TY - JOUR TI - Leaf hydraulic conductance declines in coordination with photosynthesis, transpiration and leaf water status as soybean leaves age regardless of soil moisture AU - Locke, Anna M. AU - Ort, Donald R. T2 - Journal of Experimental Botany AB - Photosynthesis requires sufficient water transport through leaves for stomata to remain open as water transpires from the leaf, allowing CO2 to diffuse into the leaf. The leaf water needs of soybean change over time because of large microenvironment changes over their lifespan, as leaves mature in full sun at the top of the canopy and then become progressively shaded by younger leaves developing above. Leaf hydraulic conductance (K(leaf)), a measure of the leaf's water transport capacity, can often be linked to changes in microenvironment and transpiration demand. In this study, we tested the hypothesis that K(leaf) would decline in coordination with transpiration demand as soybean leaves matured and aged. Photosynthesis (A), stomatal conductance (g(s)) and leaf water potential (Ψ(leaf)) were also measured at various leaf ages with both field- and chamber-grown soybeans to assess transpiration demand. K(leaf) was found to decrease as soybean leaves aged from maturity to shading to senescence, and this decrease was strongly correlated with midday A. Decreases in K(leaf) were further correlated with decreases in g(s), although the relationship was not as strong as that with A. Separate experiments investigating the response of K(leaf) to drought demonstrated no acclimation of K(leaf) to drought conditions to protect against cavitation or loss of g(s) during drought and confirmed the effect of leaf age in K(leaf) observed in the field. These results suggest that the decline of leaf hydraulic conductance as leaves age keeps hydraulic supply in balance with demand without K(leaf)becoming limiting to transpiration water flux. DA - 2014/10/3/ PY - 2014/10/3/ DO - 10.1093/jxb/eru380 VL - 65 IS - 22 SP - 6617-6627 LA - en OP - SN - 1460-2431 0022-0957 UR - http://dx.doi.org/10.1093/jxb/eru380 DB - Crossref ER - TY - JOUR TI - Influences of finite probe property on soil thermal property estimated by heat pulse technique AU - Fu, Y. AU - Lu, Y. AU - Ren, T. T2 - Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering DA - 2014/// PY - 2014/// DO - 10.3969/j.issn.1002-6819.2014.19.009 VL - 30 IS - 19 SP - 71-77 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-84910048844&partnerID=MN8TOARS ER - TY - JOUR TI - Rice straw incorporated just before soil flooding increases acetic acid formation and decreases available nitrogen,A incorporação da palha do arroz próximo ao alagamento do solo aumenta a formação de ácido acético e diminui a disponibilidade de nitrogênio AU - Knoblauch, R. AU - Ernani, P.R. AU - Deschamps, F.C. AU - Gatiboni, L.C. AU - Walker, T.W. AU - Louren?o, K.S. AU - Martins, A.A. AU - Pegoraro, A. T2 - Revista Brasileira de Ciencia do Solo AB - Incorporation of rice straw into the soil just before flooding for water-seeded rice can immobilize mineral nitrogen (N) and lead to the production of acetic acid harmful to the rice seedlings, which negatively affects grain yield. This study aimed to evaluate the formation of organic acids and variation in pH and to quantify the mineral N concentration in the soil as a function of different times of incorporation of rice straw or of ashes from burning the straw before flooding. The experiment was carried out in a greenhouse using an Inceptisol (Typic Haplaquept) soil. The treatments were as follows: control (no straw or ash); incorporation of ashes from previous straw burning; rice straw incorporated to drained soil 60 days before flooding; straw incorporated 30 days before flooding; straw incorporated 15 days before flooding and straw incorporated on the day of flooding. Experimental units were plastic buckets with 6.0 kg of soil. The buckets remained flooded throughout the trial period without rice plants. Soil samples were collected every seven days, beginning one day before flooding until the 13th week of flooding for determination of mineral N- ammonium (NH4+) and nitrate (NO3-). Soil solution pH and concentration of organic acids (acetic, propionic and butyric) were determined. All NO3- there was before flooding was lost in approximately two weeks of flooding, in all treatments. There was sigmoidal behavior for NH4+ formation in all treatments, i.e., ammonium ion concentration began to rise shortly after soil flooding, slightly decreased and then went up again. On the 91st day of flooding, the NH4+ concentrations in soil was 56 mg kg-1 in the control treatment, 72 mg kg-1 for the 60-day treatment, 73 mg kg-1 for the 30-day treatment and 53 mg kg-1 for the ash incorporation treatment. These ammonium concentrations correspond to 84, 108, 110 and 80 kg ha-1 of N-NH4+, respectively. When the straw was incorporated on the day of flooding or 15 days before, the concentration of N-NH4+ in the soil was 28 and 54 mg kg-1, equivalent to an accumulation of 42 and 81 kg ha-1 of N-NH4+, respectively. There was formation of acetic acid in which toxic concentrations were reached (7.2 mmol L-1) on the 15th day of flooding only for the treatment with straw incorporated on the day of flooding. The pH of the soil solution of all the treatments increased after flooding and this increase was faster in the treatments with incorporation of straw, followed by the ash treatment and then the control. After 60 days of flooding, however, the pH values were around 6.5 for all treatments, except for the control, which reached a pH of 6.3. Rice straw should be incorporated into the soil at least 30 days before flooding; otherwise, it may immobilize part of the mineral N and produce acetic acid in concentrations toxic to rice seedlings. DA - 2014/// PY - 2014/// DO - 10.1590/S0100-06832014000100017 VL - 38 IS - 1 SP - 177-184 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-84897949371&partnerID=MN8TOARS ER - TY - JOUR TI - Response of one-, Five-, And nine-year-old pinus taeda to npk fertilization in southern brazil,Resposta de pinus taeda com diferentes idades À adubaÇÃo npk no planalto sul catarinense AU - Moro, L. AU - Gatiboni, L.C. AU - Simonete, M.A. AU - Cassol, P.C. AU - Chaves, D.M. T2 - Revista Brasileira de Ciencia do Solo AB - Na região do Planalto Sul-catarinense, a maioria das florestas de Pinus foi implantada sem fertilização do solo na fase de plantio. Atualmente, muitas áreas encontram-se em segunda ou terceira rotação de Pinus e sem nenhuma fertilização, o que pode limitar a produtividade pela baixa fertilidade do solo. Uma alternativa para a mitigação desse problema seria a adubação em povoamentos já estabelecidos. Com o objetivo de avaliar o efeito da adubação com N, P e K, em diferentes fases de crescimento de Pinus taeda, foram conduzidos experimentos no campo, em plantios de um, cinco e nove anos de idade, todos de segunda rotação, sobre Cambissolos no município de Otacílio Costa, SC. Os tratamentos consistiram de combinações de doses de N (N0 = 0, N1 = 70 e N2 = 140 kg ha-1 de N), P (P0 = 0, P1 = 75 e P2 = 150 kg ha-1 P2O5) e K (K0 = 0, K1 = 60 e K2 = 120 kg ha-1 de K2O), além de uma testemunha, nas seguintes combinações: N0P0K0, N0P1K0, N1P1K1, N1P2K1, N1P2K2 e N2P2K1. O delineamento experimental utilizado foi de blocos ao acaso com três repetições. Foram avaliados altura e diâmetro no colo ou à altura do peito das árvores e calculado o volume de tronco das plantas e teores de N, P e K nas acículas aos seis e 18 meses, após a aplicação dos tratamentos. Os resultados evidenciaram que nas plantas de um ano de idade houve incremento significativo no volume de madeira com a aplicação de 70 kg ha-1 de P2O5. Para os plantios de cinco e nove anos, a adição de doses a partir de 70, 75 e 60 kg ha-1 de N, P2O5 e K2O, respectivamente, promoveram incrementos significativos no volume de madeira, mostrando que a adubação em florestas já estabelecida é uma estratégia a ser considerada em sítios de baixa fertilidade. DA - 2014/// PY - 2014/// DO - 10.1590/S0100-06832014000400014 VL - 38 IS - 4 SP - 1181-1189 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-84923368709&partnerID=MN8TOARS ER - TY - JOUR TI - Phosphorus fractions in the vineyard soil of the Serra Gaúcha of Rio Grande do Sul, Brazil,Frações de fósforo no solo de vinhedo na Serra Gaúcha do Rio Grande do Sul AU - Schmitt, D.E. AU - Gatiboni, L.C. AU - Girotto, E. AU - Lorensini, F. AU - Melo, G.W.B. AU - Brunetto, G. T2 - Revista Brasileira de Engenharia Agricola e Ambiental AB - The study aimed to evaluate the accumulation of P fractions in a vineyard soil profile with successive applications of phosphate fertilizers. In January 2010 an area was selected of native forest and a vineyard at age 33 with a history of phosphate fertilizer application, in Bento Gonçalves, Rio Grande do Sul state. Soil samples were collected from 0-5, 5-10 and 10-20 cm layers, prepared and submitted to chemical fractionation of P. The excessive application of phosphate fertilizers during 33 years in the vineyard soil increased the levels of organic and inorganic P until the 20 cm layer in all P fractions. The highest levels of P in the vineyard soil were found mainly in the labile fractions extracted with anion exchange resin and NaHCO3, which indicates high nutrient availability to plants, but also indicates the potential of transfer of solution from soil to surface run-off or percolated through the soil profile, which represents greater potential for contamination of surface and subsurface waters. DA - 2014/// PY - 2014/// DO - 10.1590/S1415-43662014000200002 VL - 18 IS - 2 SP - 134-140 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-84893633688&partnerID=MN8TOARS ER - TY - JOUR TI - Phosphorus application and liming effects on forage production, floristic composition and soil chemical properties in the Campos biome, southern Brazil AU - Tiecher, T. AU - Oliveira, L.B. AU - Rheinheimer, D.S. AU - Quadros, F.L.F. AU - Gatiboni, L.C. AU - Brunetto, G. AU - Kaminski, J. T2 - Grass and Forage Science AB - Abstract Studies of responses of native and introduced grassland species to lime and phosphorus ( P ) applications could contribute to improved understanding of the potential production of S outh A merican natural grasslands. To determine the effect of applying lime and different P sources on forage production, diversity and floristic composition, and on soil chemical properties, a small‐plot experiment was conducted over 12 years in natural grassland oversown with L olium multiflorum and T rifolium vesiculosum in the C ampos of southern B razil. In treatments with soluble phosphate application, dry‐matter ( DM ) yield in November 2008, after 164 d of winter and early spring growth, increased from 2·3 to 3·2 t ha −1 . Differences in DM yield in M arch 2009, after 111 d of growth during late spring and early summer, were not significant. The DM yield in April 2010, after 419 d of growth, increased from 7·7 to 9·2 t ha −1 in the treatments with P , regardless of the P source. Increased forage yield during the slow growth period in winter was only possible with the introduction of winter‐growing species ( L . multiflorum and T . vesiculosum ) and soluble phosphate application. Assessment of annual forage yield showed that the effectiveness of G afsa rock phosphate was equivalent to that of soluble phosphates in the long term. Soluble phosphates and liming modified the botanical composition of natural C ampos grassland in the long term, but floristic diversity was not altered. DA - 2014/// PY - 2014/// DO - 10.1111/gfs.12079 VL - 69 IS - 4 SP - 567-579 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-84907879794&partnerID=MN8TOARS ER - TY - JOUR TI - Partial substitution of soluble phosphate by rock phosphate in the planting of Eucalyptus benthamii and Eucalyptus dunnii in southern Brazil,Substituição parcial de fosfato solúvel por natural na implantação de Eucalyptus benthamii e Eucalyptus dunnii no planalto sul catarinense AU - Dias, L.P.R. AU - Gatiboni, L.C. AU - Ernani, P.R. AU - Miquelluti, D.J. AU - Chaves, D.M. AU - Brunetto, G. T2 - Revista Brasileira de Ciencia do Solo AB - A adubação fosfatada é importante para o crescimento inicial do eucalipto, porque suplementa o solo na fase de maior demanda da cultura. O fosfato solúvel (FS) é a fonte comumente utilizada para esse fim, pois apresenta dissolução rápida no solo; contudo, tem custo mais elevado que os fosfatos naturais (FNs), que por sua vez têm dissolução mais lenta. Este trabalho objetivou avaliar o uso de FN como substituinte parcial do FS para o fornecimento de P para Eucalyptus benthamii e E. dunnii. Foram conduzidos dois experimentos no campo, um com cada espécie, no município de Otacílio Costa, SC, no período de novembro de 2010 a dezembro de 2011. O delineamento experimental utilizado foi de blocos casualizados com parcelas subdivididas, com três repetições. Na parcela principal, testou-se a presença ou ausência do FN (0 ou 60 kg ha-1 de P2O5, usando a fonte FN de Bayovar) e nas subparcelas testaram-se as doses de FS (0, 75; 150; e 300 kg ha-1 de P2O5, usando a fonte superfosfato triplo). Foram realizadas medidas de diâmetro à altura do colo e altura das árvores aos 340 dias, após a aplicação das fontes de P. Os resultados evidenciaram que a adubação fosfatada aumentou o crescimento em diâmetro e altura e incrementou o volume das plantas de E. benthamii e E. dunnii, durante o primeiro ano de cultivo. O E. benthamii foi mais exigente à adubação fosfatada, mas permitiu a substituição parcial da dose de fosfato solúvel por fonte de menor solubilidade. Não houve resposta do E. dunnii à aplicação de fosfato natural, devendo a adubação ser realizada com fosfato solúvel. DA - 2014/// PY - 2014/// DO - 10.1590/S0100-06832014000200016 VL - 38 IS - 2 SP - 516-523 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-84903307068&partnerID=MN8TOARS ER - TY - JOUR TI - Nitrogen mineralization of cover plant litter, intercropped or not, in a soil with a history of onion plantation,Mineralizac¸a&tild;o do nitrogeˆnio de plantas de cobertura, solteiras e consorciadas, depositadas sobre um solo com histo´rico de cultivo de cebola AU - Martins, R.P. AU - Comin, J.J. AU - Gatiboni, L.C. AU - Soares, C.R.F. AU - Couto, R.R. AU - Brunetto, G. T2 - Revista Ceres AB - A decomposição das plantas de cobertura de inverno, depositadas sobre o solo, podem aumentar a disponibilidade de formas de nitrogênio (N), durante o ciclo da cebola. O trabalho objetivou avaliar a mineralização de N da massa de plantas de cobertura, solteiras e consorciadas, em um solo com histórico de cultivo de cebola. Porções de solo foram coletadas, preparadas, acondicionadas em recipientes de acrílico. Matéria seca de aveia preta, centeio, nabo-forrageiro, aveia preta+nabo-forrageiro e centeio+nabo-forrageiro, foram adicionadas sobre a superfície do solo e incubadas por 90 dias. No tempo zero e aos 18, 36, 54, 72 e 90 dias após a incubação (DAI), as porções de solo foram amostradas e determinados os teores de N total, N-NO3- e N-NH4+ de cada uma. Calcularam-se os valores de N mineral, N mineral líquido, N mineralizado e N total-N mineralizado. Os maiores teores de N-NH4+ foram observados nas porções de solo com a deposição de massa de nabo-forrageiro e do consórcio centeio+nabo-forrageiro. Os maiores teores de N-NO3- e N-mineral dos 36 até os 90 DAI e de N-mineralizado dos 18 até os 92 DAI foram observados nas porções de solo com a deposição de massa de centeio + nabo-forrageiro. A taxa de mineralização foi positiva em todas as amostras do solo com deposição de massa de centeio e nabo-forrageiro, e dos consórcios aveia preta+nabo-forrageiro e centeio+nabo-forrageiro e negativa aos 18 e 72 DAI, nas porções de solo com deposição de massa de aveia. Os resíduos de nabo-forrageiro e do consórcio centeio+nabo-forrageiro apresentaram o maior potencial de mineralização. DA - 2014/// PY - 2014/// DO - 10.1590/0034-737X201461040020 VL - 61 IS - 4 SP - 587-596 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-84907250855&partnerID=MN8TOARS ER - TY - JOUR TI - Forms of soil phosphorus in natural pastures subjected to additions of phosphates,Formas de fósforo no solo sob pastagens naturais submetidas à adição de fosfatos AU - Oliveira, L.B. AU - Tiecher, T. AU - Quadros, F.L.F. AU - Trindade, J.P.P. AU - Gatiboni, L.C. AU - Brunetto, G. AU - Santos, D.R. T2 - Revista Brasileira de Ciencia do Solo AB - A maioria das pastagens naturais no bioma Campos no sul do Brasil cresce em solos com baixa disponibilidade de fósforo (P), mas com altos teores de P total e de P orgânico. Este trabalho objetivou avaliar as alterações nas formas de P no solo, ao longo de um ciclo de crescimento de pastagens naturais, decorrentes da aplicação de fontes de fosfato. Em três experimentos instalados em áreas de pastagem natural, foi aplicado P nas formas de hiperfosfato de Gafsa, superfosfato triplo e testemunha, arranjados em blocos casualizados com três repetições. Nos experimentos instalados no município de Candiota, RS, em pastagens naturais sob Luvissolo Úmbrico e Neossolo Litólico, foram aplicados 100 kg ha-1 de P2O5 em setembro de 2010. Na pastagem sob Argissolo Vermelho no município de Santa Maria, RS, foram aplicados 180, 90, 100 e 100 kg ha-1 de P2O5 nos anos de 1997, 1998, 2002 e 2010, respectivamente. Amostras de solo foram coletadas (0-10 cm) ao longo da estação de crescimento da pastagem (0, 55, 116, 171 e 232 dias, após aplicação do fosfato em Candiota; e 0, 50, 83, 129, 159 e 186 dias, após aplicação do fosfato em Santa Maria). Foram analisados os teores de P disponível por resina de troca aniônica, o P imobilizado na biomassa microbiana do solo, o P extraído por NaOH 0,1 mol L-1, o P orgânico total e o P total. Os teores de P disponível aumentaram rapidamente com a aplicação de fosfato solúvel, mas no final do período de avaliação esses se equivaleram ao do fosfato natural, que foi semelhante à testemunha. A aplicação de fertilizantes fosfatados sob pastagens naturais com baixa disponibilidade de P aumentou a importância das frações inorgânicas lábeis às plantas, tornando-as menos dependentes da mineralização das frações orgânicas. As frações orgânicas, inclusive o P microbiano, não são bons indicadores da biodisponibilidade de P em pastagens naturais sob Argissolos, Neossolos e Luvissolos do sul do Brasil fertilizadas com fosfatos. DA - 2014/// PY - 2014/// DO - 10.1590/S0100-06832014000300018 VL - 38 IS - 3 SP - 867-878 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-84905164825&partnerID=MN8TOARS ER - TY - JOUR TI - Cu and Zn adsorption in an Oxisol treated with pig slurry,Adsorção de Cu e Zn num Latossolo Vermelho tratado com dejetos suínos AU - Lopes, C. AU - Campos, M.L. AU - Silveira, C.B. AU - Gatiboni, L.C. AU - Miquelutti, D.J. AU - Cassol, P.C. AU - Freitas Medeiros, I. T2 - Revista Ceres AB - O Cu e Zn oriundos dos dejetos suínos podem se acumular no solo, oferecendo riscos para a saúde humana e a animal. O objetivo deste trabalho foi determinar a capacidade de adsorção e a competição de Cu e Zn num Latossolo Vermelho distroférrico, que recebeu aplicações continuadas de dejetos suínos, com taxa de aplicação de 200 m³ ha-1 ano-1,durante sete anos, e comparar a adsorção com solo que nunca recebeu dejeto. Para avaliar a adsorção do Cu e Zn, foram aplicados ao solo soluções de Cu e Zn, nas doses de 0, 25, 50, 100, 150, 200, 400, 1.200 µmol L-1 e relação solo: solução final de 1:100. Para a obtenção das doses de Zn e Cu foi utilizada solução padrão Merck® Certipur 1.000 mg L-1. A adsorção de Cu apresentou comportamento sigmoide (isoterma tipo S), em solo sem dejeto (SD), e comportamento linear (isoterma tipo C), em solo com dejeto (CD). A capacidade máxima de adsorção (CMA) de Cu no solo SD foi de 3.021 mg kg-1. Para Zn, todas as isotermas apresentaram comportamento linear. Não foi atingida a capacidade máxima de adsorção, no tratamento CD, para Cu e Zn. Esses resultados indicam que o Latossolo estudado apresenta alta capacidade para reter o Cu e Zn oriundos dos dejetos suínos. DA - 2014/// PY - 2014/// DO - 10.1590/0034-737X201461060016 VL - 61 IS - 6 SP - 997-1005 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-84920443191&partnerID=MN8TOARS ER - TY - JOUR TI - Chemical changes and evaluation of available P near the granules of triple superphosphate and diammonium phosphate in acid soils,Alterações químicas e avaliação de P disponível na região adjacente aos grânulos de superfosfato triplo e diamônio fosfato em solos ácidos AU - Oliveira, J.P.M. AU - Ernani, P.R. AU - Gatiboni, L.C. AU - Pegoraro, A. T2 - Revista Brasileira de Ciencia do Solo AB - O P tem baixa mobilidade no solo resultando em altas concentrações nas regiões adjacentes aos grânulos de fertilizantes fosfatados. Isso pode interferir na disponibilidade de P e na composição química do solo nesses locais. O objetivo deste estudo foi avaliar a composição química do solo e a mobilidade de P nas adjacências de regiões fertilizadas com fosfatos de amônio ou de cálcio, em solos ácidos. Este trabalho foi realizado em 2009, com amostras de dois solos catarinenses. Os tratamentos consistiram de combinações de superfosfato triplo (SFT) ou de fosfato diamônico (DAP) com KCl, além de um controle somente com KCl. As unidades experimentais foram constituídas por colunas de PVC com 10,0 cm de diâmetro e 12,0 cm de comprimento, preenchidas com 1,60 kg de solo (base úmida). Foram aplicadas quantidades equivalentes a 200 kg ha-1 de P2O5 e de K2O, considerando a área de contato superficial de solo de 10(4) m². Tentando simular a aplicação localizada de fertilizantes, essas quantidades foram estipuladas para contatarem com 357 m² de solo, tendo sido aplicadas 10,47; 9,56; e 7,33 g por coluna de SFT, DAP e KCl respectivamente, numa área de contato de 0,00785 m². Quarenta e cinco dias após a aplicação dos fertilizantes, as colunas foram desmontadas e o solo foi analisado a cada centímetro distante do local de aplicação dos grânulos. O P foi quantificado pelos métodos Mehlich-1 e da resina trocadora de ânions (RTA), numa sequencia de nove extrações cumulativas. O DAP aumentou o pH e diminuiu o Al nas adjacências dos grânulos, porém o SFT aumentou Ca e Mg. A quantidade cumulativa extraída de P variou com o tipo de adubo fosfatado, a distância dos grânulos, o tipo de solo e o método de extração. Na camada distante até 1,0 cm dos adubos, o SFT proporcionou os maiores valores de P, que chegaram a atingir 10.276 mg dm-3; nas duas camadas seguintes (1,0-2,0 e 2,0-3,0 cm), isso normalmente ocorreu com o DAP. O Mehlich-1 quantificou sempre mais P do que a RTA nas adjacências dos fertilizantes fosfatados. A movimentação do P nos dois solos ocorreu até o quarto centímetro distante do local de aplicação dos adubos, e a composição química nessas adjacências variou com o fertilizante fosfatado, o tipo de solo, o método de extração e a distância dos grânulos, mas necessita ser mais bem estudada. DA - 2014/// PY - 2014/// DO - 10.1590/S0100-06832014000500018 VL - 38 IS - 5 SP - 1526-1536 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-84908691632&partnerID=MN8TOARS ER - TY - JOUR TI - Maximum phosphorus adsorption capacity and binding energy constant of an oxisol fitting different langmuir models,Capacidade máxima de adsorção de fósforo e constante de energia de ligação em latossolo bruno em razão de diferentes ajustes do modelo de langmuir AU - De Oliveira, C.M.B. AU - Gatiboni, L.C. AU - Miquelluti, D.J. AU - Smyth, T.J. AU - Almeida, J.A. T2 - Revista Brasileira de Ciencia do Solo DA - 2014/// PY - 2014/// VL - 38 IS - 6 SP - 1805-1815 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-84922278978&partnerID=MN8TOARS ER - TY - JOUR TI - Genetics, Breeding, and Marker‐Assisted Selection for Verticillium Wilt Resistance in Cotton AU - Zhang, Jinfa AU - Fang, Hui AU - Zhou, Huiping AU - Sanogo, Soum AU - Ma, Zhiying T2 - Crop Science AB - ABSTRACT Verticillium wilt (VW), caused by the soil‐borne fungus Verticillium dahliae Kleb., is one of the most destructive diseases in Upland cotton ( Gossypium hirsutum L.) production in the U.S. and worldwide. Development of VW‐resistant cultivars remains the only economic option for controlling the disease. The objective of this review was to summarize the progress in screening methods, resistance sources, and genetics, quantitative trait locus (QTL) mapping, marker‐assisted selection (MAS) and breeding for VW resistance in cotton. Even though Gossypium barbadense L. carries high levels of resistance, its resistance has not been transferred into commercial Upland cultivars. Many Acala cotton cultivars developed in New Mexico and California between the 1940s and the 1990s, and some commercial transgenic cultivars are tolerant or moderately resistant to VW. However, due to difficulties in achieving consistent and uniform inoculation and infection with V. dahliae , both qualitative and quantitative inheritance of VW resistance have been reported in numerous studies for resistant G. barbadense and Upland genotypes. Several QTL analyses have shown the existence of VW resistance QTLs on almost all the tetraploid cotton chromosomes; however, QTLs have most frequently been detected on c5, c7, c8, c11, c16, c17, c19, c21, c23, c24, and c26. This has led to MAS for progeny with favorable QTL alleles for VW resistance in several experiments. Phenotypic selection for VW resistance has been inefficient, while the effectiveness and efficiency of MAS remain to be validated. There is an urgent need for the development of better plant inoculation and screening methods, and for more molecular mapping studies to discern the genetic basis of VW resistance in cotton. DA - 2014/7// PY - 2014/7// DO - 10.2135/cropsci2013.08.0550 VL - 54 IS - 4 SP - 1289-1303 UR - http://dx.doi.org/10.2135/cropsci2013.08.0550 ER - TY - JOUR TI - Evaluation of Verticillium wilt resistance in commercial cultivars and advanced breeding lines of cotton AU - Zhou, Huiping AU - Fang, Hui AU - Sanogo, Soum AU - Hughs, Sidney E. AU - Jones, Don C. AU - Zhang, Jinfa T2 - Euphytica DA - 2014/4// PY - 2014/4// DO - 10.1007/s10681-013-1045-5 VL - 196 IS - 3 SP - 437-448 UR - http://dx.doi.org/10.1007/s10681-013-1045-5 KW - Cotton KW - Germplasm KW - Verticillium wilt KW - Resistance ER - TY - JOUR TI - Quantitative trait locus analysis of Verticillium wilt resistance in an introgressed recombinant inbred population of Upland cotton AU - Fang, Hui AU - Zhou, Huiping AU - Sanogo, Soum AU - Lipka, Alexander E. AU - Fang, David D. AU - Percy, Richard G. AU - Hughs, Sidney E. AU - Jones, Don C. AU - Gore, Michael A. AU - Zhang, Jinfa T2 - Molecular Breeding DA - 2014/3// PY - 2014/3// DO - 10.1007/s11032-013-9987-9 VL - 33 IS - 3 SP - 709-720 UR - http://dx.doi.org/10.1007/s11032-013-9987-9 KW - Upland cotton KW - Recombinant inbred line KW - Verticillium wilt KW - Disease resistance KW - Quantitative trait loci ER - TY - JOUR TI - Development of STS markers for Verticillium wilt resistance in cotton based on RGA–AFLP analysis AU - Fang, Hui AU - Zhou, Huiping AU - Sanogo, Soum AU - Zhang, Jinfa T2 - Molecular Breeding DA - 2014/10// PY - 2014/10// DO - 10.1007/s11032-014-0085-4 VL - 34 IS - 3 SP - 917-926 UR - http://dx.doi.org/10.1007/s11032-014-0085-4 KW - Upland cotton KW - Backcross inbred line (BIL) KW - RGA-AFLP KW - Verticillium wilt resistance KW - Sequence-tagged site (STS) ER - TY - JOUR TI - Anatomical characteristics of rubber tree bark related to the production of natural rubber. T2 - Australian Journal of Basic and Applied Sciences DA - 2014/// PY - 2014/// UR - https://publons.com/publon/15259783/ ER - TY - JOUR TI - Anatomical characteristics of rubber tree bark related to the production of natural rubber. AU - Souza, G. A. de AU - Oliveira, L. E. M. de AU - Alvarenga, A. de P. AU - Pires, R. M. de O. AU - Pires, M. F. AU - Cardoso, A. A. AU - O. Pires, R. M. AU - Souza, G. A. AU - Oliveira, L. E. M. T2 - Australian Journal of Basic and Applied Sciences DA - 2014/// PY - 2014/// VL - 8 IS - 16 SP - 79-84 UR - http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=ORCID&SrcApp=OrcidOrg&DestLinkType=FullRecord&DestApp=CABI&KeyUT=CABI:20143424408&KeyUID=CABI:20143424408 ER - TY - CONF TI - Turf Selection for NC AU - Miller, Grady T2 - Regional Turf Conference C2 - 2014/1/31/ CY - Greensboro, NC DA - 2014/1/31/ PY - 2014/1/31/ ER - TY - CONF TI - Turfgrass Evaluations in NC AU - Miller, Grady T2 - NC Sod Producers Association Meeting C2 - 2014/1/9/ CY - Greensboro, NC DA - 2014/1/9/ PY - 2014/1/9/ ER - TY - SOUND TI - Tall Fescue Trials at NCSU AU - Miller, Grady DA - 2014/2/18/ PY - 2014/2/18/ ER - TY - SOUND TI - Establishment of Turfgrasses AU - Miller, Grady DA - 2014/2/12/ PY - 2014/2/12/ ER - TY - CONF TI - Why Research Matters AU - Miller, Grady T2 - Sports Turf Managers Association Meeting C2 - 2014/1/22/ CY - San Antonio, TX DA - 2014/1/22/ PY - 2014/1/22/ ER - TY - RPRT TI - 2014 Recommended Kentucky bluegrass cultivars for North Carolina AU - Miller, G.L. A3 - North Carolina State University DA - 2014/8/8/ PY - 2014/8/8/ M3 - North Carolina Cooperative Extension Publications PB - North Carolina State University ER - TY - CONF TI - Evaluation and Preparation of Fields for Heavy Use AU - Miller, Grady T2 - Sports Turf Managers Association meeting C2 - 2014/1/21/ CY - San Antonio, TX DA - 2014/1/21/ PY - 2014/1/21/ ER - TY - SOUND TI - Mowing, Aerification, and Other Cultural Practices AU - Miller, Grady DA - 2014/2/12/ PY - 2014/2/12/ ER - TY - RPRT TI - 2014 Recommended tall fescue cultivars for North Carolina AU - Miller, G.L. A3 - North Carolina State University DA - 2014/8/8/ PY - 2014/8/8/ M3 - North Carolina Extension Service Publications PB - North Carolina State University ER - TY - CONF TI - Using Colorants Rather than Overseeding AU - Miller, Grady T2 - Golf Course Superintendents Association of America meeting C2 - 2014/2/6/ CY - Orlando, FL DA - 2014/2/6/ PY - 2014/2/6/ ER - TY - CONF TI - Sports Turf Research at NC AU - Miller, Grady T2 - NC Sports Turf Managers Association Meeting C2 - 2014/9/24/ CY - Elon University, Elon, North Carolina DA - 2014/9/24/ PY - 2014/9/24/ ER - TY - JOUR TI - Turf colorants for aesthetics or as an alternative to overseeding AU - Miller, G.L. AU - Pinnix, D. T2 - USGA Turfgrass and Environmental Research Online DA - 2014/7// PY - 2014/7// VL - 13 IS - 4 SP - 17-19 ER - TY - CONF TI - The End of the Painted Block S? AU - Miller, Grady T2 - Turf Centere Symposium C2 - 2014/5/15/ CY - Raleigh, NC DA - 2014/5/15/ PY - 2014/5/15/ ER - TY - CONF TI - Colorant Use for Sports Fields AU - Miller, Grady AU - Pinnix, Drew T2 - NC Sports Turf Managers Meeting C2 - 2014/8/26/ CY - Greenville, NC DA - 2014/8/26/ PY - 2014/8/26/ ER - TY - CONF TI - Turf Selection and Management in NC AU - Miller, Grady T2 - Granville Gardeners Meeting C2 - 2014/8/25/ CY - Oxford, NC DA - 2014/8/25/ PY - 2014/8/25/ ER - TY - CONF TI - Practical Options and Strategies for Irrigating Landscapes AU - Miller, Grady T2 - Green and Grow Summer Conference C2 - 2014/8/14/ CY - Raleigh, NC DA - 2014/8/14/ PY - 2014/8/14/ ER - TY - CONF TI - Grasses that Should or Should Not be Used in NC AU - Miller, Grady T2 - Green and Grow Summer Conference C2 - 2014/8/14/ CY - Raleigh, NC DA - 2014/8/14/ PY - 2014/8/14/ ER - TY - CONF TI - Fertilizing, Mowing, and Painting AU - Miller, Grady T2 - Carolina Sports Turf Managers Association Meeting C2 - 2014/11/18/ CY - Myrtle Beach, SC DA - 2014/11/18/ PY - 2014/11/18/ ER - TY - SOUND TI - Athletic Field Turfgrass Management AU - Miller, Grady DA - 2014/6/17/ PY - 2014/6/17/ ER - TY - RPRT TI - 2014 Spring green-up of warm-season grasses AU - Miller, G.L. A3 - North Carolina State University DA - 2014/4/22/ PY - 2014/4/22/ PB - North Carolina State University ER - TY - RPRT TI - Winter damage of warm-season grasses AU - Miller, G.L. A3 - North Carolina State University DA - 2014/6/4/ PY - 2014/6/4/ PB - North Carolina State University 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 - 2014/// PY - 2014/// M1 - AG-408 M3 - NC Cooperative Extension Publication PB - North Carolina State University SN - AG-408 ER - TY - SOUND TI - Calibration for Turf Systems AU - Miller, Grady DA - 2014/1/20/ PY - 2014/1/20/ ER - TY - JOUR TI - Too late, winter hit AU - Miller, G.L. T2 - SportsTurf DA - 2014/// PY - 2014/// VL - 30 IS - 7 SP - 54 ER - TY - JOUR TI - Green sports fields using turf colorants AU - Miller, G.L. AU - Pinnix, D. T2 - SportsTurf DA - 2014/// PY - 2014/// VL - 30 IS - 8 SP - 20-22 ER - TY - JOUR TI - Even new fields can need core aeration AU - Miller, G.L. T2 - SportsTurf DA - 2014/// PY - 2014/// VL - 30 IS - 9 SP - 50 ER - TY - JOUR TI - Part-time field? AU - Miller, G.L. T2 - SportsTurf DA - 2014/// PY - 2014/// VL - 30 IS - 11 SP - 50 ER - TY - JOUR TI - The importance of research AU - Miller, G.L. T2 - SportsTurf DA - 2014/// PY - 2014/// VL - 30 IS - 5 SP - 50 ER - TY - JOUR TI - Development and bin mapping of gene-associated interspecific SNPs for cotton (Gossypium hirsutum L.) introgression breeding efforts. AU - Hulse-Kemp, AM AU - Ashrafi, H AU - Zheng, X AU - Wang, F AU - Hoegenauer, KA AU - Maeda, AB AU - Yang, SS AU - Stoffel, K AU - Matvienko, M AU - Clemons, K AU - Udall, JA AU - Van, Deynze A AU - Jones, DC AU - Stelly, DM T2 - BMC genomics AB - Cotton (Gossypium spp.) is the largest producer of natural fibers for textile and is an important crop worldwide. Crop production is comprised primarily of G. hirsutum L., an allotetraploid. However, elite cultivars express very small amounts of variation due to the species monophyletic origin, domestication and further bottlenecks due to selection. Conversely, wild cotton species harbor extensive genetic diversity of prospective utility to improve many beneficial agronomic traits, fiber characteristics, and resistance to disease and drought. Introgression of traits from wild species can provide a natural way to incorporate advantageous traits through breeding to generate higher-producing cotton cultivars and more sustainable production systems. Interspecific introgression efforts by conventional methods are very time-consuming and costly, but can be expedited using marker-assisted selection. Using transcriptome sequencing we have developed the first gene-associated single nucleotide polymorphism (SNP) markers for wild cotton species G. tomentosum, G. mustelinum, G. armourianum and G. longicalyx. Markers were also developed for a secondary cultivated species G. barbadense cv. 3–79. A total of 62,832 non-redundant SNP markers were developed from the five wild species which can be utilized for interspecific germplasm introgression into cultivated G. hirsutum and are directly associated with genes. Over 500 of the G. barbadense markers have been validated by whole-genome radiation hybrid mapping. Overall 1,060 SNPs from the five different species have been screened and shown to produce acceptable genotyping assays. This large set of 62,832 SNPs relative to cultivated G. hirsutum will allow for the first high-density mapping of genes from five wild species that affect traits of interest, including beneficial agronomic and fiber characteristics. Upon mapping, the markers can be utilized for marker-assisted introgression of new germplasm into cultivated cotton and in subsequent breeding of agronomically adapted types, including cultivar development. DA - 2014/// PY - 2014/// DO - 10.1186/1471-2164-15-945 VL - 15 SP - 945, UR - http://europepmc.org/abstract/med/25359292 KW - Cotton KW - Gossypium barbadense KW - Gossypium tomentosum KW - Gossypium mustelinum KW - Gossypium armourianum KW - Gossypium longicalyx KW - RNA-seq KW - Interspecific SNP ER - TY - CONF TI - Golf course irrigation systems’ distribution uniformity affects soil moisture variability AU - Miller, Grady T2 - European Turfgrass Conference C2 - 2014/7/8/ CY - Osnabruck, Germany DA - 2014/7/8/ PY - 2014/7/8/ ER - TY - CONF TI - Using Colorants on the Golf Course AU - Miller, Grady T2 - Southeastern Turfgrass Conference C2 - 2014/4/28/ CY - Wilmington, NC DA - 2014/4/28/ PY - 2014/4/28/ ER - TY - CONF TI - Natural versus Synthetic Turfgrass AU - Miller, Grady T2 - Western Turfgrass Conference C2 - 2014/3/11/ CY - Asheville, NC DA - 2014/3/11/ PY - 2014/3/11/ ER - TY - CONF TI - Maintenance on a Shoestring Budget AU - Miller, Grady T2 - Western Turfgrass Conference C2 - 2014/3/11/ CY - Asheville, NC DA - 2014/3/11/ PY - 2014/3/11/ ER - TY - SOUND TI - Athletic Field Paint Research AU - Miller, Grady AU - Pinnix, Drew DA - 2014/8/13/ PY - 2014/8/13/ ER - TY - SOUND TI - Specialty Crop Replicated Field Trial AU - Miller, Grady AU - Brinton, Scott DA - 2014/8/13/ PY - 2014/8/13/ ER - TY - SOUND TI - NTEP Bermudagrass and Zoysiagrass Evaluations AU - Miller, Grady DA - 2014/8/13/ PY - 2014/8/13/ ER - TY - JOUR TI - Preventing cold temperature damage AU - Miller, G.L. T2 - SportsTurf DA - 2014/// PY - 2014/// VL - 30 IS - 1 SP - 50 ER - TY - JOUR TI - Getting rid of your ryegrass overseed AU - Miller, G.L. T2 - SportsTurf DA - 2014/// PY - 2014/// VL - 30 IS - 3 SP - 50 ER - TY - JOUR TI - Effects of Poultry Litter Injection on Ammonia Volatilization, Nitrogen Availability, and Nutrient Losses in Runoff AU - Kulesza, Stephanie B. AU - Maguire, Rory O. AU - Thomason, Wade E. AU - Hodges, Steven C. AU - Pote, Dan H. T2 - Soil Science AB - Poultry litter is a common organic amendment in agricultural production, but nutrient losses can reduce its effectiveness as a fertilizer. Three experiments were conducted to evaluate ammonia nitrogen (NH3-N) volatilization, N availability, and runoff losses of nutrients by conducting a closed chamber volatilization study, a soil incubation, and a rainfall simulation. In all studies, poultry litter was applied at a rate of 6.7 Mg · ha−1 either on the surface or injected and compared with an unamended control. In the volatilization and soil incubation studies, Braddock Loam and Bojac Sandy Loam surface soils were compared. Of the ammonium N added, cumulative loss of NH3-N by volatilization was 3% from injected and 121% from surface applied poultry litter after 7 days in the Loam. In the Sandy Loam, cumulative loss of NH3-N was 9% from injected and 153% from surface applied poultry litter after 7 days. After a 40-day soil incubation, injection increased total inorganic N by 52% and 99% for the Loam and Sandy Loam soils, respectively, when compared with surface application. Injection reduced total Kjeldahl N by 59%, total Kjeldahl P by 53%, dissolved reactive P, dissolved nitrate N by 73%, and dissolved NH3-N in runoff by 99%, compared with surface application. Injection reduced NH3-N volatilization and nutrients in runoff to levels of the control. These studies show that injection increases plant available N while decreasing losses through volatilization and runoff. DA - 2014/4// PY - 2014/4// DO - 10.1097/ss.0000000000000058 VL - 179 IS - 4 SP - 190-196 KW - Injection KW - poultry litter KW - volatilization KW - N mineralization KW - runoff ER - TY - JOUR TI - Protein profiling reveals novel proteins in pollen and pistil of W22 (ga1; Ga1) in maize AU - Yu, J. AU - Roy, S.K. AU - Kamal, A.H.M. AU - Cho, K. AU - Kwon, S.-J. AU - Cho, S.-W. AU - So, Y.-S. AU - Holland, J.B. AU - Woo, S.H. T2 - Proteomes AB - Gametophytic factors mediate pollen-pistil interactions in maize (Zea mays L.) and play active roles in limiting gene flow among maize populations and between maize and teosinte. This study was carried out to identify proteins and investigate the mechanism of gametophytic factors using protein analysis. W22 (ga1); which did not carry a gametophytic factor and W22 (Ga1), a near iso-genic line, were used for the proteome investigation. SDS-PAGE was executed to investigate proteins in the pollen and pistil of W22 (ga1) and W22 (Ga1). A total of 44 differentially expressed proteins were identified in the pollen and pistil on SDS-PAGE using LTQ-FTICR MS. Among the 44 proteins, a total of 24 proteins were identified in the pollen of W22 (ga1) and W22 (Ga1) whereas 20 differentially expressed proteins were identified from the pistil of W22 (ga1) and W22 (Ga1). However, in pollen, 2 proteins were identified only in the W22 (ga1) and 12 proteins only in the W22 (Ga1) whereas 10 proteins were confirmed from the both of W22 (ga1) and W22 (Ga1). In contrary, 10 proteins were appeared only in the pistil of W22 (ga1) and 7 proteins from W22 (Ga1) while 3 proteins confirmed in the both of W22 (ga1) and W22 (Ga1). Moreover, the identified proteins were generally involved in hydrolase activity, nucleic acid binding and nucleotide binding. These results help to reveal the mechanism of gametophytic factors and provide a valuable clue for the pollen and pistil research in maize. DA - 2014/// PY - 2014/// DO - 10.3390/proteomes2020258 VL - 2 IS - 2 SP - 258-271 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-84947263088&partnerID=MN8TOARS KW - maize KW - pollen KW - pistil KW - gametophytic factors KW - proteomics ER - TY - CHAP TI - Mining natural variation for maize improvement: Selection on phenotypes and genes AU - Sood, S. AU - Flint-Garcia, S. AU - Willcox, M.C. AU - Holland, J.B. T2 - Genomics of Plant Genetic Resources: Volume 1. Managing, Sequencing and Mining Genetic Resources PY - 2014/// DO - 10.1007/978-94-007-7572-5_25 SP - 615-649 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-84951209506&partnerID=MN8TOARS ER - TY - CHAP TI - Breeding: Plants, Modern AU - Holland, J.B. T2 - Encyclopedia of Agriculture and Food Systems AB - Historically, plant breeding has progressed from the initial domestication of crops to highly intensive and effective cultivar improvement methods that integrate genomic information with phenotypic evaluations of breeding populations. Plant breeders employ a wide variety of breeding methods, the choice of which is largely driven by the mating system of the species, and the type of cultivar that can be disseminated easily to farmers. Recent improvements in breeding methods include statistical methods that can combine information across different breeding families and the application of genomic information to improve selection response under certain circumstances. PY - 2014/// DO - 10.1016/B978-0-444-52512-3.00226-6 SP - 187-200 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-85042835077&partnerID=MN8TOARS ER - TY - JOUR TI - Yield effects of two southern leaf blight resistance loci in maize hybrids AU - Santa-Cruz, J.H. AU - Kump, K.L. AU - Arellano, C. AU - Goodman, M.M. AU - Krakowsky, M.D. AU - Holland, J.B. AU - Balint-Kurti, P.J. T2 - Crop Science AB - ABSTRACT In this study we examined the effects of two quantitative trait loci (QTL) for southern leaf blight (SLB) resistance on several agronomic traits including disease resistance and yield. B73–3B and B73–6A are two near‐isogenic lines (NILs) in the background of the maize ( Zea mays L.) inbred B73, each carrying one introgression (called 3B and 6A respectively) encompassing a QTL for SLB resistance. Sets of isohybrid triplets were developed by crossing B73, B73–3B, and B73–6A to several inbred lines. A subset of these triplets for which the B73–3B and/or B73–6A hybrid was significantly more SLB resistant than the B73 check hybrid was selected and assessed in multi‐environment yield trials with and without disease. In the presence of SLB, 3B was associated with an approximately 3% yield increase over B73. 6A was associated with a yield advantage in the presence of SLB in specific pedigrees where the 6A resistance phenotype was highly expressed. Results suggested that both introgressions might confer a yield cost in the absence of SLB, but only introgression 6A was associated with a statistically significant reduction. We present evidence to suggest that the yield cost is associated with the resistance phenotype rather than with linkage drag. DA - 2014/// PY - 2014/// DO - 10.2135/cropsci2013.08.0553 VL - 54 IS - 3 SP - 882-894 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-84898430312&partnerID=MN8TOARS ER - TY - JOUR TI - A Genome-Wide Association Study of the Maize Hypersensitive Defense Response Identifies Genes That Cluster in Related Pathways AU - Olukolu, B.A. AU - Wang, G.-F. AU - Vontimitta, V. AU - Venkata, B.P. AU - Marla, S. AU - Ji, J. AU - Gachomo, E. AU - Chu, K. AU - Negeri, A. AU - Benson, J. AU - Nelson, R. AU - Bradbury, P. AU - Nielsen, D. AU - Holland, J.B. AU - Balint-Kurti, P.J. AU - Johal, G. T2 - PLoS Genetics AB - Much remains unknown of molecular events controlling the plant hypersensitive defense response (HR), a rapid localized cell death that limits pathogen spread and is mediated by resistance (R-) genes. Genetic control of the HR is hard to quantify due to its microscopic and rapid nature. Natural modifiers of the ectopic HR phenotype induced by an aberrant auto-active R-gene (Rp1-D21), were mapped in a population of 3,381 recombinant inbred lines from the maize nested association mapping population. Joint linkage analysis was conducted to identify 32 additive but no epistatic quantitative trait loci (QTL) using a linkage map based on more than 7000 single nucleotide polymorphisms (SNPs). Genome-wide association (GWA) analysis of 26.5 million SNPs was conducted after adjusting for background QTL. GWA identified associated SNPs that colocalized with 44 candidate genes. Thirty-six of these genes colocalized within 23 of the 32 QTL identified by joint linkage analysis. The candidate genes included genes predicted to be in involved programmed cell death, defense response, ubiquitination, redox homeostasis, autophagy, calcium signalling, lignin biosynthesis and cell wall modification. Twelve of the candidate genes showed significant differential expression between isogenic lines differing for the presence of Rp1-D21. Low but significant correlations between HR-related traits and several previously-measured disease resistance traits suggested that the genetic control of these traits was substantially, though not entirely, independent. This study provides the first system-wide analysis of natural variation that modulates the HR response in plants. DA - 2014/// PY - 2014/// DO - 10.1371/journal.pgen.1004562 VL - 10 IS - 8 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-84923033904&partnerID=MN8TOARS ER - TY - CHAP TI - Breeding and genetic diversity AU - Goodman, M.M. AU - Holland, J.B. AU - Sánchez G, J.J. T2 - Genetics, Genomics and Breeding of Maize AB - Since the beginnings in the early part of the 20th Century, hybrid maize breeding has continued to evolve as new genetic understanding of traits and new technologies have become available. We review some of the early innovations that were involved in the transition of maize from an open pollinated crop to a hybrid crop and from the use of the Double Cross hybrid system to the Single Cross hybrid system. Today molecular technologies have opened up many new opportunities. These technologies and our understanding of trait genetics have enabled the further evolution of maize breeding methodology to include a range of molecular breeding methods. High throughput genotyping at the DNA sequence level has enabled the use of both marker assisted breeding for specifi c traits and whole genome prediction methodology for complex quantitative traits. The characterization of trait functional diversity and understanding its underlying genetic bases at the molecular level will continue to offer new tools to assist hybrid maize breeding. Furthermore, recent transgenic approaches provide new opportunities for commercial maize hybrid development. PY - 2014/// DO - 10.1201/b17274 SP - 14-50 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-85020851622&partnerID=MN8TOARS ER - TY - JOUR TI - Potassium nutrition of ectomycorrhizal Pinus pinaster : overexpression of the Hebeloma cylindrosporum Hc Trk1 transporter affects the translocation of both K + and phosphorus in the host plant AU - Garcia, Kevin AU - Delteil, Amandine AU - Conéjéro, Geneviève AU - Becquer, Adeline AU - Plassard, Claude AU - Sentenac, Hervé AU - Zimmermann, Sabine T2 - New Phytologist AB - Summary Mycorrhizal associations are known to improve the hydro‐mineral nutrition of their host plants. However, the importance of mycorrhizal symbiosis for plant potassium nutrition has so far been poorly studied. We therefore investigated the impact of the ectomycorrhizal fungus H ebeloma cylindrosporum on the potassium nutrition of P inus pinaster and examined the involvement of the fungal potassium transporter H c T rk1. H c T rk1 transcripts and proteins were localized in ectomycorrhizas using in situ hybridization and EGFP translational fusion constructs. Importantly, an overexpression strategy was performed on a H . cylindrosporum endogenous gene in order to dissect the role of this transporter. The potassium nutrition of mycorrhizal pine plants was significantly improved under potassium‐limiting conditions. Fungal strains overexpressing H c T rk1 reduced the translocation of potassium and phosphorus from the roots to the shoots of inoculated plants in mycorrhizal experiments. Furthermore, expression of H c T rk1 and the phosphate transporter H c PT 1.1 were reciprocally linked to the external inorganic phosphate and potassium availability. The development of these approaches provides a deeper insight into the role of ectomycorrhizal symbiosis on host plant K + nutrition and in particular, the K + transporter H c T rk1. The work augments our knowledge of the link between potassium and phosphorus nutrition via the mycorrhizal pathway. DA - 2014/// PY - 2014/// DO - 10.1111/nph.12603 VL - 201 IS - 3 SP - 951-960 KW - ectomycorrhizal symbiosis KW - Hebeloma cylindrosporum KW - in situ hybridization KW - overexpression KW - phosphate transporter HcPT1.1 KW - plant potassium nutrition KW - potassium-sodium transporter HcTrk1 KW - protein-EGFP fusion ER - TY - JOUR TI - Changes in the cell wall and cellulose content of developing cotton fibers investigated by FTIR spectroscopy AU - Abidi, Noureddine AU - Cabrales, Luis AU - Haigler, Candace H. T2 - Carbohydrate Polymers AB - Fourier transform infrared (FTIR) spectra of cotton fibers harvested at different stages of development were acquired using Universal Attenuated Total Reflectance FTIR (UATR-FTIR). The main goal of the study was to monitor cell wall changes occurring during different phases of cotton fiber development. Two cultivars of Gossypium hirsutum L. were planted in a greenhouse (Texas Marker-1 and TX55). On the day of flowering, individual flowers were tagged and bolls were harvested. From fibers harvested on numerous days between 10 and 56 dpa, the FTIR spectra were acquired using UATR (ZnSe-Diamond crystal) with no special sample preparation. The changes in the FTIR spectra were used to document the timing of the transition between primary and secondary cell wall synthesis. Changes in cellulose during cotton fiber growth and development were identified through changes in numerous vibrations within the spectra. The intensity of the vibration bands at 667 and 897 cm(-1) correlated with percentage of cellulose analyzed chemically. DA - 2014/1// PY - 2014/1// DO - 10.1016/j.carbpol.2013.01.074 VL - 100 SP - 9-16 J2 - Carbohydrate Polymers LA - en OP - SN - 0144-8617 UR - http://dx.doi.org/10.1016/j.carbpol.2013.01.074 DB - Crossref KW - Cellulose KW - FTIR KW - Cotton KW - Fiber development KW - Maturity KW - Cell wall ER - TY - CHAP TI - Nitrogen and phosphorus fertility management in organic field crop production AU - Woodley, A. AU - Audette, Y. AU - Fraser, T. AU - Arcand, M.M. AU - Voroney, P. AU - Knight, J.D. AU - Lynch, D.H. T2 - Managing Energy, Nutrients, and Pests in Organic Field Crops PY - 2014/// DO - 10.1201/b16044 SP - 59-106 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-84937570091&partnerID=MN8TOARS ER - TY - JOUR TI - Soil Water: From Molecular Structure to Behavior AU - Duckworth, O.W. AU - Heitman, J.L. AU - Polizzotto, M.L. T2 - Nature Education DA - 2014/// PY - 2014/// VL - 5 IS - 1 ER - TY - JOUR TI - Implications of Tall Fescue for Inter-Row Water Dynamics in a Vineyard AU - Holland, S. AU - Howard, A. AU - Heitman, J. L. AU - Sauer, T. J. AU - Giese, W. AU - Sutton, T. B. AU - Agam, N. AU - Ben-Gal, A. AU - Havlin, J. T2 - Agronomy Journal AB - Vineyards in the southeastern United States face challenges including poor internal soil drainage, high precipitation, and warm temperatures. This environment causes elevated humidity, creating ideal conditions for fungal diseases. Maintaining tall fescue ( Schedonorus arundinaceus Shreb) and resident vegetation ground cover in vineyard inter‐rows is a common cultural practice in the region, believed to benefit grape ( Vitis vinifera L.) production by increasing competition for soil water and thereby favorably reducing vine vegetative growth. We hypothesized that, although inter‐row fescue may reduce soil water availability, it may also increase humidity within the vineyard. Our objectives were to assess surface vapor flux from two inter‐row treatments (bare soil and tall fescue) and to determine any corresponding effects on soil water content and humidity within the inter‐row. Surface vapor flux, soil water content, and vapor pressure (30 cm height aboveground) were measured in inter‐rows subjected to each treatment. Observed surface vapor flux for fescue inter‐row exceeded that of bare soil by a daily average of 1.1 mm during the grape growing season. Despite fescue inter‐row evapotranspiration (ET), soil water depletion was insufficient to produce stress in the vines. Fescue inter‐row vapor pressure increased compared to bare soil inter‐rows by an average of 2% ( P < 0.09) during the growing season. Data suggest that fescue ET may increase inter‐row humidity in warm, humid environments, while providing only modest influence on soil water availability. Additional work including increased plot size to accommodate fetch for microclimate measurements, and biological assessment of humidity implications for disease is warranted. DA - 2014/7// PY - 2014/7// DO - 10.2134/agronj13.0488 VL - 106 IS - 4 SP - 1267-1274 J2 - Agronomy Journal LA - en OP - SN - 0002-1962 UR - http://dx.doi.org/10.2134/agronj13.0488 DB - Crossref ER - TY - JOUR TI - Genetic variation in peanut leaf maintenance and transpiration recovery from severe soil drying AU - Rosas-Anderson, Pablo AU - Shekoofa, Avat AU - Sinclair, Thomas R. AU - Balota, Maria AU - Isleib, Thomas G. AU - Tallury, Shyam AU - Rufty, Thomas T2 - Field Crops Research AB - Peanut (Arachis hypogaea L.) is an important food crop that is often grown in areas prone to intermittent drought. After drought is relieved, plant recovery from soil drying is an important factor for continued productivity. While recovery can involve a multitude of physiological processes, transpiration is one of the most important for carbon fixation. Two greenhouse experiments and a field experiment were conducted to screen and evaluate a total of 19 peanut genotypes for transpiration recovery and leaf maintenance after experiencing a drying cycle. In the greenhouse experiments, plants were allowed to transpire all available transpirable soil water from their pots before being re-watered. The transpiration of plants was measured in subsequent days and a visual rating scale was used to rate leaf maintenance on plants. Significant differences were detected among genotypes for both transpiration recovery and leaf maintenance, and superior genotypes were identified for both traits. The superior genotypes included ICGV 86015, TMV 2, PI 497579 and PI 404020 in the greenhouse. In the field, a regression between stomatal conductance before and after re-watering gave an estimate for recovery of stomatal conductance. Breeding lines N05006 and SPT 06-07 had the greatest estimated stomata conductance recovery in the field. Genotypes which recovered poorly in the greenhouse also had low estimated recovery in the field. DA - 2014/3// PY - 2014/3// DO - 10.1016/J.FCR.2013.12.019 VL - 158 SP - 65-72 J2 - Field Crops Research LA - en OP - SN - 0378-4290 UR - http://dx.doi.org/10.1016/J.FCR.2013.12.019 DB - Crossref KW - Drought KW - Leaf recovery KW - Peanut KW - Stomata conductance KW - Transpiration recovery ER - TY - JOUR TI - Multivariate spatial modeling of conditional dependence in microscale soil elemental composition data AU - Guinness, J. AU - Fuentes, M. AU - Hesterberg, D. AU - Polizzotto, M. T2 - Spatial Statistics AB - The mobility and environmental impacts of toxic trace elements are regulated by their reactions with soils, which are complex heterogeneous mixtures of minerals and organic matter. We describe an experiment that maps the composition of elements on an individual soil sand grain using X-ray fluorescence microprobe analyses, after the grain is treated with arsenic solutions, resulting in multivariate spatial lattice maps of elemental abundance. To understand the behavior of arsenic in soils, it is important to disentangle the complex multivariate relationships among the elements in the sample. The abundance of most elements, including arsenic, correlates strongly with that of iron; but conditional on the amount of iron, some elements mitigate or potentiate the accumulation of arsenic. This problem motivates our work to define conditional correlation in spatial lattice models and give general conditions under which two components are conditionally uncorrelated given the rest. We describe how to enforce that two components are conditionally uncorrelated given a third in parametric models, which provides a basis for likelihood ratio tests for conditional correlation between arsenic and chromium given iron. We show how to apply our results to big datasets using the Whittle likelihood, and we demonstrate through simulation that tapering improves Whittle likelihood parameter estimates governing cross covariance. DA - 2014/// PY - 2014/// DO - 10.1016/j.spasta.2014.03.009 VL - 9 IS - C SP - 93-108 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-84899663663&partnerID=MN8TOARS ER - TY - BOOK TI - Fertilizer formulation effect on pH of fallow versus planted container substrate AU - Barnes, J. AU - Nelson, P. AU - Whipker, B.E. AU - Hesterberg, D. AU - Shi, W. DA - 2014/// PY - 2014/// VL - 1034 SE - 465-470 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-84902270094&partnerID=MN8TOARS ER - TY - JOUR TI - Effect of Weed-Free Strip Width on Newly Established ‘Navaho' Blackberry Growth, Yield, and Fruit Quality AU - Meyers, Stephen L. AU - Jennings, Katherine M. AU - Monks, David W. AU - Mitchem, Wayne E. T2 - Weed Technology AB - Field studies were conducted in 2011 and 2012 at the Sandhills Research Station near Jackson Springs, NC to determine the influence of weed-free strip width (WFSW) on newly planted ‘Navaho' blackberry plant growth, fruit yield, and fruit quality. Treatments consisted of 0-, 0.3-, 0.6-, 1.2-, 1.8-, and 2.4-m WFSW. Predicted blackberry yield increased from 718 to 1,015 kg ha −1 at WFSW of 0 to 2.4 m. The currently recommended WFSW of 1.2 m resulted in a blackberry yield of 1,013 kg ha −1 . Predicted individual blackberry fruit weight displayed a positive linear response to WFSW and increased from 3.1 to 3.6 g fruit −1 at WFSW of 0 to 2.4 m. Soluble solids content (SSC) of dull black blackberry fruit was greatest (15.1 Brix) when WFSW was 0 m. Relative to a WFSW of 0 m, SSC was reduced 2.3 to 3.4% as WFSW increased from 0.3 to 2.4 m, respectively. WFSW did not influence shiny black blackberry fruit SSC, nor titratable acidity, sugar-to-acid ratio, or pH of shiny or dull black blackberry fruit or primocane number, length, and stem caliper. DA - 2014/6// PY - 2014/6// DO - 10.1614/wt-d-13-00028.1 VL - 28 IS - 2 SP - 426-431 J2 - Weed technol. LA - en OP - SN - 0890-037X 1550-2740 UR - http://dx.doi.org/10.1614/wt-d-13-00028.1 DB - Crossref KW - Orchard floor management ER - TY - SOUND TI - In Search of the Agronomy Holy Grail (panel) AU - Miller, Grady DA - 2014/11/18/ PY - 2014/11/18/ ER - TY - CHAP TI - Design of lysimeter for turfgrass water use AU - Wherley, B.G. AU - Sinclair, T. AU - Dukes, M. AU - Miller, G.L. T2 - Evapotranspiration: Principles and Applications for Water Management A2 - Goyal, M.R. A2 - Harmsen, E.W. PY - 2014/// SP - 75–85 PB - Apple Academc Press ER - TY - SOUND TI - Improvement of genetic transformation of perennial ryegrass and introduction of important agronomic traits AU - Patel, M. AU - Puthigae, S. AU - Zhang, W. AU - Templeton, K. AU - Reynolds, C. AU - Richardson, K. AU - Biswas, M. AU - Zuleta, M.C. AU - Milla-Lewis, S.R. AU - Dewey, R. AU - Qu, R. DA - 2014/6/9/ PY - 2014/6/9/ ER - TY - SOUND TI - Turf quality and transition of annual and intermediate ryegrass lines in southern USA in 2011-12 AU - Nelson, L. AU - Chandra, A. AU - Wherley, B. AU - Martin, D. AU - Miller, G. AU - Milla-Lewis, S.R. AU - Kenworthy, K. AU - Raymer, P. AU - Schwartz, B. AU - Wu, Y. DA - 2014/11/2/ PY - 2014/11/2/ ER - TY - JOUR TI - St. Augustinegrass germplasm resistant to southern chinch bug, Blissus insularis Barber (Hemiptera: Blissidae) AU - Youngs, K.M. AU - Milla-Lewis, S.R. AU - Brandenburg, R.L. AU - Cardoza, Y.J. T2 - Journal of Economic Entomology DA - 2014/// PY - 2014/// VL - 107 IS - 4 SP - 1688–1694 ER - TY - SOUND TI - St. Augustinegrass freezing protocol development for diversity assessments AU - Kimball, J.A. AU - Tuong, T.D. AU - Livingston, D.P. AU - Milla-Lewis, S.R. DA - 2014/11/2/ PY - 2014/11/2/ ER - TY - SOUND TI - Shade tolerance evaluation of South African bermudagrass germplasm AU - Dunne, J.C. AU - Milla-Lewis, S.R. DA - 2014/11/2/ PY - 2014/11/2/ ER - TY - SOUND TI - SSR development and linkage mapping in St. Augustinegrass AU - Milla-Lewis, S.R. AU - Mulkey, S.E. AU - Zuleta, M.C. AU - Ma, B. AU - Arellano, C. AU - Tredway, L.P. DA - 2014/6/9/ PY - 2014/6/9/ ER - TY - SOUND TI - Breeding turfgrasses for pest and stress resistance AU - Milla-Lewis, S.R. DA - 2014/1/22/ PY - 2014/1/22/ M3 - invited presentation ER - TY - SOUND TI - Breeding for combined shade and cold tolerance in bermudagrass AU - Milla-Lewis, S.R. DA - 2014/11/17/ PY - 2014/11/17/ M3 - invited presentation ER - TY - SOUND TI - Beyond ANOVA... exploratory statistical analysis for a germplasm evaluation under shade AU - Dunne, J.C. AU - Milla-Lewis, S.R. AU - Arellano, C. DA - 2014/11/2/ PY - 2014/11/2/ ER - TY - CONF TI - Evaluation of African bermudagrass (Cynodon trasnvaalensis) germplasm for cold tolerance AU - Milla-Lewis, S.R. AU - Dunne, J.C. AU - Reynolds, W.C. C2 - 2014/11/2/ C3 - Proceedings of the American Agronomy International Annual Meeting DA - 2014/11/2/ ER - TY - SOUND TI - Development of screening methodologies for cold acclimation and freezing tolerance in St. Augustinegrass AU - Kimball, J.A. AU - Tuong, T.D. AU - Livingston, D.P. AU - Milla-Lewis, S.R. DA - 2014/8/5/ PY - 2014/8/5/ ER - TY - JOUR TI - Comparative Analysis of Metal Concentrations and Sediment Accumulation Rates in Two Virginian Reservoirs, USA: Lakes Moomaw and Pelham AU - Clark, Elyse V. AU - Odhiambo, Ben K. AU - Ricker, Matthew C. T2 - Water, Air, & Soil Pollution DA - 2014/2// PY - 2014/2// DO - 10.1007/s11270-013-1860-2 VL - 225 IS - 2 J2 - Water Air Soil Pollut LA - en OP - SN - 0049-6979 1573-2932 UR - http://dx.doi.org/10.1007/s11270-013-1860-2 DB - Crossref KW - Reservoir sedimentation KW - Pb-210 sediment accumulation KW - Trace metals KW - Enrichment factors ER - TY - JOUR TI - Comparison of Soil Organic Carbon Dynamics in Forested Riparian Wetlands and Adjacent Uplands AU - Ricker, Matthew C. AU - Stolt, Mark H. AU - Zavada, Michael S. T2 - Soil Science Society of America Journal AB - Wetland riparian soils typically have greater C pools than adjacent uplands, yet quantifying soil organic C (SOC) sequestration in riparian systems remains difficult. Quantification of major inputs and losses of autochthonous SOC through process‐based measurements would allow for better comparisons between riparian and upland systems. In this study, we quantified major soil C fluxes within five paired headwater riparian and upland sites in Rhode Island. The difference between total C inputs and losses were used to construct net annual landscape‐scale SOC sequestration rates. Annual SOC inputs were statistically similar between landscapes, with the exception of those from understory herbaceous vegetation, which were significantly greater ( p < 0.001) in riparian zones than uplands. Mean annual C losses via soil respiration were also statistically similar between landscapes, but estimates of microbial respiration (actual loss of SOC) were significantly less ( p < 0.01) in riparian ecosystems. Thus, riparian forests had greater net annual SOC sequestration (range 2.4–3.4 Mg C ha −1 yr −1 ) than paired upland sites (range 0.4–2.1 Mg C ha −1 yr −1 ). Our results suggest that process‐based SOC sequestration measures can yield similar results to traditional methods, such as chronosequences, but our averaged estimates (2.0 Mg C ha −1 yr −1 ) were greater than those typically reported using alternate approaches. DA - 2014/// PY - 2014/// DO - 10.2136/sssaj2014.01.0036 VL - 78 IS - 5 SP - 1817 LA - en OP - SN - 0361-5995 UR - http://dx.doi.org/10.2136/sssaj2014.01.0036 DB - Crossref ER - TY - JOUR TI - Soil Biogeochemical Processes across a Lateral Toposequence in an Old-Growth Floodplain Forest AU - Ricker, Matthew C. AU - Lockaby, B. Graeme T2 - Soil Science Society of America Journal AB - Floodplain forests are important landscapes that retain and transform nutrients derived from watershed sources. Although research has been conducted regarding biogeochemical processes in floodplains, few studies have been in old‐growth bottomland forests. Therefore, the goal of this study was to quantify how landscape variability and environmental factors influence floodplain biogeochemistry in old‐growth ecosystems of Congaree National Park (CONG), SC. During a 2‐yr period, we measured biogeochemical indices along an alluvial soil toposequence that included seasonal variation in microbial biomass and net N mineralization. Soil microbial biomass was relatively consistent throughout the study and displayed few relationships to environmental variables. Net N mineralization showed distinct seasonal variations ranging from 37 ± 9 to 412 ± 73 g N ha −1 d −1 during cool winter and warm summer months, respectively. Nitrate‐N was the major product of net N mineralization in all seasons, and only hydric soils in low‐lying topographic positions had appreciable net NH 4 –N production (>15% total N mineralized), which typically occurred after spring flooding. These results suggest that the intrinsic biogeochemical processes within the old‐growth bottomland forests of CONG differ from those of aggrading floodplain forests of the southeastern United States, especially with regard to production of excess NO 3 –N. DA - 2014/// PY - 2014/// DO - 10.2136/sssaj2014.05.0205 VL - 78 IS - 6 SP - 2100 LA - en OP - SN - 0361-5995 UR - http://dx.doi.org/10.2136/sssaj2014.05.0205 DB - Crossref ER - TY - JOUR TI - Amicarbazone Application Timing Influences Overseeded Perennial Ryegrass (Lolium perenne) Safety and Annual Bluegrass (Poa annua) Control AU - Leon, Ramon G. AU - McCarty, Lambert B. AU - Estes, Alan G. T2 - Applied Turfgrass Science AB - Amicarbazone controls annual bluegrass (Poa annua L.) in bermudagrass [Cynodon dactylon (L.) Pers.] turf overseeded with perennial ryegrass (Lolium perenne L.). There is, however, a risk of perennial ryegrass injury, depending on application timing. The objective of this research was to determine the effect of the timings between overseeding and amicarbazone applications on perennial ryegrass. Amicarbazone was applied at 0, 2.1, and 2.8 oz a.i./acre at 6, 8, 10, and 12 weeks after overseeding (WAOS) in Florida and South Carolina. In Florida, perennial ryegrass maximum injury was greater at 6 WAOS (79%) than at 8 to 12 WAOS (6 to 30%). Conversely, in South Carolina, minor perennial ryegrass injury was observed in plots treated 6 to 10 WAOS, but 48% injury was observed in plots treated 12 WAOS. In all sites, plots treated at 6 WAOS exhibited up to fourfold reduction in perennial ryegrass cover compared with the untreated control (88%). Overall, annual bluegrass control was acceptable to excellent (73–99%) with amicarbazone applications in South Carolina. In Florida 24 weeks after initial treatment, all treatments controlled annual bluegrass 64 to 98% except applications at 6 WAOS (25–42%). Results suggest that amicarbazone should be applied at least 8 to 10 WAOS to minimize loss of perennial ryegrass cover, but applications at this time will provide adequate annual bluegrass control. DA - 2014/// PY - 2014/// DO - 10.2134/ATS-2014-0042-RS VL - 11 IS - 1 SP - 0 LA - en SN - 1552-5821 UR - https://www.agronomy.org/publications/ats/abstracts/11/1/ATS-2014-0042-RS DB - Crossref Y2 - 2019/2/8/ ER - TY - JOUR TI - Vinasse and biochar effects on germination and growth of Palmer amaranth (Amaranthus palmeri), sicklepod (Senna obtusifolia) and southern crabgrass (Digitaria ciliaris) AU - Soni, N. AU - Leon, R.G. AU - Erickson, J.E. AU - Ferrell, J.A. AU - Silveira, M.L. AU - Giurcanu, M.C. T2 - Weed Technology AB - Vinasse and biochar are by-products of biofuel production that can be used as sources of nutrients to crops or soil amendments to improve soil quality. Despite the recent interest in biochar and vinasse effects on soil properties, little is known about their effect on weed communities. We hypothesized that the addition of biochar and vinasse to the soil could affect weed seed germination and growth, and that different weed species would show different responses to these soil amendments. Therefore, the objectives of this study were to determine the effects of vinasse and biochar on the germination and growth of Palmer amaranth, sicklepod, and southern crabgrass. The study was conducted under laboratory and growth chamber conditions. Treatments consisted of four levels of vinasse (0, 10, 20, and 40 L m −2 ) and biochar (0, 0.5, 2.5, and 12.5 kg m −2 ) applied to a sandy loam soil. Biochar at 0.5 and 2.5 kg m −2 increased germination of Palmer amaranth but had no effect on sicklepod and southern crabgrass. Vinasse reduced germination of all species. However, sicklepod germination was less affected by vinasse at 10 and 20 L m −2 than the other two species. Vinasse at 40 L m −2 decreased Palmer amaranth, southern crabgrass and sicklepod germination 57, 26 and 87%, respectively. Biochar had no consistent effect on the vegetative growth of the species studied. Vinasse at 10 L m −2 stimulated growth of sicklepod and southern crabgrass compared to the nontreated control. Our results suggested that vinasse used as a soil amendment could affect weed community structure by decreasing germination of susceptible species, but plants and weed species that can get established in vinasse amended soils might show higher growth rates. DA - 2014/// PY - 2014/// DO - 10.1614/wt-d-14-00044.1 VL - 28 IS - 04 SP - 694-702 KW - Charcoal KW - plant growth KW - seed viability KW - soil amendments KW - stillage ER - TY - JOUR TI - Structuring international development decisions: Confronting tradeoffs between land-use and community development in Costa Rica AU - Arvai, J. AU - Kellon, D. AU - Leon, R. AU - Gregory, R. AU - Richardson, R. T2 - Environmental Systems and Decisions DA - 2014/// PY - 2014/// DO - 10.1007/s10669-014-9495-4 VL - 34 IS - 2 SP - 224–236 ER - TY - JOUR TI - Management of spreading pricklypear (Opuntia humifusa) with fluroxypyr and aminopyralid AU - Ferrell, J.A. AU - Sellers, B. AU - Leon, R. T2 - Weed Technology AB - Experiments were conducted throughout central Florida from 2010 to 2014 to determine the effectiveness of fluroxypyr or aminopyralid for control of spreading pricklypear. Aminopyralid + 2,4-D (0.09 + 0.75 kg ae ha −1 ) was not effective and provided only 15% control by 18 mo after application (MAT). However, fluroxypyr at 0.55 kg ae ha −1 or sequential applications of 0.27 kg ha −1 provided greater than 82% control at 18 MAT. Reducing fluroxypyr rates to 0.32 kg ha −1 reduced control to 40 and 71% for spring versus fall applications, respectively. However, the addition of aminopyralid + 2,4-D to fluroxypyr at 0.32 kg ha −1 improved pricklypear control to 92%, regardless of application timing. DA - 2014/// PY - 2014/// DO - 10.1614/wt-d-14-00041.1 VL - 28 IS - 04 SP - 734–738 KW - Cactus KW - pasture KW - perennial weed ER - TY - JOUR TI - Impact of exposure to 2,4-D and dicamba on peanut injury and yield AU - Leon, R.G. AU - Ferrell, J.A. AU - Brecke, B.J. T2 - Weed Technology AB - The potential widespread adoption of cotton and soybean varieties with 2,4-D and dicamba resistance traits in the southeastern US will increase the risk of accidental exposure of peanut to these herbicides because of drift or application errors. When such accidents occur, growers must decide between continuing the crop and terminating it. In order to make this decision, growers need to estimate the potential yield reduction caused by 2,4-D or dicamba. Dose-response studies were conducted under field conditions in Citra and Jay, FL in 2012 and 2013 to determine peanut injury and yield reduction after exposure to 70, 140, 280, 560, and 1120 g ae ha −1 of 2,4-D or to 35, 70, 140, 280, and 560 g ae ha −1 of dicamba at 21 and 42 d after planting (DAP). Only herbicide by rate interactions were significant (P < 0.04). Dicamba caused 2 to 5 times higher peanut injury and 0.5 to 2 times higher yield reductions than 2,4-D. Injury ranged from 0 to 35% when peanut plants were treated with 2,4-D and from 20 to 78% with dicamba. The maximum yield reduction was 41% with 1,120 g ha −1 of 2,4-D and 65% with 560 g ha −1 of dicamba. Linear regression indicated that the intercept for yield reduction was 12% for 2,4-D and 23% for dicamba, and there was a 2.5% and 7.7% increase in yield reduction per additional 100 g ha −1 , respectively. Although high variability was observed for the different variables, there was a positive correlation between injury and peanut yield reduction (P < 0.0001) with Pearson's Rho values ranging from 0.45 to 0.59 for 2,4-D and from 0.27 to 0.55 for dicamba, suggesting that growers can use injury data to make rough projections of yield reduction and decide if they continue their crop, especially when injury is evident. DA - 2014/// PY - 2014/// DO - 10.1614/wt-d-13-00187.1 VL - 28 IS - 03 SP - 465–470 KW - Chemical control KW - dose-response KW - drift KW - herbicide injury KW - synthetic auxin ER - TY - JOUR TI - Characterization of fluazifop-P-butyl tolerance in zoysiagrass cultivars AU - Leon, R.G. AU - Unruh, J.B. AU - Brecke, B.J. AU - Kenworthy, K.E. T2 - Weed Technology AB - POST control of grass weed species and contaminant turfgrass species, such as common and hybrid bermudagrass, is a major challenge in zoysiagrass. Fluazifop-P-butyl is a POST herbicide that can provide selective grass weed control with limited injury to zoysiagrass. However, because of the extent of genetic variation among zoysiagrass cultivars, it was proposed that fluazifop-P-butyl tolerance was cultivar dependent. Dose–response field studies were conducted in Jay, FL, in 2012 and 2013, evaluating the tolerance of 11 commercial zoysiagrass cultivars and common bermudagrass to 0, 44, 88, 131, 175, and 263 g ai ha −1 of fluazifop-P-butyl. ‘Empire' and ‘Meyer' zoysiagrass were injured 30% or less at 2 wk after treatment (WAT) when treated with 131 g ha −1 of fluazifop-P-butyl or less. Conversely, ‘Zeon' and ‘PristineFlora' reached from 30 to more than 50% injury between 2 and 4 WAT with 44 and 88 g ha −1 fluazifop-P-butyl. ‘Geo', ‘Crowne', ‘JaMur', and ‘UltimateFlora' showed intermediate injury (i.e. ≤ 60% with 175 and 264 g ha −1 ) and a recovery period longer than 4 WAT. ‘Emerald', ‘Palisades', and ‘Royal' also showed intermediate injury (i.e., 30 to 65% with 175 and 264 g ha −1 ), which peaked at 2 WAT and then rapidly declined below 25% injury at 4 WAT. By 8 WAT, all zoysiagrass cultivars had recovered, and no injury was observed. Results from a greenhouse experiment demonstrated that differences observed in the field were cultivar related, especially for the lower tolerance level observed in Zeon and PristineFlora. There is potential to increase fluazifop-P-butyl tolerance in zoysiagrass because of the observed variation among 80 zoysiagrass breeding lines. DA - 2014/// PY - 2014/// DO - 10.1614/wt-d-13-00142.1 VL - 28 IS - 02 SP - 385–394 KW - Chemical control KW - genetic resources KW - integrated weed management KW - turfgrass ER - TY - SOUND TI - Grafted Tomatoes: A Sustainable Alternative to Soil Fumigation AU - Suchoff, D.H. AU - Schultheis, J.R. AU - Gunter, C.C. AU - Louws, F.J. DA - 2014/10/17/ PY - 2014/10/17/ M3 - poster ER - TY - SOUND TI - 2013 On-farm Grafted Tomato Trial to Manage Bacterial Wilt AU - Suchoff, D.H. AU - Schultheis, J.R. AU - Gunter, C.C. AU - Louws, F.J. DA - 2014/5/21/ PY - 2014/5/21/ M3 - poster ER - TY - SOUND TI - 2013 On-farm Grafted Tomato Trial to Manage Bacterial Wilt AU - Suchoff, D.H. AU - Schultheis, J.R. AU - Gunter, C.C. AU - Louws, F.J. DA - 2014/3/26/ PY - 2014/3/26/ M3 - poster ER - TY - JOUR TI - 2013 On-farm Grafted Tomato Trial to Manage Bacterial Wilt AU - Suchoff, D.H. AU - Louws, F.J. AU - Gunter, C.C. AU - Schultheis, J.R. T2 - Acta Horticulturae (ISHS) 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 - 2014/// PY - 2014/// DO - 10.17660/actahortic.2015.1086.14 VL - 1086 SP - 119–127 KW - grafted tomato KW - on-farm KW - bacterial wilt ER - TY - JOUR TI - St. Augustinegrass Germplasm Resistant to Blissus insularis (Hemiptera: Blissidae) AU - Youngs, Katharine M. AU - Milla-Lewis, Susana R. AU - Brandenburg, Rick L. AU - Cardoza, Yasmin J. T2 - j econ entomol AB - Journal Article St. Augustinegrass Germplasm Resistant to Blissus insularis (Hemiptera: Blissidae) Get access Katharine M. Youngs, Katharine M. Youngs 1Department of Entomology, North Carolina State University, Raleigh, NC 27695–7613. Search for other works by this author on: Oxford Academic PubMed Google Scholar Susana R. Milla-Lewis, Susana R. Milla-Lewis 2Department of Crop Science, North Carolina State University, Raleigh, NC 27695–7620. Search for other works by this author on: Oxford Academic PubMed Google Scholar Rick L. Brandenburg, Rick L. Brandenburg 1Department of Entomology, North Carolina State University, Raleigh, NC 27695–7613. Search for other works by this author on: Oxford Academic PubMed Google Scholar Yasmin J. Cardoza Yasmin J. Cardoza 3 1Department of Entomology, North Carolina State University, Raleigh, NC 27695–7613. 3Corresponding author, e-mail: yasmin_cardoza@ncsu.edu Search for other works by this author on: Oxford Academic PubMed Google Scholar Journal of Economic Entomology, Volume 107, Issue 4, 1 August 2014, Pages 1688–1694, https://doi.org/10.1603/EC14044 Published: 01 August 2014 Article history Received: 04 February 2014 Accepted: 10 June 2014 Published: 01 August 2014 DA - 2014/8/1/ PY - 2014/8/1/ DO - 10.1603/ec14044 VL - 107 IS - 4 SP - 1688-1694 KW - host plant resistance KW - antibiosis KW - antixenosis KW - Stenotaphrum secundatum KW - southern chinch bug 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 Biotechnol J 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 - 2014/// PY - 2014/// DO - 10.1111/pbi.12291 VL - 13 IS - 5 SP - 689-699 KW - drought tolerance KW - HUB1 KW - Lolium perenne KW - small ORF KW - transgenic ER - TY - JOUR TI - Development and characterization of simple sequence repeat (SSR) markers for St. Augustinegrass (Stenotaphrum secundatum (Walt.) Kuntze) AU - Mulkey, S.E. AU - Zuleta, M.C. AU - Keebler, J.E. AU - Schaff, J.E. AU - Milla-Lewis, S.R. T2 - Crop Science AB - ABSTRACT Illumina sequencing data was used to develop simple sequence repeat (SSR) markers for St. Augustinegrass [ Stenotaphrum secundatum (Walter) Kuntze], an economically important warm‐season turfgrass. Polymorphism was observed in 190 of 215 designed SSR markers among a panel of eight diverse germplasm accessions. Of these, 94 were subsequently used to assess levels of diversity within a diverse collection of S. secundatum and pembagrass [ Stenotaphrum dimidiatum (L.) Brongn.] germplasm. A total of 982 alleles ranging in size from 63 to 250 bp were amplified. Levels of polymorphism were high, with number of alleles amplified per loci ranging from 5 to 23 (μ = 10) and with polymorphic information content values ranging from 0.09 to 0.83 (μ = 0.54). Cluster and principal coordinate analyses of S. secundatum and S. dimidiatum accessions showed groupings based primarily on ploidy level. Analysis of population structure identified six subpopulations with some admixture present among them. Additionally, the ability of these newly developed SSR markers to uniquely identify specific cultivars was assessed. A set of five SSR markers were capable of producing unique banding patterns for all but two cultivars. These markers, the first developed for the species, should be useful for linkage mapping, diversity and pedigree analyses, accurate varietal identification, and marker‐assisted selection in St. Augustinegrass. DA - 2014/// PY - 2014/// DO - 10.2135/cropsci2013.04.0246 VL - 54 IS - 1 SP - 401-412 ER - TY - JOUR TI - The role of mycorrhizal associations in plant potassium nutrition AU - Garcia, Kevin AU - Zimmermann, Sabine D. T2 - Frontiers in Plant Science AB - Potassium (K+) is one of the most abundant elements of soil composition but its very low availability limits plant growth and productivity of ecosystems. Because this cation participates in many biological processes, its constitutive uptake from soil solution is crucial for the plant cell machinery. Thus, the understanding of strategies responsible of K+ nutrition is a major issue in plant science. Mycorrhizal associations occurring between roots and hyphae of underground fungi improve hydro-mineral nutrition of the majority of terrestrial plants. The contribution of this mutualistic symbiosis to the enhancement of plant K+ nutrition is not well understood and poorly studied so far. This mini-review examines the current knowledge about the impact of both arbuscular mycorrhizal and ectomycorrhizal symbioses on the transfer of K+ from the soil to the plants. A model summarizing plant and fungal transport systems identified and hypothetically involved in K+ transport is proposed. In addition, some data related to benefits for plants provided by the improvement of K+ nutrition thanks to mycorrhizal symbioses are presented. DA - 2014/7// PY - 2014/7// DO - 10.3389/fpls.2014.00337 VL - 5 KW - potassium KW - plant nutrition KW - arbuscular mycorrhizal symbiosis KW - ectomycorrhizal symbiosis KW - transport systems ER - TY - JOUR TI - Azoxystrobin, Butralin, and Flumetralin Residues in Flue-Cured Tobacco T2 - Tobacco Science DA - 2014/// PY - 2014/// DO - 10.3381/14-034R.1 UR - http://www.tobaccoscienceonline.org/doi/pdf/10.3381/14-034R.1 ER - TY - JOUR TI - Azoxystrobin, butralin, and flumetralin residues in flue-cured tobacco AU - Vann, M.C AU - Fisher, L.R. T2 - Tobacco Science DA - 2014/// PY - 2014/// VL - 51 SP - 23-28 ER - TY - JOUR TI - Tissue culture, genetic transformation, and improvement of switchgrass through genetic engineering AU - Zhao, B. Y. AU - Qu, R. D. AU - Li, R. Y. AU - Xu, B. AU - Frazier, T. T2 - Compendium of bioenergy plants: switchgrass DA - 2014/// PY - 2014/// SP - 253-293 ER - TY - JOUR TI - Soil microbial responses to elevated CO2 and O-3 in a nitrogen-aggrading agroecosystem AU - Cheng, L. AU - Booker, F. L. AU - Burkey, K. O. AU - Tu, C. AU - Shew, H. D. AU - Rufty, T. W. AU - Fiscus, E. L. AU - Deforest, J. L. AU - Hu, S. J. T2 - Carbon Capture and Storage: CO2 Management Technologies DA - 2014/// PY - 2014/// DO - 10.1201/b16845-14 SP - 277-307 ER - TY - JOUR TI - Polysaccharides Natural Fibers in Food and Nutrition Foreword AU - Livingston, D. T2 - Polysaccharides: Natural Fibers in Food and Nutrition DA - 2014/// PY - 2014/// SP - IX- ER - TY - JOUR TI - Phenotyping M. sieversii Collections from Kazakhstan for Leaf Traits and Tree Architecture AU - Maguylo, K. AU - Bassett, C. T2 - X INTERNATIONAL SYMPOSIUM ON INTEGRATING CANOPY, ROOTSTOCK AND ENVIRONMENTAL PHYSIOLOGY IN ORCHARD SYSTEMS DA - 2014/// PY - 2014/// DO - 10.17660/actahortic.2014.1058.40 VL - 1058 SP - 335-341 SN - 0567-7572 KW - apple KW - drought tolerance KW - water use efficiency (WUE) KW - stomatal size and number KW - delta C-13 ER - TY - CONF TI - Fusarium Head Blight resistance QTL in the NC-Neuse / AGS2000 recombinant inbred population AU - Petersen, S. AU - J.H. Lyerly, P.V. Maloney AU - R.A. Navarro, C. Cowger AU - G. Brown-Guedira, J.M. Costa AU - C.A. Griffey, AU - Murphy, J. P. C2 - 2014/// C3 - National Fusarium Head Blight Forum DA - 2014/// ER - TY - JOUR TI - Dynamics of Apple Architecture with Respect to Fruit Development in a Cool versus a Warm Climate AU - Maguylo, K. AU - Cook, N. C. AU - Theron, K. I. T2 - X INTERNATIONAL SYMPOSIUM ON INTEGRATING CANOPY, ROOTSTOCK AND ENVIRONMENTAL PHYSIOLOGY IN ORCHARD SYSTEMS AB - Branch architecture in apple (Malus A— domestica Borkh.) is defined according to the location, type (vegetative or reproductive), and length of lateral shoots. This is related to both an inherent genetic basis for architecture and the response of the lateral buds and shoots to environmental constraints. Architecture is typically viewed as the result of time and position bud burst and outgrowth, or branching dynamics, and therefore is related to the competition among buds within an annual shoot. However, while both differences in budburst and in branch formation have been observed, the relationship between budburst and characteristics of the reproductive bud are somewhat unknown. In warm climates, foliation and flowering are delayed and prolonged, and therefore we have used this phenomenon to better understand how branches are formed in warm areas. In a study performed in two areas with different degrees of winter chilling in South Africa, we studied differences in both climate and genotype using three apple cultivars, ‘Red Delicious’, ‘Granny Smith’ and ‘Golden Delicious’, grown in two different locations with differing degrees of winter chilling. Between the warmer and cooler are in the study, we observed architectural characteristics related to differences in fruit size and dry weight. DA - 2014/// PY - 2014/// DO - 10.17660/actahortic.2014.1058.35 VL - 1058 SP - 299-304 SN - 0567-7572 ER - TY - JOUR TI - Yield Improvement and Genotype x Environment Analyses of Peanut Cultivars in Multilocation Trials in West Africa AU - Narh, Stephen AU - Boote, Kenneth J. AU - Naab, Jesse B. AU - Abudulai, Mumuni AU - Bertin, Zagre M'Bi AU - Sankara, Philippe AU - Burow, Mark D. AU - Tillman, Barry L. AU - Brandenburg, Rick L. AU - Jordan, David L. T2 - CROP SCIENCE AB - ABSTRACT Yield trials are used in plant breeding programs to evaluate the yield potential and stability of selected lines. The objectives of this study were to evaluate yield potential, genotype × environment interactions, and stability of peanut genotypes for the savannah region of West Africa. Twenty peanut ( Arachis hypogaea L.) genotypes were tested at two sites in Ghana and two sites in Burkina Faso in 2010 and 2011. The experimental design was a randomized complete block design with three replicates. Genotype, location, and genotype × environment interactions were highly significant, indicating genetic variability among genotypes across changing environments. Stability analyses showed that genotypes ICGV‐IS 96814, ICGV (FDRS)‐20 × F‐MIX 39, Gusie Balin (92099), ICGV‐IS 92093, and ICGV‐IS 92101 had broad adaptability, with above‐average yield across sites and a regression coefficient close to 1.0. Genotype ICGV‐IS 96814 produced the highest pod yield (1760 kg ha −1 ) across all environments and had a regression coefficient close to unity ( b = 1.06). Therefore, genotype ICGV‐IS 96814 is less responsive to varied environmental and soil conditions. However, the released cultivar Nkatesari was considered equivalent in some respects because it had pod yield equal to ICGV‐IS 96814 but with a higher regression coefficient. High‐yielding cultivars, mostly from ICRISAT‐derived crosses, yielded nearly 80% more than the three farmer check cultivars TS 32–1, Doumbala, and Chinese, which had pod yields from 890 to 980 kg ha −1 . The higher‐yielding cultivars had longer life cycle, greater leaf spot resistance, and higher partitioning than the farmer check cultivars. DA - 2014/// PY - 2014/// DO - 10.2135/cropsci2013.10.0657 VL - 54 IS - 6 SP - 2413-2422 SN - 1435-0653 ER - TY - JOUR TI - Molecular genetic mapping of the major effect photoperiod response locus in Pima cotton (Gossypium barbadense L.) AU - Zhu, L. L. AU - Kuraparthy, V. T2 - Crop Science DA - 2014/// PY - 2014/// VL - 54 IS - 6 SP - 2492-2498 ER - TY - JOUR TI - Growth Habit of Rhizoma Peanut Affects Establishment and Spread when Strip Planted in Bahiagrass Pastures AU - Mullenix, M. Kimberly AU - Sollenberger, Lynn E. AU - Blount, Ann R. AU - Vendramini, Joao M. B. AU - Silveira, Maria L. AU - Castillo, Miguel S. T2 - CROP SCIENCE AB - ABSTRACT Planting rhizoma peanut (RP; Arachis glabrata Benth.) in strips in bahiagrass ( Paspalum notatum Flügge) pastures may be an economical approach to increase sward nutritive value, decrease dependence on N fertilizer, and promote sustainable mixed‐species pastures. Released cultivars and germplasms of RP range in growth habit from decumbent to upright, differences that may affect their spread and response to defoliation in grass pastures. The objectives were to quantify initial establishment characteristics and subsequent spread of RP entries following strip planting. Treatments were the factorial combinations of two defoliation practices after planting (haying or grazing every 28 d) and four RP entries (Arblick, Ecoturf, Florigraze, and UF Peace). By the year after planting, decumbent types Arblick (51%) and Ecoturf (48%) had greater RP ground cover than upright‐growing UF Peace (34%), but they were not different in cover than the intermediate type Florigraze (40%). Haying resulted in greater cover than grazing (51 vs. 31%). Spread of RP into adjacent bahiagrass was reduced by grazing compared with haying during the year of planting (0 and 0.24 m, respectively) and year after planting (0.34 and 0.67 m, respectively). Results suggest that decumbent Ecoturf and Arblick and intermediate growth habit Florigraze can be established successfully in strips in bahiagrass pasture, and establishment is favored when swards are used for hay rather than grazing during the first 2 yr. DA - 2014/// PY - 2014/// DO - 10.2135/cropsci2014.03.0254 VL - 54 IS - 6 SP - 2886-2892 SN - 1435-0653 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-84908179193&partnerID=MN8TOARS ER - TY - JOUR TI - Computational and genetic evidence that different structural conformations of a non-catalytic region affect the function of plant cellulose synthase AU - Slabaugh, Erin AU - Sethaphong, Latsavongsakda AU - Xiao, Chaowen AU - Amick, Joshua AU - Anderson, Charles T. AU - Haigler, Candace H. AU - Yingling, Yaroslava G. T2 - Journal of Experimental Botany AB - The β-1,4-glucan chains comprising cellulose are synthesized by cellulose synthases in the plasma membranes of diverse organisms including bacteria and plants. Understanding structure–function relationships in the plant enzymes involved in cellulose synthesis (CESAs) is important because cellulose is the most abundant component in the plant cell wall, a key renewable biomaterial. Here, we explored the structure and function of the region encompassing transmembrane helices (TMHs) 5 and 6 in CESA using computational and genetic tools. Ab initio computational structure prediction revealed novel bi-modal structural conformations of the region between TMH5 and 6 that may affect CESA function. Here we present our computational findings on this region in three CESAs of Arabidopsis thaliana (AtCESA1, 3, and 6), the Atcesa3ixr1-2 mutant, and a novel missense mutation in AtCESA1. A newly engineered point mutation in AtCESA1 (Atcesa1F954L) that altered the structural conformation in silico resulted in a protein that was not fully functional in the temperature-sensitive Atcesa1rsw1-1 mutant at the restrictive temperature. The combination of computational and genetic results provides evidence that the ability of the TMH5–6 region to adopt specific structural conformations is important for CESA function. DA - 2014/9/26/ PY - 2014/9/26/ DO - 10.1093/jxb/eru383 VL - 65 IS - 22 SP - 6645-6653 LA - en OP - SN - 1460-2431 0022-0957 UR - http://dx.doi.org/10.1093/jxb/eru383 DB - Crossref KW - Cellulose biosynthesis KW - CESA KW - genetic complementation KW - protein structural modelling KW - rsw1 mutant KW - transmembrane helix ER - TY - JOUR TI - MAXIMUM PHOSPHORUS ADSORPTION CAPACITY AND BINDING ENERGY CONSTANT OF AN OXISOL FITTING DIFFERENT LANGMUIR MODELS AU - Oliveira, Clovisson Menotti AU - Gatiboni, Luciano Colpo AU - Miquelluti, David Jose AU - Smyth, Thomas Jot AU - Almeida, Jaime Antonio T2 - REVISTA BRASILEIRA DE CIENCIA DO SOLO AB - A capacidade máxima de adsorção de fósforo (CMAP) é um parâmetro bastante útil para caracterizar a capacidade de adsorção de fósforo (P) do solo e, por isso, o modelo de Langmuir, que possibilita essa estimativa, é bastante difundido. Porém, se o ajuste da equação for realizado por modelos não lineares ou linearizados, ou se forem escolhidos modelos de região única ou múltiplas, nem sempre os valores estimados da CMAP e da constante de energia de ligação (k) são semelhantes. O objetivo deste trabalho foi avaliar o efeito do uso de diferentes métodos de ajuste do modelo de Langmuir sobre os valores estimados de CMAP e k. Para isso, utilizouse um único solo de alta capacidade de adsorção de P, o qual foi misturado a quantidades crescentes de areia lavada, construindo-se sistemas com capacidades de sorção crescentes, mas com a fase sólida constituída da mesma mineralogia. Foi utilizado solo do horizonte B de um Latossolo Bruno com 800 g kg-1 de argila, o qual foi misturado com areia em quantidades para obterem-se solos artificiais com 0, 200, 400, 600 e 800 g kg-1 de argila. Esses solos artificiais foram incubados por 30 dias com calcário para elevar o pH(H2O) até 6,0 e, após, foram secos em estufa e peneirados. Foram realizadas as isotermas de adsorção e os dados ajustados pelo modelo de Langmuir, usando os seguintes métodos: NLin - não linear com região única; L-1R - linearização com região única; L-2RG - linearização com duas regiões, ajuste gráfico; L-3RG - linearização com três regiões, ajuste gráfico; L-2RE linerização com duas regiões, ajuste estatístico. Os resultados evidenciaram que todos os métodos utilizados estimaram valores de CMAP proporcionais ao teor de argila dos solos e poderiam ser usados para caracterizar os solos. Contudo, quando utilizados ajustes com mais de uma região de adsorção, os valores da CMAP para a última região foram sensivelmente superiores àqueles observados após a incubação do solo com doses de P em um teste adicional. Isso indica que a CMAP da última região deve ser evitada como caracterizadora da capacidade de adsorção do solo. Conforme era esperado, os valores de k foram proporcionais aos teores de argila do solo na primeira (ou única) região dos modelos linearizados; contudo, não seguiram essa tendência no modelo não linear, recomendando-se cautela na interpretação da constante k ajustada por modelos não lineares. DA - 2014/// PY - 2014/// DO - 10.1590/s0100-06832014000600015 VL - 38 IS - 6 SP - 1805-1815 SN - 0100-0683 KW - isotherms KW - Pmax KW - maximum adsorption KW - adsorption models KW - phosphorus sorption ER - TY - JOUR TI - Genome-wide association study of Fusarium ear rot disease in the USA maize inbred line collection AU - Zila, Charles T. AU - Ogut, Funda AU - Romay, Maria C. AU - Gardner, Candice A. AU - Buckler, Edward S. AU - Holland, James B. T2 - BMC PLANT BIOLOGY AB - Resistance to Fusarium ear rot of maize is a quantitative and complex trait. Marker-trait associations to date have had small additive effects and were inconsistent between previous studies, likely due to the combined effects of genetic heterogeneity and low power of detection of many small effect variants. The complexity of inheritance of resistance hinders the use marker-assisted selection for ear rot resistance.We conducted a genome-wide association study (GWAS) for Fusarium ear rot resistance in a panel of 1687 diverse inbred lines from the USDA maize gene bank with 200,978 SNPs while controlling for background genetic relationships with a mixed model and identified seven single nucleotide polymorphisms (SNPs) in six genes associated with disease resistance in either the complete inbred panel (1687 lines with highly unbalanced phenotype data) or in a filtered inbred panel (734 lines with balanced phenotype data). Different sets of SNPs were detected as associated in the two different data sets. The alleles conferring greater disease resistance at all seven SNPs were rare overall (below 16%) and always higher in allele frequency in tropical maize than in temperate dent maize. Resampling analysis of the complete data set identified one robust SNP association detected as significant at a stringent p-value in 94% of data sets, each representing a random sample of 80% of the lines. All associated SNPs were in exons, but none of the genes had predicted functions with an obvious relationship to resistance to fungal infection.GWAS in a very diverse maize collection identified seven SNP variants each associated with between 1% and 3% of trait variation. Because of their small effects, the value of selection on these SNPs for improving resistance to Fusarium ear rot is limited. Selection to combine these resistance alleles combined with genomic selection to improve the polygenic background resistance might be fruitful. The genes associated with resistance provide candidate gene targets for further study of the biological pathways involved in this complex disease resistance. DA - 2014/12/30/ PY - 2014/12/30/ DO - 10.1186/s12870-014-0372-6 VL - 14 IS - 1 SP - SN - 1471-2229 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-84964314102&partnerID=MN8TOARS KW - Association analysis KW - Disease resistance KW - Genomic selection KW - Maize KW - Quantitative trait ER - TY - JOUR TI - Evaluation of Elite Southern Maturity Soybean Breeding Lines for Drought-Tolerant Traits AU - Devi, Jyostna Mura AU - Sinclair, Thomas R. AU - Chen, Pengyin AU - Carter, Thomas E. T2 - AGRONOMY JOURNAL AB - Breeding efforts in soybean [ Glycine max (L.) Merr.] have addressed the challenge of water‐limited yields by incorporating parental stocks which exhibit drought‐tolerant traits. Multiple cycles of empirical selection for improved yielding ability in water‐deficient field environments have produced new generations of adapted breeding lines. However, the impact of this selection process on specific putative drought‐tolerant traits is unknown. The objective of this study was to determine if breeders’ selection of 10 elite lines for high seed yield under dry conditions is associated with the presence of physiological expression of three putative drought‐tolerant traits: (i) limited transpiration rate under high vapor pressure deficit (VPD), (ii) early decrease in transpiration rate with soil drying, and (iii) drought‐tolerant N 2 fixation. Greenhouse experiments were undertaken to characterize each genotypes for their phenotype of each of these three traits. Unlike most soybean cultivars, 9 of the 10 elite lines expressed a limited transpiration rate under elevated VPD. The VPD at which transpiration rate became limited was 1.9 kPa or less. There was no difference among genotypes in the threshold for decline in transpiration rate with soil drying, although all genotypes expressed high thresholds indicating an ability to conserve soil water. All lines expressed drought tolerance in their N 2 fixation rates, which was superior to that commonly observed in soybean. This study demonstrated that mating of parents that expressed a drought trait and multiple rounds of progeny selection based on improved yield under water‐limited conditions resulted in the elite lines expressing improved drought traits. DA - 2014/// PY - 2014/// DO - 10.2134/agronj14.0242 VL - 106 IS - 6 SP - 1947-1954 SN - 1435-0645 ER - TY - JOUR TI - Soil microbial responses to winter, legume cover crop management during organic transition AU - Liang, Shangtao AU - Grossman, Julie AU - Shi, Wei T2 - EUROPEAN JOURNAL OF SOIL BIOLOGY AB - Legume cover cropping has been widely used as an efficient strategy to improve soil fertility. Although this management practice is important to resolve N deficiency for the transition from conventional to organic production systems, optimization is necessary to determine legume cover crop species and termination methods. This study used soil microbial properties and processes to evaluate the suitability of several legume cover crops and termination methods for organic transition in southeastern USA. Soil samples were taken from two newly-established study sites, each containing 12 treatments of three termination methods (disk, flail, and spray) and four cover types (no cover crop, Austrian winter pea, hairy vetch, and crimson clover). Compared to disking and spraying, flail mowing significantly increased soil microbial biomass C by ∼17%, C mineralization by ∼25%, N mineralization by ∼16%, and nitrification potential by ∼36%, 12 weeks after cover crop termination. However, cover cropping only stimulated nitrification potential, but not C and N mineralization. Furthermore, the activities of soil enzymes (exoglucanase, β-glucosidase, and β-glucosaminidase) appeared to be more responsive to cover types than to termination methods. Among three cover crops, Austrian winter pea showed the greatest positive effects on nitrification potential, β-glucosidase, and β-glucosaminidase. The ratio of C mineralization to microbial biomass C also differed with cover types, being lowest in Austrian winter pea. Our results indicated that legume species even with small differences in C-to-N ratio and lignin and cellulose contents could have varied effects on soil microbial properties and processes. Nitrification potential, representing the function of a small group of soil microbial community, was proved to be sensitive to both legume species and termination methods. DA - 2014/// PY - 2014/// DO - 10.1016/j.ejsobi.2014.08.007 VL - 65 SP - 15-22 SN - 1778-3615 KW - Nitrification potential KW - Soil enzyme activity KW - Cover crop KW - Legume species KW - Flail mowing KW - Organic transition ER - TY - JOUR TI - Short-term effects of plant litter on the dynamics, amount, and stoichiometry of soil enzyme activity in agroecosystems AU - Tian, Lei AU - Shi, Wei T2 - EUROPEAN JOURNAL OF SOIL BIOLOGY AB - Addition of plant litter can affect soil enzyme activity at three scales: dynamics, amount, and stoichiometry. In this study, we examined the dependence of soil enzyme activity at all three scales on litter quality. Soils of similar texture were collected from conventional and organic farming systems, the Center for Environmental Farming Systems, Goldsboro, North Carolina, USA. Soil samples were then amended with senescent pine needles, grass materials, and soybean residues of C:N ratio 139, 50, and 9, respectively, at 2 mg C g−1 soil, and the activities of soil β-glucosidase, exoglucanase, β-glucosaminidase, and phenol oxidase were measured over the course of 90-d incubation. Relationships between the dynamics of enzyme activity and litter quality appeared to be enzyme specific. Time patterns of soil β-glucosidase and β-glucosaminidase activity were independent of litter quality, with rapid increase in enzyme activity and reaching a peak several weeks after litter addition. In contrast, time patterns of polymer-degrading enzymes (exoglucanase and phenol oxidase) were dependent on litter quality. Exoglucanase activity showed a concave function with time following the addition of soybean residues or grass materials, but increased slightly following the addition of pine needles. Cumulative activities of soil enzymes were upregulated following litter addition and could be qualitatively assessed by litter C:N ratio. The activity of β-glucosaminidase was negatively related to litter C:N ratio, being greatest in soybean residues-amended soil. Litter of a low C:N ratio was generally better than litter of a high C:N ratio for increasing soil cellulase activity and vice versa for phenol oxidase. However, the stoichiometry of soil enzyme activity was decoupled with litter C:N ratio. Soybean residues and pine needles at opposite ends of the litter C:N range were more similar in the ratio of C- to N-acquiring enzyme activity. We also examined pH effects on the expression of added enzymes. Soil enzyme activities were enhanced as soil pH increased from 6 to 8. pH-associated changes in enzyme activity were generally smaller as compared to changes caused by other factors during the 42-d incubation. Our results suggest that litter effects on the dynamics, amount, and stoichiometry of soil enzyme activity were independent of soil pH. Litter C:N was a good indicator for the total amount, but not for the dynamics or stoichiometry of soil enzyme activity. DA - 2014/// PY - 2014/// DO - 10.1016/j.ejsobi.2014.08.004 VL - 65 SP - 23-29 SN - 1778-3615 KW - Plant litter KW - Soil enzyme activity KW - beta-glucosidase KW - beta-glucosaminidase KW - Exoglucanase KW - Phenol oxidase ER - TY - JOUR TI - Effect of Simulated Indaziflam Drift Rates on Various Plant Species AU - Jeffries, Matthew D. AU - Mahoney, Denis J. AU - Gannon, Travis W. T2 - WEED TECHNOLOGY AB - Indaziflam is a PRE herbicide for control of annual grass and broadleaf weeds in numerous settings, including managed roadsides, railroads, and noncroplands. There is a need for new and improved PRE herbicides for herbaceous vegetation management along roadsides; however, off-target crop injury via spray drift is a concern because of the close proximity of roadside applications to the wide array of crops grown throughout the southeastern United States where indaziflam is used. Greenhouse research was conducted to evaluate the effect of PRE and POST simulated indaziflam spray drift rates on the growth of cotton, bell pepper, soybean, squash, tobacco, and tomato. Simulated indaziflam spray drift rates were 100, 20, 10, 5, or 2.5% of a 73 g ai ha −1 application rate, whereas other herbicide treatments included for comparative purposes were applied at 10% of a typical North Carolina roadside vegetation management application rate. These included sulfometuron (4 g ai ha −1 ), aminocyclopyrachlor + metsulfuron (11 + 3.5 g ai ha −1 ), clopyralid + triclopyr (21 + 63 g ai ha −1 ), or aminopyralid (12 g ai ha −1 ). In general, plant growth responses varied among herbicides and application timings. Across all evaluated parameters, indaziflam at the 10% simulated drift rate adversely effected plant growth similarly or less than all other herbicides when applied PRE (squash and tomato), POST (bell pepper and soybean), and PRE or POST (cotton and tobacco). No clear trends were observed regarding indaziflam application timing, as PRE squash and tomato, and POST bell pepper and soybean applications were safer than their respective alternative timing, and no significant differences were detected between timings on cotton or tobacco. Across application timings, plant susceptibility to indaziflam-simulated spray drift rates ranked cotton < tobacco < tomato < squash < pepper < soybean. Finally, it should be noted that the lowest simulated indaziflam drift rate (2.5%) caused greater than 20% root mass reduction on cotton (POST), bell pepper (PRE and POST), soybean (PRE and POST), squash (PRE), and tomato (POST). Although this research supports indaziflam use along roadsides, it still poses an off-target plant injury risk. Future research should evaluate techniques to minimize spray drift from roadside pesticide applications. DA - 2014/// PY - 2014/// DO - 10.1614/wt-d-14-00004.1 VL - 28 IS - 4 SP - 608-616 SN - 1550-2740 KW - Off-target herbicide movement KW - roadside vegetation management KW - simulated spray drift ER - TY - JOUR TI - Limits on the reproducibility of marker associations with southern leaf blight resistance in the maize nested association mapping population AU - Bian, Yang AU - Yang, Qin AU - Balint-Kurti, Peter J. AU - Wisser, Randall J. AU - Holland, James B. T2 - BMC GENOMICS AB - A previous study reported a comprehensive quantitative trait locus (QTL) and genome wide association study (GWAS) of southern leaf blight (SLB) resistance in the maize Nested Association Mapping (NAM) panel. Since that time, the genomic resources available for such analyses have improved substantially. An updated NAM genetic linkage map has a nearly six-fold greater marker density than the previous map and the combined SNPs and read-depth variants (RDVs) from maize HapMaps 1 and 2 provided 28.5 M genomic variants for association analysis, 17 fold more than HapMap 1. In addition, phenotypic values of the NAM RILs were re-estimated to account for environment-specific flowering time covariates and a small proportion of lines were dropped due to genotypic data quality problems. Comparisons of original and updated QTL and GWAS results confound the effects of linkage map density, GWAS marker density, population sample size, and phenotype estimates. Therefore, we evaluated the effects of changing each of these parameters individually and in combination to determine their relative impact on marker-trait associations in original and updated analyses.Of the four parameters varied, map density caused the largest changes in QTL and GWAS results. The updated QTL model had better cross-validation prediction accuracy than the previous model. Whereas joint linkage QTL positions were relatively stable to input changes, the residual values derived from those QTL models (used as inputs to GWAS) were more sensitive, resulting in substantial differences between GWAS results. The updated NAM GWAS identified several candidate genes consistent with previous QTL fine-mapping results.The highly polygenic nature of resistance to SLB complicates the identification of causal genes. Joint linkage QTL are relatively stable to perturbations of data inputs, but their resolution is generally on the order of tens or more Mbp. GWAS associations have higher resolution, but lower power due to stringent thresholds designed to minimize false positive associations, resulting in variability of detection across studies. The updated higher density linkage map improves QTL estimation and, along with a much denser SNP HapMap, greatly increases the likelihood of detecting SNPs in linkage with causal variants. We recommend use of the updated genetic resources and results but emphasize the limited repeatability of small-effect associations. DA - 2014/12/5/ PY - 2014/12/5/ DO - 10.1186/1471-2164-15-1068 VL - 15 IS - 1 SP - SN - 1471-2164 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-84924290940&partnerID=MN8TOARS KW - Quantitative trait loci KW - Nested association mapping KW - Disease resistance KW - Genome wide association study KW - Zea mays ER - TY - JOUR TI - Integrated Field Lysimetry and Porewater Sampling for Evaluation of Chemical Mobility in Soils and Established Vegetation AU - Matteson, Audrey R. AU - Mahoney, Denis J. AU - Gannon, Travis W. AU - Polizzotto, Matthew L. T2 - JOVE-JOURNAL OF VISUALIZED EXPERIMENTS AB - Potentially toxic chemicals are routinely applied to land to meet growing demands on waste management and food production, but the fate of these chemicals is often not well understood. Here we demonstrate an integrated field lysimetry and porewater sampling method for evaluating the mobility of chemicals applied to soils and established vegetation. Lysimeters, open columns made of metal or plastic, are driven into bareground or vegetated soils. Porewater samplers, which are commercially available and use vacuum to collect percolating soil water, are installed at predetermined depths within the lysimeters. At prearranged times following chemical application to experimental plots, porewater is collected, and lysimeters, containing soil and vegetation, are exhumed. By analyzing chemical concentrations in the lysimeter soil, vegetation, and porewater, downward leaching rates, soil retention capacities, and plant uptake for the chemical of interest may be quantified. Because field lysimetry and porewater sampling are conducted under natural environmental conditions and with minimal soil disturbance, derived results project real-case scenarios and provide valuable information for chemical management. As chemicals are increasingly applied to land worldwide, the described techniques may be utilized to determine whether applied chemicals pose adverse effects to human health or the environment. DA - 2014/7// PY - 2014/7// DO - 10.3791/51862 IS - 89 SP - SN - 1940-087X KW - Environmental Sciences KW - Issue 89 KW - Lysimetry KW - porewater KW - soil KW - chemical leaching KW - pesticides KW - turfgrass KW - waste ER - TY - JOUR TI - Soil Properties Influence Saflufenacil Phytotoxicity AU - Gannon, Travis W. AU - Hixson, Adam C. AU - Keller, Kyle E. AU - Weber, Jerome B. AU - Knezevic, Stevan Z. AU - Yelverton, Fred H. T2 - WEED SCIENCE AB - Saflufenacil, a pyrimidinedione herbicide, is used for contact and residual broadleaf weed control in various crops. Bioactivity of saflufenacil in soil was tested in greenhouse and laboratory studies on 29 soils representing a wide range of soil properties and geographic areas across the United States. A greenhouse bioassay method was developed using various concentrations of saflufenacil applied PPI to each soil. Whole canola plants were harvested 14 d after treatment, and fresh and dry weights were recorded. Nonlinear regression analysis was used to determine the effective saflufenacil doses for 50% (ED 50 ,), 80% (ED 80 ), and 90% (ED 90 ) inhibition of total plant fresh weight. Bioactivity of saflufenacil in soil was strongly correlated to soil organic ( R = 0.85) and humic matter ( R = 0.81), and less correlated to cation exchange capacity ( R = 0.49) and sand content ( R = −0.32). Stepwise regression analysis indicated that organic matter was the major soil constituent controlling bioactivity in soil and could be used to predict the bioactivity of saflufenacil. Saflufenacil phytotoxicity was found to be dependent on soil property; therefore, efficacy and crop tolerance from PRE and PPI applications may vary based on soil organic matter content and texture classification. DA - 2014/// PY - 2014/// DO - 10.1614/ws-d-13-00171.1 VL - 62 IS - 4 SP - 657-663 SN - 1550-2759 KW - Bioactivity KW - bioassay KW - dose-response curve KW - herbicide KW - soil organic matter KW - soil properties ER - TY - JOUR TI - Park Use Among Youth and Adults: Examination of Individual, Social, and Urban Form Factors AU - Baran, Perver K. AU - Smith, William R. AU - Moore, Robin C. AU - Floyd, Myron F. AU - Bocarro, Jason N. AU - Cosco, Nilda G. AU - Danninger, Thomas M. T2 - ENVIRONMENT AND BEHAVIOR AB - This article examines park use in relation to neighborhood social (safety and poverty) and urban form (pedestrian infrastructure and street network pattern) characteristics among youth and adult subpopulations defined by age and gender. We utilized System for Observing Play and Recreation in Communities (SOPARC) and Geographic Information Systems to objectively measure park use and park and neighborhood characteristics in 20 neighborhood parks. Heterogeneous negative binomial regression models indicated that the relationship between park use and types of activity settings, and park use and neighborhood attributes vary by age and gender. In general, the study found that park and activity setting size; activity settings such as playgrounds, basketball courts, pool and water features, shelters, and picnic areas; and availability of sidewalks and intersections in the park’s neighborhood were positively associated with park use, whereas crime, poverty, and racial heterogeneity of the surrounding neighborhood were negatively associated with park use. DA - 2014/8// PY - 2014/8// DO - 10.1177/0013916512470134 VL - 46 IS - 6 SP - 768-800 SN - 1552-390X KW - neighborhood park use KW - crime KW - urban form KW - street connectivity KW - pedestrian infrastructure ER - TY - JOUR TI - Metal oxyhydroxide dissolution as promoted by structurally diverse siderophores and oxalate AU - Akafia, Martin M. AU - Harrington, James M. AU - Bargar, John R. AU - Duckworth, Owen W. T2 - GEOCHIMICA ET COSMOCHIMICA ACTA AB - Siderophores, a class of biogenic ligands with high affinities for Fe(III), promote the dissolution of metal ions from sparingly soluble mineral phases. However, most geochemical studies have focused on quantifying the reactivity of DFOB, a model trishydroxamate siderophore. This study utilized three different siderophores, desferrioxamine B, rhizoferrin, and protochelin, with structures that contain the most commonly observed binding moieties of microbial siderophores to examine the siderophore-promoted dissolution rates of FeOOH, CoOOH, and MnOOH in the absence and presence of the ubiquitous low molecular mass organic acid oxalate by utilizing batch dissolution experiments at pH = 5–9. Metal-siderophore complex and total dissolved metal concentrations were monitored for durations of one hour to fourteen days, depending on the metal oxyhydroxide identity and solution pH. The results demonstrate that MnOOH and CoOOH generally dissolve more quickly in the presence of siderophores than FeOOH. Whereas FeOOH dissolved exclusively by a ligand-promoted dissolution mechanism, MnOOH and CoOOH dissolved predominantly by a reductive dissolution mechanism under most experimental conditions. For FeOOH, siderophore-promoted dissolution rates trended with the stability constant of the corresponding aqueous Fe(III) complex. In the presence of oxalate, measured siderophore-promoted dissolution rates were found to increase, decrease, or remain unchanged as compared to the observed rates in single-ligand systems, depending on the pH of the system, the siderophore present, and the identity of the metal oxyhydroxide. Increases in observed dissolution rates in the presence of oxalate were generally greater for FeOOH than for MnOOH or CoOOH. These results elucidate potential dissolution mechanisms of both ferric and non-ferric oxyhydroxide minerals by siderophores in the environment, and may provide further insights into the biological strategies of metal acquisition facilitated by coordinated exudation of low molecular weight organic acids and siderophores. DA - 2014/9/15/ PY - 2014/9/15/ DO - 10.1016/j.gca.2014.06.024 VL - 141 SP - 258-269 SN - 1872-9533 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-84904861957&partnerID=MN8TOARS ER - TY - JOUR TI - Identification of the molecular genetic basis of the low palmitic acid seed oil trait in soybean mutant line RG3 and association analysis of molecular markers with elevated seed stearic acid and reduced seed palmitic acid AU - Gillman, Jason D. AU - Tetlow, Ashley AU - Hagely, Katherine AU - Boersma, Jeffery G. AU - Cardinal, Andrea AU - Rajcan, Istvan AU - Bilyeu, Kristin T2 - MOLECULAR BREEDING DA - 2014/8// PY - 2014/8// DO - 10.1007/s11032-014-0046-y VL - 34 IS - 2 SP - 447-455 SN - 1572-9788 KW - Soybean KW - Oil improvement KW - Palmitic acid KW - Stearic acid KW - Mutagenesis ER - TY - JOUR TI - Granular and Dissolved Polyacrylamide Effects on Erosion and Runoff under Simulated Rainfall AU - Kang, Jihoon AU - Amoozegar, Aziz AU - Heitman, Joshua L. AU - McLaughlin, Richard A. T2 - JOURNAL OF ENVIRONMENTAL QUALITY AB - Polyacrylamide (PAM) has been demonstrated to reduce erosion under many conditions, but less is known about the effects of its application method on erosion and concentrations in the runoff water. A rainfall simulation study was conducted to evaluate the performance of an excelsior erosion control blanket (cover) and two PAM application methods. The treatments were (i) no cover + no PAM (control), (ii) cover + no PAM, (iii) cover + granular PAM (GPAM), and (iv) cover + dissolved PAM (DPAM) applied to soil packed in wooden runoff boxes. The GPAM or DPAM (500 mg L) was surface-applied at a rate of 30 kg ha 1 d before rainfall simulation. Rainfall was applied at 83 mm h for 50 min and then repeated for another 20 min after a 30-min rest period. Runoff samples were analyzed for volume, turbidity in nephelometric turbidity units (NTU), total suspended solids (TSS), sediment particle size distribution, and PAM concentration. The cover alone reduced turbidity and TSS in runoff by >60% compared with the control (2315 NTU, 2777 mg TSS L). The PAM further reduced turbidity and TSS by >30% regardless of the application method. The median particle diameter of eroded sediments for PAM treatments was seven to nine times that of the control (12.4 μm). Loss of applied PAM in the runoff water (not sediment) was 19% for the GPAM treatment but only 2% for the DPAM treatment. Both GPAM and DPAM were effective at improving groundcover performance, but DPAM resulted in much less PAM loss. DA - 2014/// PY - 2014/// DO - 10.2134/jeq2014.01.0022 VL - 43 IS - 6 SP - 1972-1979 SN - 1537-2537 ER - TY - JOUR TI - Detection of DNA and ploidy variation within vegetatively propagated zoysiagrass cultivars AU - Harris-Shultz, K. R. AU - Milla-Lewis, S. AU - Patton, A. J. AU - Kenworthy, K. AU - Chandra, A. AU - Waltz, F. C. AU - Hodnett, G. L. AU - Stelly, D. M. T2 - Journal of the American Society for Horticultural Science DA - 2014/// PY - 2014/// VL - 139 IS - 5 SP - 547-552 ER - TY - JOUR TI - Benchmark study on glyphosate-resistant crop systems in the United States. Economics of herbicide resistance management practices in a 5 year field-scale study AU - Edwards, C. Blake AU - Jordan, David L. AU - Owen, Michael D. K. AU - Dixon, Philip M. AU - Young, Bryan G. AU - Wilson, Robert G. AU - Weller, Steven C. AU - Shaw, David R. T2 - PEST MANAGEMENT SCIENCE AB - Abstract BACKGROUND Since the introduction of glyphosate‐resistant ( GR ) crops, growers have often relied on glyphosate‐only weed control programs. As a result, multiple weeds have evolved resistance to glyphosate. A 5 year study including 156 growers from Illinois, Iowa, Indiana, Nebraska, North Carolina and Mississippi in the United States was conducted to compare crop yields and net returns between grower standard weed management programs ( SPs ) and programs containing best management practices ( BMPs ) recommended by university weed scientists. The BMPs were designed to prevent or mitigate/manage evolved herbicide resistance. RESULTS Weed management costs were greater for the BMP approach in most situations, but crop yields often increased sufficiently for net returns similar to those of the less expensive SPs . This response was similar across all years, geographical regions, states, crops and tillage systems. CONCLUSIONS Herbicide use strategies that include a diversity of herbicide mechanisms of action will increase the long‐term sustainability of glyphosate‐based weed management strategies. Growers can adopt herbicide resistance BMPs with confidence that net returns will not be negatively affected in the short term and contribute to resistance management in the long term. © 2014 Society of Chemical Industry DA - 2014/12// PY - 2014/12// DO - 10.1002/ps.3759 VL - 70 IS - 12 SP - 1924-1929 SN - 1526-4998 KW - Glyphosate KW - herbicide resistance KW - economics KW - resistance management ER - TY - JOUR TI - Assessment of irrigation scenarios to improve performances of Lingot bean (Phaseolus vulgaris) in southwest France AU - Marrou, H. AU - Sinclair, T. R. AU - Metral, R. T2 - EUROPEAN JOURNAL OF AGRONOMY AB - In the context of climate change, producing the same amount of food with less water has become a challenge all over the world. This is also true for the Lingot bean production in the area of Castelnaudary of southwest France where market competition with imported bean has made it crucial to achieve high yields to maintain production in the area. The use of an appropriate and robust crop model can help to identify crop management solutions to face such issues. We used SSM-legumes, a crop model generic to legume species, as well as field observations recorded over five years on eight farms of the Castelnaudary area to assess the effect of different irrigation scenarios on bean yield and water consumption. First, it was demonstrated that the SSM-legumes model is robust in simulating the development and growth of Lingot bean in non-stressed or moderately stressed conditions of this region regarding water and nutrient availability. Then, the use of the model to compare irrigation scenarios provided guidance on how to improve irrigation management for Lingot bean production. These results showed that farmers could achieve slightly higher yields with less water by basing irrigation decisions on the water content of the soil. DA - 2014/9// PY - 2014/9// DO - 10.1016/j.eja.2014.05.006 VL - 59 SP - 22-28 SN - 1873-7331 KW - Phaseolus KW - Model KW - SSM-legumes KW - Irrigation KW - Water stress ER - TY - JOUR TI - Visualizing surface area and volume of lumens in three dimensions using images from histological sections AU - Livingston, David P., III AU - Tuong, Tan D. AU - Kissling, Grace E. AU - Cullen, John M. T2 - JOURNAL OF MICROSCOPY AB - Visualizing the interior (lumen) of a tubular structure within tissue can provide a unique perspective on anatomical organization of the tissue. Portal tracts of the liver contain several vessels and ducts in various patterns of intertwining branches and are an example of such spaces. An inexpensive method, using light microscopy and a sample of conventionally stained canine livers, was used to colorize and allow visualization of the lumens of vessels within the portal tract in three dimensions. When the colour of the background was digitally cleared and the lumen filled with a solid colour, it was possible to measure areas and volumes of the portal vein, arteries, bile ducts and lymphatics. Significant differences between vessels and ducts across lobes and gender in control samples are discussed. Differences were also found between control and mixed breed dogs and between controls and a dog that died of accidental traumatic haemorrhage. These differences are discussed in relation to visualizing lumens using images generated from a light microscope. Vessels in plants such as xylem and continuously formed spaces resulting from ice formation are other examples where this technique could be applied. DA - 2014/12// PY - 2014/12// DO - 10.1111/jmi.12171 VL - 256 IS - 3 SP - 190-196 SN - 1365-2818 KW - 3-D reconstruction KW - histology KW - liver KW - negative space KW - portal tract ER - TY - JOUR TI - Vibrational sum-frequency-generation (SFG) spectroscopy study of the structural assembly of cellulose microfibrils in reaction woods AU - Kafle, Kabindra AU - Shi, Rui AU - Lee, Christopher M. AU - Mittal, Ashutosh AU - Park, Yong Bum AU - Sun, Ying-Hsuan AU - Park, Sunkyu AU - Chiang, Vincent AU - Kim, Seong H. T2 - CELLULOSE DA - 2014/8// PY - 2014/8// DO - 10.1007/s10570-014-0322-3 VL - 21 IS - 4 SP - 2219-2231 SN - 1572-882X KW - Reaction wood KW - Tension wood KW - Compression wood KW - Cellulose microfibril assembly KW - Sum KW - frequency KW - generation spectroscopy KW - X-ray KW - diffraction ER - TY - JOUR TI - Vernalization Duration Requirement in Soft Winter Wheat is Associated with Variation at the VRN-B1 Locus AU - Guedira, Mohammed AU - Maloney, Peter AU - Xiong, Mai AU - Petersen, Stine AU - Murphy, J. Paul AU - Marshall, David AU - Johnson, Jerry AU - Harrison, Steve AU - Brown-Guedira, Gina T2 - CROP SCIENCE AB - ABSTRACT Genetic variation in the factors controlling flowering in wheat ( Triticum aestivum L.) allow it to be grown in a wide range of environments. The aim of this study was to identify genetic determinants of flowering time in winter wheat cultivars adapted to regions of the United States differing in latitude and the duration of cold temperatures during winter. Quantitative trait locus (QTL) analysis was performed in a recombinant inbred line (RIL) population from the cross between cultivars NC‐Neuse and AGS 2000 that are adapted to the Mid‐Atlantic and Southeastern regions, respectively. We identified a QTL for heading date (HD) in the greenhouse after 4 wk of vernalization, designated Qvdr.nc‐5BL , which also had a large effect on winter dormancy release and HD when the population was evaluated in the field at locations in North Carolina, Georgia, and Louisiana during 2012 and North Carolina during 2013. However, Qvdr.nc‐5BL did not have a significant effect on HD in greenhouse grown plants vernalized for 8 wk or in plants grown in the field at Raleigh, NC during 2011. In those environments where Qvdr.nc‐5BL was not significant, a region on chromosome 2B, probably associated with the Ppd‐B1 locus, was determined to have a HD effect. Interrogation of the population with gene‐based markers for Vrn‐B1 and Ppd‐B1 suggests that these loci are major determinants of HD in winter wheat and are important for adaptation to diverse growing environments. DA - 2014/// PY - 2014/// DO - 10.2135/cropsci2013.12.0833 VL - 54 IS - 5 SP - 1960-1971 SN - 1435-0653 ER - TY - JOUR TI - Understanding the response of winter cereals to freezing stress through freeze-fixation and 3D reconstruction of ice formation in crowns AU - Livingston, David P., III AU - Tuong, Tan D. T2 - ENVIRONMENTAL AND EXPERIMENTAL BOTANY AB - One of the more difficult aspects of discovering mechanisms involved in winterhardiness is detecting where ice is formed and how it interacts with tissues in the frozen state. Many tissues recover and change shape during thawing which prevents a clear picture of ice formation and how individual cells might have responded to this form of stress. Cryo-sectioning and related techniques, while providing valuable information, only allow a two-dimensional view of what is in fact, a three-dimensional phenomenon. In this study, an established freeze-fixation protocol was used in conjunction with histology to visualize empty spaces or voids created by ice within crowns of oat. Images of sections were aligned and background color was cleared to provide 3D visualization of voids that had formed within tissues as a result of freezing. Reconstruction in 3 dimensions revealed that ice had formed continuously in the roots but terminated at the root-shoot junction. This supports previous research that a barrier exists at the base of the crown in freezing tolerant cultivars of winter cereals. In addition, ice-induced voids within the crown were narrow and vertically inclined; they did not form large spherical shapes as had previously been suggested from two-dimensional analysis. Within apical regions of the crown, voids always formed just below the epidermis on what would eventually become the lower surface of the leaf. The 3D structure of these formations resembled a curtain with a termination point at the top of the transition zone and which extended continuously into the leaves. These results suggest that multiple mechanisms must be operative concurrently for the crown to survive. This underscores the need for a variety of approaches that includes clear and detailed observational data to fully comprehend winter survival of cereal crops. DA - 2014/10// PY - 2014/10// DO - 10.1016/j.envexpbot.2013.12.010 VL - 106 SP - 24-33 SN - 1873-7307 KW - Winter cereal KW - Crown KW - Freezing tolerance KW - Ice KW - 3D reconstruction KW - Freeze fixation KW - Histology KW - Tetrazolium ER - TY - JOUR TI - Transport of E. coli in a sandy soil as impacted by depth to water table AU - Stall, C. AU - Amoozegar, A. AU - Lindbo, D. AU - Graves, A. AU - Rashash, D. T2 - Journal of Environmental Health DA - 2014/// PY - 2014/// VL - 76 IS - 6 SP - 92-100 ER - TY - JOUR TI - RTK GPS and automatic steering for peanut digging AU - Roberson, G. T. AU - Jordan, D. L. T2 - Applied Engineering in Agriculture AB - <italic>Abstract. </italic> Peanut harvesting is a two-stage process. In the first stage, a digger-shaker-inverter implement is used to plow peanut from the ground. In the second stage, a combine is used to thresh peanut pods from the vines. Yield loss can be significant, especially during the digging stage where the implement may not be properly aligned over the rows of peanut. In this study, RTK-based automatic steering was compared to manual steering to determine the potential for reduced yield losses. In addition, peanut response to the plant growth regulator prohexadione calcium was compared to a non-treated peanut to determine if reduced yield losses were obtainable. Prohexadione calcium regulator did not improve yield significantly. However, use of RTK based automatic steering was significant, increasing harvested yield by 510 kg/ha or 11%. DA - 2014/// PY - 2014/// DO - 10.13031/aea.30.10432 VL - 30 IS - 3 SP - 405-409 ER - TY - JOUR TI - Persistence and Bioavailability of Aminocyclopyrachlor and Clopyralid in Turfgrass Clippings: Recycling Clippings for Additional Weed Control AU - Lewis, Dustin F. AU - Jeffries, Matthew D. AU - Gannon, Travis W. AU - Richardson, Robert J. AU - Yelverton, Fred H. T2 - WEED SCIENCE AB - The synthetic auxin herbicides, aminocyclopyrachlor and clopyralid, control dicotyledonous weeds in turf. Clippings of turfgrass treated with synthetic auxin herbicides have injured off-target plants exposed to herbicide-laden clippings. Labels of aminocyclopyrachlor and clopyralid recommend that clippings of treated turfgrass remain on the turf following a mowing event. Alternative uses for synthetic auxin-treated turfgrass clippings are needed because large quantities of clippings on the turf surface interfere with the functionality and aesthetics of golf courses, athletic fields, and residential turf. A white clover bioassay was conducted to determine the persistence and bioavailability of aminocyclopyrachlor and clopyralid in turfgrass clippings. Aminocyclopyrachlor and clopyralid were each applied at 79 g ae ha −1 to mature tall fescue at 56, 28, 14, 7, 3.5, and 1.75 d before clipping collection (DBCC). Clippings were collected, and the treated clippings were recycled onto adjacent white clover plots to determine herbicidal persistence and potential for additional weed control. Clippings of tall fescue treated with aminocyclopyrachlor produced a nonlinear regression pattern of response on white clover. Calculated values for 50% response (GR 50 ) for visual control, for normalized difference vegetative index (NDVI), and for reduction in harvested biomass were 20.5, 17.3, and 18.7 DBCC, respectively, 8 wk after clippings were applied. Clippings of tall fescue treated with clopyralid did not demonstrate a significant pattern for white clover control, presumably because clopyralid was applied at a less-than-label rate. The persistence and bioavailability of synthetic auxin herbicides in clippings harvested from previously treated turfgrass creates the opportunity to recycle clippings for additional weed control. DA - 2014/// PY - 2014/// DO - 10.1614/ws-d-13-00119.1 VL - 62 IS - 3 SP - 493-500 SN - 1550-2759 KW - Compost KW - mulch KW - regrassing ER - TY - JOUR TI - Patterns of simple sequence repeats in cultivated blueberries (Vaccinium section Cyanococcus spp.) and their use in revealing genetic diversity and population structure AU - Bian, Yang AU - Ballington, James AU - Raja, Archana AU - Brouwer, Cory AU - Reid, Robert AU - Burke, Mark AU - Wang, Xinguo AU - Rowland, Lisa J. AU - Bassil, Nahla AU - Brown, Allan T2 - MOLECULAR BREEDING DA - 2014/8// PY - 2014/8// DO - 10.1007/s11032-014-0066-7 VL - 34 IS - 2 SP - 675-689 SN - 1572-9788 KW - Blueberry KW - Vaccinium KW - Genetic diversity KW - SSR KW - STRUCTURE ER - TY - JOUR TI - Impacts of flocculation on sediment basin performance and design AU - Kang, J. AU - King, S. E. AU - McLaughlin, R. A. T2 - Transactions of the ASABE AB - Abstract. There is increasing interest in controlling turbidity in construction site runoff using chemical flocculant treatments. Since flocculated sediment is likely to behave much differently from untreated sediment, changes to current sediment basin designs may be appropriate. This study evaluated a system consisting of three fiber check dams in a lined ditch discharging to sediment basins that differed in their configuration. Three different basin configurations were tested with and without granular polyacrylamide (PAM) applied to the weir of each check dam: (1) standard basin with a 2:1 length to width (L/W) ratio, (2) horizontal basin with a 1:2 L/W ratio, and (3) standard basin with a rising floor toward the exit (spillway). All configurations included two porous baffles of jute/coir netting across the full width of the basin. For each treatment of PAM and basin configuration, sediment-laden stormwater flows (0.014 to 0.056 m3 s-1) were introduced to the ditch for 29 min, and water samples were collected at the ditch entrance (influent), ditch exit, and basin exit. Regardless of PAM treatment, total suspended solids (TSS) concentrations were reduced by more than 55% at the ditch exit and by up to 90% at the basin exit relative to the influent (3,700 mg L-1). The 1:2 L/W basin reduced TSS more than either of the 2:1 L/W basins without flocculation, but there was no significant difference in TSS when sediment was treated with PAM. Turbidity at the ditch exit was similar to the influent (less than 10% difference) without flocculation but was greatly reduced (>66%) with flocculation. The PAM treatment lowered turbidity further (>88%) at the basin exit and was similar among all basin configurations. The particle size distribution of flocculated sediment was shifted into coarser fractions, enhancing settling in the basin. The estimation of basin surface area requirement based on the measured particle size suggested that basins receiving flocculated sediment could be reduced in surface area and altered in configuration while improving water quality for construction site discharges. DA - 2014/// PY - 2014/// DO - 10.13031/trans.57.10652 VL - 57 IS - 4 SP - 1099-1107 ER - TY - JOUR TI - Growth under field conditions affects lignin content and productivity in transgenic Populus trichocarpa with altered lignin biosynthesis AU - Stout, Anna T. AU - Davis, Aletta A. AU - Domec, Jean-Christophe AU - Yang, Chenmin AU - Shi, Rui AU - King, John S. T2 - BIOMASS & BIOENERGY AB - This study evaluated the potential of transgenic Populus trichocarpa with antisense 4CL for reduced total lignin and sense Cald5H for increased S/G ratio in a short rotation woody cropping (SRWC) system for bioethanol production in the Southeast USA. Trees produced from tissue-culture were planted in the Coastal Plain, Piedmont, and Mountain regions of North Carolina, USA. Trees were observed for growth differences and biomass recorded for two coppices. Insoluble lignin and S/G ratio were determined by molecular beam mass spectroscopy after the second coppice. Survival, growth form, and biomass were very consistent within construct lines. Higher total lignin content and S/G ratio were positively correlated with total aboveground biomass. The low-lignin phenotype was not completely maintained in the field, with total lignin content increasing on average more than 30.0% at all sites by the second coppice The capacity to upregulate lignin in the event of environmental stress may have helped some low-lignin lines to survive. More research focused on promising construct lines in appropriate environmental conditions is needed to clarify if a significant reduction in lignin can be achieved on a plantation scale, and whether that reduction will translate into increased efficiency of enzymatic hydrolysis. DA - 2014/9// PY - 2014/9// DO - 10.1016/j.biombioe.2014.06.008 VL - 68 SP - 228-239 SN - 1873-2909 KW - Populus KW - Lignin KW - Field trial KW - Transgenic KW - Bioenergy ER - TY - JOUR TI - Flocculated sediment and runoff quality improvement by polyacrylamide AU - Kang, J. AU - King, S. E. AU - McLaughlin, R. A. AU - Wiseman, J. D. T2 - Transactions of the ASABE AB - Abstract. Increasing regulations on construction site runoff requires improved sediment and erosion control practices, including the application of polyacrylamide (PAM) to enhance turbidity reduction. We evaluated water quality improvement and particle size distribution of suspended sediments affected by various types of passive PAM dosing under simulated stormwater flows. Three straw wattles were installed in a 7% sloped channel, and six different treatments were tested individually: (1) wattle with no jute netting and no PAM, (2) solid block PAM (BPAM) after the wattle + no jute netting, (3) granular PAM (GPAM) on wattles + no jute netting, (4) wattle + jute netting with no PAM, (5) wattle + jute netting where GPAM was applied to the wattle, and (6) wattle + jute netting where GPAM was applied to the jute netting. For each treatment, three repeated turbid stormwater flows were run in the channel, and water samples were collected from the entrance (influent) and exit (effluent) of the channel. There was no turbidity reduction with wattles and/or jute netting unless PAM was introduced to the channel system. The use of GPAM reduced effluent turbidity by 58% to 67% relative to influent, with the best treatment being GPAM on jute netting. The addition of jute netting to the GPAM + wattle treatment did not improve sediment reduction but did reduce turbidity. Applying GPAM to jute netting shifted the mean particle size from 24 to 211 μm and the 10th percentile from 1.6 to 66 μm, indicating the greatly increased particle size distribution of the flocculated sediment. This study emphasizes that the passive treatment of stormwater runoff using GPAM is a very effective method of flocculating sediments in turbid water. DA - 2014/// PY - 2014/// DO - 10.13031/trans.57.10532 VL - 57 IS - 3 SP - 861-867 ER - TY - JOUR TI - Fate and transport of phosphate from an onsite wastewater system in Beaufort County, North Carolina AU - Humphrey, C. AU - O'Driscoll, M. AU - Deal, N. AU - Lindbo, D. T2 - Journal of Environmental Health DA - 2014/// PY - 2014/// VL - 76 IS - 6 SP - 28-33 ER - TY - JOUR TI - Digital Image Analysis Method for Estimation of Fusarium-Damaged Kernels in Wheat AU - Maloney, Peter V. AU - Petersen, Stine AU - Navarro, Rene A. AU - Marshall, David AU - McKendry, Anne L. AU - Costa, Jose M. AU - Murphy, J. Paul T2 - CROP SCIENCE AB - ABSTRACT Fusarium head blight (FHB) of wheat ( Triticum aestivum L.), or head scab, causes a reduction in grain yield and quality through the formation of shriveled, dull‐grey seeds called “tombstones” or Fusarium‐damaged kernels (FDK). Fusarium‐damaged kernels are commonly quantified on a percentage basis by visually separating damaged from healthy kernels following harvest, in a process that is both time consuming and labor intensive. The objective of this study was to evaluate an alternative method for quantifying FDK through the use of the digital image analysis program ImageJ. The ‘NC‐Neuse’ × ‘AGS 2000’ F 5 –derived recombinant inbred population of 172 lines and the NC‐Neuse בBess’ double haploid population of 112 lines were used in this study. NC‐Neuse and Bess were moderately resistant and AGS 2000 was susceptible to FHB. The populations were evaluated under moderate to heavy FHB epidemics in a total of five environments in North Carolina, Maryland, and Missouri with two to three replications per environment during the 2010 to 2011 and 2011 to 2012 seasons. Following hand harvest and grain processing, FDK was estimated by (i) visual separation of diseased kernels and (ii) digital image analysis using ImageJ on captured images of grain samples. The correlation between the two methods ranged from 0.72 to 0.80 over five environments. A lower correlation was observed in one environment due to cracked and broken kernels in the samples. Digital image analysis was three times faster than the visual method and estimated FDK on a larger scale per plot sample, whereas labor and time constraints limited the sample size for the visual method. Digital image analysis was consistent over samples and appears well suited as an alternative form to estimate percent of FDK in grain that is not damaged in other ways. DA - 2014/// PY - 2014/// DO - 10.2135/cropsci2013.07.0432 VL - 54 IS - 5 SP - 2077-2083 SN - 1435-0653 ER - TY - JOUR TI - Differential Physiological and Metabolic Responses to Drought Stress of Peanut Cultivars and Breeding Lines AU - Singh, Daljit AU - Collakova, Eva AU - Isleib, Thomas G. AU - Welbaum, Gregory E. AU - Tallury, Shyam P. AU - Balota, Maria T2 - CROP SCIENCE AB - ABSTRACT The Virginia–Carolina region is the most important peanut ( Arachis hypogaea L.) production region for the large‐seeded, virginia‐type peanut in the United States, but 85% of the production is rainfed and predisposed to water deficit stress. The mechanisms virginia‐type peanut uses in response to drought stress are poorly understood. We evaluated several physiological and metabolic characteristics and their relationship with pod yield in eight virginia‐type cultivars and advanced breeding lines in rainfed and irrigated field trials in 2011 and 2012. Each year, evaluations were performed at three sampling dates in conjunction with growth stages beginning flower, pod, and seed. Significant ( p ≤ 0.05) genotypic variation in membrane injury, chlorophyll fluorescence ( F v / F m ratio), and relative levels of metabolites and lipid‐derived fatty acids was observed in response to water regime and sampling time. In general, in both years, the F v / F m ratio, organic acids, and fatty acids decreased in rainfed vs. irrigated plants, while the relative levels of sugar and cyclic polyols increased. Because higher levels of organic acids and lower levels of sugars were associated ( p ≤ 0.05) with higher pod yield, we conclude that natural stress responses rather than adaptive mechanisms to drought prevailed for the genotypes used in this study. Based on its minimal changes in the F v / F m ratio and metabolite levels of the rainfed vs. irrigated plants, line SPT 06‐07 showed improved tolerance to water deficit stress; this line can be an important source for drought tolerance improvement of the virginia‐type peanut. DA - 2014/// PY - 2014/// DO - 10.2135/cropsci2013.09.0606 VL - 54 IS - 5 SP - 2262-2274 SN - 1435-0653 ER - TY - JOUR TI - Cultural Strategies for Managing Weeds and Soil Moisture in Cover Crop Based No-Till Soybean Production AU - Wells, M. Scott AU - Reberg-Horton, S. Chris AU - Mirsky, Steven B. T2 - WEED SCIENCE AB - A four site-year study was conducted in North Carolina to evaluate the effects of soybean planting timing and row spacing on soil moisture, weed density, soybean lodging, and yield in a cover crop-based no-till organic soybean production system. Soybean planting timing included roll-kill/planting and roll-kill/delayed planting where soybean planting occurred either on the same day or approximately 2 wk later, respectively. Soybean row spacing included 19, 38, and 76 cm, and all treatments included a weedy check and weed-free treatment. Rye biomass production averaged above 10,000 kg ha −1 dry matter, which resulted in good weed control across all sites. Despite having good weed control throughout all treatments, weed coverage was highest in the 76-cm row-space treatment when compared to both the 19-cm and 38-cm row spacing in two of the four site-years. Soybean lodging is a potential consequence of no-till planting of soybeans in high residue mulches, and of the three row spacings, the 19-cm spacing exhibited the greatest incidence of lodging. Row spacing also influenced soybean yield; the 19- and 38-cm row spacing out yielded the 76-cm spacing by 10%. Soil volumetric water content (VWC) was higher in the cereal rye mulch treatments compared to the no rye checks. Furthermore, delaying soybean planting lowered soil water evaporation. However, the increased soil VWC in the rolled-rye treatment did not translate into increased soybean yield. The rolled-rye treatment exhibited significant (P < 0.01) increases in soil VWC when compared to the no-rye treatment at three of the four site-years. These results highlight planting date flexibility and potential risk to lodging that producers face when no-till planting organic soybeans. DA - 2014/// PY - 2014/// DO - 10.1614/ws-d-13-00142.1 VL - 62 IS - 3 SP - 501-511 SN - 1550-2759 KW - Cereal rye cover crop KW - conservation-tillage KW - no-till KW - organic soybean KW - roll-kill KW - roller-crimper KW - rotational no-till KW - soil moisture ER - TY - JOUR TI - Yield Results and Stability Analysis from the Sorghum Regional Biomass Feedstock Trial AU - Gill, John R. AU - Burks, Payne S. AU - Staggenborg, Scott A. AU - Odvody, Gary N. AU - Heiniger, Ron W. AU - Macoon, Bisoondat AU - Moore, Ken J. AU - Barrett, Michael AU - Rooney, William L. T2 - BIOENERGY RESEARCH DA - 2014/9// PY - 2014/9// DO - 10.1007/s12155-014-9445-5 VL - 7 IS - 3 SP - 1026-1034 SN - 1939-1242 KW - Sorghum KW - Bioenergy KW - Ethanol KW - Regional biomass feedstock trial ER - TY - JOUR TI - Predominant bacterial and fungal assemblages in agricultural soils during a record drought/heat wave and linkages to enzyme activities of biogeochemical cycling AU - Acosta-Martinez, V. AU - Cotton, J. AU - Gardner, T. AU - Moore-Kucera, J. AU - Zak, J. AU - Wester, D. AU - Cox, S. T2 - APPLIED SOIL ECOLOGY AB - Identification of microbial assemblages predominant under natural extreme climatic events will aid in our understanding of the resilience and resistance of microbial communities to climate change. From November 2010 to August 2011, the Southern High Plains (SHP) of Texas, USA, received only 39.6 mm of precipitation (vs. the historical average of 373 mm) and experienced the three hottest months (June–August 2011) since record keeping began in 1911. The objective of this study was to characterize soil bacterial (16 S rRNA gene) and fungal (internal transcribed spacer 1–4, ITS1-ITS4) species distribution and diversity via pyrosequencing during the peak of the drought/heat wave in July 2011 and when the Drought Index and temperatures were lower in March 2012. Samples were collected from two different soil types (loam and sandy loam) under two different dryland cropping histories (monoculture vs. rotation). Fungal Diversity Indexes were significantly higher after the drought/heat wave while Bacterial Indexes were similar. Bacterial phyla distribution in July 2011 was characterized by lower relative abundance of Acidobacteriaand Verrucomicrobia, and greater relative abundance of Proteobacteria, Chloroflexi, Actinobacteria and Nitrospirae than March 2012 samples. Further grouping of pyrosequencing data revealed approximately equal relative proportions of Gram positive (G+) and Gram negative (G−) bacteria in July 2011, while G− bacteria predominated in March 2012. Fungal class Dothideomycetes was approximately two times greater in July 2011 than in March 2012, while the class Sordariomycetes and a group of unidentified OTUs from Ascomycota increased from July 2011 to March 2012. Microbial community composition was less influenced by management history than by the difference in climatic conditions between the sampling times. Correspondence analysis identified assemblages of fungal and bacterial taxa associated with greater enzyme activities (EAs) of C, N, or P cycling found during the drought/heat wave. Microbial assemblages associated with arylsulfatase activity (key to S cycling), which increased after the drought/heat wave, were identified (Streptomyces parvisporogenes, Terrimonas ferruginea and Syntrophobacter sp.) regardless of the soil and management history. The distinct microbial composition found in July 2011 may represent assemblages essential to maintaining ecosystem function during extreme drought and intense heat waves in semiarid agroecosystems. DA - 2014/12// PY - 2014/12// DO - 10.1016/j.apsoil.2014.06.005 VL - 84 SP - 69-82 SN - 1873-0272 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-84904319460&partnerID=MN8TOARS KW - Climate change KW - Pyrosequencing KW - Enzyme activities KW - Microbial diversity KW - Soil microbial community ER - TY - JOUR TI - Penman's sink-strength model as an improved approach to estimating plant canopy transpiration AU - Sinclair, Thomas R. AU - Wherley, Benjamin G. AU - Dukes, Michael D. AU - Cathey, Sarah E. T2 - AGRICULTURAL AND FOREST METEOROLOGY AB - The Penman energy balance equation has become a common approach to estimating the evaporation of plant canopies. Unfortunately, implementation of the energy balance equation requires various assumptions and empiricisms, including “crop coefficients”, so that in practice the Penman equation is used as a framework in which to apply empirical approximations. These limitations are reviewed in this paper. An alternative to the energy balance approach suggested by Penman was a “sink strength” model in which the gradient in vapor pressure was considered the prime driver of plant water loss. In this paper, the sink strength model is developed for determining plant canopy transpiration based on explicitly defined properties of the plants. The key variables are the carbon assimilation pathway of photosynthesis and the biochemical composition of the plant material being synthesized. These two parameters define the transpiration efficiency coefficient and radiation use efficiency that are required in the calculation of transpiration. Also, it is necessary to define a weighted vapor pressure gradient for transpiration when making estimates of the amount of transpiration on a daily basis. The derived expression of the sink strength model was used to compare predicted transpiration with measured values of four turf grass species measured over three years. A close linear correlation was observed for all grasses (P < 0.0001). However, there was an indication that the grasses may vary slightly in their radiation use efficiencies, which with measurement of photosynthetic capacity would further improve the predicted transpiration rates. The ability to directly compute transpiration from explicitly defined variables based on plant traits offers an attractive alternative to the Penman energy balance approach. DA - 2014/10/15/ PY - 2014/10/15/ DO - 10.1016/j.agrformet.2014.06.012 VL - 197 SP - 136-141 SN - 1873-2240 KW - Penman equation KW - Transpiration KW - Turfgrass KW - Vapor pressure deficit ER - TY - JOUR TI - POSTEMERGENCE CONTROL OF MICROSTEGIUM VIMINEUM ON RIPARIAN RESTORATION SITES WITH AQUATIC-USE REGISTERED HERBICIDES AU - Hall, Karen R. AU - Spooner, Jean AU - Richardson, Robert J. AU - Hoyle, Steve T. AU - Frederick, Douglas J. T2 - JOURNAL OF THE AMERICAN WATER RESOURCES ASSOCIATION AB - Abstract Microstegium vimineum is an invasive grass introduced from Asia that has spread throughout riparian areas of the eastern United States threatening native riparian vegetation. Postemergence ( POST ) herbicides registered for aquatic use were evaluated for control of M. vimineum on two riparian restoration sites in the Piedmont and Upper Coastal Plain of North Carolina. This study found that standard and lower than standard rates of diquat, fluridone, flumioxazin, glyphosate, imazamox, and imazapyr reduced weed stem density and biomass at 6 and 30 weeks after treatment ( WAT ). Both rates of bispyribac and penoxsulam provided less control of M. vimineum . Visual ratings showed both rates of diquat, flumioxazin, imazamox, and imazapyr controlled 63‐100% of M. vimineum at 6 WAT and 84‐100% at 30 WAT . Fluridone and glyphosate provided slightly less control. Bispyribac and penoxsulam treatments provided less control at 6 and 30 WAT compared to the other treatments. Plots treated with both rates of diquat, flumioxazin, imazamox, and imazapyr were nearly devoid of all vegetation at 30 WAT . Recommendations include POST application of lower than standard rates of diquat, flumioxazin, fluridone, glyphosate, imazamox, and imazapyr on riparian restoration sites infested with M. vimineum . Immediate vegetation management measures including temporary and permanent plant cover should be employed on treated sites where weeds are completely eradicated to prevent erosion. DA - 2014/6// PY - 2014/6// DO - 10.1111/jawr.12210 VL - 50 IS - 3 SP - 533-542 SN - 1752-1688 KW - herbicides KW - invasive plant KW - exotic plant control KW - stiltgrass KW - Microstegium vimineum KW - restoration KW - streams KW - riparian ecology ER - TY - JOUR TI - Measuring Near-Surface Soil Thermal Properties with the Heat-Pulse Method: Correction of Ambient Temperature and Soil-Air Interface Effects AU - Zhang, Xiao AU - Heitman, Joshua AU - Horton, Robert AU - Ren, Tusheng T2 - SOIL SCIENCE SOCIETY OF AMERICA JOURNAL AB - Large temperature gradients and proximity to the soil–air interface affect the measurement accuracy of thermal properties with the heat‐pulse probe (HPP). The objective of this study is to improve the HPP methodology for measuring soil heat capacity ( C ) and thermal conductivity (λ) in the surface soil layer by reducing the effects of ambient temperature variation and the soil–air interface. Thermal properties of eight soil layers (0–6, 2–6, 6–12, 12–18, 18–24, 24–30, 30–36, and 36–42 mm) were measured with the HPP in a loamy sand soil in two experiments with varying moisture conditions. Results were compared with values estimated with the de Vries models. Temperature drift caused by natural warming and cooling was removed from the observed trend of ambient temperature change with time. The influence of the soil–air interface was taken into account with a new solution using pulsed infinite line source theory with adiabatic boundary conditions. When ambient temperature change was considered, the HPP were capable of providing reasonable thermal property results at soil depths greater than 6 mm. For the 0‐ to 6‐mm depth layer, the HPP signals were affected simultaneously by ambient temperature drift and the soil‐air interface, and mixed scenarios were produced. Around midday, the HPP temperature by time curves were distorted so seriously that the effect of ambient temperature drift could not be removed. At other times, large errors were observed in the estimated C and λ data, even when ambient temperature drift was removed. When the effect of the soil–air interface was accounted for, however, C and λ measurement accuracies in the 0‐ to 6‐mm layer were improved significantly. The RMSE of C was reduced from 0.43 MJ m −3 °C −1 to 0.29 MJ m −3 °C −1 in Exp. 1, and from 0.52 MJ m −3 °C −1 to 0.34 MJ m −3 °C −1 in Exp. 2. Significant error reduction was also observed in λ measurements. Thus, to obtain accurate field measurements of shallow soil thermal properties, the ambient temperature drift and the impact of the soil–air interface must be properly taken into account. DA - 2014/// PY - 2014/// DO - 10.2136/sssaj2014.01.0014 VL - 78 IS - 5 SP - 1575-1583 SN - 1435-0661 ER - TY - JOUR TI - Invasive populations of elephantgrass differ in morphological and growth characteristics from taxa selected for biomass production AU - Sollenberger, L.E. AU - Woodard, K.R. AU - Vendramini, J.M.B. AU - Erickson, J.E. AU - Langeland, K.A. AU - Mullenix, M.K. AU - Na, C. AU - Castillo, M.S. AU - Gallo, M. AU - Chase, C.D. AU - López, Y. T2 - Bioenergy Research DA - 2014/// PY - 2014/// DO - 10.1007/s12155-014-9478-9 VL - 7 IS - 4 SP - 1382-1391 SN - 1939-1242 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-84912120918&partnerID=MN8TOARS KW - Pennisetum purpureum KW - Napiergrass KW - Bioenergy grasses KW - Weed assessment KW - Invasiveness ER - TY - JOUR TI - Inception and Magnitude of Subsurface Evaporation for a Bare Soil with Natural Surface Boundary Conditions AU - Deol, Pukhraj K. AU - Heitman, Joshua L. AU - Amoozegar, Aziz AU - Ren, Tusheng AU - Horton, Robert T2 - SOIL SCIENCE SOCIETY OF AMERICA JOURNAL AB - A dry surface layer (DSL) forms when wet soil is exposed to the sun; development of a DSL coincides with a shift between surface and subsurface evaporation. There remains debate as to when this shift from surface to subsurface evaporation occurs relative to the timing of the shift between potential and falling‐rate evaporation. We performed a field experiment to investigate the onset of subsurface evaporation, development of the DSL, and the extent of the evaporation zone. Our objective was to determine the timing of the onset of subsurface evaporation with respect to decline in evaporation rates. We estimated total (surface plus subsurface) and subsurface soil evaporation rates using microlysimeter (water mass balance) and sensible heat balance (SHB) approaches, respectively, for a bare loamy sand soil under natural wetting and drying cycles. Results showed that the onset of subsurface evaporation coincided with the beginning of falling‐rate evaporation. The evaporation zone extended into the subsurface when evaporation rates fell below the potential rate but were still as high as 50% of potential evaporation. Over a 5‐d drying event, estimated evaporation zones were as deep as 4 to 9 mm, and the estimated DSL had a maximum depth of approximately 6 mm. A low soil water content‐dependent albedo was observed when evaporation occurred at potential rates, but albedo increased as evaporation rates declined. Data from the intensive observation period suggest that this increase in albedo corresponded to formation of a DSL and onset of subsurface evaporation. Overall, surface drying and formation of a DSL appeared to be a dominant process for this coarse‐texture soil exposed to ambient boundary conditions, even as evaporation rates remained relatively high (0.3 mm h −1 ). DA - 2014/// PY - 2014/// DO - 10.2136/sssaj2013.12.0520 VL - 78 IS - 5 SP - 1544-1551 SN - 1435-0661 ER - TY - JOUR TI - Golf course irrigation systems' distribution uniformity affects soil moisture variability AU - Miller, G. L. AU - Dukes, M. D. AU - Pressler, N. D. T2 - European Journal of Horticultural Science DA - 2014/// PY - 2014/// VL - 79 IS - 3 SP - 135-141 ER - TY - JOUR TI - GROUNDWATER NITRATE CONCENTRATION REDUCTIONS IN A RIPARIAN BUFFER ENROLLED IN THE NC CONSERVATION RESERVE ENHANCEMENT PROGRAM AU - Wiseman, Jacob D. AU - Burchell, Michael R. AU - Grabow, Garry L. AU - Osmond, Deanna L. AU - Messer, T. L. T2 - JOURNAL OF THE AMERICAN WATER RESOURCES ASSOCIATION AB - Abstract Riparian buffers have been used for many years as a best management practice to decrease the effects of nonpoint pollution from watersheds. The NC Conservation Reserve Enhancement Program ( NC CREP ) has established buffers to treat groundwater nitrate‐nitrogen ( NO 3 − ‐N) from agricultural sources in multiple river basins. A maturing 46 m wide riparian buffer enrolled in NC CREP was studied to determine its effectiveness in reducing groundwater NO 3 − ‐N concentrations from a cattle pasture fertilized with poultry litter. Three monitoring blocks that included groundwater quality wells, water table wells, and soil redox probes, were established in the buffer. NO 3 − ‐N concentrations decreased significantly across the buffer in all of the monitoring blocks with mean reductions of 76‐92%. Many biological processes, including denitrification and plant uptake, may have been responsible for the observed NO 3 − ‐N reductions but could not be differentiated in this study. However, mean reductions in Cl − concentrations ranged from 48‐65% through the blocks, which indicated that dilution was an important factor in observed NO 3 − ‐N reductions. These findings should be carefully considered for future buffer enrollments when assigning nitrogen removal credits. DA - 2014/6// PY - 2014/6// DO - 10.1111/jawr.12209 VL - 50 IS - 3 SP - 653-664 SN - 1752-1688 KW - riparian buffer KW - CREP KW - nitrate KW - denitrification KW - dilution KW - nitrogen ER - TY - JOUR TI - Field Test and Sensitivity Analysis of a Sensible Heat Balance Method to Determine Soil Ice Contents AU - Kojima, Yuki AU - Heitman, Joshua L. AU - Flerchinger, Gerald N. AU - Ren, Tusheng AU - Ewing, Robert P. AU - Horton, Robert T2 - Vadose Zone Journal AB - Soil ice content impacts winter vadose zone hydrology. It may be possible to estimate changes in soil ice content with a sensible heat balance (SHB) method, using measurements from heat pulse (HP) sensors. Feasibility of the SHB method is unknown because of difficulties in measuring soil thermal properties in partially frozen soils. The objectives of this study were (i) to examine the SHB method for determining in situ ice content, and (ii) to evaluate the required accuracy of HP sensors for use in the SHB method. Heat pulse sensors were installed in a bare field to measure soil temperatures and thermal properties during freezing and thawing events. In situ soil ice contents were determined at 60‐min intervals with SHB theory. Sensitivity of the SHB method to temperature, heat capacity, thermal conductivity, and time step size was analyzed based on numerically produced soil freezing and thawing events. The in situ ice contents determined with the SHB method were sometimes unrealistically large or even negative. Thermal conductivity accuracy and time step size were the key factors contributing to SHB errors, while temperature and heat capacity accuracy had less influence. Ice content estimated with a 15‐min SHB time step was more accurate than that estimated with a 60‐min time step. Sensitivity analysis indicated that measurement errors in soil temperature and thermal conductivity should be less than ±0.05°C and ±20%, respectively, but the error in the soil heat capacity could vary by ±50%. Thus, improving the accuracy of thermal conductivity measurements and using short time steps are required to accurately estimate soil ice contents with the SHB method. DA - 2014/9// PY - 2014/9// DO - 10.2136/vzj2014.04.0036 VL - 13 IS - 9 SP - vzj2014.04.0036 J2 - Vadose Zone Journal LA - en OP - SN - 1539-1663 UR - http://dx.doi.org/10.2136/vzj2014.04.0036 DB - Crossref ER - TY - JOUR TI - Dislodgeable 2,4-D from athletic field turfgrass AU - Gannon, T. W. AU - Jeffries, M. D. T2 - European Journal of Horticultural Science DA - 2014/// PY - 2014/// VL - 79 IS - 3 SP - 116-122 ER - TY - JOUR TI - Diffuse-reflectance mid-infrared spectroscopy reveals chemical differences in soil organic matter carried in different size wind eroded sediments AU - Padilla, Julio E. AU - Calderon, Francisco J. AU - Acosta-Martinez, Veronica AU - Van Pelt, Scott AU - Gardner, Terrence AU - Baddock, Matthew AU - Zobeck, Ted M. AU - Noveron, Juan C. T2 - AEOLIAN RESEARCH AB - Soil organic matter (SOM) is essential for soil water holding capacity, aggregation, and biodiversity. Little information is available regarding the carbon (C) functional groups carried away in wind eroded sediments away from the source soil. Mid-infrared (MidIR) spectroscopy was used on wind tunnel-blown sediments eroded from a loam soil during the fallow period of different cropping systems and tillage managements in Akron, Colorado. The soil was managed as fallow-winter wheat (Triticum aestivum L.) under conventional tillage (F–Wct) or no tillage (F–Wnt) and fallow–wheat–corn under no tillage (F–W–Cnt). Two wind eroded sediments were evaluated: fine dust (<35 μm mean dia.) and saltation-size material (<175 μm mean dia.). Our study showed that there is a partition of C groups within wind eroded sediments of different sizes and that they can reflect the tillage management history of soil. The fine dust had higher levels of aliphatic CH (2930 cm−1), and clays (3690–3620 cm−1). The saltation-sized material showed higher absorbance for quartz from 2000–1800 cm−1 and reduced absorbance from 1250–1050 cm−1. Both wind eroded sediments showed higher absorbance for –OH/NH groups and aliphatic CH from no-till soil. Finer dust sediments, which travel greater distances from the source soil than saltation size material, can carry away higher levels of aliphatic-carbon compounds and clays with potential negative impacts on SOM quantity and quality, and consequently the sustainability of these agroecosystems. DA - 2014/12// PY - 2014/12// DO - 10.1016/j.aeolia.2014.06.003 VL - 15 SP - 193-201 SN - 2212-1684 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-84908288231&partnerID=MN8TOARS KW - Wind erosion KW - MidIR KW - Soil organic matter KW - Cropping systems KW - Tillage KW - Soil quality ER - TY - JOUR TI - Differential expression of a novel gene EaF82a in green and yellow sectors of variegated Epipremnum aureum leaves is related to uneven distribution of auxin AU - Hung, Chiu-Yueh AU - Umstead, Makendra L. AU - Chen, Jianjun AU - Holliday, Bronwyn M. AU - Kittur, Farooqahmed S. AU - Henny, Richard J. AU - Burkey, Kent O. AU - Xie, Jiahua T2 - PHYSIOLOGIA PLANTARUM AB - EaF82 , a gene identified in previous studies of the variegated plant Epipremnum aureum , exhibited a unique expression pattern with greater transcript abundance in yellow sectors than green sectors of variegated leaves, but lower abundance in regenerated pale yellow plants than in green plants derived from leaf tissue culture. Studies of its full‐length cDNA and promoter region revealed two members with only the EaF82a expressed. Immunoblotting confirmed that EaF82a encodes a 12 kDa protein and its accumulation consistent with its gene expression patterns in different color tissues. Transient expression of EaF82a‐sGFP fusion proteins in protoplasts showed that EaF82a seems to be present in the cytosol as unidentified spots. Sequence motif search reveals a potential auxin responsive element in promoter region. Using transgenic Arabidopsis seedlings carrying EaF82a promoter driving the bacterial uid A ( GUS ) gene, an increased GUS activity was observed when IAA (indole‐3‐acetic acid) concentration was elevated. In E. aureum , EaF82a is more abundant at the site where axillary buds emerge and at the lower side of bending nodes where more IAA accumulates relative to the upper side. The measurement of endogenous IAA levels in different color tissues revealed the same pattern of IAA distribution as that of EaF82a expression, further supporting that EaF82a is an IAA responsive gene. EaF82a expression in etiolated transgenic Arabidopsis seedlings responded to IAA under the influence of light suggesting a microenvironment of uneven light condition affects the EaF82a transcript levels and protein accumulation in variegated leaves. DA - 2014/12// PY - 2014/12// DO - 10.1111/ppl.12219 VL - 152 IS - 4 SP - 749-762 SN - 1399-3054 ER - TY - JOUR TI - Weed Control with Liquid Carbon Dioxide in Established Turfgrass AU - Mahoney, Denis J. AU - Jeffries, Matthew D. AU - Gannon, Travis W. T2 - WEED TECHNOLOGY AB - In recent years, increasing implementation of biological, cultural, and mechanical weed-control methods is desired; however, many of these techniques are not viable in established turfgrass systems. The use of freezing or frost for weed control has previously been researched; however, is not well elucidated. Field and greenhouse experiments were conducted to evaluate liquid carbon dioxide (LCD) for weed control in established turfgrass systems. LCD was applied with handheld prototypes that were modified to reduce the amount of LCD required for weed control. Common annual and perennial turfgrass weeds included common chickweed, corn speedwell, goosegrass, large crabgrass, smooth crabgrass, Virginia buttonweed, and white clover. Turfgrass tolerance was evaluated on the following species: hybrid bermudagrass, Kentucky bluegrass, tall fescue, and zoysiagrass. The final modification allowed for lower output (0.5 kg LCD min −1 ) when compared with the initial prototype (3 kg LCD min −1 ). In general, weed control increased as LCD increased. When comparing weed species life cycles, annuals were controlled more than perennials (P < 0.0001) at 14 and 28 d after treatment (DAT). Further, exposure time affected control as white clover, Virginia buttonweed, and large crabgrass control was greater (18, 14, 15%, respectively) from the longer exposure time (30 vs. 15 s), although equivalent amounts of LCD (30 kg m −2 ) were applied. These data also suggest that plant maturity affects control, as large crabgrass control in one- to two- and three- to four-leaf stages (> 90%) was greater than in the one- to two-tiller stage (< 70%). Turfgrass injury at 7 DAT was unacceptable (> 30%) on all species, but declined to 0% by 28 DAT. These data suggest that LCD has the potential to provide an alternative for weed control of select species where synthetic herbicides are not allowed or desired. DA - 2014/// PY - 2014/// DO - 10.1614/wt-d-14-00003.1 VL - 28 IS - 3 SP - 560-568 SN - 1550-2740 KW - Nonchemical weed control KW - turf ER - TY - JOUR TI - Spatial and diurnal below canopy evaporation in a desert vineyard: Measurements and modeling AU - Kool, D. AU - Ben-Gal, A. AU - Agam, N. AU - Simunek, J. AU - Heitman, J. L. AU - Sauer, T. J. AU - Lazarovitch, N. T2 - WATER RESOURCES RESEARCH AB - Abstract Evaporation from the soil surface ( E ) can be a significant source of water loss in arid areas. In sparsely vegetated systems, E is expected to be a function of soil, climate, irrigation regime, precipitation patterns, and plant canopy development and will therefore change dynamically at both daily and seasonal time scales. The objectives of this research were to quantify E in an isolated, drip‐irrigated vineyard in an arid environment and to simulate below canopy E using the HYDRUS (2‐D/3‐D) model. Specific focus was on variations of E both temporally and spatially across the inter‐row. Continuous above canopy measurements, made in a commercial vineyard, included evapotranspiration, solar radiation, air temperature and humidity, and wind speed and direction. Short‐term intensive measurements below the canopy included actual and potential E and solar radiation along transects between adjacent vine‐rows. Potential and actual E below the canopy were highly variable, both diurnally and with distance from the vine‐row, as a result of shading and distinct wetted areas typical to drip irrigation. While the magnitude of actual E was mostly determined by soil water content, diurnal patterns depended strongly on position relative to the vine‐row due to variable shading patterns. HYDRUS (2‐D/3‐D) successfully simulated the magnitude, diurnal patterns, and spatial distribution of E , including expected deviations as a result of variability in soil saturated hydraulic conductivity. DA - 2014/8// PY - 2014/8// DO - 10.1002/2014wr015409 VL - 50 IS - 8 SP - 7035-7049 SN - 1944-7973 KW - evaporation KW - HYDRUS (2-D KW - 3-D) KW - diurnal variability KW - spatial variability KW - evapotranspiration partitioning KW - potential evaporation ER - TY - JOUR TI - Soil peroxidase regulates organic matter decomposition through improving the accessibility of reducing sugars and amino acids AU - Tian, Lei AU - Shi, Wei T2 - BIOLOGY AND FERTILITY OF SOILS DA - 2014/7// PY - 2014/7// DO - 10.1007/s00374-014-0903-1 VL - 50 IS - 5 SP - 785-794 SN - 1432-0789 KW - Peroxidase KW - Phenolics KW - Reducing sugars KW - Amino acids KW - Soil enzyme activity KW - Soil C and N mineralization ER - TY - JOUR TI - Sealing Rice Field Boundaries in Bangladesh: A Pilot Study Demonstrating Reductions in Water Use, Arsenic Loading to Field Soils, and Methane Emissions from Irrigation Water AU - Neumann, Rebecca B. AU - Pracht, Lara E. AU - Polizzotto, Matthew L. AU - Badruzzaman, A. Borhan M. AU - Ali, M. Ashraf T2 - ENVIRONMENTAL SCIENCE & TECHNOLOGY AB - Irrigation of rice fields in Bangladesh with arsenic-contaminated and methane-rich groundwater loads arsenic into field soils and releases methane into the atmosphere. We tested the water-savings potential of sealing field bunds (raised boundaries around field edges) as a way to mitigate these negative outcomes. We found that, on average, bund sealing reduced seasonal water use by 52 ± 17% and decreased arsenic loading to field soils by 15 ± 4%; greater savings in both water use and arsenic loading were achieved in fields with larger perimeter-to-area ratios (i.e., smaller fields). Our study is the first to quantify emission of methane from irrigation water in Bangladesh, a currently unaccounted-for methane source. Irrigation water applied to unsealed fields at our site emits 18 to 31 g of methane per square-meter of field area per season, potentially doubling the atmospheric input of methane from rice cultivation. Bund sealing reduced the emission of methane from irrigation water by 4 to 19 g/m2. While the studied outcomes of bund sealing are positive and compelling, widespread implementation of the technique should consider other factors, such as effect on yields, financial costs, and impact on the hydrologic system. We provide an initial and preliminary assessment of these implementation factors. DA - 2014/8/19/ PY - 2014/8/19/ DO - 10.1021/es500338u VL - 48 IS - 16 SP - 9632-9640 SN - 1520-5851 ER - TY - JOUR TI - Molecular Modeling and Imaging of Initial Stages of Cellulose Fibril Assembly: Evidence for a Disordered Intermediate Stage AU - Haigler, Candace H. AU - Grimson, Mark J. AU - Gervais, Julien AU - Le Moigne, Nicolas AU - Höfte, Herman AU - Monasse, Bernard AU - Navard, Patrick T2 - PLoS ONE AB - The remarkable mechanical strength of cellulose reflects the arrangement of multiple β-1,4-linked glucan chains in a para-crystalline fibril. During plant cellulose biosynthesis, a multimeric cellulose synthesis complex (CSC) moves within the plane of the plasma membrane as many glucan chains are synthesized from the same end and in close proximity. Many questions remain about the mechanism of cellulose fibril assembly, for example must multiple catalytic subunits within one CSC polymerize cellulose at the same rate? How does the cellulose fibril bend to align horizontally with the cell wall? Here we used mathematical modeling to investigate the interactions between glucan chains immediately after extrusion on the plasma membrane surface. Molecular dynamics simulations on groups of six glucans, each originating from a position approximating its extrusion site, revealed initial formation of an uncrystallized aggregate of chains from which a protofibril arose spontaneously through a ratchet mechanism involving hydrogen bonds and van der Waals interactions between glucose monomers. Consistent with the predictions from the model, freeze-fracture transmission electron microscopy using improved methods revealed a hemispherical accumulation of material at points of origination of apparent cellulose fibrils on the external surface of the plasma membrane where rosette-type CSCs were also observed. Together the data support the possibility that a zone of uncrystallized chains on the plasma membrane surface buffers the predicted variable rates of cellulose polymerization from multiple catalytic subunits within the CSC and acts as a flexible hinge allowing the horizontal alignment of the crystalline cellulose fibrils relative to the cell wall. DA - 2014/4/10/ PY - 2014/4/10/ DO - 10.1371/journal.pone.0093981 VL - 9 IS - 4 SP - e93981 J2 - PLoS ONE LA - en OP - SN - 1932-6203 UR - http://dx.doi.org/10.1371/journal.pone.0093981 DB - Crossref ER - TY - JOUR TI - Insights into the effects of long-term artificial selection on seed size in maize AU - Hirsch, C.N. AU - Flint-Garcia, S.A. AU - Beissinger, T.M. AU - Eichten, S.R. AU - Deshpande, S. AU - Barry, K. AU - McMullen, M.D. AU - Holland, James AU - Buckler, E.S. AU - Buckler, E.S. AU - Buell, C. Robin AU - Leon, N. AU - Kaeppler, S.M. T2 - Genetics AB - Abstract Grain produced from cereal crops is a primary source of human food and animal feed worldwide. To understand the genetic basis of seed-size variation, a grain yield component, we conducted a genome-wide scan to detect evidence of selection in the maize Krug Yellow Dent long-term divergent seed-size selection experiment. Previous studies have documented significant phenotypic divergence between the populations. Allele frequency estimates for ∼3 million single nucleotide polymorphisms (SNPs) in the base population and selected populations were estimated from pooled whole-genome resequencing of 48 individuals per population. Using FST values across sliding windows, 94 divergent regions with a median of six genes per region were identified. Additionally, 2729 SNPs that reached fixation in both selected populations with opposing fixed alleles were identified, many of which clustered in two regions of the genome. Copy-number variation was highly prevalent between the selected populations, with 532 total regions identified on the basis of read-depth variation and comparative genome hybridization. Regions important for seed weight in natural variation were identified in the maize nested association mapping population. However, the number of regions that overlapped with the long-term selection experiment did not exceed that expected by chance, possibly indicating unique sources of variation between the two populations. The results of this study provide insights into the genetic elements underlying seed-size variation in maize and could also have applications for other cereal crops. DA - 2014/// PY - 2014/// DO - 10.1534/genetics.114.167155 VL - 198 IS - 1 SP - 409- UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-84907998638&partnerID=MN8TOARS ER - TY - JOUR TI - Genome-Wide Association Study Reveals Novel Quantitative Trait Loci Associated with Resistance to Multiple Leaf Spot Diseases of Spring Wheat AU - Gurung, Suraj AU - Mamidi, Sujan AU - Bonman, J. Michael AU - Xiong, Mai AU - Brown-Guedira, Gina AU - Adhikari, Tika B. T2 - PLOS ONE AB - Accelerated wheat development and deployment of high-yielding, climate resilient, and disease resistant cultivars can contribute to enhanced food security and sustainable intensification. To facilitate gene discovery, we assembled an association mapping panel of 528 spring wheat landraces of diverse geographic origin for a genome-wide association study (GWAS). All accessions were genotyped using an Illumina Infinium 9K wheat single nucleotide polymorphism (SNP) chip and 4781 polymorphic SNPs were used for analysis. To identify loci underlying resistance to the major leaf spot diseases and to better understand the genomic patterns, we quantified population structure, allelic diversity, and linkage disequilibrium. Our results showed 32 loci were significantly associated with resistance to the major leaf spot diseases. Further analysis identified QTL effective against major leaf spot diseases of wheat which appeared to be novel and others that were previously identified by association analysis using Diversity Arrays Technology (DArT) and bi-parental mapping. In addition, several identified SNPs co-localized with genes that have been implicated in plant disease resistance. Future work could aim to select the putative novel loci and pyramid them in locally adapted wheat cultivars to develop broad-spectrum resistance to multiple leaf spot diseases of wheat via marker-assisted selection (MAS). DA - 2014/9/30/ PY - 2014/9/30/ DO - 10.1371/journal.pone.0108179 VL - 9 IS - 9 SP - SN - 1932-6203 ER - TY - JOUR TI - Genes Conferring Sensitivity to Stagonospora nodorum Necrotrophic Effectors in Stagonospora Nodorum Blotch-Susceptible US Wheat Cultivars AU - Bertucci, Matthew AU - Brown-Guedira, Gina AU - Murphy, J. Paul AU - Cowger, Christina T2 - PLANT DISEASE AB - Stagonospora nodorum is a necrotrophic fungal pathogen that causes Stagonospora nodorum blotch (SNB), a yield- and quality-reducing disease of wheat. S. nodorum produces a set of necrotrophic effectors (NEs) that interact with the products of host sensitivity genes to cause cell death and increased susceptibility to disease. The focus of this study was determination of NE sensitivity among 25 winter wheat cultivars, many of them from the southeastern United States, that are susceptible to SNB, as well as the moderately resistant ‘NC-Neuse’. Thirty-three isolates of S. nodorum previously collected from seven southeastern U.S. states were cultured for NE production, and the culture filtrates were used in an infiltration bioassay. Control strains of Pichia pastoris that expressed SnToxA, SnTox1, or SnTox3 were also used. All SNB-susceptible cultivars were sensitive to at least one NE, while NC-Neuse was insensitive to all NEs tested. Among the sensitive lines, 32% contained sensitivity gene Tsn1 and 64% contained sensitivity gene Snn3. None were sensitive to SnTox1. Additionally, 10 molecular markers for sensitivity genes Tsn1, Snn1, Snn2, and Snn3 were evaluated for diagnostic potential. Only the marker Xfcp623 for Tsn1 was diagnostic, and it was in perfect agreement with the results of the infiltration bioassays. The results illuminate which NE sensitivity genes may be of concern in breeding for resistance to SNB in the southeastern United States. DA - 2014/6// PY - 2014/6// DO - 10.1094/pdis-08-13-0820-re VL - 98 IS - 6 SP - 746-753 SN - 1943-7692 ER - TY - JOUR TI - Development of a genetic linkage map for Pinus radiata and detection of pitch canker disease resistance associated QTLs AU - Moraga-Suazo, P. AU - Orellana, L. AU - Quiroga, P. AU - Balocchi, C. AU - Sanfuentes, E. AU - Whetten, R. W. AU - Hasbun, R. AU - Valenzuela, S. T2 - TREES-STRUCTURE AND FUNCTION DA - 2014/12// PY - 2014/12// DO - 10.1007/s00468-014-1090-2 VL - 28 IS - 6 SP - 1823-1835 SN - 1432-2285 KW - Radiata pine KW - Fusarium circinatum KW - Linkage analysis KW - Quantitative resistance KW - Molecular markers ER - TY - JOUR TI - Determining the Most Important Physiological and Agronomic Traits Contributing to Maize Grain Yield through Machine Learning Algorithms: A New Avenue in Intelligent Agriculture AU - Shekoofa, Avat AU - Emam, Yahya AU - Shekoufa, Navid AU - Ebrahimi, Mansour AU - Ebrahimie, Esmaeil T2 - PLOS ONE AB - Prediction is an attempt to accurately forecast the outcome of a specific situation while using input information obtained from a set of variables that potentially describe the situation. They can be used to project physiological and agronomic processes; regarding this fact, agronomic traits such as yield can be affected by a large number of variables. In this study, we analyzed a large number of physiological and agronomic traits by screening, clustering, and decision tree models to select the most relevant factors for the prospect of accurately increasing maize grain yield. Decision tree models (with nearly the same performance evaluation) were the most useful tools in understanding the underlying relationships in physiological and agronomic features for selecting the most important and relevant traits (sowing date-location, kernel number per ear, maximum water content, kernel weight, and season duration) corresponding to the maize grain yield. In particular, decision tree generated by C&RT algorithm was the best model for yield prediction based on physiological and agronomical traits which can be extensively employed in future breeding programs. No significant differences in the decision tree models were found when feature selection filtering on data were used, but positive feature selection effect observed in clustering models. Finally, the results showed that the proposed model techniques are useful tools for crop physiologists to search through large datasets seeking patterns for the physiological and agronomic factors, and may assist the selection of the most important traits for the individual site and field. In particular, decision tree models are method of choice with the capability of illustrating different pathways of yield increase in breeding programs, governed by their hierarchy structure of feature ranking as well as pattern discovery via various combinations of features. DA - 2014/5/15/ PY - 2014/5/15/ DO - 10.1371/journal.pone.0097288 VL - 9 IS - 5 SP - SN - 1932-6203 ER - TY - JOUR TI - Causes and Consequences of Genetic Background Effects Illuminated by Integrative Genomic Analysis AU - Peiffer, J. A. AU - Romay, M. C. AU - Gore, M. A. AU - Flint-Garcia, S. A. AU - Zhang, Z. W. AU - Millard, M. J. AU - Gardner, C. A. C. AU - McMullen, M. D. AU - Holland, James AU - Bradbury, P. J. AU - Buckler, E. S. T2 - GENETICS AB - Abstract The phenotypic consequences of individual mutations are modulated by the wild-type genetic background in which they occur. Although such background dependence is widely observed, we do not know whether general patterns across species and traits exist or about the mechanisms underlying it. We also lack knowledge on how mutations interact with genetic background to influence gene expression and how this in turn mediates mutant phenotypes. Furthermore, how genetic background influences patterns of epistasis remains unclear. To investigate the genetic basis and genomic consequences of genetic background dependence of the scallopedE3 allele on the Drosophila melanogaster wing, we generated multiple novel genome-level datasets from a mapping-by-introgression experiment and a tagged RNA gene expression dataset. In addition we used whole genome resequencing of the parental lines—two commonly used laboratory strains—to predict polymorphic transcription factor binding sites for SD. We integrated these data with previously published genomic datasets from expression microarrays and a modifier mutation screen. By searching for genes showing a congruent signal across multiple datasets, we were able to identify a robust set of candidate loci contributing to the background-dependent effects of mutations in sd. We also show that the majority of background-dependent modifiers previously reported are caused by higher-order epistasis, not quantitative noncomplementation. These findings provide a useful foundation for more detailed investigations of genetic background dependence in this system, and this approach is likely to prove useful in exploring the genetic basis of other traits as well. DA - 2014/4// PY - 2014/4// DO - 10.1534/genetics.113.159426 VL - 196 IS - 4 SP - 1321-+ SN - 1943-2631 KW - transcriptional profiling KW - introgression mapping KW - genetic background effects KW - mutant expressivity KW - modifier genes KW - epistasis ER - TY - JOUR TI - A simple improved-throughput xylem protoplast system for studying wood formation AU - Lin, Ying-Chung AU - Li, Wei AU - Chen, Hao AU - Li, Quanzi AU - Sun, Ying-Hsuan AU - Shi, Rui AU - Lin, Chien-Yuan AU - Wang, Jack P. AU - Chen, Hsi-Chuan AU - Chuang, Ling AU - Qu, Guan-Zheng AU - Sederoff, Ronald R. AU - Chiang, Vincent L. T2 - NATURE PROTOCOLS DA - 2014/9// PY - 2014/9// DO - 10.1038/nprot.2014.147 VL - 9 IS - 9 SP - 2194-2205 SN - 1750-2799 ER - TY - JOUR TI - A robust chromatin immunoprecipitation protocol for studying transcription factor-DNA interactions and histone modifications in wood-forming tissue AU - Li, Wei AU - Lin, Ying-Chung AU - Li, Quanzi AU - Shi, Rui AU - Lin, Chien-Yuan AU - Chen, Hao AU - Chuang, Ling AU - Qu, Guan-Zheng AU - Sederoff, Ronald R. AU - Chiang, Vincent L. T2 - NATURE PROTOCOLS DA - 2014/9// PY - 2014/9// DO - 10.1038/nprot.2014.146 VL - 9 IS - 9 SP - 2180-2193 SN - 1750-2799 ER - TY - JOUR TI - Seedbed Preparation Techniques and Weed Control Strategies for Strip-Planting Rhizoma Peanut into Warm-Season Grass Pastures AU - Castillo, Miguel AU - Sollenberger, Lynn AU - Blount, Ann AU - Ferrell, Jason AU - Na, Chae-In AU - Williams, Mary AU - Mackowiak, Cheryl T2 - CROP SCIENCE AB - ABSTRACT Planting rhizoma peanut ( Arachis glabrata Benth.; RP) in strips into bahiagrass ( Paspalum notatum Flüggé) pastures can reduce establishment cost relative to conventional techniques, but research is needed to determine the best seedbed preparation methods. The objectives were to quantify the effects of four seedbed preparation techniques: glyphosate + tillage, tillage only, glyphosate + no‐till, and sod removal; and four postemergence weed control strategies: control (no herbicides, no mowing), mowing (every 28 d to 10‐cm stubble height), imazapic (0.29 L ha –1 ), and imazapic + 2,4‐D amine (0.29 and 0.58 L ha –1 , respectively). Sprout emergence ranged from 90 to 119 m 2 in treatments where tillage occurred compared with 54 to 58 m –2 in no‐till and sod removal. Nevertheless, by season end RP canopy cover and frequency of occurrence favored no‐till (21% cover and 70% frequency) compared with the other treatments (≤14% cover and 53% frequency). Weed control strategy after planting had a greater effect on establishment success than seedbed preparation. By season end, RP cover and frequency were greater for imazapic (25 and 64%, respectively) and imazapic + 2,4‐D (23 and 64%, respectively) than for the control (10 and 42%, respectively) and mowing treatments (7 and 36%, respectively). Glyphosate followed by no‐till planting and postemergence use of imazapic with or without 2,4‐D is a viable option for reduced‐cost establishment of RP in strips into bahiagrass pastures. DA - 2014/// PY - 2014/// DO - 10.2135/cropsci2013.06.0408 VL - 54 IS - 4 SP - 1868-1875 SN - 1435-0653 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-84903176368&partnerID=MN8TOARS ER - TY - JOUR TI - Phenotypic variation, heterosis and heritability of a tomato interspecific cross AU - Hernandez-Bautista, A. AU - Lobato-Ortiz, R. AU - Cruz-Izquierdo, S. AU - Garcia-Zavala, J. J. AU - Chavez-Servia, J. L. T2 - Interciencia DA - 2014/// PY - 2014/// VL - 39 IS - 5 SP - 327-332 ER - TY - JOUR TI - Peanut Response to Planting Date, Tillage, and Cultivar in North Carolina AU - Drake, W. L. AU - Jordan, D. L. AU - Johnson, P. D. AU - Shew, B. B. AU - Brandenburg, R. L. AU - Corbett, T. T2 - AGRONOMY JOURNAL AB - Production of peanut ( Arachis hypogaea L.) in reduced tillage is an effective alternative to conventional tillage in the southeastern United States under some conditions. Research was conducted to determine interactions of planting date, tillage system, and cultivar with respect to disease reaction and pod yield of peanut. The cultivars Bailey, CHAMPS, Gregory, Perry, and Phillips were planted in early or late May in reduced or conventional tillage systems from 2008 through 2011 at one location in North Carolina. The interaction of year, tillage system, and cultivar was significant for plant condition rating (PCR), a visible estimate of disease, within 3 d before digging from late September through mid‐October. Pod yield was correlated with PCR in mid‐September ( P = 0.0001, R 2 = –0.22) and PCR just before digging ( P ≤ 0.0001, R 2 = –0.31). Disease was less prevalent for the cultivar Bailey and most prevalent for the cultivar Phillips, with disease for the other cultivars intermediate between Bailey and Phillips. Pod yield was influenced independently by cultivar, planting date, and tillage system although each of these factors was affected by year of the experiment. Pod yield was similar in strip tillage and conventional tillage in 3 of 4 yr with yield in strip tillage exceeding conventional tillage in 1 yr. Peanut planted in early May yielded more than peanut planted in late May in 2 of 4 yr. Results indicate that while some differences in disease reaction will occur when comparing cultivars, planting dates, and tillage systems, pod yield will be affected independently by these cultural practices. DA - 2014/// PY - 2014/// DO - 10.2134/agronj2013.0340 VL - 106 IS - 2 SP - 486-490 SN - 1435-0645 ER - TY - JOUR TI - MlUM15: an Aegilops neglecta-derived powdery mildew resistance gene in common wheat AU - Worthington, M. AU - Lyerly, J. AU - Petersen, S. AU - Brown-Guedira, G. AU - Marshall, D. AU - Cowger, C. AU - Parks, R. AU - Murphy, J. P. T2 - Crop Science DA - 2014/// PY - 2014/// VL - 54 IS - 4 SP - 1397-1406 ER - TY - JOUR TI - Corn, cotton, and peanut response to tillage and subsurface drip irrigation in north carolina AU - Jordan, D. L. AU - Johnson, P. D. AU - Grabow, G. L. AU - Corbett, T. T2 - Agronomy Journal AB - Determining response of agronomic crops to subsurface drip irrigation (SDI) in conventional and reduced tillage systems is important in defining utility of SDI. Therefore, the objectives of this research were to define interactions of SDI and tillage with respect to yield and economic return of corn ( Zea mays L.), cotton ( Gossypium hirsutum L.), and peanut ( Arachis hypogaea L.) planted in rotation. Research was conducted in two 4‐yr periods (2007–2010 and 2008–2011) in North Carolina using continuous strip tillage vs. continuous conventional tillage without irrigation or with SDI using a crop sequence of 1 yr of cotton, 2 yr of corn, followed by 1 yr of peanut. Corn, cotton, and peanut yields increased with SDI compared with no irrigation regardless of tillage system. Cotton and peanut yields were not affected by tillage system or the interaction of tillage and irrigation; corn yield was affected by this interaction. In the second year of corn, yield and economic return were higher in conventional tillage with SDI than strip tillage with SDI. Economic return for the sum of crops in the rotation was affected by the interaction of irrigation and tillage. Economic return was higher in both periods during each year corn was grown under SDI compared with non‐irrigated corn while higher economic returns for cotton and peanut under SDI were noted in one of two periods. When pooled over periods, crops, and tillage, economic return for SDI was US$1,552 ha −1 higher than non‐irrigated production over 4 yr. DA - 2014/// PY - 2014/// DO - 10.2134/agronj13.0486 VL - 106 IS - 3 SP - 962-967 ER - TY - JOUR TI - Allopolyploidy and the evolution of plant virus resistance AU - Gottula, John AU - Lewis, Ramsey AU - Saito, Seiya AU - Fuchs, Marc T2 - BMC EVOLUTIONARY BIOLOGY AB - The relationship between allopolyploidy and plant virus resistance is poorly understood. To determine the relationship of plant evolutionary history and basal virus resistance, a panel of Nicotiana species from diverse geographic regions and ploidy levels was assessed for resistance to non-coevolved viruses from the genus Nepovirus, family Secoviridae. The heritability of resistance was tested in a panel of synthetic allopolyploids. Leaves of different positions on each inoculated plant were tested for virus presence and a subset of plants was re-inoculated and assessed for systemic recovery.Depending on the host-virus combination, plants displayed immunity, susceptibility or intermediate levels of resistance. Synthetic allopolyploids showed an incompletely dominant resistance phenotype and manifested systemic recovery. Plant ploidy was weakly negatively correlated with virus resistance in Nicotiana species, but this trend did not hold when synthetic allopolyploids were taken into account. Furthermore, a relationship between resistance and geographical origin was observed.The gradients of resistance and virulence corresponded to a modified matching allele model of resistance. Intermediate resistance responses of allopolyploids corresponded with a model of multi-allelic additive resistance. The variable virus resistance of extant allopolyploids suggested that selection-based mechanisms surpass ploidy with respect to evolution of basal resistance to viruses. DA - 2014/7/3/ PY - 2014/7/3/ DO - 10.1186/1471-2148-14-149 VL - 14 SP - SN - 1471-2148 KW - Allopolyploidy KW - Grapevine fanleaf virus (GFLV) KW - Nepovirus KW - Nicotiana KW - Resistance KW - Susceptibility KW - Tomato ringspot virus (ToRSV) ER - TY - JOUR TI - Usefulness and uses of climate forecasts for agricultural extension in South Carolina, USA AU - Templeton, Scott R. AU - Shane Perkins, M. AU - Aldridge, Heather Dinon AU - Bridges, William C., Jr. AU - Lassiter, Bridget Robinson T2 - REGIONAL ENVIRONMENTAL CHANGE DA - 2014/4// PY - 2014/4// DO - 10.1007/s10113-013-0522-7 VL - 14 IS - 2 SP - 645-655 SN - 1436-378X KW - Agricultural extension KW - AgroClimate KW - Benefits of forecasts KW - Cochran and McNemar statistics KW - Decision support tools KW - South Carolina agriculture KW - Usefulness and uses of forecasts ER - TY - JOUR TI - Toward a Synthesis: Lessons from Thirteen Cropland Watershed-Scale Studies AU - Woods, Brad R. AU - Luloff, A. E. AU - Osmond, Deanna AU - Hoag, Dana T2 - SOCIETY & NATURAL RESOURCES AB - To integrate lessons from the U.S. Department of Agriculture (USDA), National Institute of Food and Agriculture–Conservation Effects Assessment Project (NIFA CEAP) program, key informant (KI) interviews were conducted in all 13 project areas. The purpose of these interviews was to supplement technical information about watersheds, their contaminants, modeling, economics, and key findings. We interviewed a wide range of people to develop a systematic look at individual project results, synthesize meanings, and derive principles useful in guiding future watershed management. Findings revealed common themes, which tended to align with KI categories, regardless of location. For instance, farmers and ranchers often understood water quality problems as well as federal and state personnel and university employees do. Conservation adoption by farmers was related to perceived need, cost, and convenience of the practice, as well as practice specifics and individual situations. Possible implications of these findings are advanced. DA - 2014/4/1/ PY - 2014/4/1/ DO - 10.1080/08941920.2013.861551 VL - 27 IS - 4 SP - 341-357 SN - 1521-0723 KW - watershed KW - adoption KW - key informant KW - conservation KW - agriculture KW - qualitative KW - fertilizer KW - farmers ER - TY - JOUR TI - Registration of Two Multiple Disease-Resistant Peanut Germplasm Lines Derived from Arachis cardenasii Krapov. & WC Gregory, GKP 10017 AU - Tallury, S. P. AU - Isleib, T. G. AU - Copeland, S. C. AU - Rosas-Anderson, P. AU - Balota, M. AU - Singh, D. AU - Stalker, H. T. T2 - JOURNAL OF PLANT REGISTRATIONS AB - Two tetraploid (2n = 4x = 40) peanut (Arachis hypogaea L. subsp. hypogaea var. hypogaea) germplasm lines, GP-NC WS 16 (SPT 06-06) (Reg. No. GP-235, PI 669445) and GP-NC WS 17 (SPT 06-07) (Reg. No. GP-236, PI 669446), derived from interspecific hybridization, were developed in the peanut genetics program at North Carolina State University (NCSU), Raleigh, NC. These two lines were tested extensively by the North Carolina Agricultural Research Service from 2006 through 2012 in disease evaluation tests. They have unique alleles introgressed from the diploid (2n = 2x = 20) wild species, A. cardenasii Krapov. & W.C. Gregory. The germplasm lines are also unique in that they exhibited multiple disease resistances superior to the germplasm lines derived from A. cardenasii that were released previously by NCSU. Resistance to multiple diseases included early leaf spot (ELS), Cylindrocladium black rot (CBR), Sclerotinia blight (SB), and tomato spotted wilt (TSW). One of the lines, GP-NC WS 17, also exhibited drought tolerance in field and greenhouse studies. Thus, it can be concluded that these two peanut germplasm lines derived from diploid wild species have multiple biotic stress resistances, specifically for ELS, CBR, SB, and TSWV, as well as abiotic stress resistance in the case of GP-NC WS 17. These two lines should provide unique, improved germplasm for breeders interested in multiple disease resistance and in expanding the germplasm pool of A. hypogaea. DA - 2014/1// PY - 2014/1// DO - 10.3198/jpr2013.04.0017crg VL - 8 IS - 1 SP - 86-89 SN - 1940-3496 ER - TY - JOUR TI - Registration of Scab-Resistant KY06C-11-3-10 Soft Red Winter Wheat Germplasm AU - Clark, Anthony J. AU - Costa, Jose M. AU - Griffey, Carl A. AU - Brown-Guedira, Gina L. AU - Dong, Yanhong AU - Souza, Edward J. AU - Murphy, J. Paul AU - Van Sanford, David A. T2 - JOURNAL OF PLANT REGISTRATIONS AB - Fusarium head blight (FHB) is a serious disease of wheat (Triticum aestivum L.) worldwide that has elicited a widespread resistance-breeding effort. One approach to breeding relies on deployment of exotic quantitative trait loci (QTL) from wheat outside North America. Germplasm line KY06C-11-3-10 (Reg. No. GP-965, PI 669817) is a soft red winter wheat that is a product of an accelerated backcrossing program performed jointly by the Kentucky Agricultural Experiment Station, Maryland Agricultural Experiment Station, Virginia Polytechnic Institute and State University, North Carolina State University, and the USDA–ARS. KY06C-11-3-10 carries exotic FHB resistance alleles from Chinese spring wheat ‘Ning7840’ at Fhb1, and at QTL on chromosomes 5A and 2DL. These QTL, backcrossed into ‘McCormick’—which itself has nonexotic, native moderate resistance—reduced FHB spike symptoms, percentage Fusarium-damaged kernels, and concentration of the mycotoxin deoxynivalenol (DON). KY06C-11-3-10 has additionally been selected for yield, test weight, heading date, height, milling and baking quality, and resistance to lodging. The combination of exotic resistance QTL, moderately resistant genetic background, widespread adaptation, and competitive agronomic and quality characteristics makes KY06C-11-3-10 a useful germplasm for wheat breeders. DA - 2014/5// PY - 2014/5// DO - 10.3198/jpr2013.07.0039crg VL - 8 IS - 2 SP - 211-216 SN - 1940-3496 ER - TY - JOUR TI - Metabolic Changes in Avena sativa Crowns Recovering from Freezing AU - Henson, Cynthia A. AU - Duke, Stanley H. AU - Livingston, David P., III T2 - PLOS ONE AB - Extensive research has been conducted on cold acclimation and freezing tolerance of fall-sown cereal plants due to their economic importance; however, little has been reported on the biochemical changes occurring over time after the freezing conditions are replaced by conditions favorable for recovery and growth such as would occur during spring. In this study, GC-MS was used to detect metabolic changes in the overwintering crown tissue of oat (Avena sativa L.) during a fourteen day time-course after freezing. Metabolomic analysis revealed increases in most amino acids, particularly proline, 5-oxoproline and arginine, which increased greatly in crowns that were frozen compared to controls and correlated very significantly with days after freezing. In contrast, sugar and sugar related metabolites were little changed by freezing, except sucrose and fructose which decreased dramatically. In frozen tissue all TCA cycle metabolites, especially citrate and malate, decreased in relation to unfrozen tissue. Alterations in some amino acid pools after freezing were similar to those observed in cold acclimation whereas most changes in sugar pools after freezing were not. These similarities and differences suggest that there are common as well as unique genetic mechanisms between these two environmental conditions that are crucial to the winter survival of plants. DA - 2014/3/27/ PY - 2014/3/27/ DO - 10.1371/journal.pone.0093085 VL - 9 IS - 3 SP - SN - 1932-6203 ER - TY - JOUR TI - Limited-transpiration trait evaluated in growth chamber and field for sorghum genotypes AU - Shekoofa, A. AU - Balota, M. AU - Sinclair, T. R. T2 - ENVIRONMENTAL AND EXPERIMENTAL BOTANY AB - Sorghum [Sorghum bicolor (L.) Moench] is commonly grown in water-limited environments throughout the world. Plant traits could be useful allowing for early-season water conservation so that more water is available for use later in the season when drought is most likely to develop. One trait that might result in early-season water conservation is the expression of a limited-transpiration trait defined as a limitation on further increases in transpiration rate (TR) under high vapor pressure deficit (VPD) conditions. The objective of this study was to compare the expression of the limited-TR trait measured for nine sorghum genotypes under both controlled chamber and field conditions. In the growth chamber, plant TR was measured over a range of imposed VPD to provide a direct measure of plant transpiration under high VPD. In the field, stomatal conductance (gs) was measured over the daily cycle, which resulted in a range of ambient VPD. A decrease in gs under high VPD was evidence of the limited-TR trait. This study identified three sorghum genotypes (DKS 36-06, DKS 44-20, and DKS 54-00) that did not show any limitation on water loss at high VPD in either the greenhouse or field. On the other hand, four genotypes (BTX 2752, SC 599, SC 982, and B 35) exhibited the limited-TR trait in the growth chamber with breakpoints in response to VPD at values of 2.33 kPa and above. These four genotypes also expressed a breakpoint in gs in response to increasing VPD in the field. Two genotypes (TX ARG 1, TX 436) that differed between the growth chamber and field showed consistency in response on close examination of the field results. The overall general correspondence within genotypes between the controlled chamber and the field in expression or lack of expression of a breakpoint in response to increasing VPD demonstrated the possibility of selecting genotypes for the TRlim trait under differing environmental conditions. DA - 2014/3// PY - 2014/3// DO - 10.1016/j.envexpbot.2013.11.018 VL - 99 SP - 175-179 SN - 1873-7307 KW - Drought stress KW - Sorghum KW - Stomatal conductance KW - Vapor pressure deficit ER - TY - JOUR TI - Hydraulic conductance differences among sorghum genotypes to explain variation in restricted transpiration rates AU - Choudhary, Sunita AU - Sinclair, Thomas R. T2 - FUNCTIONAL PLANT BIOLOGY AB - Sorghum (Sorghum bicolor L.) is an important crop for production in dryland regions of the globe. Traits identified in many sorghum lines that apparently make them adapted for dryland conditions are restricted transpiration rate both early in the soil drying cycle and under high atmospheric vapour pressure deficit. It was hypothesised that these responses could be a result of differences in hydraulic conductance of the plants: those with low hydraulic conductance would be more likely to express restricted transpiration rates. The location of the lower hydraulic conductance in the plant could also be important with a low conductance in the leaf xylem to stomata pathway possibly being more advantageous than in the root. In this study, the amount and location of the hydraulic conductance was measured in 20 sorghum genotypes. Those genotypes that expressed an early decrease in transpiration rate with soil drying had greater plant and leaf hydraulic conductance than those genotypes that had the later decreases in transpiration rate, which was in contrast with what was hypothesised. However, sorghum genotypes that segregated between two groups based on expression of a maximum transpiration trait also segregated based on their hydraulic conductance. Those genotypes that expressed the maximum transpiration trait had lower hydraulic conductance for the intact plant and in the leaves. DA - 2014/// PY - 2014/// DO - 10.1071/fp13246 VL - 41 IS - 3 SP - 270-275 SN - 1445-4416 KW - drought tolerance KW - soil water conservation KW - water use ER - TY - JOUR TI - Turfgrass management duration and intensities influence soil microbial dynamics and carbon sequestration AU - Wang, Y. AU - Tu, C. AU - Li, C. Y. AU - Tredway, L. AU - Lee, D. AU - Snell, M. AU - Zhang, X. C. AU - Hu, S. J. T2 - International Journal of Agriculture and Biology DA - 2014/// PY - 2014/// VL - 16 IS - 1 SP - 139-145 ER - TY - JOUR TI - The Genetic Architecture Of Maize Height AU - Peiffer, Jason A. AU - Romay, Maria C. AU - Gore, Michael A. AU - Flint-Garcia, Sherry A. AU - Zhang, Zhiwu AU - Millard, Mark J. AU - Gardner, Candice A. C. AU - McMullen, Michael D. AU - Holland, James B. AU - Bradbury, Peter J. AU - Buckler, Edward S. T2 - GENETICS AB - Abstract Height is one of the most heritable and easily measured traits in maize (Zea mays L.). Given a pedigree or estimates of the genomic identity-by-state among related plants, height is also accurately predictable. But, mapping alleles explaining natural variation in maize height remains a formidable challenge. To address this challenge, we measured the plant height, ear height, flowering time, and node counts of plants grown in &gt;64,500 plots across 13 environments. These plots contained &gt;7300 inbreds representing most publically available maize inbreds in the United States and families of the maize Nested Association Mapping (NAM) panel. Joint-linkage mapping of quantitative trait loci (QTL), fine mapping in near isogenic lines (NILs), genome-wide association studies (GWAS), and genomic best linear unbiased prediction (GBLUP) were performed. The heritability of maize height was estimated to be &gt;90%. Mapping NAM family-nested QTL revealed the largest explained 2.1 ± 0.9% of height variation. The effects of two tropical alleles at this QTL were independently validated by fine mapping in NIL families. Several significant associations found by GWAS colocalized with established height loci, including brassinosteroid-deficient dwarf1, dwarf plant1, and semi-dwarf2. GBLUP explained &gt;80% of height variation in the panels and outperformed bootstrap aggregation of family-nested QTL models in evaluations of prediction accuracy. These results revealed maize height was under strong genetic control and had a highly polygenic genetic architecture. They also showed that multiple models of genetic architecture differing in polygenicity and effect sizes can plausibly explain a population’s variation in maize height, but they may vary in predictive efficacy. DA - 2014/4// PY - 2014/4// DO - 10.1534/genetics.113.159152 VL - 196 IS - 4 SP - 1337-+ SN - 1943-2631 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-84901312138&partnerID=MN8TOARS KW - GBLUP KW - height KW - maize KW - plant ER - TY - JOUR TI - Systems Biology of Lignin Biosynthesis in Populus trichocarpa: Heteromeric 4-Coumaric Acid: Coenzyme A Ligase Protein Complex Formation, Regulation, and Numerical Modeling AU - Chen, Hsi-Chuan AU - Song, Jina AU - Wang, Jack P. AU - Lin, Ying-Chung AU - Ducoste, Joel AU - Shuford, Christopher M. AU - Liu, Jie AU - Li, Quanzi AU - Shi, Rui AU - Nepomuceno, Angelito AU - Isik, Fikret AU - Muddiman, David C. AU - Williams, Cranos AU - Sederoff, Ronald R. AU - Chiang, Vincent L. T2 - PLANT CELL AB - As a step toward predictive modeling of flux through the pathway of monolignol biosynthesis in stem differentiating xylem of Populus trichocarpa, we discovered that the two 4-coumaric acid:CoA ligase (4CL) isoforms, 4CL3 and 4CL5, interact in vivo and in vitro to form a heterotetrameric protein complex. This conclusion is based on laser microdissection, coimmunoprecipitation, chemical cross-linking, bimolecular fluorescence complementation, and mass spectrometry. The tetramer is composed of three subunits of 4CL3 and one of 4CL5. 4CL5 appears to have a regulatory role. This protein–protein interaction affects the direction and rate of metabolic flux for monolignol biosynthesis in P. trichocarpa. A mathematical model was developed for the behavior of 4CL3 and 4CL5 individually and in mixtures that form the enzyme complex. The model incorporates effects of mixtures of multiple hydroxycinnamic acid substrates, competitive inhibition, uncompetitive inhibition, and self-inhibition, along with characteristic of the substrates, the enzyme isoforms, and the tetrameric complex. Kinetic analysis of different ratios of the enzyme isoforms shows both inhibition and activation components, which are explained by the mathematical model and provide insight into the regulation of metabolic flux for monolignol biosynthesis by protein complex formation. DA - 2014/3// PY - 2014/3// DO - 10.1105/tpc.113.119685 VL - 26 IS - 3 SP - 876-893 SN - 1532-298X ER - TY - JOUR TI - Statistical model for describing macronutrient impacts on container substrate pH over time AU - Barnes, J. AU - Nelson, P. AU - Whipker, B.E. AU - Dickey, D.A. AU - Hesterberg, D. AU - Shi, W. T2 - HortScience DA - 2014/// PY - 2014/// VL - 49 IS - 2 SP - 207-214 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-84894102893&partnerID=MN8TOARS ER - TY - JOUR TI - Soil biological properties, soil losses and corn yield in long-term organic and conventional farming systems AU - Larsen, Erika AU - Grossman, Julie AU - Edgell, Joshua AU - Hoyt, Greg AU - Osmond, Deanna AU - Hu, Shuijin T2 - SOIL & TILLAGE RESEARCH AB - Topsoil losses through surface runoff have severe implications for farmers, as well as surrounding ecosystems and waterbodies. However, integrating management systems that enhance soil organic matter (SOM) can stabilize the soil surface from erosion. Little is known about how differences in both tillage and cropping system management affect carbon and subsequent sediment losses in horticultural fields, particularly in the humid climate of the southeast. Research was conducted in the Appalachian Mountains in Mills River, NC on a fine-sandy loam Acrisol from 2010 to 2012 on long-term plots established in 1994. Project objectives included to: (1) quantify labile and total organic matter based on tillage and cropping system practices, (2) determine if relationships exist between SOC ad sediment losses, and (3) determine long-term management and tillage impacts on total organic matter lost via runoff. We hypothesized that organic management and reduced tillage would lead to increased soil carbon, which subsequently reduce losses as soil is stabilized. Organic no tillage and conventional till treatments contained on average 14.34 and 6.80 g kg−1 total carbon (TC) respectively, with the organic no till treatments containing twice the quantity of TC and light fraction particulate organic matter (LPOM) in the upper 15 cm as compared with the conventionally tilled treatments, and four times the quantity of microbial biomass carbon (MBC). LPOM and HPOM, the heavier fraction of POM, did not differ in the organic till and conventional no till treatments.Data support our hypothesis that organic production in combination with no tillage increases C pools (both total and labile) as compared with tilled conventional plots. However, organic no till treatments produced sweet corn (Zea mays var. saccharata) yields less than 50% of that of conventional treatments, attributed to weed competition and lack of available N. No tillage treatments lost two to four times less soil C via surface runoff than tilled systems. Additionally, we found that as total soil C increased, suspended solids lost through surface runoff decreased. Overall, our results indicate tillage to be an important factor in enhancing soil C and decreasing soil loss through surface runoff. DA - 2014/6// PY - 2014/6// DO - 10.1016/j.still.2014.02.002 VL - 139 SP - 37-45 SN - 1879-3444 KW - Particulate organic matter KW - Sediment loss KW - No tillage KW - Carbon loss KW - Organic agriculture KW - Microbial biomass ER - TY - JOUR TI - Sensible Heat Balance Measurements of Soil Water Evaporation beneath a Maize Canopy AU - Xiao, X. AU - Heitman, J. L. AU - Sauer, T. J. AU - Ren, T. AU - Horton, R. T2 - SOIL SCIENCE SOCIETY OF AMERICA JOURNAL AB - Soil water evaporation is an important component of the water budget in cropped fields; few methods are available for continuous and independent measurement. A sensible heat balance (SHB) approach has been demonstrated for continuously determining soil water evaporation under bare surface conditions. Applicability of SHB measurements beneath a crop canopy cover has not been evaluated. We tested SHB using heat-pulse sensors to estimate evaporation beneath a full maize (Zea mays L.) canopy. We also implemented a modified SHB approach incorporating below-canopy net radiation, which extended the range of conditions under which SHB is applicable. Evaporation was measured at three positions: row (R), interrow (I), and interrow with roots excluded (IE). Evaporation rates were generally small, averaging <0.7 mm d−1 across all dates, positions, and measurement methods during the drying period. The SHB evaporation estimates varied among R, I, and IE, with cumulative totals of 4.4, 7.4, and 7.9 mm, respectively, during a 12-d drying period. Lower soil water contents from plant water uptake reduced evaporation rates at R more appreciably with time than at the other positions; I and IE provided similar evaporation patterns. The SHB evaporation estimates at R and I were compared with microlysimeter data on 8 d. Correlation between approaches was modest (r2 = 0.61) but significant (p < 0.001) when compared separately at R and I positions. Correlation was improved (r2 = 0.81) when evaporation estimates were combined across positions, with differences between SHB and microlysimeters typically within the range of values obtained from microlysimeter replicates. Overall, the results suggest good potential for using SHB and modified SHB approaches to determine soil water evaporation in a cropped field. The SHB approach allowed continuous daily estimates of evaporation, separate from evapotranspiration and without destructive sampling. DA - 2014/// PY - 2014/// DO - 10.2136/sssaj2013.08.0371 VL - 78 IS - 2 SP - 361-368 SN - 1435-0661 KW - DOY KW - day of the year KW - HP KW - heat pulse KW - I KW - interrow position KW - IE KW - interrow position with roots excluded KW - R KW - row position KW - SHB KW - sensible heat balance ER - TY - JOUR TI - Roller-Crimper Termination for Legume Cover Crops in North Carolina: Impacts on Nutrient Availability to a Succeeding Corn Crop AU - Parr, Mary AU - Grossman, Julie M. AU - Reberg-Horton, S. Chris AU - Brinton, Carrie AU - Crozier, Carl T2 - COMMUNICATIONS IN SOIL SCIENCE AND PLANT ANALYSIS AB - Nitrogen (N) release from roll-killed legume cover crops was determined for hairy vetch (Vicia villosa Roth), crimson clover (Trifolium incarnatum L.), and a hairy vetch + rye (Secale cereale L.) biculture in an organic corn production system in North Carolina, USA. Cover crops were planted at two locations in fall 2008 and 2009, roll-killed in May, and no-till planted with corn (Zea mays L.). Inorganic soil N and mineral N flux were determined using potassium chloride (KCl) extractions and ion-exchange resin (Plant Root Simulator, PRS) probes at 2-week intervals for 12 weeks and compared to fertilized controls of 0 and 168 kg N ha−1. In 2009, greater plant available N under hairy vetch than under either 0 N control or crimson clover was found, with peak soil N occurring between 4 and 6 weeks after roll kill. Available soil N under crimson clover mulches was less than or equal to 0 N, suggesting net immobilization. DA - 2014/4/28/ PY - 2014/4/28/ DO - 10.1080/00103624.2013.867061 VL - 45 IS - 8 SP - 1106-1119 SN - 1532-2416 KW - Vicia villosa KW - nutrient cycling KW - N synchrony KW - N mineralization KW - Trifolium incarnatum KW - Legume cover crops KW - organic cropping systems ER - TY - JOUR TI - Quantitative trait loci controlling aluminum tolerance in soybean: candidate gene and single nucleotide polymorphism marker discovery AU - Abdel-Haleem, Hussein AU - Carter, Thomas E., Jr. AU - Rufty, Thomas W. AU - Boerma, H. Roger AU - Li, Zenglu T2 - MOLECULAR BREEDING DA - 2014/4// PY - 2014/4// DO - 10.1007/s11032-013-9999-5 VL - 33 IS - 4 SP - 851-862 SN - 1572-9788 KW - Aluminum toxicity KW - Candidate gene KW - Citrate synthase KW - QTL KW - Root extension KW - Soybean KW - Tap root ER - TY - JOUR TI - Modeling of ammonia dry deposition to a pocosin landscape downwind of a large poultry facility AU - Walker, John T. AU - Robarge, Wayne P. AU - Austin, Robert T2 - AGRICULTURE ECOSYSTEMS & ENVIRONMENT AB - A semi-empirical bi-directional flux modeling approach is used to estimate NH3 air concentrations and dry deposition fluxes to a portion of the Pocosin Lakes National Wildlife Refuge (PLNWR) downwind of a large poultry facility. Meteorological patterns at PLNWR are such that some portion of the refuge is downwind of the poultry facility 52%, 66%, 57%, and 50% of time during winter, spring, summer, and fall, respectively. Air concentrations and dry deposition rates are highest in the northeasterly direction from the facility, consistent with prevailing wind patterns. Dry deposition rates along the axis of highest concentrations are 10.1 kg N ha−1 yr−1 at the refuge boundary closest to the facility, decreasing to 5.4 kg N ha−1 yr−1 1.5 km further downwind and continuing to decrease non-linearly to a deposition rate of 1.4 kg N ha−1 yr−1 8–10 km downwind. Approximately 10% of the refuge model domain receives ≥3.0 kg N ha−1 yr−1 as dry NH3 deposition. Depending on the definition of the background air concentration, annual nitrogen loading to the refuge from background NH3 dry deposition and NH3 dry deposition associated with elevated concentrations downwind of the facility is between 41% and 79% higher than background dry NH3 deposition alone. Relative to the total N deposition budget for the refuge, which includes all nitrogen compounds, total background N deposition plus NH3 dry deposition associated with elevated concentrations downwind of the facility is, correspondingly, 6–10% greater than background total N deposition alone. From a process standpoint, predicted fluxes are most sensitive to uncertainty in the parameterization of the cuticular resistance. DA - 2014/3/1/ PY - 2014/3/1/ DO - 10.1016/j.agee.2013.10.029 VL - 185 SP - 161-175 SN - 1873-2305 KW - Ammonia KW - Dry deposition KW - Bi-directional flux KW - Resistance modeling KW - Animal facility ER - TY - JOUR TI - Hydraulic Conductance of Maize Hybrids Differing in Transpiration Response to Vapor Pressure Deficit AU - Sunita, Choudhary AU - Sinclair, Thomas R. AU - Messina, Carlos D. AU - Cooper, Mark T2 - CROP SCIENCE AB - ABSTRACT Limited transpiration rate (TR) under high vapor pressure deficit (VPD) conditions has been proposed as a desirable trait for crop yield improvement. The limited‐TR trait has been identified in several single‐cross maize hybrids, and among these hybrids, a range in the VPD breakpoint for limited TR was identified. It was hypothesized that the variation in the VPD breakpoint was due to differences in hydraulic conductance in their roots or leaves, or both. Therefore, the objective of this study was to compare relative hydraulic conductance in the roots and leaves across the maize hybrids expressing the VPD breakpoint. It was found that the VPD of the breakpoint was correlated with each of three indices of hydraulic conductance. That is, low VPD breakpoint was associated with low hydraulic conductance in both leaves and roots indicating a common, underlying limiting mechanism in these two tissues. It was hypothesized that expression of similar aquaporin populations influencing hydraulic flow across membranes in the roots and leaves may account for the consistency in results across the indices of hydraulic conductance. DA - 2014/// PY - 2014/// DO - 10.2135/cropsci2013.05.0303 VL - 54 IS - 3 SP - 1147-1152 SN - 1435-0653 ER - TY - JOUR TI - Genetic and Phenotypic Correlations of Quantitative Traits in Two Long-Term, Randomly Mated Soybean Populations AU - Recker, Jill R. AU - Burton, Joseph W. AU - Cardinal, Andrea AU - Miranda, Lilian T2 - CROP SCIENCE AB - ABSTRACT The genetic effects of long‐term random mating and natural selection aided by genetic male sterility were evaluated in two soybean [ Glycine max (L.) Merr.] populations designated RSII and RSIII. These populations were evaluated in the field at three locations, each with two replications. Genotypic and phenotypic correlations were estimated to determine the effects of 26 generations of random mating. Data was collected on flowering date (R2), maturity date (R8), plant height, lodging, yield, seed weight, protein concentration, and oil concentration. The genotypic correlation between yield and protein was not significant and small (<|0.2|) in both populations, however negative in RSII. The genotypic correlation between yield and oil was not significant but positive in both populations. In contrast, for both populations the genotypic correlations between protein and oil were significantly negative and large (>|0.5|). As these populations were randomly mated for many generations, linkage phase disequilibrium is likely close to zero; therefore, it was concluded that pleiotropic effects, probably caused by interrelated physiological processes, maintain the negative association between oil and protein. The genetic correlations between yield and protein or oil in these populations, however, do suggest that with the right breeding scheme, the negative associations can be reduced and allow for improvement in more than one trait simultaneously. DA - 2014/// PY - 2014/// DO - 10.2135/cropsci2013.07.0447 VL - 54 IS - 3 SP - 939-943 SN - 1435-0653 ER - TY - JOUR TI - Genetic Variation for Epidermal Conductance in Peanut AU - Rosas-Anderson, Pablo AU - Sinclair, Thomas R. AU - Balota, Maria AU - Tallury, Shyam AU - Isleib, Thomas G. AU - Rufty, Thomas T2 - CROP SCIENCE AB - ABSTRACT Peanut ( Arachis hypogaea L.) is an important legume that is often grown in drought‐prone areas. Low epidermal conductance (EC) may delay the dehydration of leaves and improve plant survival of severe water‐deficit stress. No reports of genetic variation for EC in peanut have been found in the literature. Therefore, the main objective of this study was to document genetic variation for EC among 21 peanut ( Arachis spp.) genotypes in two greenhouse experiments and a field experiment. The effects of water‐deficit stress on EC and the association between EC and stomata density (SD) were also investigated. Tests for an influence of water‐deficit stress on EC were inconclusive. Comparison of EC and SD among genotypes failed to show any significant correlations in the various test environments. However, genetic variation for EC in peanut was found in both greenhouse experiments, with genotypes TMV 2, PI 298639, and VA 98R having very low EC. In the field, genotype SPT 06‐07 was found to have low EC. These results indicate that selection of genotypes with low EC is a viable approach in identifying peanut genotypes with improved capacity to survive severe soil water deficits. DA - 2014/// PY - 2014/// DO - 10.2135/cropsci2013.07.0461 VL - 54 IS - 2 SP - 730-737 SN - 1435-0653 ER - TY - JOUR TI - Evaluating Responses of Four Wetland Plant Species to Different Hydroperiods AU - Slusher, C. E. AU - Vepraskas, M. J. AU - Broome, S. W. T2 - JOURNAL OF ENVIRONMENTAL QUALITY AB - Previous work has estimated the hydroperiod requirements (saturation duration and frequency) of wetland plant communities by modeling their hydrologic regimes in natural (never drained) wetlands for a 40-yr period. This study tested the modeled predictions in a controlled greenhouse study using tree species representing three of the plant communities plus an additional species from another community. Bald cypress ( L. Rich.), sweet bay ( L.), pond pine ( Michx.), and swamp chestnut oak ( Nutt.) were grown under three hydroperiods (continuously ponded for 100 d, intermittently ponded for 14 d, and unsaturated) in loamy sand and sapric (organic) materials. Bald cypress (representing a Nonriverine Swamp Forest community) adapted well to 100 d of ponding by producing lateral roots near the soil surface and aerenchyma tissue in roots and stem. Sweet bay (Bay Forest community) also adapted well to 100 d of ponding by producing adventitious roots on the submerged portion of the stem. Pond pine (Pond Pine Woodland) and swamp chestnut oak (Nonriverine Wet Hardwood Forest) were intolerant of 100 d of ponded conditions. Seventy-five percent of the pond pine seedlings and 87% of the swamp chestnut oak seedlings died in the continuously ponded treatment level, whereas 100% of the bald cypress and 88% of the sweet bay seedlings survived. Results from this study suggest that modeled long-term hydroperiods of natural wetland plant communities can be used for restoration of these communities. DA - 2014/// PY - 2014/// DO - 10.2134/jeq2013.06.0227 VL - 43 IS - 2 SP - 723-731 SN - 1537-2537 ER - TY - JOUR TI - Effects of rotational infrastructure within pasture-raised pig operations on ground cover, soil nutrient distribution, and bulk density AU - Bordeaux, C. AU - Grossman, J. AU - White, J. AU - Osmond, D. AU - Poore, M. AU - Pietrosemoli, S. T2 - JOURNAL OF SOIL AND WATER CONSERVATION AB - Interest in pasture-based pork products has increased significantly in recent years. However, nitrogen (N) losses resulting from these systems are common due to importation of feed, high stocking rates, and pig behavior. This study was conducted to evaluate soil inorganic N, soil-test phosphorus (STP), ground cover, and compaction changes as impacted by rotational shade, water, and feed structures in a pasture-raised pig operation over two 12-week pig occupations. Shade and watering structures were rotated weekly for 12 weeks within a rotational (mobile) scheme; data were compared to a stationary structure system as well as to a managed hay operation with no pigs. Soil samples were acquired from subplots and analyzed for distribution of inorganic N concentrations among main plot treatments, including nitrate (NO3), ammonium (NH4), and STP values. Soil inorganic N concentrations were higher in exterior subplot positions than in interior positions. This pattern was not maintained after a second pig group occupied the plots. Soil test phosphorus was unaffected by either pig occupation. Ground cover percentages were higher in control (hay) treatments than for pig treatments, however no difference was found between mobile and stationary structure treatments in either pig occupation. Soil compaction, as measured by soil bulk density, was found to be higher under permanent shade structure locations as compared to mobile and control treatments. Mobile and control compaction levels were not different for the second occupation, utilizing a more intensive sampling scheme, suggesting a benefit to the rotation of shade, water and feed infrastructure. The weekly rotation of infrastructure performed during both occupations was both labor intensive and time consuming. The observed lack of improvement in nutrient distribution to a rotational infrastructure may limit its utility in pastured-pig systems. However, further options are available that would allow the production of pasture-raised pigs while minimizing associated nutrient loading and pasture degradation. DA - 2014/// PY - 2014/// DO - 10.2489/jswc.69.2.120 VL - 69 IS - 2 SP - 120-130 SN - 1941-3300 KW - ground cover KW - nutrient KW - pasture KW - pig KW - soil ER - TY - JOUR TI - Effect of an Introgressed Nicotiana tomentosa Leaf Number QTL on Yield and Quality Characteristics in Flue-Cured Tobacco AU - Eickholt, David P. AU - Lewis, Ramsey S. T2 - CROP SCIENCE AB - ABSTRACT Increased cured leaf yield is an important breeding target for flue‐cured tobacco ( Nicotiana tabacum L.), but genetic improvement for this trait has slowed in the last thirty years. Yield is positively correlated with days to flowering and leaf number in this species. Use of novel allelic diversity influencing these traits might contribute to further yield improvement. In this study, an introgressed quantitative trait locus (QTL) affecting flowering time and leaf number, designated as Many Leaves ( Ml ), was backcrossed into three genetic backgrounds of flue‐cured tobacco. Field evaluation of nearly isogenic MlMl lines and Mlml hybrids indicated that the QTL acted in an additive to partially dominant fashion to delay flowering and increase leaf number. This resulted in significant increases in yield and cash return per hectare. As the zygosity of Ml increased, corresponding decreases in percentage total alkaloids and increases in percentage reducing sugars were observed, however. Incorporation of Ml into flue‐cured tobacco breeding programs may be useful for increasing cured leaf yields in certain environments. Concurrent modification of the genetic potential to accumulate alkaloids would be also important under current industry requirements, however. DA - 2014/// PY - 2014/// DO - 10.2135/cropsci2013.07.0464 VL - 54 IS - 2 SP - 586-594 SN - 1435-0653 ER - TY - JOUR TI - Complete vineyard floor cover crops favorably limit grapevine vegetative growth AU - Giese, Gill AU - Velasco-Cruz, Ciro AU - Roberts, Lucas AU - Heitman, Josh AU - Wolf, Tony K. T2 - SCIENTIA HORTICULTURAE AB - Complete vineyard floor cover crops were evaluated in a long-term study for their ability to regulate excessive vegetative growth of the grapevine (Vitis vinifera L.) variety ‘Cabernet Sauvignon’. Treatments were: tall fescue (Festuca arundinacea Shreb.) ‘KY-31′ and ‘Elite II’, hard fescue (Festuca ovina L.) ‘Aurora Gold’, perennial ryegrass (Lolium perenne L.), orchardgrass (Dactylis glomerata L.), and an under-trellis herbicide strip combined with KY-31 fescue interrows. Compared to herbicide-treated soil strip, Elite II fescue reduced vine pruning weights (kg/vine) 28%, individual cane weight (g) 20%, and canopy leaf layer number 25%. KY-31 fescue produced the greatest biomass and stand density, while perennial ryegrass produced the least biomass and Aurora Gold hard fescue produced the lowest stand density. Elite II fescue produced less biomass but equivalent stand density compared to KY-31 fescue. Treatments minimally impacted vine water potential (Ψmd, Ψstem), indicating that the grasses were not overly competitive with grapevines for soil moisture. All grass treatments tended to depress grapevine nitrogen levels relative to the under-trellis herbicide strip treatment, but no treatment resulted in vine nitrogen levels below the acceptable sufficiency range. Because of its establishment and growth characteristics, desired suppression of vine vegetative growth, and its low impact on crop yield, we considered Elite II fescue the optimal cover crop evaluated. DA - 2014/5/7/ PY - 2014/5/7/ DO - 10.1016/j.scienta.2014.03.011 VL - 170 SP - 256-266 SN - 1879-1018 KW - Vineyard cover crop KW - Evapotranspiration KW - Grapevine vegetative vigor KW - Mini-lysimeters ER - TY - JOUR TI - Siderophore-promoted dissolution of chromium from hydroxide minerals AU - Duckworth, Owen W. AU - Akafia, Martin M. AU - Andrews, Megan Y. AU - Bargar, John R. T2 - ENVIRONMENTAL SCIENCE-PROCESSES & IMPACTS AB - Biomolecules have significant impacts on the fate and transport of contaminant metals in soils and natural waters. Siderophores, Fe(III)-binding agents that are exuded by microbes and plants, may form strong complexes with and promote the dissolution of contaminant metal ions, such as Co(III), U(IV), or Pu(IV). Although aqueous Cr(III)-siderophore complexes have been recognized in the laboratory setting for almost 40 years, few studies have explored interactions of siderophores with Cr-bearing minerals or considered their impacts on environmental chemistry. To better understand the possible effects of siderophores on chromium mobility, we conducted a series of dissolution experiments to quantify the dissolution rates of Cr(III)(OH)3 in the presence of hydroxamate, catecholate, and α-hydroxycarboxylate siderophores over a range of environmentally relevant pH values. At pH = 5, dissolution rates in the presence of siderophores are similar to control experiments, suggesting a predominantly proton-promoted dissolution mechanism. At pH = 8, the sorption of the siderophores desferrioxamine B and rhizoferrin can be modeled by using Langmuir isotherms. The dissolution rates for these siderophores are proportional to the surface concentrations of sorbed siderophore, and extended X-ray absorption fine structure spectra of dissolution products indicates the formation of Cr(III)HDFOB+ and Cr(III)rhizoferrin3− complexes, suggesting a ligand-promoted dissolution mechanism at alkaline pH. Because siderophores promote Cr(III)(OH)3 dissolution at rates similar in magnitude to those of iron hydroxides and the resulting Cr(III)-siderophore complexes may be persistent in solution, siderophores could potentially contribute to the mobilization of Cr in soils and sediments where it is abundant due to geological or anthropogenic sources. DA - 2014/// PY - 2014/// DO - 10.1039/c3em00717k VL - 16 IS - 6 SP - 1348-1359 SN - 2050-7895 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-84901660425&partnerID=MN8TOARS ER - TY - JOUR TI - Identification of epitopes of the beta subunit of soybean beta-conglycinin that are antigenic in pigs, dogs, rabbits and fish AU - Taliercio, Earl AU - Loveless, Telisa M. AU - Turano, Marc J. AU - Kim, Sung Woo T2 - JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE AB - BACKGROUND β-Conglycinin (conglycinin) is one of the major seed storage proteins of soybean. Conglycinin is a 7S trimer composed of different combinations of β, α and α′ subunits. All subunits of conglycinin have been reported to be allergenic in humans. The goal of this research is to identify epitopes of the β subunit of conglycinin that are antigenic in multiple animal species. RESULTS Sera from pigs, dogs, rabbits and hybrid striped bass that had antibodies against soybean conglycinin were identified by ELISA. Most of these sera recognized peptides that represent the β subunit of conglycinin. One antigenic region of the β subunit of conglycinin had considerable overlap among all species tested. One region that was similar to a peanut allergenic epitope in humans overlapped with a region that binds IgE from dogs. One region was antigenic in multiple rabbits and pigs, suggesting it may play a role in the response of pigs to soybean in the diet. CONCLUSION One region of the β subunit of conglycinin is an important antigen across species and abuts a region similar to the peanut allergen ARA h 1. A second region is particularly antigenic in pigs and rabbits. Variants of these antigenic regions of the β subunit of conglycinin may be useful in determining the role these regions play in the health of animals fed soybean. Published 2014. This article is a U.S. Government work and is in the public domain in the USA. DA - 2014/8// PY - 2014/8// DO - 10.1002/jsfa.6556 VL - 94 IS - 11 SP - 2289-2294 SN - 1097-0010 KW - allergen KW - antibody KW - ELISA KW - seed storage protein ER - TY - JOUR TI - Hydrophysical properties, moisture retention, and drainage profiles of wood and traditional components for greenhouse substrates AU - Fields, J. S. AU - Fonteno, W. C. AU - Jackson, B. E. AU - Heitman, J. L. AU - Owen, J. S. T2 - HortScience DA - 2014/// PY - 2014/// VL - 49 IS - 6 SP - 827-832 ER - TY - JOUR TI - Genetic diversity and population structure in the US Upland cotton (Gossypium hirsutum L.) AU - Tyagi, Priyanka AU - Gore, Michael A. AU - Bowman, Daryl T. AU - Campbell, B. Todd AU - Udall, Joshua A. AU - Kuraparthy, Vasu T2 - THEORETICAL AND APPLIED GENETICS DA - 2014/2// PY - 2014/2// DO - 10.1007/s00122-013-2217-3 VL - 127 IS - 2 SP - 283-295 SN - 1432-2242 ER - TY - JOUR TI - Genetic Analysis of Diallel Progeny Test Data Using Factor Analytic Linear Mixed Models AU - Ogut, Funda AU - Maltecca, Christian AU - Whetten, Ross AU - McKeand, Steven AU - Isik, Fikret T2 - FOREST SCIENCE AB - Multienvironmental trials are commonly used in plant breeding programs to select superior genotypes for specific sites or across multiple sites for breeding and deployment decisions. We compared the efficiency of factor analytic (FA) and other covariance structures for genetic analysis of height growth in Pinus taeda L. diallel progeny trials to account for heterogeneity in variances and covariances among different environments. Among the models fitted, FA models produced the smallest Akaike information criterion (AIC) model fit statistic. An unstructured (US) variance-covariance matrix produced a log likelihood value similar to that for the FA model but had a large number of parameters. As a result, some models with US covariance failed to converge. FA models captured both variance and covariance at the genetic level better than simpler models and provided more accurate predictions of breeding values. Narrow-sense heritability estimates for height from 10 different sites were about 0.20 when more complex variance structures were used, compared with 0.13 when simpler variance structures such as identity and block-diagonal variance structures were used. FA models are robust for modeling genotype × environment interaction, and they reduce the computational requirements of mixed-model analysis. On average, all 10 environments had additive genetic correlation of 0.83 and dominance genetic correlation of 0.91, suggesting that genotype × environment interaction should not be a concern for this specific population in the environments in which the genotypes were tested. DA - 2014/2// PY - 2014/2// DO - 10.5849/forsci.12-108 VL - 60 IS - 1 SP - 119-127 SN - 1938-3738 KW - Pinus taeda KW - heritability KW - genotype x environment interactions KW - accuracy of predictions KW - heterogeneous covariance structures ER - TY - JOUR TI - Effect of Delta 9-stearoyl-ACP-desaturase-C mutants in a high oleic background on soybean seed oil composition AU - Ruddle, Paul, II AU - Whetten, Rebecca AU - Cardinal, Andrea AU - Upchurch, Robert G. AU - Miranda, Lilian T2 - THEORETICAL AND APPLIED GENETICS DA - 2014/2// PY - 2014/2// DO - 10.1007/s00122-013-2223-5 VL - 127 IS - 2 SP - 349-358 SN - 1432-2242 ER - TY - JOUR TI - Arsenic Retention in Foliage and Soil after Monosodium Methyl Arsenate (MSMA) Application to Turfgrass AU - Matteson, Audrey R. AU - Gannon, Travis W. AU - Jeffries, Matthew D. AU - Haines, Stephanie AU - Lewis, Dustin F. AU - Polizzotto, Matthew L. T2 - JOURNAL OF ENVIRONMENTAL QUALITY AB - Monosodium methyl arsenate (MSMA) is a commonly used herbicide for weed control in turfgrass systems. There is concern that arsenic from applied MSMA could leach to groundwater or run off into surface water, thereby threatening human and ecosystem health. The USEPA has proposed a phase-out of the herbicide but is seeking additional research about the toxicity and environmental impacts of MSMA before establishing a final ruling. Little research has systematically investigated MSMA in field-based settings; instead, risks have been inferred from isolated field measurements or model-system studies. Accordingly, the overall goal of this study was to quantify the fate of arsenic after MSMA application to a managed turfgrass system. After MSMA application to turfgrass-covered and bareground lysimeters, the majority of arsenic was retained in turfgrass foliage and soils throughout year-long experiments, with 50 to 101% of the applied arsenic recovered in turfgrass systems and 55 to 66% recovered in bareground systems. Dissolved arsenic concentrations from 76.2-cm-depth pore water in the MSMA-treated soils were consistently <2 μg L−1, indistinguishable from background concentrations. As measured by adsorption isotherm experiments, MSMA retention by the sandy soil from our field site was markedly less than retention by a washed sand and a clay loam. Collectively, these results suggest that under aerobic conditions, minimal arsenic leaching to groundwater would occur after a typical application of MSMA to turfgrass. However, repeated MSMA application may pose environmental risks. Additional work is needed to examine arsenic cycling near the soil surface and to define arsenic speciation changes under different soil conditions. DA - 2014/// PY - 2014/// DO - 10.2134/jeq2013.07.0268 VL - 43 IS - 1 SP - 379-388 SN - 1537-2537 ER - TY - JOUR TI - A review of approaches for evapotranspiration partitioning AU - Kool, D. AU - Agam, N. AU - Lazarovitch, N. AU - Heitman, J. L. AU - Sauer, T. J. AU - Ben-Gal, A. T2 - AGRICULTURAL AND FOREST METEOROLOGY AB - Partitioning of evapotranspiration (ET) into evaporation from the soil (E) and transpiration through the stomata of plants (T) is challenging but important in order to assess biomass production and the allocation of increasingly scarce water resources. Generally, T is the desired component with the water being used to enhance plant productivity; whereas, E is considered a source of water loss or inefficiency. The magnitude of E is expected to be quite significant in sparsely vegetated systems, particularly in dry areas or in very wet systems such as surface irrigated crops and wetlands. In these cases, ET partitioning is fundamental to accurately monitor system hydrology and to improve water management practices. This paper aims to evaluate and summarize available methods currently used to separately determine E and T components. We presuppose that, to test the accuracy of ET partitioning methods (measurements and/or modeling), all three components, i.e., E, T and ET, must be estimated independently, but recognize that sometimes one of the components is taken as the residual of the other two. Models that were validated against measurements for their ability to partition between E and T are briefly discussed. To compare approaches, 52 ET partitioning studies were considered regarding estimates of the relative amount of E and for success of agreement in closing the ET = E + T equation. The E/ET ratio was found to exceed 30% in 32 of the studies, which confirms the hypothesis that E often constitutes a large fraction of ET and deserves independent consideration. Only 20 studies estimated E and T as well as ET, and had varied results. A number of studies succeeded to estimate E + T to within 10% of measured ET. Future challenges include development of models simulating the components of ET separately and advancement of methods for continuous measurement of E, T and/or the ratio between the two. DA - 2014/1/15/ PY - 2014/1/15/ DO - 10.1016/j.agrformet.2013.09.003 VL - 184 SP - 56-70 SN - 1873-2240 KW - Evaporation KW - Transpiration KW - Sparse canopy KW - Water use efficiency KW - Energy balance KW - Water balance ER - TY - JOUR TI - The significant contribution of fungi to soil N2O production across diverse ecosystems AU - Chen, Huaihai AU - Mothapo, Nape V. AU - Shi, Wei T2 - APPLIED SOIL ECOLOGY AB - Sporadic observations from pure culture study and direct soil measurement have indicated that fungi can substantially contribute to soil N2O production. Yet, it is still uncertain whether this fungal significance is a more general ecological phenomenon. In this study, relative contributions of fungi and bacteria to soil N2O production were examined in five ecosystems, including conventional farming (CON), integrated crop and livestock system (ICL), organic farming (ORG), plantation forestry (PF), and abandoned agriculture field subjected to natural succession (SUCC). Soil N2O production was measured at 90% water-filled pore space from antibiotic-free controls and soils amended with streptomycin, cycloheximide, or both. Streptomycin and cycloheximide additions significantly reduced soil N2O fluxes from the five systems, ranging from 31% to 54% and 40% to 51%, respectively. Fungi contributed more to soil N2O fluxes than bacteria in PF, whereas fungi and bacteria made comparable contributions in other four systems. Furthermore, soil pH was correlated positively with the percentage of bacterial contribution to soil N2O flux, but negatively with the percentage of fungal contribution to soil N2O flux as well as the ratio of fungal-to-bacterial contributions. Our results showed that fungi could potentially contribute to soil N2O production in diverse agroecosystems and their contribution might be more pronounced in the acidic plantation forestry. DA - 2014/1// PY - 2014/1// DO - 10.1016/j.apsoil.2013.08.011 VL - 73 SP - 70-77 SN - 1873-0272 KW - Fungi KW - Bacteria KW - Nitrous oxide KW - Antibiotics KW - Ecosystems KW - Soil pH ER - TY - JOUR TI - Soil enzyme activities during the 2011 Texas record drought/heat wave and implications to biogeochemical cycling and organic matter dynamics AU - Acosta-Martinez, V. AU - Moore-Kucera, J. AU - Cotton, J. AU - Gardner, T. AU - Wester, D. T2 - APPLIED SOIL ECOLOGY AB - Extreme droughts and heat waves due to climate change may have permanent consequences on soil quality and functioning in agroecosystems. During November 2010 to August 2011, the Southern High Plains (SHP) region of Texas, U.S., a large cotton producing area, received only 39.6 mm of precipitation (vs. the historical avg. of 373 mm) and experienced the hottest summer since record keeping began in 1911. Several enzyme activities (EAs) important in biogeochemical cycling were evaluated in two soils (a loam and a sandy loam at 0–10 cm) with a management history of monoculture (continuous cotton) or rotation (cotton and sorghum or millet). Samplings occurred under the most extreme drought and heat conditions (July 2011), after precipitation resulted in a reduction in a drought severity index (March 2012), and 12 months after the initial sampling (July 2012; loam only). Eight out of ten EAs, were significantly higher in July 2011 compared to March 2012 for some combinations of soil type and management history. Among these eight EAs, enzymes key to C (β-glucosidase, β-glucosaminidase) and P cycling (phosphodiesterase, acid and alkaline phosphatases) were significantly higher (19–79%) in July 2011 than in March 2012 for both management histories regardless of the soil type (P > 0.05). When comparing all sampling times, the activities of alkaline phosphatase, aspartase and urease (rotation only) showed this trend: July 2011 > March 2012 > July 2012. Activities of phosphodiesterase, acid phosphatase, α-galactosidase, β-glucosidase and β-glucosaminidase were higher in July 2011 than July 2012 in at least one of the two management histories. Total C was reduced significantly from July 2011 to March 2012 in the rotation for both soils. Only the activities of arylsulfatase (avg. 36%) and asparaginase showed an increase from July 2011 to March 2012 for both soil types, which may indicate they have a different origin/location than the other enzymes. EAs continued to be a fingerprint of the soil management history (i.e., higher EAs in the rotation than in monoculture) during the drought/heat wave. This study provided some of the first evidence of the adverse effects of a natural, extreme drought and heat wave on soil quality in agroecosystems as indicated by EAs involved in biogeochemical cycling. DA - 2014/3// PY - 2014/3// DO - 10.1016/j.apsoil.2013.10.008 VL - 75 SP - 43-51 SN - 1873-0272 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-84888420330&partnerID=MN8TOARS KW - Soil enzymes KW - Drought KW - Cropping systems KW - Climate change KW - Soil quality KW - Heat wave ER - TY - JOUR TI - Persistence of Benghal dayflower (Commelina benghalensis) in sustainable agronomic systems: Potential impacts of hay bale storage, animal digestion, and cultivation AU - Riar, M. K. AU - Spears, J. F. AU - Burns, J. C. AU - Jordan, D. L. AU - Zhang, C. X. AU - Rufty, T. W. T2 - Agroecology and Sustainable Food Systems AB - Experiments were conducted to evaluate factors affecting persistence of the invasive, federal noxious weed Benghal dayflower in sustainable agronomic systems. Seeds were exposed to a range of temperatures simulating those found in hay bales in the field and periodically tested for viability over 21 days. Seeds were nonviable after one day at 65 °C and after 14 days at 50 or 45 °C. A second series of experiments examined the effects of simulated rumen digestion on germination and viability of Benghal dayflower seeds and the response was compared to that with seeds of five other common weed species. Time courses revealed that seeds from the other weeds were acutely damaged by digestion and viability depressed after 48 and 96 h, but germination of Benghal dayflower seeds was increased at 48 h, and only a slight decrease occurred after 96 h. In the third experimental series, stem fragments of Benghal dayflower were buried in soil at 2 and 6 cm depths and exposed to aerial temperatures of 20, 25, 30, and 35 °C for 30 days. Root development occurred at both depths, but leaf development was restricted at 6 cm and subterranean spathe development was not found at 2 cm. Temperatures higher than 25 °C favor regeneration at both depths. The results, collectively, show the difficulty encountered when trying to control or eradicate Benghal dayflower in sustainable farming systems. Farms must avoid using fresh hay as animal feed when Benghal dayflower is present in hay fields, as little restraint on seed viability will be exerted during digestion and generation of manure. Cultivation is unlikely to be an effective control strategy during summer months when Benghal dayflower is growing most aggressively, because soil temperatures are optimal for vegetative regeneration. DA - 2014/// PY - 2014/// DO - 10.1080/21683565.2013.839486 VL - 38 IS - 3 SP - 283-298 ER - TY - JOUR TI - Nitrogen Management for High Population Corn Production in Wide and Narrow Rows AU - Crozier, Carl R. AU - Gehl, Ronald J. AU - Hardy, David H. AU - Heiniger, Ronnie W. T2 - AGRONOMY JOURNAL AB - Recent trends of planting corn ( Zea mays L.) at higher populations and in narrower rows could influence optimum N management. This study investigates the effects of N rates (0–224 kg ha –1 N plus a low rate of uniformly applied starter) and timing (at planting, V5–V7 sidedress) on corn in wide and narrow rows (76–102 cm vs. 38–51 cm) at 13 sites over 3 yr in North Carolina. Early season N uptake, grain yield, and yield components were measured. Delaying N until sidedress increased yields, but there was an interaction effect with row spacing. Yields were greater with narrow rows and sidedress N (11.7 Mg ha –1 ) than with narrow rows and all N at planting (11.0 Mg ha –1 ) or with wide rows fertilized at either time (11.0 Mg ha –1 ), when averaged across N rates. Three ear yield components increased in response to N fertilization, leading to a 35% yield increase. Rows per ear increased from 15.5 to 15.9 ear –1 , kernels per row increased from 27 to 32 row –1 , and individual kernel mass increased from 226 to 253 mg. Aboveground plant N uptake by the V5 to V7 growth stage was only 9 kg ha –1 , with very little additional N uptake in response to higher N rates. Sidedress N application at V5 to V7 maximized the formation of the ear yield components and grain yield for high population corn in narrow rows, but N timing did not affect yield or ear yield components of wide‐row corn. DA - 2014/// PY - 2014/// DO - 10.2134/agronj2013.0280 VL - 106 IS - 1 SP - 66-72 SN - 1435-0645 ER - TY - JOUR TI - Mapping the low palmitate fap1 mutation and validation of its effects in soybean oil and agronomic traits in three soybean populations AU - Cardinal, Andrea J. AU - Whetten, Rebecca AU - Wang, Sanbao AU - Auclair, Jerome AU - Hyten, David AU - Cregan, Perry AU - Bachlava, Eleni AU - Gillman, Jason AU - Ramirez, Martha AU - Dewey, Ralph AU - Upchurch, Greg AU - Miranda, Lilian AU - Burton, Joseph W. T2 - THEORETICAL AND APPLIED GENETICS AB - fap 1 mutation is caused by a G174A change in GmKASIIIA that disrupts a donor splice site recognition and creates a GATCTG motif that enhanced its expression. Soybean oil with reduced palmitic acid content is desirable to reduce the health risks associated with consumption of this fatty acid. The objectives of this study were: to identify the genomic location of the reduced palmitate fap1 mutation, determine its molecular basis, estimate the amount of phenotypic variation in fatty acid composition explained by this locus, determine if there are epistatic interactions between the fap1 and fap nc loci and, determine if the fap1 mutation has pleiotropic effects on seed yield, oil and protein content in three soybean populations. This study detected two major QTL for 16:0 content located in chromosome 5 (GmFATB1a, fap nc) and chromosome 9 near BARCSOYSSR_09_1707 that explained, with their interaction, 66–94 % of the variation in 16:0 content in the three populations. Sequencing results of a putative candidate gene, GmKASIIIA, revealed a single unique polymorphism in the germplasm line C1726, which was predicted to disrupt the donor splice site recognition between exon one and intron one and produce a truncated KASIIIA protein. This G to A change also created the GATCTG motif that enhanced gene expression of the mutated GmKASIIIA gene. Lines homozygous for the GmKASIIIA mutation (fap1) had a significant reduction in 16:0, 18:0, and oil content; and an increase in unsaturated fatty acids content. There were significant epistatic interactions between GmKASIIIA (fap1) and fap nc for 16:0 and oil contents, and seed yield in two populations. In conclusion, the fap1 phenotype is caused by a single unique SNP in the GmKASIIIA gene. DA - 2014/1// PY - 2014/1// DO - 10.1007/s00122-013-2204-8 VL - 127 IS - 1 SP - 97-111 SN - 1432-2242 ER - TY - JOUR TI - Mapping and genomic targeting of the major leaf shape gene (L) in Upland cotton (Gossypium hirsutum L.) AU - Andres, Ryan J. AU - Bowman, Daryl T. AU - Kaur, Baljinder AU - Kuraparthy, Vasu T2 - THEORETICAL AND APPLIED GENETICS DA - 2014/1// PY - 2014/1// DO - 10.1007/s00122-013-2208-4 VL - 127 IS - 1 SP - 167-177 SN - 1432-2242 ER - TY - JOUR TI - Asset prices and expected monetary policy: evidence from daily data AU - Ivrendi, Mehmet AU - Pearce, Douglas K. T2 - APPLIED ECONOMICS AB - This article explores the relationships among Libor, gold prices, the exchange rate, oil prices, fed funds futures prices and stock prices at a daily frequency. This article examines whether expected monetary policy, measured by changes in the prices of fed funds futures contracts, reacts to high frequency changes in asset prices and, in turn, whether asset prices respond to changes in expected monetary policy. The article reveals that there are statistically significant relationships between expected US monetary policy and shocks to Libor and exchange rates. It also reveals that there is no evidence of a systematic relationship between stock prices and expected monetary policy changes. Splitting the data into expansionary and recessionary periods using NBER dating, we find results for the expansionary periods that are very similar to the results for the entire period. For the periods of recession, we find little evidence of significant linkages between markets. DA - 2014/3/24/ PY - 2014/3/24/ DO - 10.1080/00036846.2013.864038 VL - 46 IS - 9 SP - 985-995 SN - 1466-4283 KW - monetary policy KW - financial markets KW - macroeconomy KW - SVAR ER - TY - JOUR TI - Physiological properties of a drought-resistant wild soybean genotype: Transpiration control with soil drying and expression of root morphology AU - Seversike, Thomas M. AU - Sermons, Shannon M. AU - Sinclair, Thomas R. AU - Carter, Thomas E., Jr. AU - Rufty, Thomas W. T2 - PLANT AND SOIL DA - 2014/1// PY - 2014/1// DO - 10.1007/s11104-013-1757-2 VL - 374 IS - 1-2 SP - 359-370 SN - 1573-5036 KW - Glycine soja KW - Glycine max KW - Fraction of transpirable soil water KW - Drought KW - Transpiration efficiency ER - TY - JOUR TI - Components of hybrid vigor in upland cotton (Gossypium hirsutum L.) and their relationship with environment AU - Tyagi, Priyanka AU - Bowman, Daryl T. AU - Bourland, Fred M. AU - Edmisten, Keith AU - Campbell, B. Todd AU - Fraser, Dawn E. AU - Wallace, Ted AU - Kuraparthy, Vasu T2 - EUPHYTICA DA - 2014/1// PY - 2014/1// DO - 10.1007/s10681-013-0987-y VL - 195 IS - 1 SP - 117-127 SN - 1573-5060 KW - Cotton KW - Breeding KW - Heterosis KW - Lint yield KW - Yield components ER - TY - JOUR TI - Cellulose synthases: new insights from crystallography and modeling AU - Slabaugh, Erin AU - Davis, Jonathan K. AU - Haigler, Candace H. AU - Yingling, Yaroslava G. AU - Zimmer, Jochen T2 - Trends in Plant Science AB - •A crystal structure and a modeled structure of cellulose synthases are examined. •We explore similarities/differences between bacterial and plant cellulose synthase. •Molecular mechanisms for known cellulose synthase missense mutations are proposed. •We predict specific residues putatively involved in glucan translocation in plants. Detailed information about the structure and biochemical mechanisms of cellulose synthase (CelS) proteins remained elusive until a complex containing the catalytic subunit (BcsA) of CelS from Rhodobacter sphaeroides was crystalized. Additionally, a 3D structure of most of the cytosolic domain of a plant CelS (GhCESA1 from cotton, Gossypium hirsutum) was produced by computational modeling. This predicted structure contributes to our understanding of how plant CelS proteins may be similar and different as compared with BcsA. In this review, we highlight how these structures impact our understanding of the synthesis of cellulose and other extracellular polysaccharides. We show how the structures can be used to generate hypotheses for experiments testing mechanisms of glucan synthesis and translocation in plant CelS. Detailed information about the structure and biochemical mechanisms of cellulose synthase (CelS) proteins remained elusive until a complex containing the catalytic subunit (BcsA) of CelS from Rhodobacter sphaeroides was crystalized. Additionally, a 3D structure of most of the cytosolic domain of a plant CelS (GhCESA1 from cotton, Gossypium hirsutum) was produced by computational modeling. This predicted structure contributes to our understanding of how plant CelS proteins may be similar and different as compared with BcsA. In this review, we highlight how these structures impact our understanding of the synthesis of cellulose and other extracellular polysaccharides. We show how the structures can be used to generate hypotheses for experiments testing mechanisms of glucan synthesis and translocation in plant CelS. DA - 2014/2// PY - 2014/2// DO - 10.1016/j.tplants.2013.09.009 VL - 19 IS - 2 SP - 99-106 J2 - Trends in Plant Science LA - en OP - SN - 1360-1385 UR - http://dx.doi.org/10.1016/j.tplants.2013.09.009 DB - Crossref ER - TY - JOUR TI - An Experimental Study of Coupled Heat and Water Transfer in Wettable and Artificially Hydrophobized Soils AU - Davis, Dedrick D. AU - Horton, Robert AU - Heitman, Joshua L. AU - Ren, Tusheng T2 - SOIL SCIENCE SOCIETY OF AMERICA JOURNAL AB - The effect of soil wettability on coupled heat and water transfer in soil is not well understood. The objective of this work was to determine the effect of soil wettability on coupled heat and water transfer for two wettable soils and their artificially hydrophobized counterparts. Closed soil cells instrumented with heat-pulse sensors provided in situ measurements of soil temperature, soil volumetric water content (θ), soil thermal conductivity (λ), and soil thermal diffusivity (α). Nonlinear temperature distributions developed in response to the 150°C m−1 temperature gradients applied to the soil cells for both the wettable and hydrophobized soils due to soil moisture redistribution. Hydrophobized sand and silt loam soils had different responses relative to their wettable counterparts. Soil moisture redistribution was similar in the wettable and hydrophobized sand soils. Net water transfer was reduced by 56% in the hydrophobized silt loam compared with the wettable silt loam. Reduced net water transfer in the hydrophobized silt loam indicated that water vapor transfer must have been lower in the hydrophobized silt loam than in the wettable silt loam. Diffusive pathways for water vapor may increase due to hydrophobicity. In both the wettable and hydrophobized soils, λ and α decreased in the warm regions and increased in the cold regions of the soil cells due to soil moisture redistribution. Wettability is a function of water content, and relative to wettable soil, water redistribution in hydrophobized soil is reduced only when the water content is small enough for the soil to behave as hydrophobic. If the water content is large enough for a hydrophobized soil to behave as wettable, water redistribution is similar to that in a wettable soil. DA - 2014/// PY - 2014/// DO - 10.2136/sssaj2013.05.0182 VL - 78 IS - 1 SP - 125-132 SN - 1435-0661 ER - TY - JOUR TI - An Alternative to Multiple Protoporphyrinogen Oxidase Inhibitor Applications in No-Till Cotton AU - Cahoon, Charles W. AU - York, Alan C. AU - Jordan, David L. AU - Everman, Wesley J. AU - Seagroves, Richard W. T2 - WEED TECHNOLOGY AB - Glyphosate-resistant (GR) Palmer amaranth is a widespread problem in southeastern cotton production areas. Herbicide programs to control this weed in no-till cotton commonly include flumioxazin applied with preplant burndown herbicides approximately 3 wk before planting followed by fomesafen applied PRE and then glufosinate or glyphosate applied POST. Flumioxazin and fomesafen are both protoporphyrinogen oxidase (PPO) inhibitors. Multiple yearly applications of PPO inhibitors in cotton, along with widespread use of PPO inhibitors in rotational crops, raise concerns over possible selection for PPO resistance in Palmer amaranth. An experiment was conducted to determine the potential to substitute diuron for one of the PPO inhibitors in no-till cotton. Palmer amaranth control by diuron and fomesafen applied PRE varied by location, but fomesafen was generally more effective. Control by both herbicides was inadequate when timely rainfall was not received for activation. Palmer amaranth control was more consistent when programs included a preplant residual herbicide. Applied preplant, flumioxazin was more effective than diuron. Programs with diuron preplant followed by fomesafen PRE were as effective as flumioxazin preplant followed by fomesafen only if fomesafen was activated in a timely manner. Programs with flumioxazin preplant followed by diuron PRE were as effective as flumioxazin preplant followed by fomesafen PRE at all locations, regardless of timely activation of the PRE herbicide. As opposed to flumioxazin preplant followed by fomesafen PRE, which exposes Palmer amaranth to two PPO-inhibiting herbicides, one could reduce selection pressure by using flumioxazin preplant followed by diuron PRE without sacrificing Palmer amaranth control or cotton yield. DA - 2014/// PY - 2014/// DO - 10.1614/wt-d-13-00078.1 VL - 28 IS - 1 SP - 58-71 SN - 1550-2740 KW - Herbicide resistance management KW - herbicide-resistant weeds KW - PPO-inhibiting herbicides KW - weed control ER - TY - JOUR TI - 'Covington' Sweetpotato Tolerance to Flumioxazin Applied POST-Directed AU - Meyers, Stephen L. AU - Jennings, Katherine M. AU - Monks, David W. T2 - WEED TECHNOLOGY AB - Field studies were conducted at Clinton, NC (2009, 2010), and Kinston, NC (2010), to determine ‘Covington' sweetpotato tolerance to flumioxazin applied after transplanting. Flumioxazin was directed to 25% of the sweetpotato vine beginning at the distal end (shoot tip), 25% of the vine beginning at the proximal end (crown), or to the entire vine (over-the-top) and was applied at 2 or 5 wk after transplanting (WAP). Applications made at 2 WAP resulted in 10 to 16% foliar necrosis at 3 WAP. Necrosis was transient and ≤ 2% by 6 WAP. Stunting injury at 6 WAP for flumioxazin applied at 2 WAP was greatest (12%) with the over-the-top application, followed by crown (5%), and shoot tip (1%) applications. Applications made at 5 WAP resulted in 35, 23, and 15% foliar necrosis at 6 WAP for over-the-top, crown, and shoot tip applications, respectively. By 12 WAP, stunting injury for all treatments was ≤ 3%. No. 1, jumbo, canner, and total marketable sweetpotato yield of the nontreated check was 36,670; 7,610; 7,170; and 51,450 kg ha −1 , respectively. No. 1 and total marketable sweetpotato yields were reduced when flumioxazin was applied at 2 or 5 WAP. No. 1 sweetpotato yield was reduced when flumioxazin was applied to the crown or over-the-top (27,240 and 28,330 kg ha −1 , respectively). Sweetpotato receiving flumioxazin applied to the shoot tip had similar no. 1 (31,770 kg ha −1 ) yields as the nontreated check, crown, and over-the-top applications. Total marketable sweetpotato yield was reduced by flumioxazin application to shoot tip, crown, and over-the-top (45,350; 40,100; 40,370 kg ha −1 , respectively). Neither flumioxazin application timing nor placement influenced either jumbo- or canner-grade sweetpotato yields. Currently, after-transplant applications of flumioxazin do not appear to be a suitable fit for POST weed control in North Carolina sweetpotato production systems. DA - 2014/// PY - 2014/// DO - 10.1614/wt-d-13-00092.1 VL - 28 IS - 1 SP - 163-167 SN - 1550-2740 KW - Crop tolerance KW - herbicide placement KW - herbicide timing ER - TY - JOUR TI - SOIL MICROBIAL RESPONSES TO ELEVATED CO2 AND O-3 IN A NITROGEN-AGGRADING AGROECOSYSTEM AU - Cheng, Lei AU - Booker, Fitzgerald L. AU - Burkey, Kent O. AU - Tu, Cong AU - Shew, H. David AU - Rufty, Thomas W. AU - Fiscus, Edwin L. AU - Deforest, Jared L. AU - Hu, Shuijin T2 - CARBON CAPTURE AND STORAGE: CO2 MANAGEMENT TECHNOLOGIES AB - Climate change factors such as elevated atmospheric carbon dioxide (CO₂) and ozone (O₃) can exert significant impacts on soil microbes and the ecosystem level processes they mediate. However, the underlying mechanisms by which soil microbes respond to these environmental changes remain poorly understood. The prevailing hypothesis, which states that CO₂- or O₃-induced changes in carbon (C) availability dominate microbial responses, is primarily based on results from nitrogen (N)-limiting forests and grasslands. It remains largely unexplored how soil microbes respond to elevated CO₂ and O₃ in N-rich or N-aggrading systems, which severely hinders our ability to predict the long-term soil C dynamics in agroecosystems. Using a long-term field study conducted in a no-till wheat-soybean rotation system with open-top chambers, we showed that elevated CO₂ but not O₃ had a potent influence on soil microbes. Elevated CO₂(1.5×ambient) significantly increased, while O₃ (1.4×ambient) reduced, aboveground (and presumably belowground) plant residue C and N inputs to soil. However, only elevated CO₂ significantly affected soil microbial biomass, activities (namely heterotrophic respiration) and community composition. The enhancement of microbial biomass and activities by elevated CO₂ largely occurred in the third and fourth years of the experiment and coincided with increased soil N availability, likely due to CO₂-stimulation of symbiotic N₂ fixation in soybean. Fungal biomass and the fungi∶bacteria ratio decreased under both ambient and elevated CO₂ by the third year and also coincided with increased soil N availability; but they were significantly higher under elevated than ambient CO₂. These results suggest that more attention should be directed towards assessing the impact of N availability on microbial activities and decomposition in projections of soil organic C balance in N-rich systems under future CO₂ scenarios. DA - 2014/// PY - 2014/// DO - 10.1371/journal.pone.0021377 SP - 277-307 ER - TY - CONF TI - Validation of Fusarium head blight resistance QTL using the NC-Neuse / Bess doubled haploid population AU - Petersen, S. AU - J.H. Lyerly, A.L. McKendry AU - R. Navarro, C. Cowger AU - G. Brown-Guedira, S. Islam AU - Murphy, J. P. C2 - 2014/// C3 - National Fusarium Head Blight Forum DA - 2014/// ER -