kg N ha −1 as NH 4 NO 3 . Although stratification of SOC occurred under NT, no other measured properties varied with depth in NT treatments, and different recommendations are not necessary for NT crop production. Appropriate N credits from hairy vetch cover will reduce excessive acidity, production costs, and potential environmental concerns. DA - 2015/// PY - 2015/// DO - 10.2134/agronj14.0226 VL - 107 IS - 4 SP - 1259-1268 SN - 1435-0645 ER - TY - JOUR TI - Impact of Location, Cropping History, Tillage, and Chlorpyrifos on Soil Arthropods in Peanut AU - Cardoza, Yasmin J. AU - Drake, Wendy L. AU - Jordan, David L. AU - Schroeder-Moreno, Michelle S. AU - Arellano, Consuelo AU - Brandenburg, Rick L. T2 - ENVIRONMENTAL ENTOMOLOGY AB - Demand for agricultural production systems that are both economically viable and environmentally conscious continues to increase. In recent years, reduced tillage systems, and grass and pasture rotations have been investigated to help maintain or improve soil quality, increase crop yield, and decrease labor requirements for production. However, documentation of the effects of reduced tillage, fescue rotation systems as well as other management practices, including pesticides, on pest damage and soil arthropod activity in peanut production for the Mid-Atlantic US region is still limited. Therefore, this project was implemented to assess impacts of fescue-based rotation systems on pests and other soil organisms when compared with cash crop rotation systems over four locations in eastern North Carolina. In addition, the effects of tillage (strip vs. conventional) and soil chlorpyrifos application on pod damage and soil-dwelling organisms were also evaluated. Soil arthropod populations were assessed by deploying pitfall traps containing 50% ethanol in each of the sampled plots. Results from the present study provide evidence that location significantly impacts pest damage and soil arthropod diversity in peanut fields. Cropping history also influenced arthropod diversity, with higher diversity in fescue compared with cash crop fields. Corn rootworm damage to pods was higher at one of our locations (Rocky Mount) compared with all others. Cropping history (fescue vs. cash crop) did not have an effect on rootworm damage, but increased numbers of hymenopterans, acarina, heteropterans, and collembolans in fescue compared with cash crop fields. Interestingly, there was an overall tendency for higher number of soil arthropods in traps placed in chlorpyrifos-treated plots compared with nontreated controls. DA - 2015/8// PY - 2015/8// DO - 10.1093/ee/nvv074 VL - 44 IS - 4 SP - 951-959 SN - 1938-2936 KW - mite KW - springtail KW - Diabrotica KW - Arachis hypogaea KW - fescue ER - TY - JOUR TI - Economic viability and environmental impact assessment of three different strawberry production systems in the Southeastern United States AU - Rysin, O. AU - McWhirt, A. AU - Fernandez, G. AU - Louws, F. J. AU - Schroeder-Moreno, M. T2 - HortTechnology DA - 2015/// PY - 2015/// VL - 25 IS - 4 SP - 585-594 ER - TY - JOUR TI - Cotton response and Palmer amaranth control with pyroxasulfone applied preemergence and postemergence AU - Cahoon, C. W. AU - York, A. C. AU - Jordan, D. L. AU - Seagroves, R. W. AU - Everman, W. J. AU - Jennings, K. M. T2 - Journal of Cotton Science DA - 2015/// PY - 2015/// VL - 19 IS - 1 SP - 212-223 ER - TY - JOUR TI - Confirmation of delayed canopy wilting QTLs from multiple soybean mapping populations AU - Hwang, Sadal AU - King, C. Andy AU - Ray, Jeffery D. AU - Cregan, Perry B. AU - Chen, Pengyin AU - Carter, Thomas E., Jr. AU - Li, Zenglu AU - Abdel-Haleem, Hussein AU - Matson, Kevin W. AU - Schapaugh, William, Jr. AU - Purcell, Larry C. T2 - THEORETICAL AND APPLIED GENETICS DA - 2015/10// PY - 2015/10// DO - 10.1007/s00122-015-2566-1 VL - 128 IS - 10 SP - 2047-2065 SN - 1432-2242 ER - TY - JOUR TI - Comparing nitrous oxide losses from three residential landscapes under different management schemes following natural rainfall events AU - Spence, Porche L. AU - Walker, John T. AU - Robarge, Wayne P. AU - Preston, Bill AU - Osmond, Deanna L. T2 - URBAN ECOSYSTEMS DA - 2015/12// PY - 2015/12// DO - 10.1007/s11252-015-0453-9 VL - 18 IS - 4 SP - 1227-1243 SN - 1573-1642 KW - Nitrogen KW - Lawn maintenance KW - Fertilizer inputs KW - Greenhouse gas KW - Turfgrass KW - Flux KW - Measurements KW - Rainfall ER - TY - JOUR TI - Weed Control in Cotton by Combinations of Microencapsulated Acetochlor and Various Residual Herbicides Applied Preemergence AU - Cahoon, Charles W. AU - York, Alan C. AU - Jordan, David L. AU - Everman, Wesley J. AU - Seagroves, Richard W. AU - Braswell, Lewis R. AU - Jennings, Katherine M. T2 - WEED TECHNOLOGY AB - Residual herbicides are routinely recommended to aid in control of glyphosate-resistant (GR) Palmer amaranth in cotton. Acetochlor, a chloroacetamide herbicide, applied PRE, controls Palmer amaranth. A microencapsulated (ME) formulation of acetochlor is now registered for PRE application in cotton. Field research was conducted in North Carolina to evaluate cotton tolerance and Palmer amaranth control by acetochlor ME alone and in various combinations. Treatments, applied PRE, consisted of acetochlor ME, pendimethalin, or no herbicide arranged factorially with diuron, fluometuron, fomesafen, diuron plus fomesafen, and no herbicide. The PRE herbicides were followed by glufosinate applied twice POST and diuron plus MSMA directed at layby. Acetochlor ME was less injurious to cotton than pendimethalin. Acetochlor ME alone or in combination with other herbicides reduced early season cotton growth 5 to 8%, whereas pendimethalin alone or in combinations injured cotton 11 to 13%. Early season injury was transitory, and by 65 to 84 d after PRE treatment, injury was no longer noticeable. Before the first POST application of glufosinate, acetochlor ME and pendimethalin controlled Palmer amaranth 84 and 64%, respectively. Control by acetochlor ME was similar to control by diuron plus fomesafen and greater than control by diuron, fluometuron, or fomesafen alone. Greater than 90% control was obtained with acetochlor ME mixed with diuron or fomesafen. Palmer amaranth control was similar with acetochlor ME plus a full or reduced rate of fomesafen. Acetochlor ME controlled large crabgrass and goosegrass at 91 and 100% compared with control at 83 and 91%, respectively, by pendimethalin. Following glufosinate, applied twice POST, and diuron plus MSMA, at layby, 96 to 99% control was obtained late in the season by all treatments, and no differences among herbicide treatments were noted for cotton yield. This research demonstrated that acetochlor ME can be safely and effectively used in cotton weed management programs. DA - 2015/// PY - 2015/// DO - 10.1614/wt-d-15-00061.1 VL - 29 IS - 4 SP - 740-750 SN - 1550-2740 KW - Crop tolerance KW - herbicide mixtures KW - herbicide resistance management KW - herbicide-resistant weeds ER - TY - JOUR TI - SOIL PHOSPHORUS THRESHOLDS IN EVALUATING RISK OF ENVIRONMENTAL TRANSFER TO SURFACE WATERS IN SANTA CATARINA, BRAZIL AU - Gatiboni, Luciano Colpo AU - Smyth, Thomas Jot AU - Schmitt, Djalma Eugenio AU - Cassol, Paulo Cezar AU - Oliveira, Clovisson Menotti T2 - REVISTA BRASILEIRA DE CIENCIA DO SOLO AB - The State of Santa Catarina, Brazil, has agricultural and livestock activities, such as pig farming, that are responsible for adding large amounts of phosphorus (P) to soils. However, a method is required to evaluate the environmental risk of these high soil P levels. One possible method for evaluating the environmental risk of P fertilization, whether organic or mineral, is to establish threshold levels of soil available P, measured by Mehlich-1 extractions, below which there is not a high risk of P transfer from the soil to surface waters. However, the Mehlich-1 extractant is sensitive to soil clay content, and that factor should be considered when establishing such P-thresholds. The objective of this study was to determine P-thresholds using the Mehlich-1 extractant for soils with different clay contents in the State of Santa Catarina, Brazil. Soil from the B-horizon of an Oxisol with 800 g kg-1 clay was mixed with different amounts of sand to prepare artificial soils with 200, 400, 600, and 800 g kg-1 clay. The artificial soils were incubated for 30 days with moisture content at 80 % of field capacity to stabilize their physicochemical properties, followed by additional incubation for 30 days after liming to raise the pH(H2O) to 6.0. Soil P sorption curves were produced, and the maximum sorption (Pmax) was determined using the Langmuir model for each soil texture evaluated. Based on the Pmax values, seven rates of P were added to four replicates of each soil, and incubated for 20 days more. Following incubation, available P contents (P-Mehlich-1) and P dissolved in the soil solution (P-water) were determined. A change-point value (the P-Mehlich-1 value above which P-water starts increasing sharply) was calculated through the use of segmented equations. The maximum level of P that a soil might safely adsorb (P-threshold) was defined as 80 % of the change-point value to maintain a margin for environmental safety. The P-threshold value, in mg dm-3, was dependent on the soil clay content according to the model P-threshold = 40 + Clay, where the soil clay content is expressed as a percentage. The model was tested in 82 diverse soil samples from the State of Santa Catarina and was able to distinguish samples with high and low environmental risk. DA - 2015/// PY - 2015/// DO - 10.1590/01000683rbcs20140461 VL - 39 IS - 4 SP - 1225-1234 SN - 0100-0683 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-84943328551&partnerID=MN8TOARS KW - eutrophication KW - swine manure KW - environmental pollution ER - TY - JOUR TI - Response of LibertyLink and WideStrike Cotton to Varying Rates of Glufosinate AU - Dodds, Darrin M. AU - Main, Christopher L. AU - Barber, L. Thomas AU - Burmester, Charles AU - Collins, Guy D. AU - Edmisten, Keith AU - Stephenson, Daniel O. AU - Whitaker, Jared R. AU - Boykin, Deborah L. T2 - WEED TECHNOLOGY AB - Field studies were conducted in Alabama, Arkansas, Georgia, Louisiana, Mississippi, North Carolina, and Tennessee during 2010 and 2011 to determine the effect of glufosinate application rate on LibertyLink and WideStrike cotton. Glufosinate was applied in a single application (three-leaf cotton) or sequential application (three-leaf followed by eight-leaf cotton) at 0.6, 1.2, 1.8, and 2.4 kg ai ha −1 . Glufosinate application rate did not affect visual injury or growth parameters measured in LibertyLink cotton. No differences in LibertyLink cotton yield were observed because of glufosinate application rate; however, LibertyLink cotton treated with glufosinate yielded slightly more cotton than the nontreated check. Visual estimates of injury to WideStrike cotton increased with each increase in glufosinate application rate. However, the injury was transient, and by 28 d after the eight-leaf application, no differences in injury were observed. WideStrike cotton growth was adversely affected during the growing season following glufosinate application at rates of 1.2 kg ha −1 and greater; however, cotton height and total nodes were unaffected by glufosinate application rate at the end of the season. WideStrike cotton maturity was delayed, and yields were reduced following glufosinate application at rates of 1.2 kg ha −1 and above. Fiber quality of LibertyLink and WideStrike cotton was unaffected by glufosinate application rate. These data indicate that glufosinate may be applied to WideStrike cotton at rates of 0.6 kg ha −1 without inhibiting cotton growth, development, or yield. Given the lack of injury or yield reduction following glufosinate application to LibertyLink cotton, these cultivars possess robust resistance to glufosinate. Growers are urged to be cautious when increasing glufosinate application rates to increase control of glyphosate-resistant Palmer amaranth in WideStrike cotton. However, glufosinate application rates may be increased to maximum labeled rates when making applications to LibertyLink cotton without fear of reducing cotton growth, development, or yield. DA - 2015/// PY - 2015/// DO - 10.1614/wt-d-15-00012.1 VL - 29 IS - 4 SP - 665-674 SN - 1550-2740 KW - Bialaphos resistance KW - glyphosate-resistant KW - phosphinothricin acetyl transferase ER - TY - JOUR TI - Response of Grafted Tomato (Solanum lycopersicum) to Herbicides AU - Chaudhari, Sushila AU - Jennings, Katherine M. AU - Monks, David W. AU - Jordan, David L. AU - Gunter, Christopher C. AU - Louws, Frank J. T2 - WEED TECHNOLOGY AB - Tomato grafting has gained increased attention in the United States as an alternative to methyl bromide to control soilborne pests and diseases. Although several herbicides are registered in tomato production, a lack of information exists on the effect of herbicides on grafted tomato. Greenhouse and field experiments were conducted to determine herbicide tolerance of grafted tomato. In greenhouse experiments, halosulfuron (27, 54, and 108 g ai ha −1 ), metribuzin (280, 560, and 1,120 g ai ha −1 ), and S -metolachlor (1,070, 2,140, and 3,200 g ai ha −1 ) were applied posttransplant to nongrafted ‘Amelia' and Amelia scion grafted onto ‘Maxifort' or ‘RST-04-106-T' tomato rootstocks. Although herbicide injury was observed, no differences were observed in grafted and nongrafted tomato response including visible injury assessments, plant height, and fresh weight. Tomato injury at 3 wk after herbicide application increased from 3 to 12, 1 to 87, and 0 to 37% as rate of halosulfuron, metribuzin, and S -metolachlor increased, respectively. In field experiments under plasticulture, herbicides applied pretransplant included fomesafen (280 and 420 g ai ha −1 ), halosulfuron (39 and 54 g ha −1 ), metribuzin (280 and 560 g ha −1 ), napropamide (1,120 and 2,240 g ha −1 ), S -metolachlor (800 and 1,070 g ha −1 ), and trifluralin (560 and 840 g ai ha −1 ). Amelia was used as the scion and the nongrafted control. ‘Anchor-T', ‘Beaufort', or Maxifort tomato were used as rootstocks for grafted plants. Fomesafen, halosulfuron, napropamide, and trifluralin initially caused greater injury to grafted tomato than to nongrafted tomato regardless of rootstock (Anchor-T, Beaufort, or Maxifort). However, by 4 wk after treatment, all grafted and nongrafted plants had recovered from herbicide injury. A transplant type-by-herbicide interaction was not observed for yield, but grafted A-Maxifort tomato produced greater total and marketable yield than nongrafted Amelia tomato. Grafted tomato exhibited similar tolerance as nongrafted tomato for all herbicides applied post- and pretransplant. DA - 2015/// PY - 2015/// DO - 10.1614/wt-d-15-00037.1 VL - 29 IS - 4 SP - 800-809 SN - 1550-2740 KW - Crop tolerance KW - fruit number and yield KW - methyl bromide alternatives ER - TY - JOUR TI - Registration of the Ki14 x B73 Recombinant Inbred Mapping Population of Maize AU - Pratt, R. C. AU - Holland, J. B. AU - Balint-Kurti, P. J. AU - Coles, N. D. AU - Zwonitzer, J. C. AU - Casey, M. A. AU - McMullen, M. D. T2 - JOURNAL OF PLANT REGISTRATIONS AB - The Ohio Agricultural Research and Development Center released Ki14 × B73 maize (Zea mays L.) mapping population (Reg. No. MP-2, MGS 9025066 MAP; Maize Genetics COOP Stock Center no. Z042), a set of 119 recombinant inbred lines (RILs), in 2007. The mapping population was derived from a biparental cross between tropical inbred Ki14 (NCRPIS accession Ames 27259) and temperate inbred B73 (Reg. No. PL-17, PI 550473). One hundred sixteen of the original RILs were used for mapping quantitative trait loci associated with host resistance to foliar pathogens inciting southern corn leaf blight [caused by Cochliobolus heterostrophus (Drechs.)], gray leaf spot, (caused by Cercospora zeae-maydis Tehon & E.Y. Daniels), and northern corn leaf blight [caused by Setosphaeria turcica (Luttrell) K.J. Leonard & E.G. Suggs], three traits associated with maturity—days to anthesis, days to silking, and anther silk interval—and two morphological traits, plant and ear height. The genetic marker data included 765 single nucleotide polymorphisms and 74 simple sequence repeat markers genotyped on all the RILs and constructed into a genetic map. It is envisioned that the high level of host resistance of Ki14 and the agronomic performance of B73 will invite use of the population as a germplasm source for improved host resistance of temperate zone, and increased yield potential, of tropical zone maize. Distribution of the RIL mapping population will allow public access to this resource for continued mapping, gene discovery, and plant breeding. DA - 2015/5// PY - 2015/5// DO - 10.3198/jpr2014.06.0041crmp VL - 9 IS - 2 SP - 262-265 SN - 1940-3496 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-84927762625&partnerID=MN8TOARS ER - TY - JOUR TI - Registration of DALBG 1201 Hybrid Bluegrass AU - Meeks, M. AU - Chandra, A. AU - Metz, S. P. AU - Genovesi, A. D. AU - Read, J. C. AU - White, R. H. AU - Miller, Grady AU - Guertal, E. AU - Philley, H. W. AU - Sorochan, J. AU - al. T2 - JOURNAL OF PLANT REGISTRATIONS AB - DALBG 1201 (Reg. No. CV-101, PI 671854) is a turf-type interspecific F1 hybrid derived from a cross between Texas bluegrass (Poa arachnifera Torr.) 20-11 (3-88) (PI 655088) as the female parent and a Kentucky bluegrass (P. pratensis L.) ecotype, CS#4, as the pollen parent. DALBG 1201 was evaluated under the designation 01-59-5 and TAES 5653. A total of 47 experimental hybrid bluegrass lines and three commercial checks, ‘Rebel Exeda’ tall fescue (Festuca arundinacea Schreb.) and ‘Reveille’ and ‘Thermal Blue Blaze’ hybrid bluegrass (P. arachnifera × P. pratensis) were evaluated at five locations (Auburn, AL, Starkville, MS, Raleigh, NC, Knoxville, TN, and Dallas, TX) from 2009 to 2012. DALBG 1201 was characterized by its superior turfgrass quality, darker green color, and higher shoot density than Reveille and Thermal Blue Blaze. Its leaf texture was finer than Rebel Exeda and similar to the hybrid bluegrass checks. Linear regression analysis for turfgrass quality indicated that DALBG 1201 was more stress tolerant compared with the three commercial checks and was highly stable across varying environmental conditions. Its superior performance over a wide range of southern test locations suggests that DALBG 1201 cool-season turf-type hybrid bluegrass is well-suited for use on lawns, landscapes, and other recreational sites across the southern United States. DA - 2015/5// PY - 2015/5// DO - 10.3198/jpr2014.03.0015crc VL - 9 IS - 2 SP - 138-143 SN - 1940-3496 ER - TY - JOUR TI - Palmer Amaranth (Amaranthus palmeri) Management in Dicamba-Resistant Cotton AU - Cahoon, Charles W. AU - York, Alan C. AU - Jordan, David L. AU - Everman, Wesley J. AU - Seagroves, Richard W. AU - Culpepper, A. Stanley AU - Eure, Peter M. T2 - WEED TECHNOLOGY AB - Cotton growers rely heavily upon glufosinate and various residual herbicides applied preplant, PRE, and POST to control Palmer amaranth resistant to glyphosate and acetolactate synthase-inhibiting herbicides. Recently deregulated in the United States, cotton resistant to dicamba, glufosinate, and glyphosate (B2XF cotton) offers a new platform for controlling herbicide-resistant Palmer amaranth. A field experiment was conducted in North Carolina and Georgia to determine B2XF cotton tolerance to dicamba, glufosinate, and glyphosate and to compare Palmer amaranth control by dicamba to a currently used, nondicamba program in both glufosinate- and glyphosate-based systems. Treatments consisted of glyphosate or glufosinate applied early POST (EPOST) and mid-POST (MPOST) in a factorial arrangement of treatments with seven dicamba options (no dicamba, PRE, EPOST, MPOST, PRE followed by [fb] EPOST, PRE fb MPOST, and EPOST fb MPOST) and a nondicamba standard. The nondicamba standard consisted of fomesafen PRE, pyrithiobac EPOST, and acetochlor MPOST. Dicamba caused no injury when applied PRE and only minor, transient injury when applied POST. At time of EPOST application, Palmer amaranth control by dicamba or fomesafen applied PRE, in combination with acetochlor, was similar and 13 to 17% greater than acetochlor alone. Dicamba was generally more effective on Palmer amaranth applied POST rather than PRE, and two applications were usually more effective than one. In glyphosate-based systems, greater Palmer amaranth control and cotton yield were obtained with dicamba applied EPOST, MPOST, or EPOST fb MPOST compared with the standard herbicides in North Carolina. In contrast, dicamba was no more effective than the standard herbicides in the glufosinate-based systems. In Georgia, dicamba was as effective as the standard herbicides in a glyphosate-based system only when dicamba was applied EPOST fb MPOST. In glufosinate-based systems in Georgia, dicamba was as effective as standard herbicides only when dicamba was applied twice. DA - 2015/// PY - 2015/// DO - 10.1614/wt-d-15-00041.1 VL - 29 IS - 4 SP - 758-770 SN - 1550-2740 KW - Dicamba-resistant cotton KW - glyphosate-resistant weeds KW - weed management systems ER - TY - JOUR TI - Molecular Characterization and Phylogenetic Relationships of Plant-Parasitic Nematodes Associated with Turfgrasses in North Carolina and South Carolina, United States AU - Zeng, Yongsan AU - Ye, Weimin AU - Kerns, James AU - Tredway, Lane AU - Martin, Samuel AU - Martin, Matt T2 - PLANT DISEASE AB - The near-full-length 18S ribosomal DNA (rDNA) gene and internal transcribed spacer 1 region were amplified and sequenced from 52 nematode populations belonging to 28 representative species in 13 families recovered from turfgrasses in North Carolina (38 populations) and South Carolina (14 populations). This study also included 13 nematode populations from eight other plant hosts from North Carolina for comparison. Nematodes were molecularly characterized and the phylogenetic relationships were explored based on 18S rDNA sequences. Phylogenetic analysis using Bayesian inference was performed using five groups of the plant-parasitic nematode populations Tylenchids, Criconematids, Longidorids, Xiphinematids, and Trichodorids. The 65 nematode populations were clustered correspondingly within appropriate positions of 13 families, including Belonolaimidae, Caloosiidae, Criconematidae, Dolichodoridae, Hemicycliophoridae, Hoplolaimidae, Heteroderidae, Longidoridae, Meloidogynidae, Paratylenchidae, Pratylenchidae, Telotylenchidae, and Trichodoridae. This study confirms previous morphological-based identification of the plant-parasitic nematode species found in turfgrasses and provides a framework for future studies of plant-parasitic nematodes associated with turfgrasses based upon DNA sequences and phylogenetic relationships. DA - 2015/7// PY - 2015/7// DO - 10.1094/pdis-10-14-1060-re VL - 99 IS - 7 SP - 982-993 SN - 1943-7692 ER - TY - JOUR TI - MAGIC maize: a new resource for plant genetics AU - Holland, James B. T2 - GENOME BIOLOGY AB - A multiparent advanced-generation intercross population of maize has been developed to help plant geneticists identify sequence variants affecting important agricultural traits. DA - 2015/9/11/ PY - 2015/9/11/ DO - 10.1186/s13059-015-0713-2 VL - 16 IS - 1 SP - SN - 1474-760X UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-84941204292&partnerID=MN8TOARS ER - TY - JOUR TI - Identification of South African bermudagrass germplasm with shade tolerance AU - Dunne, J. C. AU - Reynolds, W. C. AU - Miller, G. L. AU - Arellano, C. AU - Brandenburg, R. L. AU - Schoeman, A. AU - Yelyerton, F. H. AU - Milla-Lewis, S. R. T2 - HortScience DA - 2015/// PY - 2015/// VL - 50 IS - 10 SP - 1419-1425 ER - TY - JOUR TI - Geographic clustering of elevated blood heavy metal levels in pregnant women AU - King, Katherine E. AU - Darrah, Thomas H. AU - Money, Eric AU - Meentemeyer, Ross AU - Maguire, Rachel L. AU - Nye, Monica D. AU - Michener, Lloyd AU - Murtha, Amy P. AU - Jirtle, Randy AU - Murphy, Susan K. AU - Mendez, Michelle A. AU - Robarge, Wayne AU - Vengosh, Avner AU - Hoyo, Cathrine T2 - BMC PUBLIC HEALTH AB - Cadmium (Cd), lead (Pb), mercury (Hg), and arsenic (As) exposure is ubiquitous and has been associated with higher risk of growth restriction and cardiometabolic and neurodevelopmental disorders. However, cost-efficient strategies to identify at-risk populations and potential sources of exposure to inform mitigation efforts are limited. The objective of this study was to describe the spatial distribution and identify factors associated with Cd, Pb, Hg, and As concentrations in peripheral blood of pregnant women.Heavy metals were measured in whole peripheral blood of 310 pregnant women obtained at gestational age ~12 weeks. Prenatal residential addresses were geocoded and geospatial analysis (Getis-Ord Gi* statistics) was used to determine if elevated blood concentrations were geographically clustered. Logistic regression models were used to identify factors associated with elevated blood metal levels and cluster membership.Geospatial clusters for Cd and Pb were identified with high confidence (p-value for Gi* statistic <0.01). The Cd and Pb clusters comprised 10.5 and 9.2 % of Durham County residents, respectively. Medians and interquartile ranges of blood concentrations (μg/dL) for all participants were Cd 0.02 (0.01-0.04), Hg 0.03 (0.01-0.07), Pb 0.34 (0.16-0.83), and As 0.04 (0.04-0.05). In the Cd cluster, medians and interquartile ranges of blood concentrations (μg/dL) were Cd 0.06 (0.02-0.16), Hg 0.02 (0.00-0.05), Pb 0.54 (0.23-1.23), and As 0.05 (0.04-0.05). In the Pb cluster, medians and interquartile ranges of blood concentrations (μg/dL) were Cd 0.03 (0.02-0.15), Hg 0.01 (0.01-0.05), Pb 0.39 (0.24-0.74), and As 0.04 (0.04-0.05). Co-exposure with Pb and Cd was also clustered, the p-values for the Gi* statistic for Pb and Cd was <0.01. Cluster membership was associated with lower education levels and higher pre-pregnancy BMI.Our data support that elevated blood concentrations of Cd and Pb are spatially clustered in this urban environment compared to the surrounding areas. Spatial analysis of metals concentrations in peripheral blood or urine obtained routinely during prenatal care can be useful in surveillance of heavy metal exposure. DA - 2015/10/9/ PY - 2015/10/9/ DO - 10.1186/s12889-015-2379-9 VL - 15 SP - SN - 1471-2458 KW - Cadmium KW - Lead KW - Mercury KW - Arsenic KW - Spatial analysis ER - TY - JOUR TI - Genetic Factors for Enhancement of Nicotine Levels in Cultivated Tobacco AU - Wang, Bingwu AU - Lewis, Ramsey S. AU - Shi, Junli AU - Song, Zhongbang AU - Gao, Yulong AU - Li, Wenzheng AU - Chen, Hongxia AU - Qu, Rongda T2 - SCIENTIFIC REPORTS AB - Nicotine has practical applications relating to smoking cessation devices and alternative nicotine products. Genetic manipulation for increasing nicotine content in cultivated tobacco (Nicotiana tabacum L.) may be of value for industrial purposes, including the possibility of enhancing the efficiency of nicotine extraction. Biotechnological approaches have been evaluated in connection with this objective, but field-based results are few. Here, we report characterization of two genes encoding basic-helix-loop-helix (bHLH) transcription factors (TFs), NtMYC2a and NtMYC2b from tobacco. Overexpression of NtMYC2a increased leaf nicotine levels in T1 transgenic lines approximately 2.3-fold in greenhouse-grown plants of tobacco cultivar 'NC 95'. Subsequent field testing of T2 and T3 generations of transgenic NtMYC2a overexpression lines showed nicotine concentrations were 76% and 58% higher than control lines, respectively. These results demonstrated that the increased nicotine trait was stably inherited to the T2 and T3 generations, indicating the important role that NtMYC2a plays in regulating nicotine accumulation in N. tabacum and the great potential of NtMYC2a overexpression in tobacco plants for industrial nicotine production. Collected data in this study also indicated a negative feedback inhibition of nicotine biosynthesis. Further enhancement of nicotine accumulation in tobacco leaf may require modification of the processes of nicotine transport and deposition. DA - 2015/12/2/ PY - 2015/12/2/ DO - 10.1038/srep17360 VL - 5 SP - SN - 2045-2322 ER - TY - JOUR TI - Ensemble Learning of QTL Models Improves Prediction of Complex Traits AU - Bian, Yang AU - Holland, James B. T2 - G3-GENES GENOMES GENETICS AB - Quantitative trait locus (QTL) models can provide useful insights into trait genetic architecture because of their straightforward interpretability but are less useful for genetic prediction because of the difficulty in including the effects of numerous small effect loci without overfitting. Tight linkage between markers introduces near collinearity among marker genotypes, complicating the detection of QTL and estimation of QTL effects in linkage mapping, and this problem is exacerbated by very high density linkage maps. Here we developed a thinning and aggregating (TAGGING) method as a new ensemble learning approach to QTL mapping. TAGGING reduces collinearity problems by thinning dense linkage maps, maintains aspects of marker selection that characterize standard QTL mapping, and by ensembling, incorporates information from many more markers-trait associations than traditional QTL mapping. The objective of TAGGING was to improve prediction power compared with QTL mapping while also providing more specific insights into genetic architecture than genome-wide prediction models. TAGGING was compared with standard QTL mapping using cross validation of empirical data from the maize (Zea mays L.) nested association mapping population. TAGGING-assisted QTL mapping substantially improved prediction ability for both biparental and multifamily populations by reducing both the variance and bias in prediction. Furthermore, an ensemble model combining predictions from TAGGING-assisted QTL and infinitesimal models improved prediction abilities over the component models, indicating some complementarity between model assumptions and suggesting that some trait genetic architectures involve a mixture of a few major QTL and polygenic effects. DA - 2015/10/1/ PY - 2015/10/1/ DO - 10.1534/g3.115.021121 VL - 5 IS - 10 SP - 2073-2084 SN - 2160-1836 UR - https://doi.org/10.1534/g3.115.021121 KW - quantitative trait loci KW - thinning and aggregating KW - ensemble modeling KW - Zea mays ER - TY - JOUR TI - Bare Soil Carbon Dioxide Fluxes with Time and Depth Determined by High-Resolution Gradient-Based Measurements and Surface Chambers AU - Xiao, X. AU - Kuang, X. AU - Sauer, T. J. AU - Heitman, J. L. AU - Horton, R. T2 - SOIL SCIENCE SOCIETY OF AMERICA JOURNAL AB - Soil CO2 production rates and fluxes vary with time and depth. The shallow near-surface soil layer is important for myriad soil processes, yet knowledge of dynamic CO2 concentrations and fluxes in this complex zone is limited. We used a concentration gradient method (CGM) to determine CO2 production and effluxes with depth in shallow layers of a bare soil. The CO2 concentration was continuously measured at 13 depths in the 0- to 200-mm soil layer. For an 11-d period, 2% of the soil CO2 was produced below a depth of 175 mm, 8% was produced in the 50- to 175-mm soil layer, and 90% was produced in the 0- to 50-mm soil layer. Soil CO2 concentration showed similar diurnal patterns with temperature in deeper soil layers and out-of-phase diurnal patterns in surface soil layers. Soil CO2 flux from most of the soil layers can be described by an exponential function of soil temperature, with temperature sensitivity (Q10) ranging from 1.40 to 2.00 (1.62 ± 0.17). The temperature-normalized CO2 fluxes are related to soil water content with a positive linear relationship in surface soil layers and a negative relationship in deep soil layers. The CO2 fluxes from CGM and chamber methods had good agreement at multiple time scales, which showed that the CGM method was able to estimate near-surface soil CO2 fluxes and production. The contrasting patterns between surface and deep layers of soil CO2 concentration and fluxes suggest the necessity of intensive CO2 concentration measurements in the surface soil layer for accurate determination of soil-atmosphere CO2 flux when using the CGM. DA - 2015/// PY - 2015/// DO - 10.2136/sssaj2015.02.0079 VL - 79 IS - 4 SP - 1073-1083 SN - 1435-0661 ER - TY - JOUR TI - A photorespiratory bypass increases plant growth and seed yield in biofuel crop Camelina sativa AU - Dalal, Jyoti AU - Lopez, Harry AU - Vasani, Naresh B. AU - Hu, Zhaohui AU - Swift, Jennifer E. AU - Yalamanchili, Roopa AU - Dvora, Mia AU - Lin, Xiuli AU - Xie, Deyu AU - Qu, Rongda AU - Sederoff, Heike W. T2 - BIOTECHNOLOGY FOR BIOFUELS AB - Camelina sativa is an oilseed crop with great potential for biofuel production on marginal land. The seed oil from camelina has been converted to jet fuel and improved fuel efficiency in commercial and military test flights. Hydrogenation-derived renewable diesel from camelina is environmentally superior to that from canola due to lower agricultural inputs, and the seed meal is FDA approved for animal consumption. However, relatively low yield makes its farming less profitable. Our study is aimed at increasing camelina seed yield by reducing carbon loss from photorespiration via a photorespiratory bypass. Genes encoding three enzymes of the Escherichia coli glycolate catabolic pathway were introduced: glycolate dehydrogenase (GDH), glyoxylate carboxyligase (GCL) and tartronic semialdehyde reductase (TSR). These enzymes compete for the photorespiratory substrate, glycolate, convert it to glycerate within the chloroplasts, and reduce photorespiration. As a by-product of the reaction, CO2 is released in the chloroplast, which increases photosynthesis. Camelina plants were transformed with either partial bypass (GDH), or full bypass (GDH, GCL and TSR) genes. Transgenic plants were evaluated for physiological and metabolic traits.Expressing the photorespiratory bypass genes in camelina reduced photorespiration and increased photosynthesis in both partial and full bypass expressing lines. Expression of partial bypass increased seed yield by 50-57 %, while expression of full bypass increased seed yield by 57-73 %, with no loss in seed quality. The transgenic plants also showed increased vegetative biomass and faster development; they flowered, set seed and reached seed maturity about 1 week earlier than WT. At the transcriptional level, transgenic plants showed differential expression in categories such as respiration, amino acid biosynthesis and fatty acid metabolism. The increased growth of the bypass transgenics compared to WT was only observed in ambient or low CO2 conditions, but not in elevated CO2 conditions.The photorespiratory bypass is an effective approach to increase photosynthetic productivity in camelina. By reducing photorespiratory losses and increasing photosynthetic CO2 fixation rates, transgenic plants show dramatic increases in seed yield. Because photorespiration causes losses in productivity of most C3 plants, the bypass approach may have significant impact on increasing agricultural productivity for C3 crops. DA - 2015/10/29/ PY - 2015/10/29/ DO - 10.1186/s13068-015-0357-1 VL - 8 SP - SN - 1754-6834 KW - Camelina KW - Seed yield KW - Biofuel KW - Photorespiratory bypass KW - Photosynthesis ER - TY - JOUR TI - Tissue-specific gene expression in maize seeds during colonization by Aspergillus flavus and Fusarium verticillioides AU - Shu, Xiaomei AU - Livingston, David P., III AU - Franks, Robert G. AU - Boston, Rebecca S. AU - Woloshuk, Charles P. AU - Payne, Gary A. T2 - MOLECULAR PLANT PATHOLOGY AB - Summary A spergillus flavus and F usarium verticillioides are fungal pathogens that colonize maize kernels and produce the harmful mycotoxins aflatoxin and fumonisin, respectively. Management practice based on potential host resistance to reduce contamination by these mycotoxins has proven difficult, resulting in the need for a better understanding of the infection process by these fungi and the response of maize seeds to infection. In this study, we followed the colonization of seeds by histological methods and the transcriptional changes of two maize defence‐related genes in specific seed tissues by RNA in situ hybridization. Maize kernels were inoculated with either A . flavus or F . verticillioides 21–22 days after pollination, and harvested at 4, 12, 24, 48, 72, 96 and 120 h post‐inoculation. The fungi colonized all tissues of maize seed, but differed in their interactions with aleurone and germ tissues. RNA in situ hybridization showed the induction of the maize pathogenesis‐related protein , maize seed ( PRms ) gene in the aleurone and scutellum on infection by either fungus. Transcripts of the maize sucrose synthase‐encoding gene, shrunken‐1 ( S h1 ), were observed in the embryo of non‐infected kernels, but were induced on infection by each fungus in the aleurone and scutellum. By comparing histological and RNA in situ hybridization results from adjacent serial sections, we found that the transcripts of these two genes accumulated in tissue prior to the arrival of the advancing pathogens in the seeds. A knowledge of the patterns of colonization and tissue‐specific gene expression in response to these fungi will be helpful in the development of resistance. DA - 2015/9// PY - 2015/9// DO - 10.1111/mpp.12224 VL - 16 IS - 7 SP - 662-674 SN - 1364-3703 KW - Aspergillus flavus KW - Fusarium verticillioides KW - histology KW - maize KW - PRms KW - RNAinsitu hybridization KW - Sh1 ER - TY - JOUR TI - Thermal Property Measurement Errors with Heat-Pulse Sensors Positioned near a Soil-Air Interface AU - Xiao, X. AU - Zhang, X. AU - Ren, T. AU - Horton, R. AU - Heitman, J. L. T2 - SOIL SCIENCE SOCIETY OF AMERICA JOURNAL AB - Heat‐pulse sensor measurements analyzed with pulsed infinite line source (PILS) theory have been widely used to measure soil properties. The PILS theory assumes that the measured soil medium is uniform and infinite. When the sensors are positioned near the soil surface, the effects of the heterogeneity associated with the soil–air interface should not be ignored. In 1999, Philip and Kluitenberg (PK99) proposed an analytical solution using an instantaneous heating model to analyze the effects of the soil–air interface on soil thermal property measurements with heat‐pulse sensors. The purpose of this study is to test the PK99 instantaneous heat source solution under controlled laboratory conditions. Soil thermal properties including volumetric heat capacity, thermal diffusivity, and thermal conductivity were measured with a commercially available dual‐needle heat‐pulse sensor buried at different depths beneath the soil surface. Three soil materials, sand, loamy sand, and sandy clay loam, were tested at both air‐dry and saturated moisture conditions. With shallow sensor burial, measured thermal properties were underestimated by up to 50%, similar to the predicted thermal properties from the PK99 analytical solution, due to the effects of the soil–air interface. Using PK99 to adjust thermal property values obtained from shallow sensors has potential to improve estimates of water content, evaporation, and other soil measurements derived from heat‐pulse sensors. DA - 2015/// PY - 2015/// DO - 10.2136/sssaj2014.12.0493n VL - 79 IS - 3 SP - 766-771 SN - 1435-0661 ER - TY - JOUR TI - Stuck between a ROS and a hard place: Analysis of the ubiquitin proteasome pathway in selenocysteine treated Brassica napus reveals different toxicities during selenium assimilation AU - Dimkovikj, Aleksandar AU - Fisher, Brian AU - Hutchison, Kim AU - Van Hoewyk, Doug T2 - JOURNAL OF PLANT PHYSIOLOGY AB - During the selenium assimilation pathway, inorganic selenate and selenite are reduced to form selenocysteine (Sec). Tolerance to selenium in plants has long been attributable to minimizing the replacement of cysteine with selenocysteine, which can result in nonspecific selenoproteins that are potentially misfolded. Despite this widely accepted assumption, there is no evidence in higher plants demonstrating that selenocysteine induces toxicity by resulting in malformed proteins. In this study, we use Brassica napus to analyze the ubiquitin-proteasome pathway, which is capable of removing misfolded proteins. Sec rapidly increased proteasome activity and levels of ubiquitinated proteins, strongly indicating that selenocysteine induces protein misfolding. Proteasome inhibition increased the amount of selenium in protein in Sec-treated plants. Collectively, these data provide a mechanism that accounts for Sec toxicity. Additionally, Sec did not cause oxidative stress as judged by examining levels of superoxide using fluorescent microscopy. Therefore, the cellular response to Sec is different compared to selenite, which was recently shown to increase antioxidant metabolism in response to elevated mitochondrial superoxide that ultimately impaired proteasome activity. Therefore, plants must contend with two divergent modes of cytotoxicity during selenium assimilation. Selenite can result in oxidative stress, but increased flux of selenite reduction can yield Sec that in turn can cause protein misfolding. DA - 2015/6/1/ PY - 2015/6/1/ DO - 10.1016/j.jplph.2015.04.003 VL - 181 SP - 50-54 SN - 1618-1328 KW - Selenocysteine KW - Proteasome KW - Ubiquitin KW - Reactive oxygen species KW - Selenium ER - TY - JOUR TI - Registration of ‘Sugg’ peanut AU - Isleib, T.G. AU - Milla-Lewis, S.R. AU - Pattee, H.E. AU - Copeland, S.C. AU - Zuleta, M.C. AU - Shew, B.B. AU - Hollowell, J.E. AU - Sanders, T.H. AU - Dean, L.O. AU - Hendrix, K.W. AU - Balota, M. AU - Chapin, J.W. AU - Monfort, W.S. T2 - J. Plant Reg. AB - ‘Sugg’ (Reg. No. CV-125, PI 666112) is a large-seeded virginia-type peanut (Arachis hypogaea L. subsp. hypogaea var. hypogaea) cultivar with partial resistance to four diseases that occur commonly in the Virginia–Carolina production area: early leafspot caused by Cercospora arachidicola S. Hori, Cylindrocladium black rot caused by Cylindrocladium parasiticum Crous, Wingfield & Alfenas, Sclerotinia blight caused by Sclerotinia minor Jagger, and tomato spotted wilt caused by the Tomato spotted wilt tospovirus. Sugg was developed as part of a program of selection for multiple disease resistance funded by growers, seed dealers, shellers, and processors. Sugg was tested under the experimental designation N03091T and released by the North Carolina Agricultural Research Service (NCARS) in 2009. Sugg was tested by the NCARS, the Virginia Agricultural Experiment Station, and five other state agricultural experiment stations and the USDA–ARS units participating in the Uniform Peanut Performance Tests. Sugg has alternate branching pattern, intermediate runner growth habit, medium green foliage, and high contents of fancy pods and medium virginia-type seeds. It has seeds with pink testa averaging 957 mg seed−1, approximately 40% jumbo and 46% fancy pods, and extra-large kernel content of ∼47%. Sugg is named in honor of Norfleet “Fleet” Sugg and the late Joseph “Joe” Sugg, cousins who served consecutively as executive directors of the North Carolina Peanut Growers Association from 1966 through 1993. DA - 2015/// PY - 2015/// DO - 10.3198/jpr2013.09.0059crc VL - 9 IS - 1 SP - 44-52 SN - 1940-3496 ER - TY - JOUR TI - Registration of the KS4895 x Jackson Soybean Mapping Population, AR93705 AU - Hwang, Sadal AU - King, C. Andy AU - Davies, Marilynn K. AU - Charlson, Dirk V. AU - Ray, Jeffery D. AU - Cregan, Perry B. AU - Sneller, Clay H. AU - Chen, Pengyin AU - Carter, Thomas E., Jr. AU - Purcell, Larry C. T2 - JOURNAL OF PLANT REGISTRATIONS AB - AR93705 (Reg. No. MP-4, NSL 503796 MAP) is a soybean [Glycine max (L.) Merr.] mapping population developed by the University of Arkansas Experiment Station. The population consists of 15 F3– and 76 F5–derived recombinant inbred lines (RILs) from a cross between ‘KS4895’ (PI 595081) and ‘Jackson’ (PI 548657). The parents were originally chosen due to differences in sensitivity of N2 fixation to drought, with Jackson being tolerant and KS4895 being sensitive. The population was selected to have a similar maturity, with a relative maturity group rating from approximately 5.2 to 5.7. The population was genotyped with 171 polymorphic simple sequence repeats by the USDA–ARS Crop Genetics Research Unit at Stoneville, MS, and with 493 polymorphic single nucleotide polymorphisms by the USDA–ARS Soybean Genomic and Improvement Laboratory in Beltsville, MD. Phenotypic data for the population were collected at multiple field sites for yield, canopy wilting, shoot ureide and N concentrations, stem N concentrations, nodule weight (mg plant−1), individual nodule weight (mg nodule−1), nodule size (mm), and nodule number per plant. Phenotypic and molecular-marker data were used to identify quantitative trait loci associated with these traits. The population offers a unique educational tool for molecular mapping exercises and genetics and for comparative physiology of drought-related, phenotypic extremes from the same genetic background. DA - 2015/5// PY - 2015/5// DO - 10.3198/jpr2014.05.0034crmp VL - 9 IS - 2 SP - 266-271 SN - 1940-3496 ER - TY - JOUR TI - Registration of DALSA 0605 St. Augustinegrass AU - Chandra, A. AU - Genovesi, A.D. AU - Wherley, B.G. AU - Metz, S.P. AU - Reinert, J.A. AU - Wu, Y.Z. AU - Skulkaew, P. AU - Engelke, M.C. AU - Hargey, D. AU - Nelson, L.R. AU - Schwartz, B.M. AU - Raymer, P.L. AU - Wu, Y.Q. AU - Martin, D.L. AU - Milla-Lewis, S.R. AU - Miller, G.L. AU - Kenworthy, K.E. AU - Muñoz, P. T2 - J. Plant Reg. AB - ‘DALSA 0605’ (Reg. No. CV-274, PI 671959) is an embryo rescue-derived interploid hybrid of St. Augustinegrass [Stenotaphrum secundatum (Walt.) Kuntze] resulting from a cross between TAES 5382 (African triploid PI 291594) and ‘Palmetto’ (diploid). DALSA 0605 was evaluated under the designation TAES 5471-18 and TXSA 19 and was approved for release as a new cultivar by Texas A&M AgriLife in 2014. DALSA 0605 is a vegetatively propagated, genetically stable, and uniform cultivar. It is distinguished from other cultivars of St. Augustinegrass for traits and characteristics that include (i) tolerance to gray leaf spot disease (caused by Magnaporthe grisea Couch), (ii) significantly reduced levels of fecundity and juvenile development of southern chinch bugs (Blissus insularis Barber) as compared to ‘Raleigh’ and ‘Texas Common’, and (iii) superior drought resistance conferred through a combination of tolerance to drying soil, deep rooting potential, and rapid recovery following drought. In addition, DALSA 0605 exhibited percentage rates of establishment and turfgrass quality ratings (normal and drought-stress conditions) comparable to commercial checks in multilocation (seven) and multiyear (two) field evaluations. DALSA 0605 is well suited for use on residential and commercial lawns, as well as other recreational sites, throughout the southern and southeastern United States. DA - 2015/// PY - 2015/// DO - 10.3198/jpr2014.05.0036crc VL - 9 IS - 1 SP - 27-34 ER - TY - JOUR TI - Predawn respiration rates during flowering are highly predictive of yield response in Gossypium hirsutum when yield variability is water-induced AU - Snider, John L. AU - Chastain, Daryl R. AU - Meeks, Calvin D. AU - Collins, Guy D. AU - Sorensen, Ronald B. AU - Byrd, Seth A. AU - Perry, Calvin D. T2 - JOURNAL OF PLANT PHYSIOLOGY AB - Respiratory carbon evolution by leaves under abiotic stress is implicated as a major limitation to crop productivity; however, respiration rates of fully expanded leaves are positively associated with plant growth rates. Given the substantial sensitivity of plant growth to drought, it was hypothesized that predawn respiration rates (RPD) would be (1) more sensitive to drought than photosynthetic processes and (2) highly predictive of water-induced yield variability in Gossypium hirsutum. Two studies (at Tifton and Camilla Georgia) addressed these hypotheses. At Tifton, drought was imposed beginning at the onset of flowering (first flower) and continuing for three weeks (peak bloom) followed by a recovery period, and predawn water potential (ΨPD), RPD, net photosynthesis (AN) and maximum quantum yield of photosystem II (Fv/Fm) were measured throughout the study period. At Camilla, plants were exposed to five different irrigation regimes throughout the growing season, and average ΨPD and RPD were determined between first flower and peak bloom for all treatments. For both sites, fiber yield was assessed at crop maturity. The relationships between ΨPD, RPD and yield were assessed via non-linear regression. It was concluded for field-grown G. hirsutum that (1) RPD is exceptionally sensitive to progressive drought (more so than AN or Fv/Fm) and (2) average RPD from first flower to peak bloom is highly predictive of water-induced yield variability. DA - 2015/7/1/ PY - 2015/7/1/ DO - 10.1016/j.jplph.2015.06.003 VL - 183 SP - 114-120 SN - 1618-1328 KW - Drought KW - Gossypium hirsutum KW - Predawn respiration KW - Water potential KW - Yield ER - TY - JOUR TI - Phylogenetic, taxonomic and functional diversity of fungal denitrifiers and associated N2O production efficacy AU - Mothapo, Nape AU - Chen, Huaihai AU - Cubeta, Marc A. AU - Grossman, Julie M. AU - Fuller, Fred AU - Shi, Wei T2 - SOIL BIOLOGY & BIOCHEMISTRY AB - Fungi generally dominate microbial biomass in various soils and play critical roles in ecosystem functioning including nutrient cycling, disease ecology and food production. Therefore, fungal denitrification, phenotypically typified by nitrous oxide (N2O) production, presents another avenue other than N mineralization and heterotrophic nitrification for progress to better understand the multiple roles of fungi in sustaining the biosphere. The discovery of N2O production and consequently denitrification in Fusarium oxysporum Schltdl. in early 1970's has led to identification of many taxonomically diverse species of N2O-producing fungi. This review evaluates the current status of knowledge on species composition of fungal denitrifiers and their N2O-producing activity. Here we describe challenges with assessment of fungal N2O-producing activity across genera and suggest prospects for future studies. We also discuss species diversity in order to gain knowledge of important taxonomic and phylogenetic groups mediating N2O production and provide insight on ecological cues associated with fungal N2O production. Currently, the extent to which species phylogeny and the functional trait, i.e. N2O-producing activity, are linked remains to be determined; even so, it is evident that some related taxa exhibit similar N2O production efficacy than distant relatives. DA - 2015/4// PY - 2015/4// DO - 10.1016/j.soilbio.2015.02.001 VL - 83 SP - 160-175 SN - 0038-0717 KW - Fungal denitrification KW - Nitrous oxide KW - Fusarium KW - Aspergillus KW - Sordariomycetes KW - Eurotiomycetes ER - TY - JOUR TI - Persistence of limited-transpiration-rate trait in sorghum at high temperature AU - Riar, Mandeep K. AU - Sinclair, Thomas R. AU - Prasad, P. V. Vara T2 - ENVIRONMENTAL AND EXPERIMENTAL BOTANY AB - A limited-transpiration (TRlim) trait has been identified in many crop species, including sorghum (Sorghum bicolor (L.) Moench), that results in restricted transpiration rate under high vapor pressure deficits (VPD). The benefit of TRlim is that under high midday-VPD conditions crop water loss is limited so that there is water conservation and positions the crop to better withstand later-season drought. Previous studies performed at 31 °C found that TRlim was commonly expressed among sorghum genotypes. It was also found that those lines with low VPD breakpoints for expression of the TRlim trait exhibited insensitivity in transpiration rate to being fed silver ions. However, it is uncertain how applicable these previous results obtained at 31 °C might be at higher temperature that may exist at midday in regions where sorghum is commonly grown. The current study tested for the expression of TRlim at 37 °C in 16 sorghum genotypes previously found to express the trait at the lower temperature. Only three of the genotypes sustained expression of TRlim at 37 °C. These results indicate that for environments where temperature may commonly reach or exceed 37 °C, sorghum genotypes have been favored that acclimate to the high temperature by losing the TRlim trait. In conditions in which very high temperatures threaten crop heat stress, those genotypes that lose the TRlim trait at high temperature may be more desirable since increasing transpiration rates at these temperatures can result in leaf cooling. The silver test failed to discriminate genotypes for expression of the TRlim trait at high temperature. DA - 2015/7// PY - 2015/7// DO - 10.1016/j.envexpbot.2015.02.007 VL - 115 SP - 58-62 SN - 1873-7307 KW - High temperature KW - Limited transpiration trait KW - Silver inhibitor KW - Sorghum KW - Vapor pressure deficit ER - TY - JOUR TI - Overexpression of ubiquitin-like LpHUB1 gene confers drought tolerance in perennial ryegrass AU - Patel, Minesh AU - Milla-Lewis, Susana AU - Zhang, Wanjun AU - Templeton, Kerry AU - Reynolds, William C. AU - Richardson, Kim AU - Biswas, Margaret AU - Zuleta, Maria C. AU - Dewey, Ralph E. AU - Qu, Rongda AU - Sathish, Puthigae T2 - PLANT BIOTECHNOLOGY JOURNAL AB - HUB1, also known as Ubl5, is a member of the subfamily of ubiquitin-like post-translational modifiers. HUB1 exerts its role by conjugating with protein targets. The function of this protein has not been studied in plants. A HUB1 gene, LpHUB1, was identified from serial analysis of gene expression data and cloned from perennial ryegrass. The expression of this gene was reported previously to be elevated in pastures during the summer and by drought stress in climate-controlled growth chambers. Here, pasture-type and turf-type transgenic perennial ryegrass plants overexpressing LpHUB1 showed improved drought tolerance, as evidenced by improved turf quality, maintenance of turgor and increased growth. Additional analyses revealed that the transgenic plants generally displayed higher relative water content, leaf water potential, and chlorophyll content and increased photosynthetic rate when subjected to drought stress. These results suggest HUB1 may play an important role in the tolerance of perennial ryegrass to abiotic stresses. DA - 2015/6// PY - 2015/6// DO - 10.1111/pbi.12291 VL - 13 IS - 5 SP - 689-699 SN - 1467-7652 KW - drought tolerance KW - HUB1 KW - Lolium perenne KW - small ORF KW - transgenic ER - TY - JOUR TI - Metabolomic and transcriptomic insights into how cotton fiber transitions to secondary wall synthesis, represses lignification, and prolongs elongation AU - Tuttle, John R. AU - Nah, Gyoungju AU - Duke, Mary V. AU - Alexander, Danny C. AU - Guan, Xueying AU - Song, Qingxin AU - Chen, Z. Jeffrey AU - Scheffler, Brian E. AU - Haigler, Candace H. T2 - BMC Genomics AB - The morphogenesis of single-celled cotton fiber includes extreme elongation and staged cell wall differentiation. Designing strategies for improving cotton fiber for textiles and other uses relies on uncovering the related regulatory mechanisms. In this research we compared the transcriptomes and metabolomes of two Gossypium genotypes, Gossypium barbadense cv Phytogen 800 and G. hirsutum cv Deltapine 90. When grown in parallel, the two types of fiber developed similarly except for prolonged fiber elongation in the G. barbadense cultivar. The data were collected from isolated fibers between 10 to 28 days post anthesis (DPA) representing: primary wall synthesis to support elongation; transitional cell wall remodeling; and secondary wall cellulose synthesis, which was accompanied by continuing elongation only in G. barbadense fiber.Of 206 identified fiber metabolites, 205 were held in common between the two genotypes. Approximately 38,000 transcripts were expressed in the fiber of each genotype, and these were mapped to the reference set and interpreted by homology to known genes. The developmental changes in the transcriptomes and the metabolomes were compared within and across genotypes with several novel implications. Transitional cell wall remodeling is a distinct stable developmental stage lasting at least four days (18 to 21 DPA). Expression of selected cell wall related transcripts was similar between genotypes, but cellulose synthase gene expression patterns were more complex than expected. Lignification was transcriptionally repressed in both genotypes. Oxidative stress was lower in the fiber of G. barbadense cv Phytogen 800 as compared to G. hirsutum cv Deltapine 90. Correspondingly, the G. barbadense cultivar had enhanced capacity for management of reactive oxygen species during its prolonged elongation period, as indicated by a 138-fold increase in ascorbate concentration at 28 DPA.The parallel data on deep-sequencing transcriptomics and non-targeted metabolomics for two genotypes of single-celled cotton fiber showed that a discrete developmental stage of transitional cell wall remodeling occurs before secondary wall cellulose synthesis begins. The data showed how lignification can be transcriptionally repressed during secondary cell wall synthesis, and they implicated enhanced capacity to manage reactive oxygen species through the ascorbate-glutathione cycle as a positive contributor to fiber length. DA - 2015/6/27/ PY - 2015/6/27/ DO - 10.1186/s12864-015-1708-9 VL - 16 IS - 1 SP - J2 - BMC Genomics LA - en OP - SN - 1471-2164 UR - http://dx.doi.org/10.1186/s12864-015-1708-9 DB - Crossref KW - Ascorbate KW - Cell elongation KW - Cell wall synthesis KW - Cotton fiber development KW - Gossypium KW - Lignification KW - Reactive oxygen species KW - Metabolomics KW - RNA Seq transcriptomics ER - TY - JOUR TI - Influence of soil inorganic nitrogen and root diameter size on legume cover crop root decomposition and nitrogen release AU - Jani, Arun D. AU - Grossman, Julie M. AU - Smyth, Thomas J. AU - Hu, Shuijin T2 - PLANT AND SOIL DA - 2015/8// PY - 2015/8// DO - 10.1007/s11104-015-2473-x VL - 393 IS - 1-2 SP - 57-68 SN - 1573-5036 KW - Legume cover crops KW - Root decomposition KW - Fine and coarse roots KW - Nitrogen release ER - TY - JOUR TI - High diversity in an urban habitat: are some animal assemblages resilient to long-term anthropogenic change? AU - Guenard, Benoit AU - Cardinal-De Casas, Adrianna AU - Dunn, Robert R. T2 - URBAN ECOSYSTEMS DA - 2015/6// PY - 2015/6// DO - 10.1007/s11252-014-0406-8 VL - 18 IS - 2 SP - 449-463 SN - 1573-1642 KW - Urban ecosystem KW - Long term study KW - Formicidae KW - Disturbance KW - Invasive species ER - TY - JOUR TI - Consumptive water use and crop coefficients for warm-season turfgrass species in the Southeastern United States AU - Wherley, B. AU - Dukes, M. D. AU - Cathey, S. AU - Miller, G. AU - Sinclair, T. T2 - AGRICULTURAL WATER MANAGEMENT AB - Increased urban demand for landscape irrigation, as well as interest in promoting water-use efficient species by municipalities, water purveyors, and homeowners associations emphasize the need for comparative data on consumptive water use by warm-season lawn grasses. The objective of this study was to quantify actual evapotranspiration (ETa) and to develop crop coefficients (Kc) for four warm-season turfgrass species, namely ‘Tifway’ bermudagrass (Cynodon dactylon (L.) Pers. x Cynodon transvaalensis Burtt-Davy), ‘Empire’ zoysiagrass (Zoysia japonica Steud.), ‘Floratam’ St. Augustinegrass [Stenotaphrum secundatum (Walter) Kuntze], and ‘Argentine’ bahiagrass (Paspalum notatum Flugge). Crop coefficients were derived by dividing ETa (measured directly from lysimeter weight change over 24 to 72-h periods) by reference evapotranspiration (ETo) calculated from the ASCE–EWRI Standardized Method using onsite weather station data. Data were collected over three seasons from non-stressed, well-watered turf. For 17 of the 30 measurement periods, Kc did not differ among the 4 species, and on 24 of 30 periods zoysiagrass, bermudagrass, and St. Augustinegrass Kc did not differ from one another. A trend toward elevated Kc was observed in bahiagrass in years 2 and 3, particularly during early spring measurement periods. Kc values for all species fluctuated across seasons and years, peaking to ∼0.8 during active growth periods when vapor pressure deficit and solar radiation were greatest, and declining to ∼0.3 in late fall and winter. Root growth differences among the species appeared to have a stronger relationship to ET rates than did shoot growth rate. Results demonstrated that the commonly recommended warm-season turf coefficient of 0.6, while approximating overall average annual ETa, under-predicted ETa during active growth periods and over-predicted ETa during late fall and winter periods, when turf was slowly growing or quiescent. The results indicate seasonal refinement of Kc values may be needed to more effectively meet consumptive water use requirements of warm-season turfgrasses. DA - 2015/7/1/ PY - 2015/7/1/ DO - 10.1016/j.agwat.2015.03.020 VL - 156 SP - 10-18 SN - 1873-2283 KW - K-c KW - Reference evapotranspiration KW - Zoysiagrass KW - Bermudagrass KW - St. Augustinegrass KW - Bahiagrass ER - TY - JOUR TI - The fate of siderophores: antagonistic environmental interactions in exudate-mediated micronutrient uptake AU - Harrington, James M. AU - Duckworth, Owen W. AU - Haselwandter, Kurt T2 - BIOMETALS DA - 2015/6// PY - 2015/6// DO - 10.1007/s10534-015-9821-4 VL - 28 IS - 3 SP - 461-472 SN - 1572-8773 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-84939962296&partnerID=MN8TOARS KW - Siderophores KW - Biogeochemistry KW - Iron acquisition KW - Rhizosphere KW - Micronutrient uptake ER - TY - JOUR TI - Seedbank and Field Emergence of Weeds in Glyphosate-Resistant Cropping Systems in the United States AU - Schwartz, Lauren M. AU - Gibson, David J. AU - Gage, Karla L. AU - Matthews, Joseph L. AU - Jordan, David L. AU - Owen, Micheal D. K. AU - Shaw, David R. AU - Weller, Stephen C. AU - Wilson, Robert G. AU - Young, Bryan G. T2 - WEED SCIENCE AB - A segment of the debate surrounding the commercialization and use of glyphosate-resistant (GR) crops focuses on the theory that the implementation of these traits is an extension of the intensification of agriculture that will further erode the biodiversity of agricultural landscapes. A large field-scale study was initiated in 2006 in the United States on 156 different field sites with a minimum 3-yr history of GR-corn, -cotton or -soybean in the cropping system. The impact of cropping system, crop rotation, frequency of using the GR crop trait, and several categorical variables on seedbank weed population density and diversity was analyzed. The parameters of total weed population density of all species in the seedbank, species richness, Shannon's H′ and evenness were not affected by any management treatment. The similarity between the seedbank and aboveground weed community was more strongly related to location than management; previous year's crops and cropping systems were also important while GR trait rotation was not. The composition of the weed flora was more strongly related to location (geography) than any other parameter. The diversity of weed flora in agricultural sites with a history of GR crop production can be influenced by several factors relating to the specific method in which the GR trait is integrated (cropping system, crop rotation, GR trait rotation), the specific weed species, and the geographical location. Continuous GR crop, compared to fields with other cropping systems, only had greater species diversity (species richness) of some life forms, i.e., biennials, winter annuals, and prostrate weeds. Overall diversity was related to geography and not cropping system. These results justify further research to clarify the complexities of crops grown with herbicide-resistance traits to provide a more complete characterization of their culture and local adaptation to the weed seedbank. DA - 2015/// PY - 2015/// DO - 10.1614/ws-d-14-00089.1 VL - 63 IS - 2 SP - 425-439 SN - 1550-2759 KW - Community structure KW - corn KW - cotton KW - glyphosate-resistant KW - multivariate analysis KW - Non-metric Dimensional Scaling KW - Procrustes Analysis KW - soybean ER - TY - JOUR TI - Production potential of Lentil (Lens culinaris Medik.) in East Africa AU - Ghanem, Michel Edmond AU - Marrou, Helene AU - Biradar, Chandrashekhar AU - Sinclair, Thomas R. T2 - AGRICULTURAL SYSTEMS AB - Lentil (Lens culinaris Medik.) could possibly become a major crop in East Africa due to its many uses as a food and feed. Also, its ability to undertake symbiotic nitrogen fixation is an advantage over cereal crops. This study simulated lentil yield potential in order to determine the geographical areas in East Africa that offer potential for consistent lentil production. Results show that there is potential to further expand the geographical area in which lentil is currently grown in East Africa into Uganda, Kenya, Tanzania and even Somalia. Response to a change in management practices on potential yield of lentil as a result of different sowing dates was also examined. In addition, the effect of phenology on yield potential was examined by comparing a short-season type vs. a long-season type. Delaying sowing alone or in combination with a long-season genotype can result in a high probability of crop yield increase in East Africa. For the long-season genotype, an optimum sowing window was found between June and July (152–229 day of year) for areas to the north of the Rift Valley. Later sowing dates (229–243 day of year) were found to be optimal in southern areas of East Africa. These simulations indicated that selection and breeding for lentil accessions in East Africa should consider changes in plant phenology and/or sowing dates. DA - 2015/7// PY - 2015/7// DO - 10.1016/j.agsy.2015.03.005 VL - 137 SP - 24-38 SN - 1873-2267 KW - East Africa KW - Lentil KW - Model KW - Yield KW - Sowing date KW - Phenology ER - TY - JOUR TI - Preemergence herbicide efficacy for crabgrass (Digitaria spp.) control in common bermudagrass managed under different mowing heights AU - Gannon, T. W. AU - Jeffries, M. D. AU - Brosnan, J. T. AU - Breeden, G. K. AU - Tucker, K. A. AU - Henry, G. M. T2 - HortScience DA - 2015/// PY - 2015/// VL - 50 IS - 4 SP - 546-550 ER - TY - JOUR TI - Plant Survival of Drought During Establishment: An Interspecific Comparison of Five Grain Legumes AU - Marrou, Helene AU - Vadez, Vincent AU - Sinclair, Thomas R. T2 - CROP SCIENCE AB - ABSTRACT Seedling establishment is obviously the first step in having successful crop production. In seasons and locations that experience early drought, potential differences among species in plant survival of drought could result in greater probability of crop establishment. In this study, plant survival capacity during crop establishment was tested for five grain legume species: soybean [ Glycine max (L.) Merr.], common bean ( Phaseolus vulgaris L.), groundnut ( Arachis hypogaea L.), cowpea ( Vigna unguiculata L. Walp.), and pigeon pea ( Cajanus cajan L. Huth). Experiments were done for four sowing conditions (two soil textures × two initial soil‐water contents). Cowpea and pigeon pea had the greatest capacity for survival, while soybean, bean, and groundnut were more sensitive. Differences among species could not be explained by differences in the temporal dynamics of water use. Conversely, plant wilting and senescence in response to soil dehydration varied among species; initial wilting of cowpea and pigeon pea occurred at lower soil‐water contents. These two species also had the longest survival after fraction transpirable soil water (FTSW) reached zero. In a comparison of 10 genotypes of each species, genotypic variation in the wilting profile during the survival phase was observed in cowpea, bean, and, to a lesser extent, groundnut and pigeon pea, but no differences were found in soybean. DA - 2015/// PY - 2015/// DO - 10.2135/cropsci2014.11.0760 VL - 55 IS - 3 SP - 1264-1273 SN - 1435-0653 ER - TY - JOUR TI - Modeling Response of Warm-Season Turfgrass to Drought and Irrigation AU - Wilkerson, Gail G. AU - Buol, Gregory S. AU - Yang, Zhengyu AU - Peacock, Charles AU - McCready, Mary S. AU - Steinke, Kurt AU - Chalmers, David T2 - AGRONOMY JOURNAL AB - When droughts occur, restrictions on outdoor water use are a frequently used tactic for reducing demand but are not always as effective as desired and can have negative impacts on homeowners and businesses. Our objective was to develop a simulation model for use in comparing irrigation strategies in terms of water usage and changes in turfgrass quality under varying levels of water restriction. Based on data from several experiments, we have developed a model for St. Augustinegrass [ Stenotaphrum secundatum (Walter) Kuntze] and bermudagrass [ Cynodon dactylon (L.) Pers.] that calculates a turfgrass drought index and a turfgrass quality index (TQI) on a daily basis. Turfgrass water demand is modeled as a function of TQI and reference evapotranspiration. Actual turf water uptake depends on plant‐available soil water as well as plant demand. Available soil water in the root zone is divided into two pools: an easily available pool and a less readily available pool. Turfgrass quality can increase when there is no drought stress and decline whenever drought stress exceeds a cultivar‐specific threshold. We used the generalized likelihood uncertainty estimation method to estimate five genetic coefficients for two cultivars of each species. The model was highly successful in predicting the observed values of TQI. Except for a few sample dates, simulated TQI was within the 95% confidence interval of the mean observed TQI. The model appears to respond accurately to both drought and irrigation and to capture species and cultivar differences in drought tolerance. DA - 2015/// PY - 2015/// DO - 10.2134/agronj14.0311 VL - 107 IS - 2 SP - 515-523 SN - 1435-0645 ER - TY - JOUR TI - Measurement of Limited-Transpiration Trait under High Vapor Pressure Deficit for Peanut in Chambers and in Field AU - Shekoofa, Avat AU - Rosas-Anderson, Pablo AU - Sinclair, Thomas R. AU - Balota, Maria AU - Isleib, Thomas G. T2 - AGRONOMY JOURNAL AB - Drought is one of the most important environmental factors that limit crop production. Based on controlled‐environment studies, it has been hypothesized that a limited‐transpiration (TR lim ) trait under high vapor pressure deficit (VPD) is a mechanism for water conservation leading to yield increase under water‐deficit conditions. The current research objective was to compare expression of TR lim in peanut ( Arachis hypogaea L.) observed by whole‐plant measurements in controlled environments and by leaf gas exchange measurements on plants grown in the field. Six peanut genotypes with different breeding backgrounds, that is, wild‐type, commercial cultivars, and advanced breeding lines were studied. Differences were observed among genotypes in their expression of TR lim with increasing VPD in the controlled environment at 31/26°C. Within each breeding background, one genotype showed a linear increase in transpiration with increasing VPD while the other expressed the TR lim trait. In a second set of controlled environment experiments at 36/26°C, none of the six genotypes expressed the TR lim trait. In the field, again none of the genotypes expressed the TR lim trait. The temperature to which the plants were exposed between the two controlled environments and field trial appeared critical in the expression of the TR lim trait of three of the genotypes. DA - 2015/// PY - 2015/// DO - 10.2134/agronj14.0570 VL - 107 IS - 3 SP - 1019-1024 SN - 1435-0645 ER - TY - JOUR TI - Management of Perennial Warm-Season Bioenergy Grasses. II. Seasonal Differences in Elephantgrass and Energycane Morphological Characteristics Affect Responses to Harvest Frequency and Timing AU - Na, Chae-In AU - Sollenberger, Lynn E. AU - Erickson, John E. AU - Woodard, Kenneth R. AU - Castillo, Miguel S. AU - Mullenix, M. Kimberly AU - Vendramini, Joao M. B. AU - Silveira, Maria L. T2 - BIOENERGY RESEARCH DA - 2015/6// PY - 2015/6// DO - 10.1007/s12155-014-9542-5 VL - 8 IS - 2 SP - 618-626 SN - 1939-1242 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-84939981437&partnerID=MN8TOARS KW - Bioenergy crops KW - Elephantgrass KW - Energycane KW - Leaf area index KW - Persistence KW - Tiller dynamics ER - TY - JOUR TI - Leaf expansion of soybean subjected to high and low atmospheric vapour pressure deficits AU - Devi, M. Jyostna AU - Taliercio, Earl W. AU - Sinclair, Thomas R. T2 - JOURNAL OF EXPERIMENTAL BOTANY AB - Vapour pressure deficit (VPD) is considered an important environmental factor that might affect leaf expansion and transpiration rate (TR) in plants. Two slow-wilting soybean (Glycine max (L.) Merr.) genotypes PI 416937 and PI 471938 along with commercial cultivar Hutcheson were subjected to low (1.2-1.6 kPa) and high VPD (2.8-3 kPa) environments to study their leaf expansion and TR over five days. Among the three genotypes, PI 416937 had the lowest increase in its TR (34%) at high VPD compared with low VPD and the greatest decrease in leaf area (31%). In contrast, Hutcheson had the highest increase in TR (87%) under high VPD and the lowest decrease in leaf expansion rate (18%). Expansin and extensin genes were isolated in PI 416937 to determine if changes in leaf expansion were associated with changes at the molecular level. The four studied genes were all suppressed after five days in the high VPD environment. DA - 2015/4// PY - 2015/4// DO - 10.1093/jxb/eru520 VL - 66 IS - 7 SP - 1845-1850 SN - 1460-2431 KW - Expansin KW - extensin KW - leaf expansion KW - soybean KW - transpiration KW - vapour pressure deficit ER - TY - JOUR TI - Joint-multiple family linkage analysis predicts within-family variation better than single-family analysis of the maize nested association mapping population AU - Ogut, F. AU - Bian, Y. AU - Bradbury, P. J. AU - Holland, J. B. T2 - HEREDITY AB - Quantitative trait locus (QTL) mapping has been used to dissect the genetic architecture of complex traits and predict phenotypes for marker-assisted selection. Many QTL mapping studies in plants have been limited to one biparental family population. Joint analysis of multiple biparental families offers an alternative approach to QTL mapping with a wider scope of inference. Joint-multiple population analysis should have higher power to detect QTL shared among multiple families, but may have lower power to detect rare QTL. We compared prediction ability of single-family and joint-family QTL analysis methods with fivefold cross-validation for 6 diverse traits using the maize nested association mapping population, which comprises 25 biparental recombinant inbred families. Joint-family QTL analysis had higher mean prediction abilities than single-family QTL analysis for all traits at most significance thresholds, and was always better at more stringent significance thresholds. Most robust QTL (detected in >50% of data samples) were restricted to one family and were often not detected at high frequency by joint-family analysis, implying substantial genetic heterogeneity among families for complex traits in maize. The superior predictive ability of joint-family QTL models despite important genetic differences among families suggests that joint-family models capture sufficient smaller effect QTL that are shared across families to compensate for missing some rare large-effect QTL. DA - 2015/6// PY - 2015/6// DO - 10.1038/hdy.2014.123 VL - 114 IS - 6 SP - 552-563 SN - 1365-2540 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-84922607318&partnerID=MN8TOARS ER - TY - JOUR TI - Genetic Diversity among Wheat Accessions from the USDA National Small Grains Collection AU - Bonman, J. Michael AU - Babiker, Ebrahiem M. AU - Cuesta-Marcos, Alfonso AU - Esvelt-Klos, Kathy AU - Brown-Guedira, Gina AU - Chao, Shiaoman AU - See, Deven AU - Chen, Jianli AU - Akhunov, Eduard AU - Zhang, Junli AU - Bockelman, Harold E. AU - Gordon, Tyler C. T2 - CROP SCIENCE AB - ABSTRACT Accessions of common wheat ( Triticum aestivum L. subsp. aestivum ) from the USDA–ARS National Small Grains Collection (NSGC) are a resource for wheat scientists worldwide. The genetic diversity of the wheat core subset, representing approximately 10% of the collection's 42,138 T. aestivum accessions, was examined using 390 diversity arrays technology (DArT) markers, 4941 single nucleotide polymorphisms (SNPs), and descriptor data. The marker profiles revealed duplicates, which were excluded to form an informative core (iCore) of 3230 accessions. The iCore population structure and diversity within various subgroups were examined with analysis of molecular variance, principal coordinate analysis, cluster analysis, and by ranking the contribution of individual accessions to overall diversity. Accession groups based on molecular marker data corresponded well to their geographic origin, and population structure was accounted for primarily by differences between Iranian landrace accessions and the rest of the accessions. Accessions classified as breeding lines were overrepresented among those ranked as most diverse based on SNP data, whereas Iranian landraces were underrepresented. Although less diverse as a group, Iranian landrace accessions had a higher frequency of resistance to bunt diseases and Russian wheat aphid compared with the iCore as a whole. The present study provides support for establishing core subsets based on geographic origin of accessions and will be a basis for further study of diversity among NSGC wheats. DA - 2015/// PY - 2015/// DO - 10.2135/cropsci2014.09.0621 VL - 55 IS - 3 SP - 1243-1253 SN - 1435-0653 ER - TY - JOUR TI - Factors affecting sediment basin efficiency on highway construction sites in the Piedmont region of North Carolina AU - Brown, R. F. AU - McLaughlin, R. A. AU - Jennings, G. D. T2 - Transactions of the ASABE AB - Sediment basins are a commonly used best management practice on North Carolina Department of Transportation (NCDOT) highway construction sites for capturing entrained sediment during stormwater runoff events. The NCDOT currently uses a sediment basin design that has a volume proportional to the disturbed catchment area and a surface area proportional to the 10-year peak runoff discharge from the catchment. This project monitored four active NCDOT sediment basins in the Piedmont region of North Carolina to evaluate several hydrologic and land use parameters for their ability to explain the variability of turbidity and total suspended solids (TSS) entering the basins as well as the efficiency of the basins with regard to these two parameters. TSS ranged from 270 to 53,000 mg L-1 entering the basins and from 87 to 70,600 mg L-1 leaving the basins. Turbidity ranged from 198 to 29,000 nephelometric turbidity units (NTU) entering the basins and from 27 to 28,700 NTU leaving the basins. There was no clear relationship between the stages of development or site activities and the turbidity and TSS entering the basins. Peak flow, which is used in the design of NCDOT sediment basins, was positively correlated with inlet turbidity and TSS. Additionally, the performance of the basins to reduce turbidity and TSS did not correlate to storm characteristics. The diversion ditches leading to the basins appeared to be a major source of sediment and likely contributed to the high variability in turbidity, TSS, and basin performance. DA - 2015/// PY - 2015/// DO - 10.13031/trans.58.10405 VL - 58 IS - 3 SP - 631-640 ER - TY - JOUR TI - Cover Crop and Root Pruning Impacts on Vegetative Growth, Crop Yield Components, and Grape Composition of Cabernet Sauvignon AU - Giese, Gill AU - Wolf, Tony K. AU - Velasco-Cruz, Ciro AU - Roberts, Lucas AU - Heitman, Josh T2 - AMERICAN JOURNAL OF ENOLOGY AND VITICULTURE AB - Complete vineyard floor cover cropping (inter- and intrarow) and vine root pruning were evaluated as tools to restrict vegetative growth of Vitis vinifera cv. Cabernet Sauvignon grapevines. Treatments were arranged in a split-plot, randomized, complete block design with cover crop schemes as main plots and annual vine root pruning (RP), or not (NRP), as subplots. Five perennial grasses as complete floor cover crops were compared to a more conventional under-trellis herbicide strip combined with KY-31 fescue interrows. KY-31 fescue and orchardgrass each reduced shoot growth rate by >30% in 2006 and >20% in 2007, below that of the herbicide-strip control vines. Root pruning independently reduced shoot growth rates. The combination of cover crop and RP decreased dormant pruning weights more than did the additive effects of either factor applied alone. Pruning weights in 2010 were reduced 8% below the control by RP, by 15% by cover crop, but by 38% when both treatments were applied. Leaf petiole N concentration at bloom was ~11% lower in RP vines in two of three years evaluated, but did not differ among vines grown with different cover crops. Stem water potential (Ψstem) was not affected by treatments. Cover cropping did not reduce crop yield with the exception of reduced yield due to KY-31 fescue in 2006. Berry weights were slightly reduced by a RP × year interaction from 2007 to 2009 and by a year effect in 2011 compared to 2010. While complete vineyard floor cover cropping and root pruning were effective tools to reduce vine size and vigor, effects on canopy architecture and primary fruit chemistry were minimal and more influenced by seasonal variation. DA - 2015/5// PY - 2015/5// DO - 10.5344/ajev.2014.14100 VL - 66 IS - 2 SP - 212-226 SN - 1943-7749 KW - competition KW - cover crops KW - fruit composition KW - root pruning KW - vine vigor ER - TY - JOUR TI - Phosphorylation is an on/off switch for 5-hydroxyconiferaldehyde O-methyltransferase activity in poplar monolignol biosynthesis AU - Wang, Jack P. AU - Chuang, Ling AU - Loziuk, Philip L. AU - Chen, Hao AU - Lin, Ying-Chung AU - Shi, Rui AU - Qu, Guan-Zheng AU - Muddiman, David C. AU - Sederoff, Ronald R. AU - Chiang, Vincent L. T2 - PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA AB - Although phosphorylation has long been known to be an important regulatory modification of proteins, no unequivocal evidence has been presented to show functional control by phosphorylation for the plant monolignol biosynthetic pathway. Here, we present the discovery of phosphorylation-mediated on/off regulation of enzyme activity for 5-hydroxyconiferaldehyde O-methyltransferase 2 (PtrAldOMT2), an enzyme central to monolignol biosynthesis for lignification in stem-differentiating xylem (SDX) of Populus trichocarpa. Phosphorylation turned off the PtrAldOMT2 activity, as demonstrated in vitro by using purified phosphorylated and unphosphorylated recombinant PtrAldOMT2. Protein extracts of P. trichocarpa SDX, which contains endogenous kinases, also phosphorylated recombinant PtrAldOMT2 and turned off the recombinant protein activity. Similarly, ATP/Mn(2+)-activated phosphorylation of SDX protein extracts reduced the endogenous SDX PtrAldOMT2 activity by ∼ 60%, and dephosphorylation fully restored the activity. Global shotgun proteomic analysis of phosphopeptide-enriched P. trichocarpa SDX protein fractions identified PtrAldOMT2 monophosphorylation at Ser(123) or Ser(125) in vivo. Phosphorylation-site mutagenesis verified the PtrAldOMT2 phosphorylation at Ser(123) or Ser(125) and confirmed the functional importance of these phosphorylation sites for O-methyltransferase activity. The PtrAldOMT2 Ser(123) phosphorylation site is conserved across 93% of AldOMTs from 46 diverse plant species, and 98% of the AldOMTs have either Ser(123) or Ser(125). PtrAldOMT2 is a homodimeric cytosolic enzyme expressed more abundantly in syringyl lignin-rich fiber cells than in guaiacyl lignin-rich vessel cells. The reversible phosphorylation of PtrAldOMT2 is likely to have an important role in regulating syringyl monolignol biosynthesis of P. trichocarpa. DA - 2015/7/7/ PY - 2015/7/7/ DO - 10.1073/pnas.1510473112 VL - 112 IS - 27 SP - 8481-8486 SN - 0027-8424 KW - AldOMT KW - COMT KW - lignin KW - phosphoproteomics KW - phosphoregulation ER - TY - JOUR TI - Occurrence, Severity and Initiation of Internal Necrosis in ‘Covington’ Sweetpotato AU - Jiang, Chen AU - Perkins-Veazie, Penelope AU - Blankenship, Sylvia M. AU - Boyette, Michael D. AU - Pesic-VanEsbroeck, Zvezdana AU - Jennings, Katherine M. AU - Schultheis, Jonathan R. T2 - HortTechnology AB - A series of studies were conducted to better understand the occurrence and causes of internal necrosis (IN) in ‘Covington’ sweetpotato ( Ipomoea batatas ). Assessment of the problem among the industry was done for 2 years and revealed that IN was widespread in commercial storage facilities throughout the state of North Carolina; both incidence and severity were generally low (<10% incidence with minimal severity of symptoms). A few storage rooms had a high percentage of IN with severe storage root symptoms but results were inconsistent across years and among rooms. Preharvest studies with commercially used insecticides did not induce IN, but the harvest aid ethephon consistently induced IN with an incidence higher than 50%. Internal necrosis symptoms were not detectable at harvest, and earliest consistent incidence was observed 6 days after harvest (DAH) during the curing phase. Symptoms became more prevalent and severe at 30 DAH. However, in commercial storage rooms, no relationship was found between IN incidence and postcuring storage temperature or relative humidity (RH) conditions. Sweetpotato storage roots stored in air-tight barrels and exposed to 100 ppm ethylene after curing showed no relationship between the presence of ethylene gas in storage and incidence of IN. Our results indicate that IN incidence of ‘Covington’ is erratic with no obvious cause among storage rooms and that initiation of IN may occur most frequently during the first week following harvest. DA - 2015/6// PY - 2015/6// DO - 10.21273/horttech.25.3.340 VL - 6 IS - 3 SP - 340-348 KW - Ipomoea batatas KW - ethylene KW - ethephon KW - storage KW - curing KW - storage root ER - TY - JOUR TI - Metallophores and Trace Metal Biogeochemistry AU - Kraemer, Stephan M. AU - Duckworth, Owen W. AU - Harrington, James M. AU - Schenkeveld, Walter D. C. T2 - AQUATIC GEOCHEMISTRY DA - 2015/7// PY - 2015/7// DO - 10.1007/s10498-014-9246-7 VL - 21 IS - 2-4 SP - 159-195 SN - 1573-1421 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-84931006609&partnerID=MN8TOARS KW - Metallophore KW - Siderophore KW - Trace metals KW - Nutrient uptake ER - TY - JOUR TI - Genome-Wide Association of Carbon and Nitrogen Metabolism in the Maize Nested Association Mapping Population AU - Zhang, Nengyi AU - Gibon, Yves AU - Wallace, Jason G. AU - Lepak, Nicholas AU - Li, Pinghua AU - Dedow, Lauren AU - Chen, Charles AU - So, Yoon-Sup AU - Kremling, Karl AU - Bradbury, Peter J. AU - Brutnell, Thomas AU - Stitt, Mark AU - Buckler, Edward S. T2 - PLANT PHYSIOLOGY AB - Carbon (C) and nitrogen (N) metabolism are critical to plant growth and development and are at the basis of crop yield and adaptation. We performed high-throughput metabolite analyses on over 12,000 samples from the nested association mapping population to identify genetic variation in C and N metabolism in maize (Zea mays ssp. mays). All samples were grown in the same field and used to identify natural variation controlling the levels of 12 key C and N metabolites, namely chlorophyll a, chlorophyll b, fructose, fumarate, glucose, glutamate, malate, nitrate, starch, sucrose, total amino acids, and total protein, along with the first two principal components derived from them. Our genome-wide association results frequently identified hits with single-gene resolution. In addition to expected genes such as invertases, natural variation was identified in key C4 metabolism genes, including carbonic anhydrases and a malate transporter. Unlike several prior maize studies, extensive pleiotropy was found for C and N metabolites. This integration of field-derived metabolite data with powerful mapping and genomics resources allows for the dissection of key metabolic pathways, providing avenues for future genetic improvement. DA - 2015/6// PY - 2015/6// DO - 10.1104/pp.15.00025 VL - 168 IS - 2 SP - 575-583 SN - 1532-2548 ER - TY - JOUR TI - Crop Utilization of Nitrogen in Swine Lagoon Sludge AU - Israel, Daniel W. AU - Smyth, T. Jot T2 - COMMUNICATIONS IN SOIL SCIENCE AND PLANT ANALYSIS AB - Swine lagoon sludge is commonly applied to soil as a source of nitrogen (N) for crop production but the fate of applied N not recovered from the soil by the receiver crop has received little attention. The objectives of this study were to (1) assess the yield and N accumulation responses of corn (Zea mays L.) and wheat (Triticum aestivum) to different levels of N applied as swine lagoon sludge, (2) quantify recovery of residual N accumulation by the second and third crops after sludge application, and (3) evaluate the effect of different sludge N rates on nitrate (NO3-N) concentrations in the soil. Sludge N trials were conducted with wheat on two swine farms and with corn on one swine farm in the coastal plain of North Carolina. Agronomic optimum N rates for wheat grown at two locations was 360 kg total sludge N ha−1 and the optimum N rate for corn at one location was 327 kg total sludge N ha−1. Residual N recovered by subsequent wheat and corn crops following the corn crop that received lagoon sludge was 3 and 12 kg N ha−1, respectively, on a whole-plant basis and 2 and 10 kg N ha−1, respectively, on a grain basis at the agronomic optimum N rate for corn (327 kg sludge N ha−1). From the 327 kg ha−1 of sludge N applied to corn, 249 kg N ha−1 were not recovered after harvest of three crops for grain. Accumulation in recalcitrant soil organic N pools, ammonia (NH3) volatilization during sludge application, return of N in stover/straw to the soil, and leaching of NO3 from the root zone probably account for much of the nonutilized N. At the agronomic sludge N rate for corn (327 kg N ha−1), downward movement of NO3-N through the soil was similar to that for the 168 kg N ha−1 urea ammonium nitrate (UAN) treatment. Thus, potential N pollution of groundwater by land application of lagoon sludge would not exceed that caused by UAN application. DA - 2015/7/4/ PY - 2015/7/4/ DO - 10.1080/00103624.2015.1043459 VL - 46 IS - 12 SP - 1525-1539 SN - 1532-2416 KW - water quality KW - soil fertility KW - Nitrogen ER - TY - JOUR TI - Management considerations to minimize environmental impacts of arsenic following monosodium methylarsenate (MSMA) applications to turfgrass AU - Mahoney, Denis J. AU - Gannon, Travis W. AU - Jeffries, Matthew D. AU - Matteson, Audrey R. AU - Polizzotto, Matthew L. T2 - JOURNAL OF ENVIRONMENTAL MANAGEMENT AB - Monosodium methylarsenate (MSMA) is an organic arsenical herbicide currently utilized in turfgrass and cotton systems. In recent years, concerns over adverse impacts of arsenic (As) from MSMA applications have emerged; however, little research has been conducted in controlled field experiments using typical management practices. To address this knowledge gap, a field lysimeter experiment was conducted during 2012-2013 to determine the fate of As following MSMA applications to a bareground and an established turfgrass system. Arsenic concentrations in soil, porewater, and aboveground vegetation, were measured through one yr after treatment. Aboveground vegetation As concentration was increased compared to nontreated through 120 d after initial treatment (DAIT). In both systems, increased soil As concentrations were observed at 0-4 cm at 30 and 120 DAIT and 0-8 cm at 60 and 365 DAIT, suggesting that As was bound in shallow soil depths. Porewater As concentrations in MSMA-treated lysimeters from a 30-cm depth (22.0-83.8 μg L(-1)) were greater than those at 76-cm depth (0.4-5.1 μg L(-1)). These results were combined with previous research to devise management considerations in systems where MSMA is utilized. MSMA should not be applied if rainfall is forecasted within 7 DAIT and/or in areas with shallow water tables. Further, disposing of MSMA-treated turfgrass aboveground vegetation in a confined area - a common management practice for turfgrass clippings - may be of concern due to As release to surface water or groundwater as the vegetation decomposes. Finally, long-term MSMA use may cause soil As accumulation and thus downward migration of As over time; therefore, MSMA should be used in rotation with other herbicides. DA - 2015/3/1/ PY - 2015/3/1/ DO - 10.1016/j.jenvman.2014.12.027 VL - 150 SP - 444-450 SN - 1095-8630 KW - Arsenic KW - Environmental fate KW - MSMA KW - Turfgrass KW - Soil KW - Porewater ER - TY - JOUR TI - Fungal and bacterial N2O production regulated by soil amendments of simple and complex substrates AU - Chen, Huaihai AU - Mothapo, Nape V. AU - Shi, Wei T2 - SOIL BIOLOGY & BIOCHEMISTRY AB - Fungal N2O production results from a respiratory denitrification that reduces NO3−/NO2− in response to the oxidation of an electron donor, often organic C. Despite similar heterotrophic nature, fungal denitrifiers may differ from bacterial ones in exploiting diverse resources. We hypothesized that complex C compounds and substances could favor the growth of fungi over bacteria, and thereby leading to fungal dominance for soil N2O emissions. Effects of substrate quality on fungal and bacterial N2O production were, therefore, examined in a 44-d incubation after soils were amended with four different substrates, i.e., glucose, cellulose, winter pea, and switchgrass at 2 mg C g−1 soil. During periodic measurements of soil N2O fluxes at 80% soil water-filled pore space and with the supply of KNO3, substrate treatments were further subjected to four antibiotic treatments, i.e., no antibiotics or soil addition of streptomycin, cycloheximide or both so that fungal and bacterial N2O production could be separated. Up to d 8 when antibiotic inhibition on substrate-induced microbial activity and/or growth was still detectable, bacterial N2O production was generally greater in glucose- than in cellulose-amended soils and also in winter pea- than in switchgrass-amended soils. In contrast, fungal N2O production was more enhanced in soils amended with cellulose than with glucose. Therefore, fungal-to-bacterial contribution ratios were greater in complex than in simple C substrates. These ratios were positively correlated with fungal-to-bacterial activity ratios, i.e., CO2 production ratios, suggesting that substrate-associated fungal or bacterial preferential activity and/or growth might be the cause. Considering substrate depletion over time and thereby becoming limited for microbial N2O production, measurements of soil N2O fluxes were also carried out with additional supply of glucose, irrespective of different substrate treatments. This measurement condition might lead to potentially high rates of fungal and bacterial N2O production. As expected, bacterial N2O production was greater with added glucose than with added cellulose on d 4 and d 8. However, this pattern was broken on d 28, with bacterial N2O production lower with added glucose than with added cellulose. In contrast, plant residue impacts on soil N2O fluxes were consistent over 44-d, with greater bacterial contribution, lower fungal contribution, and thus lower fungal-to-bacterial contribution ratios in winter pea- than in switchgrass-amended soils. Real-time PCR analysis also demonstrated that the ratios of 16S rDNA to ITS and the copy numbers of bacterial denitrifying genes were greater in winter pea- than in switchgrass-amended soils. Despite some inconsistency found on the impacts of cellulose versus glucose on fungal and bacterial leading roles for N2O production, the results generally supported the working hypothesis that complex substrates promoted fungal dominance for soil N2O emissions. DA - 2015/5// PY - 2015/5// DO - 10.1016/j.soilbio.2015.02.018 VL - 84 SP - 116-126 SN - 0038-0717 KW - Fungi KW - Bacteria KW - Nitrous oxide KW - Glucose KW - Cellulose KW - Plant residues ER - TY - JOUR TI - Anthocyanin, carotenoid, tocopherol, and ellagitannin content of red raspberry cultivars grown under field or high tunnel cultivation in the Southeastern United States AU - Bradish, C. M. AU - Yousef, G. G. AU - Ma, G. Y. AU - Perkins-Veazie, P. AU - Fernandez, G. E. T2 - Journal of the American Society for Horticultural Science DA - 2015/// PY - 2015/// VL - 140 IS - 2 SP - 163-171 ER - TY - JOUR TI - A Comparison of the Sorption Reactivity of Bacteriogenic and Mycogenic Mn Oxide Nanoparticles AU - Droz, Boris AU - Dumas, Naomi AU - Duckworth, Owen W. AU - Pena, Jasquelin T2 - ENVIRONMENTAL SCIENCE & TECHNOLOGY AB - Biogenic MnO2 minerals affect metal fate and transport in natural and engineered systems by strongly sorbing metals ions. The ability to produce MnO2 is widely dispersed in the microbial tree of life, leading to potential differences in the minerals produced by different organisms. In this study, we compare the structure and reactivity of biogenic Mn oxides produced by the biofilm-forming bacterium Pseudomonas putida GB-1 and the white-rot fungus Coprinellus sp. The rate of Mn(II) oxidation, and thus biomineral production, was 45 times lower for Coprinellus sp. (5.1 × 10–2 mM d–1) than for P. putida (2.32 mM d–1). Both organisms produced predominantly Mn(IV) oxides with hexagonal-sheet symmetry, low sheet stacking, small particle size, and Mn(II/III) in the interlayer. However, we found that mycogenic MnO2 could support a significantly lower quantity of Ni sorbed via inner-sphere coordination at vacancy sites than the bacteriogenic MnO2: 0.09 versus 0.14 mol Ni mol–1 Mn. In addition, 50–100% of the adsorbed Ni partitioned to the MnO2, which accounts for less than 20% of the sorbent on a mass basis. The vacancy content, which appears to increase with the kinetics of MnO2 precipitation, exerts significant control on biomineral reactivity. DA - 2015/4/7/ PY - 2015/4/7/ DO - 10.1021/es5048528 VL - 49 IS - 7 SP - 4200-4208 SN - 1520-5851 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-84926434041&partnerID=MN8TOARS ER - TY - JOUR TI - Residential Irrigation Water Use in the Central Piedmont of North Carolina. II: Evaluation of Smart Irrigation Technologies AU - Nautiyal, M. AU - Grabow, G. L. AU - Huffman, R. L. AU - Miller, G. L. AU - Bowman, D. T2 - JOURNAL OF IRRIGATION AND DRAINAGE ENGINEERING AB - A study was conducted in Cary, North Carolina, in the spring and summer of 2009 with the purpose of evaluating the effectiveness of two “smart irrigation” controllers based on the amount of irrigation applied and resulting turf quality in residential settings. Twenty-four residential sites were selected, in clusters of four, representing six geographical areas within the town. Each geographical cluster included one site of each treatment. The treatments were standard irrigation controller with an add-on soil moisture sensor system (SMS); standard irrigation controller with an add-on evapotranspiration-based adjustment system (ET); standard irrigation controller using seasonal runtimes based on historical climate data (ED); and a control group which used a standard irrigation controller with no intervention (CON). Weekly water usage was obtained from irrigation meter readings and turf quality was characterized using a visual rating and a normalized difference vegetation index (NDVI) meter. Maximum water savings were achieved by the SMS treatment (42% less than CON), followed by ET and ED treatments. No statistical difference in average weekly water use was found between the ET group and the ED group provided with controller run-time guidance. The mean weekly visual turf quality index was highest for the SMS treatment, but only statistically different from the ED group. Average weekly NDVI was greatest for the ED group, although average NDVI values were not statistically different among any of the groups. Although water use was less during the 2009 study period contrasted against the three previous years for those receiving some form of intervention (ED, ET, and SMS), the same trend in water use was found by the CON group, rendering any findings in change in behavior inconclusive. Variability in water application by cooperator groups receiving an intervention decreased in the study period compared to the three previous years, suggesting an impact. DA - 2015/4// PY - 2015/4// DO - 10.1061/(asce)ir.1943-4774.0000820 VL - 141 IS - 4 SP - SN - 1943-4774 KW - Evapotranspiration KW - Municipal water KW - Water management KW - Evapotranspiration (ET) controllers KW - Soil-moisture sensors KW - Irrigation scheduling ER - TY - JOUR TI - Residential Irrigation Water Use in the Central Piedmont of North Carolina. I: Measured Use and Water Requirements AU - Nautiyal, M. AU - Grabow, G. L. AU - Huffman, R. L. AU - Miller, G. L. AU - Bowman, D. T2 - JOURNAL OF IRRIGATION AND DRAINAGE ENGINEERING AB - Irrigation is the most common and standard practice for maintaining turfgrass and landscape plants in residential settings. The main objective of this study was to quantify the residential irrigation water use in Cary, North Carolina. A subobjective was to develop distributions of monthly reference evapotranspiration (ETo) and gross irrigation requirements (GIRs) for the area using long-term weather data. As part of the subobjective, an investigation was performed to compare daily measured solar radiation with two empirical methods of estimating solar radiation (Rs). The goal of this investigation was to determine the relative accuracy of these methods and to evaluate the impact of using Rs estimates in the computation of ETo and GIR for the Raleigh-Durham area, where Cary is located. Irrigation water use data from 2005 to 2007 for 120 randomly sampled residences were evaluated. The average lawn area of the sampled residences was 713 m2. None of the sampled households used drip irrigation. A negative correlation existed between the irrigated area and applied water depth. The May-October period accounted for 84–89% of the total annual outdoor water use for the 3 years evaluated. A trend of applying more water than the gross irrigation requirement was observed during the lawn renovation period (mid-September through late October). Solar radiation was computed using two methods: the Hargreaves and Samani method based on difference in maximum and minimum temperature, and the Doorenbos and Pruitt method based on percent possible sunshine. Solar radiation estimated using the percent possible sunshine method showed a strong relationship (R2=0.88) with measured solar radiation and proved to be a much more reliable way of estimating solar radiation than the temperature difference method for the Raleigh-Durham region. Estimates of mean, median, and P80 (80th percentile) monthly ETo and GIR constructed from a 60-year data set show that ETo tends to peak in July at an average of 154 mm, whereas GIR peaks in June with an average of 105 mm. The distribution of GIR is substantially more variable than ETo due mostly to variability in rainfall, illustrating the difficulty in applying the correct amount of water consistently from year to year in subhumid to humid regions. DA - 2015/4// PY - 2015/4// DO - 10.1061/(asce)ir.1943-4774.0000819 VL - 141 IS - 4 SP - SN - 1943-4774 KW - Evapotranspiration KW - Solar radiation KW - Municipal water KW - Water management irrigation KW - Effective rainfall KW - Gross irrigation requirement ER - TY - JOUR TI - Reactive Nitrogen in Turfgrass Systems: Relations to Soil Physical, Chemical, and Biological Properties AU - Lu, Caiyan AU - Bowman, Daniel AU - Rufty, Thomas AU - Shi, Wei T2 - JOURNAL OF ENVIRONMENTAL QUALITY AB - Turfgrass systems contribute to the loading of reactive N to water and air via runoff, leaching, and gas emission. Yet, a comprehensive approach has never been developed to assess N loss potential from turfgrass systems. We used pools and production of reactive N (inorganic N, extractable organic N, and N2O) to estimate N loss potential and hypothesized that this potential could be predicated by basic soil properties. A total of 68 soil samples were taken from 17 bermudagrass sites in North Carolina. Basic soil properties were analyzed, including soil C and N, C:N ratio, microbial biomass, moisture, pH, and percent silt/clay/sand. Soil samples varied most widely in texture, followed by soil C and N, microbial biomass, moisture, pH, and C:N ratio. The pools of extractable organic N and inorganic N were comparable, indicating that soluble organic N should be considered as a pathway of N loss from turfgrass. Turfgrass with large pools and production of reactive N was characterized by high soil C and N, microbial biomass, and moisture. Because soil C and N accumulate over time after turfgrass establishment, turfgrass age could be a suitable practical indicator of N loss potential and thus could be used to implement changes in management. Pools and production of reactive N in liquid and gas phases were well correlated, suggesting that if a turfgrass system has a high potential of N loss via leaching and runoff, it may also be of a high potential for N2O emissions. DA - 2015/// PY - 2015/// DO - 10.2134/jeq2014.06.0247 VL - 44 IS - 1 SP - 210-218 SN - 1537-2537 ER - TY - JOUR TI - Nitrogen and Phosphorus Fertilizer Effects on Establishment of Giant Miscanthus AU - Haines, S. A. AU - Gehl, R. J. AU - Havlin, J. L. AU - Ranney, T. G. T2 - BIOENERGY RESEARCH DA - 2015/3// PY - 2015/3// DO - 10.1007/s12155-014-9499-4 VL - 8 IS - 1 SP - 17-27 SN - 1939-1242 KW - Giant miscanthus KW - Nutrient use KW - Nitrogen KW - Phosphorus KW - Bioenergy crop production ER - TY - JOUR TI - New insight into a complex plant-fungal pathogen interaction AU - Balint-Kurti, Peter J. AU - Holland, James B. T2 - NATURE GENETICS DA - 2015/2// PY - 2015/2// DO - 10.1038/ng.3203 VL - 47 IS - 2 SP - 101-103 SN - 1546-1718 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-84926068986&partnerID=MN8TOARS ER - TY - JOUR TI - Mapping quantitative trait loci determining seed longevity in tobacco (Nicotiana tabacum L.) AU - Agacka-Modoch, M. AU - Nagel, M. AU - Doroszewska, T. AU - Lewis, R. S. AU - Boerner, A. T2 - EUPHYTICA DA - 2015/4// PY - 2015/4// DO - 10.1007/s10681-015-1355-x VL - 202 IS - 3 SP - 479-486 SN - 1573-5060 KW - Controlled deterioration KW - Germination KW - QTL mapping KW - Storability ER - TY - JOUR TI - Mapping of powdery mildew resistance gene Pm53 introgressed from Aegilops speltoides into soft red winter wheat AU - Petersen, Stine AU - Lyerly, Jeanette H. AU - Worthington, Margaret L. AU - Parks, Wesley R. AU - Cowger, Christina AU - Marshall, David S. AU - Brown-Guedira, Gina AU - Murphy, J. Paul T2 - THEORETICAL AND APPLIED GENETICS DA - 2015/2// PY - 2015/2// DO - 10.1007/s00122-014-2430-8 VL - 128 IS - 2 SP - 303-312 SN - 1432-2242 ER - TY - JOUR TI - Hallauer's Tuson: a decade of selection for tropical-to-temperate phenological adaptation in maize AU - Teixeira, J. E. C. AU - Weldekidan, T. AU - Leon, N. AU - Flint-Garcia, S. AU - Holland, J. B. AU - Lauter, N. AU - Murray, S. C. AU - Xu, W. AU - Hessel, D. A. AU - Kleintop, A. E. AU - Hawk, J. A. AU - Hallauer, A. AU - Wisser, R. J. T2 - HEREDITY AB - Crop species exhibit an astounding capacity for environmental adaptation, but genetic bottlenecks resulting from intense selection for adaptation and productivity can lead to a genetically vulnerable crop. Improving the genetic resiliency of temperate maize depends upon the use of tropical germplasm, which harbors a rich source of natural allelic diversity. Here, the adaptation process was studied in a tropical maize population subjected to 10 recurrent generations of directional selection for early flowering in a single temperate environment in Iowa, USA. We evaluated the response to this selection across a geographical range spanning from 43.05° (WI) to 18.00° (PR) latitude. The capacity for an all-tropical maize population to become adapted to a temperate environment was revealed in a marked fashion: on average, families from generation 10 flowered 20 days earlier than families in generation 0, with a nine-day separation between the latest generation 10 family and the earliest generation 0 family. Results suggest that adaptation was primarily due to selection on genetic main effects tailored to temperature-dependent plasticity in flowering time. Genotype-by-environment interactions represented a relatively small component of the phenotypic variation in flowering time, but were sufficient to produce a signature of localized adaptation that radiated latitudinally, in partial association with daylength and temperature, from the original location of selection. Furthermore, the original population exhibited a maladaptive syndrome including excessive ear and plant heights along with later flowering; this was reduced in frequency by selection for flowering time. DA - 2015/2// PY - 2015/2// DO - 10.1038/hdy.2014.90 VL - 114 IS - 2 SP - 229-240 SN - 1365-2540 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-84927567459&partnerID=MN8TOARS ER - TY - JOUR TI - Genome-wide association study reveals a set of genes associated with resistance to the Mediterranean corn borer (Sesamia nonagrioides L.) in a maize diversity panel AU - Samayoa, Luis Fernando AU - Malvar, Rosa Ana AU - Olukolu, Bode A. AU - Holland, James B. AU - Butron, Ana T2 - BMC PLANT BIOLOGY AB - Corn borers are the primary maize pest; their feeding on the pith results in stem damage and yield losses. In this study, we performed a genome-wide association study (GWAS) to identify SNPs associated with resistance to Mediterranean corn borer in a maize diversity panel using a set of more than 240,000 SNPs.Twenty five SNPs were significantly associated with three resistance traits: 10 were significantly associated with tunnel length, 4 with stem damage, and 11 with kernel resistance. Allelic variation at each significant SNP was associated with from 6 to 9% of the phenotypic variance. A set of genes containing or physically close to these SNPs are proposed as candidate genes for borer resistance, supported by their involvement in plant defense-related mechanisms in previously published evidence. The linkage disequilibrium decayed (r(2) < 0.10) rapidly within short distance, suggesting high resolution of GWAS associations.Most of the candidate genes found in this study are part of signaling pathways, others act as regulator of expression under biotic stress condition, and a few genes are encoding enzymes with antibiotic effect against insects such as the cystatin1 gene and the defensin proteins. These findings contribute to the understanding the complex relationship between plant-insect interactions. DA - 2015/2/5/ PY - 2015/2/5/ DO - 10.1186/s12870-014-0403-3 VL - 15 IS - 1 SP - SN - 1471-2229 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-84924054437&partnerID=MN8TOARS KW - Candidate genes KW - Corn borer KW - Genome-wide association study KW - Insect resistance KW - Maize KW - Mixed linear models KW - Sesamia nonagrioides ER - TY - JOUR TI - Farmers' Use of Nutrient Management: Lessons from Watershed Case Studies AU - Osmond, Deanna L. AU - Hoag, Dana L. K. AU - Luloff, Al E. AU - Meals, Donald W. AU - Neas, Kathy T2 - JOURNAL OF ENVIRONMENTAL QUALITY AB - Nutrient enrichment of water resources has degraded coastal waters throughout the world, including in the United States (e.g., Chesapeake Bay, Gulf of Mexico, and Neuse Estuary). Agricultural nonpoint sources have significant impacts on water resources. As a result, nutrient management planning is the primary tool recommended to reduce nutrient losses from agricultural fields. Its effectiveness requires nutrient management plans be used by farmers. There is little literature describing nutrient management decision-making. Here, two case studies are described that address this gap: (i) a synthesis of the National Institute of Food and Agriculture, the Conservation Effects Assessment Project, and (ii) field surveys from three nutrient-impaired river basins/watersheds in North Carolina (Neuse, Tar-Pamlico, and Jordan Lake drainage areas). Results indicate farmers generally did not fully apply nutrient management plans or follow basic soil test recommendations even when they had them. Farmers were found to be hesitant to apply N at university-recommended rates because they did not trust the recommendations, viewed abundant N as insurance, or used recommendations made by fertilizer dealers. Exceptions were noted when watershed education, technical support, and funding resources focused on nutrient management that included easing management demands, actively and consistently working directly with a small group of farmers, and providing significant resource allocations to fund agency personnel and cost-share funds to farmers. Without better dialogue with farmers and meaningful investment in strategies that reward farmers for taking what they perceive as risks relative to nutrient reduction, little progress in true adoption of nutrient management will be made. DA - 2015/// PY - 2015/// DO - 10.2134/jeq2014.02.0091 VL - 44 IS - 2 SP - 382-390 SN - 1537-2537 ER - TY - JOUR TI - Transport of dissolved polyacrylamide through a clay loam soil AU - Kang, Jihoon AU - McLaughlin, Richard A. AU - Amoozegar, Aziz AU - Heitman, Joshua L. AU - Duckworth, Owen W. T2 - GEODERMA AB - Polyacrylamide (PAM) is becoming a widely used soil conditioning and erosion control agent, and a better understanding of its transport is required to improve its use. In this study vertical PAM transport through a clay loam soil was investigated using thin soil columns (7.62-cm diameter × 2-cm thick) under saturated condition. The columns received a water-soluble, anionic PAM solution (16 Mg mol− 1 with 50 mol% charge density) under pulse and step (continuous) inputs using a constant-head method. The pulse input was 500 mg L− 1 PAM solution applied for 0.6 pore volume (PV), after which the input was switched to deionized (DI) water for 25 PVs. The step input was 25 mg L− 1 PAM solution applied continuously for 129 PVs. Saturated hydraulic conductivity (Ksat) was measured prior to PAM application and was monitored during PAM and DI water leaching. Leachate samples were collected frequently with time from each column and analyzed for the dissolved PAM concentration. The PAM applications reduced Ksat to 1% of the initial Ksat (4 cm h− 1) under the pulse input and to 0.3% of the initial Ksat under the step input. Transport of PAM was best-fitted with a two-region (dual-porosity) model. The fitted retardation factor (R) was more than two-fold greater for the step input (R = 2695) than for the pulse input (R = 1242). The results from transport modeling and pore size distribution analysis suggested that viscous PAM solution contributes to a mechanical entrapment of the PAM molecules, clogging most water-conducting pores smaller than 225–274 μm in diameter. Under saturated condition, either the pulse or step input of dissolved PAM could reduce seepage with limited mobility in the soil profile. DA - 2015/4// PY - 2015/4// DO - 10.1016/j.geoderma.2014.12.022 VL - 243 SP - 108-114 SN - 1872-6259 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-84920432092&partnerID=MN8TOARS KW - Leaching KW - Polyacrylamide KW - Solute transport KW - Hydraulic conductivity KW - Pore size distribution ER - TY - JOUR TI - Transgenic and Mutation-Based Suppression of a Berberine Bridge Enzyme-Like (BBL) Gene Family Reduces Alkaloid Content in Field-Grown Tobacco AU - Lewis, Ramsey S. AU - Lopez, Harry O. AU - Bowen, Steve W. AU - Andres, Karen R. AU - Steede, William T. AU - Dewey, Ralph E. T2 - PLOS ONE AB - Motivation exists to develop tobacco cultivars with reduced nicotine content for the purpose of facilitating compliance with expected tobacco product regulations that could mandate the lowering of nicotine levels per se, or the reduction of carcinogenic alkaloid-derived tobacco specific nitrosamines (TSNAs). A berberine bridge enzyme-like (BBL) gene family was recently characterized for N. tabacum and found to catalyze one of the final steps in pyridine alkaloid synthesis for this species. Because this gene family acts downstream in the nicotine biosynthetic pathway, it may represent an attractive target for genetic strategies with the objective of reducing alkaloid content in field-grown tobacco. In this research, we produced transgenic doubled haploid lines of tobacco cultivar K326 carrying an RNAi construct designed to reduce expression of the BBL gene family. Field-grown transgenic lines carrying functional RNAi constructs exhibited average cured leaf nicotine levels of 0.684%, in comparison to 2.454% for the untransformed control. Since numerous barriers would need to be overcome to commercialize transgenic tobacco cultivars, we subsequently pursued a mutation breeding approach to identify EMS-induced mutations in the three most highly expressed isoforms of the BBL gene family. Field evaluation of individuals possessing different homozygous combinations of truncation mutations in BBLa, BBLb, and BBLc indicated that a range of alkaloid phenotypes could be produced, with the triple homozygous knockout genotype exhibiting greater than a 13-fold reduction in percent total alkaloids. The novel source of genetic variability described here may be useful in future tobacco breeding for varied alkaloid levels. DA - 2015/2/17/ PY - 2015/2/17/ DO - 10.1371/journal.pone.0117273 VL - 10 IS - 2 SP - SN - 1932-6203 ER - TY - JOUR TI - Physiological phenotyping of plants for crop improvement AU - Edmond Ghanem, Michel AU - Marrou, Helene AU - Sinclair, Thomas R. T2 - TRENDS IN PLANT SCIENCE AB - Future progress in crop breeding requires a new emphasis in plant physiological phenotyping for specific, well-defined traits. Success in physiological phenotyping to identify parents for use in breeding efforts for improved cultivars has been achieved by employing a multi-tier screening approach with different levels of sophistication and trait resolution. Subsequently, cultivar development required an integrated mix of classical breeding approaches and one or more tiers of phenotyping to identify genotypes expressing the desired trait. The role of high throughput systems can be useful; here, we emphasize that this approach is likely to offer useful results at an initial tier of phenotyping and will need to be complemented with more directed tiers of phenotyping. DA - 2015/3// PY - 2015/3// DO - 10.1016/j.tplants.2014.11.006 VL - 20 IS - 3 SP - 139-144 SN - 1878-4372 KW - crop breeding KW - high throughput phenotyping platform KW - physiological phenotyping KW - trait screening ER - TY - JOUR TI - Iron-Binding E3 Ligase Mediates Iron Response in Plants by Targeting Basic Helix-Loop-Helix Transcription Factors AU - Selote, Devarshi AU - Samira, Rozalynne AU - Matthiadis, Anna AU - Gillikin, Jeffrey W. AU - Long, Terri A. T2 - PLANT PHYSIOLOGY AB - Iron uptake and metabolism are tightly regulated in both plants and animals. In Arabidopsis (Arabidopsis thaliana), BRUTUS (BTS), which contains three hemerythrin (HHE) domains and a Really Interesting New Gene (RING) domain, interacts with basic helix-loop-helix transcription factors that are capable of forming heterodimers with POPEYE (PYE), a positive regulator of the iron deficiency response. BTS has been shown to have E3 ligase capacity and to play a role in root growth, rhizosphere acidification, and iron reductase activity in response to iron deprivation. To further characterize the function of this protein, we examined the expression pattern of recombinant ProBTS::β-GLUCURONIDASE and found that it is expressed in developing embryos and other reproductive tissues, corresponding with its apparent role in reproductive growth and development. Our findings also indicate that the interactions between BTS and PYE-like (PYEL) basic helix-loop-helix transcription factors occur within the nucleus and are dependent on the presence of the RING domain. We provide evidence that BTS facilitates 26S proteasome-mediated degradation of PYEL proteins in the absence of iron. We also determined that, upon binding iron at the HHE domains, BTS is destabilized and that this destabilization relies on specific residues within the HHE domains. This study reveals an important and unique mechanism for plant iron homeostasis whereby an E3 ubiquitin ligase may posttranslationally control components of the transcriptional regulatory network involved in the iron deficiency response. DA - 2015/1// PY - 2015/1// DO - 10.1104/pp.114.250837 VL - 167 IS - 1 SP - 273-+ SN - 1532-2548 ER - TY - JOUR TI - Identification of Malting Quality QTLs in Advanced Generation Breeding Germplasm AU - Pauli, Duke AU - Brown-Guedira, Gina AU - Blake, Thomas K. T2 - JOURNAL OF THE AMERICAN SOCIETY OF BREWING CHEMISTS AB - Malting quality has been one of the primary foci in barley (Hordeum vulgare L.) breeding programs but has been difficult for breeders to manipulate due to the quantitative nature of the traits involved and the cost of trait measurement. To assist in breeding for malt quality traits, identifying the genomic regions that affect these traits is essential. Two populations were used to conduct genome-wide association studies in order to elucidate the alleles responsible for variation in malting traits. The first population, composed of 367 lines genotyped with 3,072 single-nucleotide polymorphism (SNP) markers, was a representative sample of the entire germplasm of the Montana State University barley breeding program, including feed, food, and malt lines. The second population, with 650 lines genotyped with 384 SNPs, consisted of 11 biparental families whose parents were cultivars and elite experimental lines developed strictly for malting purposes. Lines were phenotyped at the United States Department of Agriculture–Agricultural Research Service Cereal Crops Research Unit in Madison, WI. Mixed linear models were applied to the data using a Q+K approach in order to identify single marker–trait associations accounting for population structure and relatedness among lines. Fifty-four significant marker–trait associations were found. The results of this work give a comprehensive overview of the salient regions of the barley genome affecting malting traits that vary within a modern malting barley breeding program. DA - 2015/// PY - 2015/// DO - 10.1094/asbcj-2015-0129-01 VL - 73 IS - 1 SP - 29-40 SN - 1943-7854 KW - Barley KW - Crop genetics KW - Genome-wide association studies KW - Malting KW - QTL ER - TY - JOUR TI - Comprehensive analysis of cellulose content, crystallinity, and lateral packing in Gossypium hirsutum and Gossypium barbadense cotton fibers using sum frequency generation, infrared and Raman spectroscopy, and X-ray diffraction AU - Lee, Christopher M. AU - Kafle, Kabindra AU - Belias, David W. AU - Park, Yong Bum AU - Glick, Richard E. AU - Haigler, Candace H. AU - Kim, Seong H. T2 - Cellulose DA - 2015/1/15/ PY - 2015/1/15/ DO - 10.1007/s10570-014-0535-5 VL - 22 IS - 2 SP - 971-989 J2 - Cellulose LA - en OP - SN - 0969-0239 1572-882X UR - http://dx.doi.org/10.1007/s10570-014-0535-5 DB - Crossref KW - Sum frequency generation KW - Infrared spectroscopy KW - Raman spectroscopy KW - Cotton fiber development KW - Plant cell wall KW - X-ray diffraction ER - TY - JOUR TI - Aminocyclopyrachlor Absorption and Translocation in Three Aquatic Weeds AU - Israel, Trevor D. AU - Everman, Wesley J. AU - Richardson, Robert J. T2 - WEED SCIENCE AB - Studies were conducted to evaluate 14 C-aminocyclopyrachlor absorption and translocation in alligatorweed, waterhyacinth, and waterlettuce. Alligatorweed plants were treated at the seven-node stage, waterhyacinth was treated at the five-leaf stage, and waterlettuce was treated at the eight-leaf stage. All plants were pretreated with nonlabeled aminocyclopyrachlor at 0.14 kg ai ha −1 with 1% (v/v) methylated seed oil (MSO). 14 C-aminocyclopyrachlor was then applied to a protected leaf, and plants were harvested at 1, 2, 4, 12, 24, and 96 h after treatment (HAT). Radioactivity was determined in the treated leaf, shoots above treated leaf, shoots below treated leaf, roots, and growing solution. Absorption was rapid in all species and reached a maximum of 73, 72, and 73% of applied radioactivity for alligatorweed, waterhyacinth, and waterlettuce, respectively. In alligatorweed at 96 HAT, 43% of absorbed carbon-14 ( 14 C) was translocated to shoots above the treated leaf and 17% was translocated to lower shoot tissue. In waterhyacinth at 96 HAT, 56% of absorbed 14 C remained in the treated leaf, whereas 14 and 13% were found in parts above and below the treated leaf, respectively. In waterlettuce at 96 HAT, 50 and 33% of absorbed radioactivity was located above the treated leaf and in the growing solution, respectively. The low recovery of aminocyclopyrachlor in alligatorweed roots and growing solution might explain regrowth potential after herbicide treatment. These results also indicate that the lack of waterlettuce control with aminocyclopyrachlor is not due to reduced absorption or translocation. DA - 2015/// PY - 2015/// DO - 10.1614/ws-d-14-00020.1 VL - 63 IS - 1 SP - 248-253 SN - 1550-2759 KW - Herbicide translocation KW - herbicide uptake ER - TY - JOUR TI - The Influence of Habitat Manipulations on Beneficial Ground-Dwelling Arthropods in a Southeast US Organic Cropping System AU - Fox, Aaron F. AU - Orr, David B. AU - Cardoza, Yasmin J. T2 - ENVIRONMENTAL ENTOMOLOGY AB - Journal Article The Influence of Habitat Manipulations on Beneficial Ground-Dwelling Arthropods in a Southeast US Organic Cropping System Get access Aaron F. Fox, Aaron F. Fox 3 1 Department of Crop Science, North Carolina State University, Campus Box 7620, Raleigh, NC. 2 Current address: Department of Entomology, Michigan State University, 578 Wilson Rd., East Lansing, MI 48824. 3 Corresponding author, e-mail: aaronfox@msu.edu . Search for other works by this author on: Oxford Academic PubMed Google Scholar David B. Orr, David B. Orr 4 Department of Entomology, North Carolina State University, Campus Box 7613, Raleigh, NC. Search for other works by this author on: Oxford Academic PubMed Google Scholar Yasmin J. Cardoza Yasmin J. Cardoza 4 Department of Entomology, North Carolina State University, Campus Box 7613, Raleigh, NC. Search for other works by this author on: Oxford Academic PubMed Google Scholar Environmental Entomology, Volume 44, Issue 1, February 2015, Pages 114–121, https://doi.org/10.1093/ee/nvu002 Published: 10 January 2015 Article history Received: 08 April 2014 Accepted: 01 October 2014 Published: 10 January 2015 DA - 2015/2// PY - 2015/2// DO - 10.1093/ee/nvu002 VL - 44 IS - 1 SP - 114-121 SN - 1938-2936 KW - habitat manipulation KW - Amara cupreolata KW - Megacephala carolina KW - Araneae KW - Collembola ER - TY - JOUR TI - Soil Moisture and pH Control Relative Contributions of Fungi and Bacteria to N2O Production AU - Chen, Huaihai AU - Mothapo, Nape V. AU - Shi, Wei T2 - MICROBIAL ECOLOGY DA - 2015/1// PY - 2015/1// DO - 10.1007/s00248-014-0488-0 VL - 69 IS - 1 SP - 180-191 SN - 1432-184X ER - TY - JOUR TI - Relative Contributions of Allelopathy and Competitive Traits to the Weed Suppressive Ability of Winter Wheat Lines Against Italian Ryegrass AU - Worthington, Margaret AU - Reberg-Horton, S. Chris AU - Brown-Guedira, Gina AU - Jordan, David AU - Weisz, Randy AU - Murphy, J. Paul T2 - CROP SCIENCE AB - ABSTRACT Allelopathy and competitive ability have been identified as independent factors contributing to the weed suppressive ability of crop cultivars; however, it is not clear whether these factors have equal influence on weed suppression outcomes of winter wheat ( Triticum aestivum L.) lines in the field. Fifty‐eight winter wheat lines adapted to the southeastern United States were screened for allelopathic activity against Italian ryegrass ( Lolium perenne L. ssp. multiflorum [Lam.] Husnot) in an agar‐based seedling bioassay. Eight strongly and weakly allelopathic lines were identified and evaluated for weed suppressive ability and grain yield tolerance in a replicated field experiment conducted in North Carolina. Significant genotypic differences in weed suppressive ability were found in three of four study environments, while genotypic differences in yield tolerance were identified in all environments. Although the allelopathic activity of genotypes varied in the seedling bioassay, no correlations between allelopathy and weed suppressive ability or grain yield tolerance were observed. Weed suppressive ability was correlated with competitive traits, including vigor and erect growth habit during tillering (Zadoks GS 29), high leaf area index (LAI) at stem extension (GS 31), plant height at tillering and stem extension (GS 29, 31), grain yield in weedy conditions, and grain yield tolerance. Therefore, breeders in the southeastern United States should focus their efforts on improving competitive traits within adapted germplasm rather than selecting for cultivars with high allelopathic activity to achieve maximum gains in weed suppressive ability against Italian ryegrass. DA - 2015/// PY - 2015/// DO - 10.2135/cropsci2014.02.0150 VL - 55 IS - 1 SP - 57-64 SN - 1435-0653 ER - TY - JOUR TI - Phosphorus speciation of clay fractions from long-term fertility experiments in Sweden AU - Eriksson, Ann Kristin AU - Gustafsson, Jon Petter AU - Hesterberg, Dean T2 - GEODERMA AB - Phosphorus (P) losses from agricultural soils constitute a main driver for eutrophication of the Baltic Sea. There is limited knowledge about sorption and release processes of P in these soils, especially concerning the effects of fertilization. In this study, P speciation of the clay fractions from six different soils in long-term fertility experiments in Sweden was investigated by P K-edge XANES spectroscopy. As expected, unfertilized soils had lower concentrations of acid-digestible P compared with fertilized soils. Based on best-fit standards that emerged from linear combination fitting (LCF) of XANES spectra, phosphate sorbed on iron (Fe) (hydr)oxides was a dominant P species in clay fractions from unfertilized soils containing more than 35 mmol kg− 1 of oxalate-extractable Fe. In contrast, P sorbed on aluminum (Al) (hydr)oxides predominated in soils with lower concentrations of oxalate-extractable Fe. A greater proportion of organically bound P was fit for soil samples containing > 2% organic carbon. The soils included one calcareous soil for which a greater proportion of P was fit as apatite. After long-term fertilization, P had accumulated mainly as P adsorbed to Al (hydr)oxides according to the XANES analysis. Our research shows that P speciation in fertilized agricultural soils depended on the level of P buildup and on the soil properties. DA - 2015/3// PY - 2015/3// DO - 10.1016/j.geoderma.2014.10.023 VL - 241 SP - 68-74 SN - 1872-6259 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-84919934924&partnerID=MN8TOARS KW - Soils KW - X-ray absorption spectroscopy KW - Sweden KW - Phosphorus KW - Phosphate KW - Clays ER - TY - JOUR TI - Phosphorus Dissolution in the Rhizosphere of Bald Cypress Trees in Restored Wetland Soils AU - Moorberg, Colby J. AU - Vepraskas, Michael J. AU - Niewoehner, Christopher P. T2 - SOIL SCIENCE SOCIETY OF AMERICA JOURNAL AB - Phosphorus release to ground or surface waters has been observed in wetlands restored from farmland. This study examined whether rhizospheres of bald cypress (Taxodium distichum L.) are a source of increased P dissolution compared with the soil matrix. The study was conducted in root-box rhizotrons filled with mineral and organic soil materials (Aeric Alaquods and Terric Haplosaprists, respectively) from a Carolina bay wetland restored from row crop agriculture. Rhizotrons were planted with bald cypress saplings or left unplanted to simulate rhizosphere and matrix conditions, respectively. Ponding was imposed for 128 d. Soil pore water was sampled in three layers (0–22, 22–41, and 41–59 cm) in each rhizotron twice monthly for dissolved total and reactive P, dissolved organic C (DOC), Fe2+, and redox potential (Eh). Manual root counts monitored growth and death monthly. Root death was most prevalent at 41 to 59 cm, while vigorous root growth was observed near the surface. The rhizosphere treatments exhibited increased Fe2+ dissolution and increased concentrations of DOC relative to matrix conditions; however, no corresponding P increase occurred. Near the surface, rhizosphere P concentrations declined below matrix concentrations after 60 d of ponding. Our results show that the rhizosphere of bald cypress did not cause higher P concentrations than matrix values for mineral and organic soils with 3.5 and 19.5% C, respectively. In addition, root growth near the surface resulted in more oxidizing conditions and/or plant uptake of P, which decreased P concentrations below matrix values. DA - 2015/// PY - 2015/// DO - 10.2136/sssaj2014.07.0304 VL - 79 IS - 1 SP - 343-355 SN - 1435-0661 ER - TY - JOUR TI - Morphological Traits Associated with Superior Weed Suppressive Ability of Winter Wheat against Italian Ryegrass AU - Worthington, M. AU - Reberg-Horton, S.C. AU - Brown-Guedira, G. AU - Jordan, D. AU - Weisz, R. AU - Murphy, J.P. T2 - Crop Science AB - ABSTRACT Weed‐suppressive wheat ( Triticum aestivum L.) cultivars have been suggested as a complement to chemical and cultural methods of weed control. The objectives of this study were to assess the range of weed‐suppressive ability against Italian ryegrass [ Lolium perenne L. ssp. multiflorum (Lam.) Husnot] existing in winter wheat lines adapted to North Carolina and to identify wheat morphological traits that could facilitate indirect selection for weed suppression in the southeastern United States. Fifty‐three commercially available cultivars and advanced experimental lines were overseeded with a uniform, high rate of Italian ryegrass, evaluated for various morphological traits throughout the growing season, and investigated for weed‐suppressive ability at a total of four field sites. Genotypic differences in Italian ryegrass seed head density ( P ≤ 0.05) were detected among the wheat lines. Reduced Italian ryegrass seed head density was correlated ( P ≤ 0.05) with high vigor during tillering and heading (Zadoks growth stage [GS] 25, 29, 55), erect growth habit (GS 29), low normalized difference vegetation index (NDVI) (GS 29), high leaf area index (LAI) at stem extension (GS 31), early heading date, and tall height throughout the growing season (GS 29, 31, 55, 70 to 80) in three of four sites. Multiple regression models show that 71% of variation in weed‐suppressive ability was accounted for by final height (GS 70 to 80) and either height or plant vigor at late tillering (GS 29). Thus, breeders could improve weed‐suppressive ability using weighted index selection for genotypes that are tall or vigorous during tillering with tall final height. DA - 2015/// PY - 2015/// DO - 10.2135/cropsci2014.02.0149 VL - 55 IS - 1 SP - 50–56 SN - 1435-0653 ER - TY - JOUR TI - Molecular characterization of a new powdery mildew resistance gene Pm54 in soft red winter wheat AU - Hao, Y. F. AU - Parks, R. AU - Cowger, C. AU - Chen, Z. B. AU - Wang, Y. Y. AU - Bland, D. AU - Murphy, J. P. AU - Guedira, M. AU - Brown-Guedira, Gina AU - Johnson, J. AU - al. T2 - THEORETICAL AND APPLIED GENETICS DA - 2015/3// PY - 2015/3// DO - 10.1007/s00122-014-2445-1 VL - 128 IS - 3 SP - 465-476 SN - 1432-2242 ER - TY - JOUR TI - Identifying and developing maize germplasm with resistance to accumulation of aflatoxins AU - Williams, W. P. AU - Krakowsky, M. D. AU - Scully, B. T. AU - Brown, R. L. AU - Menkir, A. AU - Warburton, M. L. AU - Windham, G. L. T2 - WORLD MYCOTOXIN JOURNAL AB - Efforts to identify maize germplasm with resistance to Aspergillus flavus infection and subsequent accumulation of aflatoxins were initiated by the US Department of Agriculture, Agricultural Research Service at several locations in the late 1970s and early 1980s. Research units at four locations in the south-eastern USA are currently engaged in identification and development of maize germplasm with resistance to A. flavus infection and accumulation of aflatoxins. The Corn Host Plant Resistance Research Unit, Mississippi State, MS, developed procedures for screening germplasm for resistance to A. flavus infection and accumulation of aflatoxins. Mp313E, released in 1990, was the first line released as a source of resistance to A. flavus infection. Subsequently, germplasm lines Mp420, Mp715, Mp717, Mp718, and Mp719 were released as additional sources of resistance. Quantitative trait loci associated with resistance have also been identified in four bi-parental populations. The Crop Protection and Management Research Unit and Crop Genetics and Breeding Research Unit, Tifton, GA, created a breeding population GT-MAS:gk. GT601, GT602, and GT603 were developed from GT-MAS:gk. The Food and Feed Safety Research Unit, New Orleans, LA, in collaboration with the International Institute for Tropical Agriculture used a kernel screening assay to screen germplasm and develop six germplasm lines with resistance to aflatoxins. The Plant Science Research Unit, Raleigh, NC, through the Germplasm Enhancement of Maize (GEM) Project provides to co-operators diverse germplasm that is a valuable source of resistance to A. flavus infection and accumulation of aflatoxins in maize. DA - 2015/// PY - 2015/// DO - 10.3920/wmj2014.1751 VL - 8 IS - 2 SP - 193-209 SN - 1875-0796 KW - Aspergillus flavus KW - aflatoxin KW - maize KW - plant resistance ER - TY - JOUR TI - Evaluation of widestrike cotton response to repeated applications of glufosinate at various application timings AU - Barnett, K. A. AU - Culpepper, A. S. AU - York, A. C. AU - Steckel, L. E. T2 - Weed Technology DA - 2015/// PY - 2015/// VL - 29 IS - 1 SP - 154-160 ER - TY - JOUR TI - Chemical Composition, Speciation, and Elemental Associations in Coal Fly Ash Samples Related to the Kingston Ash Spill AU - Rivera, Nelson AU - Kaur, Navdeep AU - Hesterberg, Dean AU - Ward, Colin R. AU - Austin, Robert E. AU - Duckworth, Owen W. T2 - ENERGY & FUELS AB - Environmental impacts of potentially toxic trace elements from coal fly ash are controlled in part by the mineralogy of the ash matrix and the chemical speciation of the trace elements. Our objective was to characterize the chemical and mineralogical composition of fly ash samples that are pertinent to the 2008 release of coal ash from a containment area at the Tennessee Valley Authority (TVA) Kingston fossil plant, which left 4 to 500 t of trace elements in adjoining river systems. Three fly ash samples were analyzed for elemental composition by digestion or neutron activation analysis, mineralogy and macroelement speciation by conventional and synchrotron-based X-ray diffraction (XRD and SXRD) and X-ray absorption spectroscopy (XAS), and for spatial associations of elements by electron probe microanalysis (EPMA). Ash samples were mainly composed of Si (20–27% w/w), Al (10–14% w/w), Fe (4–6% w/w), and Ca (4–6% w/w). Concentrations of selected trace elements ranged from 8 to 1480 mg kg–1, with the following general trend: Sr > Mn ≈ Zn ≈ Cu ≈ Cr > As ≈ Pb > Se ≈ U. XRD and EPMA analyses indicated that fly ash matrices were heterogeneous mixtures of minerals and aluminosilicate glass containing Fe, Ca, Ti, Mg, Na, and K. XAS fitting analyses suggested that Fe was mostly in a poorly ordered, polymerized hydroxyl-Fe(III) phase, with minor proportions of magnetite, and hematite or maghemite. Consistent with XRD data, fits to Ca XAS data included standards of glass, anhydrite, lime, and calcite; and fits to S XAS data included anhydrite and reduced organic S forms. Electron microprobe analysis showed frequent correlations among Ca, Si, and Al (and with Sr), consistent with the glass and mineral phases identified. Ash composition and mineralogy help to define a geochemical basis for projecting the long-term fate of trace elements in residual ash left in sediments following cleanup operations at the TVA-Kingston site. DA - 2015/2// PY - 2015/2// DO - 10.1021/ef501258m VL - 29 IS - 2 SP - 954-967 SN - 1520-5029 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-84923296129&partnerID=MN8TOARS ER - TY - JOUR TI - Characterization of stem rust resistance in wheat cultivar gage AU - Kumssa, T. T. AU - Baenziger, P. S. AU - Rouse, M. N. AU - Guttieri, M. AU - Dweikat, I. AU - Brown-Guedira, G. AU - Williamson, S. AU - Graybosch, R. A. AU - Wegulo, S. N. AU - Lorenz, A. J. AU - Poland, J. T2 - Crop Science DA - 2015/// PY - 2015/// VL - 55 IS - 1 SP - 229-239 ER - TY - JOUR TI - Black Shank Resistance and Agronomic Performance of Flue-Cured Tobacco Lines and Hybrids Carrying the Introgressed Nicotiana rustica Region, Wz AU - Drake, Katherine E. AU - Moore, J. Michael AU - Bertrand, Paul AU - Fortnum, Bruce AU - Peterson, Paul AU - Lewis, Ramsey S. T2 - CROP SCIENCE AB - ABSTRACT Black shank, caused by Phytophthora nicotianae , is one of the most important diseases affecting tobacco ( Nicotiana tabacum L.) production in the United States. Genetic mechanisms are needed that provide resistance to current races and that can be combined into cultivars that provide high yields of cured leaf with acceptable quality. Previous research identified DNA markers associated with an introgressed N. rustica genomic region (designated as Wz ) found to contribute to resistance to race 0 and race 1 isolates. Objectives of the current research were to use DNA markers to transfer Wz into the elite genetic background of flue‐cured tobacco cultivar K 326 and to develop nearly isogenic lines and hybrids with and without the race 0 immunity gene Php . These materials were evaluated in multiple environments for black shank resistance, yield, and quality characteristics. Wz was observed to positively affect resistance in the seven diverse disease environments tested. Genotypes in which Wz was combined with Php exhibited the greatest levels of resistance. No evidence of a negative relationship between Wz and yield and/or quality was observed. Data suggest commercial value for Wz in flue‐cured tobacco‐breeding programs with the goal of developing high‐yielding tobacco cultivars with resistance to race 0 and race 1. Further studies are necessary to determine the durability of Wz ‐mediated resistance, however. DA - 2015/// PY - 2015/// DO - 10.2135/cropsci2014.02.0164 VL - 55 IS - 1 SP - 79-86 SN - 1435-0653 ER - TY - JOUR TI - Amending irrigation channels with jute-mesh structures to decrease arsenic loading to rice fields in Bangladesh AU - Polizzotto, Matthew L. AU - Birgand, Francois AU - Badruzzaman, A. Borhan M. AU - Ali, M. Ashraf T2 - ECOLOGICAL ENGINEERING AB - Abstract Extensive use of arsenic-contaminated well water for irrigation of rice fields in Bangladesh has led to elevated arsenic concentrations in rice plants, decreased rice yields, and increased human exposure to arsenic. The goal of this study was to investigate whether arsenic removal from irrigation water could be improved within distribution channels by amending them with physical structures that both induce water treatment and maintain water-conveyance capacities. Chemical and hydraulic effects of amending channels with jute-mesh structures were characterized within 27 m-long experimental channels at a Bangladesh field site. Removal of total arsenic, iron and phosphorus from solution was enhanced within amended channels over unamended channels, with 7% of total As removed in amended channels vs. 3% in unamended channels. Increased elemental removal in amended channels was largely due to increases in residence time and particle-trapping efficiency, but removal via oxidative particle formation did not appear to be substantially enhanced. Results suggest that in-channel structures could be a useful tool for decreasing arsenic loading to rice fields, particularly where constrained channel spatial geometries limit the ability to overcome hydrogeochemical thresholds for enhanced arsenic removal. To improve the practical utility of structure-amended channels, future work could optimize structure designs and establish the season-long sustainability of enhanced arsenic-removal strategies. DA - 2015/1// PY - 2015/1// DO - 10.1016/j.ecoleng.2014.10.030 VL - 74 SP - 101-106 SN - 1872-6992 KW - Arsenic KW - Irrigation KW - Rice KW - Bangladesh KW - Channels KW - Mitigation ER - TY - JOUR TI - A comparison of four wheat models with respect to robustness and transparency: Simulation in a temperate, sub-humid environment AU - Soltani, Afshin AU - Sinclair, Thomas R. T2 - FIELD CROPS RESEARCH AB - There is debate over determining the appropriate model complexity to simulate crop development, growth, and yield. An approach that is sometimes suggested is to compare the performance of models using common datasets for ability to reproduce specific sets of observations. However, this narrow-focused approach overlooks the critical heuristic aspects in using models to explore and understand the behavior of cropping systems at the process level. We argue that the key criteria of model evaluation are both transparency and overall robustness. While model robustness (often mislabeled as “validation”) is sometimes presented at some level, model transparency has normally been ignored in model comparison studies. The objective of this paper is to examine the transparency and robustness of four wheat (Triticum aestivum L.) models that are markedly different in detail: CropSyst and SSM as simpler models and APSIM and DSSAT as more complex models. Data for development, growth and yield of the crop were collected from a wide range of environmental and growth conditions in the Grogan region of Iran. Models parameterization was done according to the guidelines for each model and then model testing and comparison were performed using different datasets. The two simpler models were found to be more robust than the complex models; across all the evaluated crop variables, the coefficient of variation in yield prediction was lower for SSM (8.2%) and CropSyst (14.3%) than APSIM (15.0%) and DSSAT (18.5%). Transparency of the models was mainly gauged by the number of input parameters needed by the models. Simulations using APSIM (292 parameters) and DSSAT (211 parameters) required the definition of about fourfold more parameters than CropSyst (50 parameters) and SSM (55 parameters). The simulation results showed no significant relationship between model performance and parameter number; the lack of transparency sacrificed in complexity was not rewarded by increased robustness in the output. DA - 2015/4// PY - 2015/4// DO - 10.1016/j.fcr.2014.10.019 VL - 175 SP - 37-46 SN - 1872-6852 KW - Simulation KW - Model comparison KW - Model complexity KW - Model transparency KW - Wheat ER - TY - JOUR TI - Inhibitor screen for limited-transpiration trait among maize hybrids AU - Choudhary, Sunita AU - Sinclair, Thomas R. AU - Messina, Carlos D. AU - Cai, Weiguo AU - Warner, Dave AU - Cooper, Mark T2 - ENVIRONMENTAL AND EXPERIMENTAL BOTANY AB - A plant trait to minimize the impact of drought on crop yield is limited-transpiration rate (TR) under high ambient vapor pressure deficit (VPD) so that soil water is conserved to sustain grain fill. Variation among maize (Zea mays L.) hybrids has been identified for the existence of the limited-TR trait at high atmospheric VPD, and the VPD at which TR becomes limited. Further, it has been shown that the TR limitation at high VPD is related to plant hydraulic conductance, which may be due to differences in aquaporin expression. This paper reports studies to relate the TR response of 21 maize hybrids to treatment of leaves and intact plants with cycloheximide (CHX) and four aquaporin inhibitors: silver (AgNO3), gold (HAuCl4), zinc (ZnCl2), and mercury (HgCl2). There was no discrimination among hybrids based on treatment with Hg or CHX. Segregation between hybrids for response to increasing VPD corresponded with differences in leaf response to Ag and Au treatment and intact plant response to Zn. The highest correlation (r = 0.90) between VPD breakpoint and TR response to inhibitor was with Ag treatment of leaves. These results indicate that Ag may be an effective initial screen for expression of the limited-TR trait under high VPD. DA - 2015/1// PY - 2015/1// DO - 10.1016/j.envexpbot.2014.07.015 VL - 109 SP - 161-167 SN - 1873-7307 KW - Aquaporin inhibitors KW - Drought KW - Genetic screen KW - Maize KW - Silver KW - Transpiration ER -