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Yu, Shaobing. "Winter wheat nitrogen management in south coastal British Columbia." Thesis, University of British Columbia, 1990. http://hdl.handle.net/2429/29888.
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Nitrogen is essential to obtain high yields of winter wheat in south coastal British Columbia, which includes Vancouver Island and the lower Fraser Valley. An accurate recommendation for N application is required to keep input costs down for most economical returns and to limit environmental problems related to leaching of excess N. The questions are how much, when and which form of N should be applied to winter wheat. The general objective of this study is to improve our understanding of winter wheat growth and N uptake. This study monitors the soil N supply and characterizes the plant development, dry matter accumulation, and N uptake of winter wheat in South Coastal B.C.. Also, it compares the effectiveness of conventional and intensive crop N management and urea and ammonium nitrate sources of fertilizer N under intensive crop management.
A series of field experiments was conducted in 1986-87 and 1987-88 with winter wheat to evaluate conventional and intensive N management in the area. Additionally, a N source
study was carried out in the latter year to compare ammonium nitrate and urea.
Soil N supply for winter wheat ranged from 52 to 151 kg N/ha through the two years of field experiments at five sites. Available N in the 0-50 cm soil depth varied from 10 to 100 kg N/ha through the growing season in the different treatments. An accurate estimate of N behavior involves N accumulation in the crop. During the early spring until harvest, the crop dry matter yield and N uptake patterns were plotted. The grain yields ranged from 4 to 9 t/ha for the conventional management (75 kg N/ha), and from 4 to 11 t/ha for the intensive crop management (I.CM. 225 kg N/ha) system. Between the conventional and I.CM., there was no significant difference in grain yield but there was in quality, specifically grain protein. Grain protein ranged from 8.2 to 9.7% for the conventional and from 10 to 13.7% for the I.CM. treatment. Also, there was no difference in grain yield or quality between ammonium nitrate and urea fertilized plots at final harvest. However, in the early stage at GS31, crop took up more N from ammonium nitrate (97 kg N/ha) than from urea (75 kg N/ha) and soil mineral N levels with urea were higher than with ammonium nitrate.Land and Food Systems, Faculty of
Graduate
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Lotfollahi, Mohammad. "The effect of subsoil mineral nitrogen on grain protein concentration of wheat." Title page, table of contents and summary only, 1996. http://web4.library.adelaide.edu.au/theses/09PH/09phl882.pdf.
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Copy of author's previously published work inserted. Bibliography: leaves 147-189. This project examines the uptake of mineral N from the subsoil after anthesis and its effect on grain protein concentration (GPC) of wheat. The overall objective is to examine the importance of subsoil mineral N and to investigate the ability of wheat to take up N from the subsoil late in the season under different conditions of N supply and soil water availability. Greenhouse experiments investigate the importance of subsoil mineral N availability on GPC of wheat and the factors that contribute to the effective utilisation of N. The recovery of N from subsoil, the effect of split N application on GPC and short term N uptake by the wheat at different rooting densities are also studied.
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Sarvestani, Zeinolabedin Tahmasebi. "Water stress and remobilization of dry matter and nitrogen in wheat and barley genotypes /." Title page, table of contents and summary only, 1995. http://web4.library.adelaide.edu.au/theses/09PH/09phs251.pdf.
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Wang, Guangyao (Sam), Kevin Brunson, Kelly Thorp, and Mike Ottman. "Cultivar and Nitrogen Effects on Yield and Grain Protein in Irrigated Durum Wheat, 2012." College of Agriculture and Life Sciences, University of Arizona (Tucson, AZ), 2013. http://hdl.handle.net/10150/312150.
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The grain yield and nitrogen use efficiency of durum wheat vary in response to genotypic and nitrogen fertilization were studied in field during two growth seasons. The aim of this study was to evaluate the effects the N fertilizer rate on grain yield and quality under irrigated desert conditions in relation to N utilization. Six durum wheat cultivars (Duraking, Havasu, Kronos, Ocotillo, Orita, Topper) were grown in field trails under irrigated regimes at five N levels (0, 65, 110, 160, 240 lbs/acre) in 2010-2011 and six N levels (0, 65, 110, 160, 240, 360 kg ha-1) in 2011-2012 at Maricopa Ag Center. The results showed the varieties and N levels both significantly affected grain yield, grain protein concentration, and nitrogen use efficiency. A simple and rapid method to measure crop N status using SPAD meters was also developed. The results showed that using the differences in SPAD readings between the first and second fully expanded leaves is a useful way to improve effectiveness of SPAD meters in durum wheat N management.
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Ottman, M. J., T. A. Doerge, and E. C. Martin. "Late Season Water and Nitrogen Effects on Durum Quality, 1996." College of Agriculture, University of Arizona (Tucson, AZ), 1997. http://hdl.handle.net/10150/202456.
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Durum grain quality is affected by many factors, but water and nitrogen are factors that the grower can control. The purpose of this research was to determine 1) the nitrogen application rate required at pollen shed to maintain adequate grain protein levels if irrigation is excessive or deficient during grain fill and 2) if nitrogen applications during grain fill can elevate grain protein. Field research was conducted at the Maricopa Agricultural Center using the durum varieties Duraking, Minos, and Turbo. The field was treated uniformly until pollen shed when nitrogen was applied at rates of 0, 30, and 60 lbs /acre. During grain fill, the plots were irrigated based on 30, 50, or 70% moisture depletion. In a separate experiment, nitrogen fertilizer was applied at a rate of 30 lbs N /acre at pollen shed only, pollen shed and the first irrigation after pollen shed, and pollen shed and the first and second irrigation after pollen shed. Increased irrigation frequency during grain fill decreased HVAC from 93 to 81%. Increasing nitrogen rate at pollen shed from 0 to 30 and 30 to 60 lbs N /acre increased protein from 11.6 to 12.5% and 12.5 to 13.3% and increased HVAC from 79 to 89% and 89 to 94 %. Nitrogen fertilizer application at the first irrigation after pollen shed increased grain protein content from 12.9 to 13.6% and application at the first and second irrigation after pollen shed increased grain protein content further to 14.1% averaged over varieties. Nitrogen fertilizer application during grain fill may not be too late to increase grain protein content.
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Silva, Cristiano Lemes da. "Caracterização de genótipos brasileiros de trigo para eficiência de uso do nitrogênio e qualidade industrial em multi-ambientes." Universidade Tecnológica Federal do Paraná, 2013. http://repositorio.utfpr.edu.br/jspui/handle/1/453.
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CAPESCaracterizar a presença de variabilidade genética quanto a eficiência de uso de nitrogênio (EUN) e identificar ambientes que maximizem a produtividade e qualidade industrial de grãos é de fundamental importância para a sustentabilidade e competitividade da cultura do trigo no Brasil. O primeiro experimento objetivou avaliar os níveis de desoxinivalenol (DON) e caracterizar cultivares de trigos brasileiros recentemente disponibilizados para cultivo, quanto à eficiência de uso do N (EUN) em dois locais de cultivo (Pato Branco-PR e Coxilha-RS), na safra agrícola de 2011. Os experimentos foram conduzidos em Pato Branco-PR e Coxilha-RS, na safra agrícola de 2011 em delineamento experimental de blocos casualizados com três repetições e analisados de forma conjunta. A micotoxina DON foi detectada em 97.23% das amostras variando de 200 a 4140 μg kg-1, com valores médios de 1058 μg kg-1 em Pato Branco e 1357μg kg-1 em Coxilha. De um total de 108 amostras, 17% representadas pelos cultivares IPR Catuara TM, IPR 144, BRS Tangará e BRS 220, apresentaram níveis de DON superiores ao limite tolerado pela Anvisa para o ano de 2012. Também foi identificado variabilidade genética para a eficiência de uso do nitrogênio pelos grãos (EUNg – 47.6 a 81.1 kg/kg) e índice de colheita de nitrogênio (ICN – 71.3 a 84.6%), com destaque para os cultivares Mirante, Quartzo, F. Cristalino, F. Raízes e CD 150. O rendimento de grãos dos cultivares de trigo atuais associou-se positivamente com a maior produção de biomassa total (0,85** e 0,82**) em ambos os locais. O segundo experimento objetivou avaliar a capacidade geral e específica de combinação de componentes da EUN em cruzamentos dialélicos e investigar possíveis associações com caracteres agronômicos. Seis genitores e 15 populações segregantes F2 foram avaliadas a campo em delineamento de blocos casualizados com três repetições. Efeitos gênicos aditivos e não-aditivos afetaram os componentes da EUN. Os genitores Mirante, Valente e BRS Tangará apresentaram os maiores valores de CGC para componentes da EUN. O índice relativo de clorofila B foi significativamente associado com o RG (0,49*), peso de mil grãos (0,44*) e EUNg (0,50*), indicando que esse caractere pode ser utilizado seleção indireta de progênies superiores em gerações precoces. Por último 29 linhagens e 10 cultivares de trigo foram testadas em 11 locais de cultivo no Paraná nas safras agrícolas 2010 e 2011, com o objetivo de selecionar linhagens de trigo e identificar ambientes de testes ideais para a maximização do rendimento de grãos e qualidade de panificação. Foram usadas as metodologias em gráfico biplot AMMI e GGE para a análise dos dados. Em 2010, Nova Fátima e Ventania forma ambientes representativos e discriminantes para rendimento de grãos (RG). Em 2011, Apucarana e Astorga destacaram-se como ambientes ideais para seleção de genótipos para qualidade de panificação. A análise de genótipo-ideal indicou as linhagens BIO-08528 e BIO-08228 para RG e concentração protéica dos grãos (CPG), respectivamente. Em 2011, as linhagens BIO-10161 e BIO-10141 foram superiores para RG e qualidade de panificação e devem ser selecionadas. A CPG e o teste de sedimentação SDS correlacionaram-se entre si (r=0,61**) e foram moderadamente associados com a forca de glúten(r=0,49** e 0,74**), indicando que podem ser empregados na seleção indireta para qualidade de panificação em programas de melhoramento genético de trigo.
To characterize the genetic variability as the nitrogen use efficiency (NUE) and identify environments that maximize grain yield and baking quality is of essential importance for the competitiveness and sustainability of crop wheat in Brazil. The first experiment was objective to evaluate the levels of deoxynivalenol (DON) and to characterize Brazilian wheat cultivars recently release and available for cultivation, as the efficiency of use of N (EUN) in two growing locations (Pato Branco, Paraná and Coxilha-RS), in 2011 crop season. The experimental design was a randomized block with three replications and analyzed jointly. The mycotoxin DON was detected in 97.23% of samples ranging from 200 to 4140 μg kg-1, with mean values of 1058 μg kg-1 in Pato Branco and 1357 μg kg-1 in Coxilha. From a total of 108 samples, 17% represented by cultivars IPR Catuara TM, IPR 144, BRS 220 and BRS Tangará, had DON levels above the limit tolerated by ANVISA for 2012 crop season. Additionally, was identified genetic variability for nitrogen use efficiency by grains (NUEg – 47,6 to 81,1 kg/kg) and nitrogen harvest index (NHI – 71,3 to 84,6%), highlighting the cultivars Mirante, Quartzo, F. Cristalino, F. Raízes and CD 150. Grain yield of current brasilian wheat cultivars was positively associated with total biomass production (0,85 ** and 0,82 **) at both locations. The objective of the second experiment was to evaluate the general ability combination (GCA) and specific ability (SCA) of NUE components and investigate possible associations with agronomic traits in diallel crosses. Six parents and 15 F2 segregating populations were evaluated in the field in a randomized block design with three replications. Additive and non-additive genetic effects influenced the expression of the components of NUE. The parents Mirante, Valente and BRS Tangará showed the highest CGC values for components of NUE. The relative relative chlorophyll B was significantly associated with the RG (0,49*), thousand kernel weight (0,44*) and NUEg (0,50*), indicating that this traits can be used for indirect selection of superior genotypes in early generations. Lastly, 29 wheat lines and 10 cultivars were tested in 11 cultivation sites in Paraná in the 2010 and 2011 growing seasons, with the objective of this study was to select wheat lines and identify ideal test environments for maximizing yield and baking quality. AMMI and GGE Biplot graphic methodologies were used for data analysis. In 2010 crop season, Nova Fatima e Ventania locals classified themselves as discriminating and representative for grain yield (GY). In 2011 crop season, Apucarana and Astorga showed out as ideal environments to selection of genotypes with high baking quality. The ideal-genotype analysis indicated the BIO-08528 BIO-08228 lines to GY and protein concentration, respectively. In the 2011 crop season, BIO-10161 and BIO-10141 lines and were higher for GY and baking quality and should be selected. Grain protein concentration SDS-sedimentation test correlated with each other (r = 0,61**) and were positively associated with gluten strength (r = 0,49** and 0,74**), indicating that they can be used as indirect selection criteria for bread-making quality in wheat breeding programs.
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Ottman, M. J., T. A. Doerge, and E. C. Martin. "Late Season Water and Nitrogen Effects on Durum Quality, 1995 (Final)." College of Agriculture, University of Arizona (Tucson, AZ), 1996. http://hdl.handle.net/10150/202421.
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Durum grain quality is affected by many factors, but water and nitrogen are factors that the grower can control. The purpose of this research was to determine 1) the nitrogen application rate required at pollen shed to maintain adequate grain protein levels if irrigation is excessive or deficient during grain fill and 2) if nitrogen applications during grain fill can elevate grain protein. Field research was conducted at the Maricopa Agricultural Center using the durum varieties Duraking, Minos, and Turbo. The field was treated uniformly until pollen shed when nitrogen was applied at rates of 0, 30, and 60 lbs/acre. During grain fill, the plots were irrigated based on 30, 50, or 70% moisture depletion. In a separate experiment, nitrogen fertilizer was applied at a rate of 30 lbs N/acre at pollen shed only, pollen shed and the first irrigation after pollen shed, and pollen shed and the first and second irrigation after pollen shed. Irrigation had no effect on grain protein level, although increasing nitrogen rates at pollen shed from 0 to 30 and 30 to 60 lbs N/acre increased protein by 1 percentage point. Nitrogen fertilizer application at the first irrigation after pollen shed increased grain protein content from 10.4 to 11.4% and application at the first and second irrigation after pollen shed increased grain protein content further to 11.9% averaged over varieties. Irrigation management during grain fill may not play as large a role in controlling grain protein content as was originally thought except perhaps on heavy soils, and nitrogen fertilizer application during grain fill may not be too late to increase grain protein content.
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Ottman, M. J., T. A. Doerge, and E. C. Martin. "Late Season Water and Nitrogen Effects on Durum Quality, 1995 (Preliminary)." College of Agriculture, University of Arizona (Tucson, AZ), 1995. http://hdl.handle.net/10150/201443.
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Durum grain quality is affected by many factors, but water and nitrogen are factors that the grower can control. The purpose of this research was to determine 1) the nitrogen application rate required at pollen shed to maintain adequate grain protein levels if irrigation is excessive or deficient during grain fill and 2) if nitrogen applications during grain fill can elevate grain protein. Field research was conducted at the Maricopa Agricultural Center using the durum varieties Duraking, Minos, and Turbo. The field was treated uniformly until pollen shed when nitrogen was applied at rates of 0, 30, and 60 lbs /acre. During grain fill, the plots were irrigated based on 30, 50, or 70% moisture depletion. In a separate experiment, nitrogen fertilizer was applied at a rate of 30 lbs N /acre at pollen shed only, pollen shed and the first irrigation after pollen shed, and pollen shed and the first and second irrigation after pollen shed. Irrigation had no effect on grain protein level, although increasing nitrogen rates at pollen shed from 0 to 30 and 30 to 60 lbs N /acre increased protein by 1 percentage point. Nitrogen fertilizer application at the first irrigation after pollen shed increased grain protein content from 10.4 to 11.4% and application at the first and second irrigation after pollen shed increased grain protein content further to 11.9% averaged over varieties. Irrigation management during grain fill may not play as large a role in controlling grain protein content as was originally thought except perhaps on heavy soils, and nitrogen fertilizer application during grain fill may not be too late to increase grain protein content.
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Fauzi, Mohamad Taufik. "The effect of growth regulators and nitrogen on Fusarium head blight of wheat /." Thesis, McGill University, 1992. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=69547.
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Plant growth regulators and nitrogen fertilization have been associated with the increased incidence of fusarium head blight, a destructive disease of wheat (Triticum aestivum L.). In Canada, the major causal organism of this disease is Fusarium graminearum Schwabe, the conidial state of Gibberella zeae (Schw.) Petch. Most studies concerning the effect of plant growth regulators on fusarium head blight were conducted in fields with natural infection. The objective of this research was to evaluate the effect of growth regulators and nitrogen fertilizer on the incidence of fusarium head blight of wheat with artificial inoculations.A survey conducted in a field trial testing the effect of the plant growth regulator Cerone on the yield components of several cultivars of spring wheat showed that Cerone treatments increased Fusarium infection only in cultivar Columbus. Further research was conducted using cultivar Max, a cultivar susceptible to fusarium head blight, which is widely grown in Quebec. In controlled-condition greenhouse trials, the growth regulators Cycocel and Cerone, as well as nitrogen fertilization did not influence the disease progress. In the 1991 field experiment, the highest incidence of seed infection was observed in Cycocel treatments when the macroconidia of F. graminearum were directly applied to the heads, but not significantly different from the non-treated control. None of the nitrogen levels affect the incidence of seed infection. In the 1992 field trial, the plots were treated with macroconidia of F. graminearum applied to the heads or with Fusarium-colonized corn applied to the rows. Both Cycocel and Cerone significantly increased the incidence of spikelet only in the colonized corn treatments. Cycocel also increased the incidence of seed infection, but only in colonized corn treatments. Cycocel also increased the incidence of seed infection in the non-inoculated treatments. Growth regulators had no effect on the disease when heads were inoculated directly with macroconidia.
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Beche, Eduardo. "Caracteres agronômicos e fisiológicos associados ao progresso do melhoramento genético de trigo no Brasil." Universidade Tecnológica Federal do Paraná, 2013. http://repositorio.utfpr.edu.br/jspui/handle/1/465.
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CNPqConhecer os processos responsáveis pelo avanço do progresso genético do rendimento de grãos é uma etapa essencial para o desenvolvimento de cultivares mais produtivas. Os objetivos do estudo foram: a) Avaliar a duração dos subperíodos de desenvolvimento de cultivares de trigo brasileiros, lançados entre 1940 e 2009, e quantificar a importância de cada fenofase sobre o rendimento de grãos e seus componentes. b) Caracterizar, fisiologica e agronomicamente, cultivares de trigo desenvolvidos entre 1940 e 2009, a fim de identificar critérios de seleção mais efetivos à continuidade do progresso genético de melhoramento no Brasil. c) Caracterizar cultivares antigos e modernos brasileiros, lançados em diferentes décadas, quanto à eficiência do uso do nitrogênio e seus componentes. Dez cultivares de trigo brasileiros, antigos e modernos, foram avaliados em ensaios de competição, em duas safras agrícolas (2010 e 2011); na safra agrícola de 2011 um ensaio foi conduzido em casa de vegetação, com quatro doses de nitrogênio (0, 60, 120 e 180 kg N ha-1). Comparou-se a duração dos subperíodos, caracteres agronômicos e fisiológicos (trocas gasosas) e caracteres da eficiência do uso do nitrogênio (EUN). O melhoramento reduziu a fase de semeadura a antese e aumentou a fase de enchimento de grãos, contribuindo com o aumento da massa de mil grãos. Os genótipos modernos tiveram o subperíodo de espigueta terminal a antese aumentado (0,68 a 1,35 graus dias ano-1) ao longo dos anos, contribuindo com o incremento do número de grãos por espigueta, número de grãos por espiga, peso seco de espiga em antese e índice de fertilidade da espiga. O incremento de rendimento de grãos foi de 29 kg ha-1 ano-1, com um ganho genético de 0,92% ano-1 no período de 1940 e 2009. O progresso genético para rendimento de grãos foi principalmente relacionado ao incremente do índice de colheita, número de grãos e rendimento biológico, que foram alcançados pelo aumento da condutância estomática e da taxa fotossintética em pré e pós-antese e redução da estatura de planta. A eficiência de absorção de nitrogênio (EAN) foi positivamente associada com a eficiência do uso do nitrogenio (EUN) na ausência de adubação nitrogenada. A eficiência de utilização do nitrogenio (EUtN) e a EAN foram positivamente associadas a EUN nas doses elevadas de N. Os cultivares mais recentemente disponibilizados para cultivo (Quartzo, CD 117, BRS Tangará, BRS 220, BRS 208 e BRS Guamirim) foram mais eficientes no uso do nitrogênio e mais tolerantes a baixas doses em comparação ao grupo formado pelos cultivares BRS 179, BR 23, Toropi e Frontana.
Knowledge the processes responsible for the progress of genetic gain in grain yield in wheat plant is an essential step for the development of high yield cultivars. The aims of the study were: a) Evaluate the duration of developmental phases in wheat cultivars and quantify the importance of each phase on grain yield and its components. b) characterize physiological and agronomically wheat cultivars released in different decades, to identify selection criteria for continued improvement of genetic progress in Brazil. c) Characterize Brazilian wheat cultivars developed in different decades for the nitrogen use efficiency (NUE). Ten wheat cultivars released from1940 to 2009, were examined for two years in a competition essay (2010 and 2011) and in 2011 an essay in green house was conducted with four nitrogen rates (0, 60, 120 e 180 kg N ha-1). We compared the duration of periods, agronomic and physiological traits (gas exchange) and nitrogen use efficiency (EUN) characters. The Breeding reduced time to anthesis and increased the grain filling, contributing to the increase in thousand kernel weight. The modern cultivars had the period terminal spikelet to anthesis increased (0,68 to 1,35 degree days year-1) over the years, contributing to the increase in the number of grains per spikelet, number of grains per spike, spike dry weight at anthesis and spike fertility index. The increase in grain yield was 29 kg ha-1 yr-1, with a genetic gain of 0,92% yr-1 from 1940 to 2009, this is largely related to the increased of harvest index, number of grains m-2 and biological yield, which were achieved through improving stomatal conductance and photosynthetic rate in pre and post-anthesis and reduced in plant height. The nitrogen uptake efficiency (NUpE) was positively associated with nitrogen use efficiency (NUE) in the absence of fertilization. Nitrogen utilization efficiency (NutE) and NUpE were positively associated with NUE in higher N. The modern cultivars (Quartzo, CD 117, BRS Tangará, BRS 220, BRS 208 and BRS Guamirim) were more efficient in the use of nitrogen and more tolerant to low N input compared to the group formed by BRS 179, BR 23, Toropi and Frontana.
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Doerge, T. A., T. C. Knowles, L. Clark, and E. Carpenter. "Effects of Early Season Nitrogen Rates on Stem Nitrate Levels and Nitrogen Fertilizer Requirements During Grain Filling for Irrigated Durum Wheat." College of Agriculture, University of Arizona (Tucson, AZ), 1989. http://hdl.handle.net/10150/201074.
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A field experiment was conducted on a Pima clay loam at the Safford Agricultural Center to: 1) determine the optimum rates of late season N needed to achieve optimum yield and quality of irrigated durum wheat in conjunction with varying rates of early season N; and 2) evaluate the usefulness of stern NO₃-N analysis in predicting the late season N rates which optimize grain production but minimize the potential for nitrate pollution of groundwater. The application of 75, 175 and 350 lbs. N/a during vegetative growth resulted in wheat with deficient, sufficient and excessive N status at the boot stage, as indicated by stem NO₃-N analysis. The application of 60 lbs. N/a at heading to N- deficient wheat and 15-20 lbs. N/a to N-sufficient wheat resulted in grain protein levels above 14 %, but the applications had little effecton grain yield. Applications of N at heading to wheat which had previously received excessive N did not affect grain yield or quality. The use of stein NO₃-N analysis appears to be a useful tool in predicting the minimum N rate to be applied during the early reproductive period to insure acceptable levels of grain protein at harvest.
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Trevizan, Diego Maciel. "Eficiência de uso e doses de nitrogênio em trigo sob diferentes arranjos espaciais de plantas." Universidade Tecnológica Federal do Paraná, 2017. http://repositorio.utfpr.edu.br/jspui/handle/1/2288.
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CAPES; CNPqUma das alternativas para minimizar as perdas de nitrogênio (N), além do uso de cultivares de trigo (Triticum aestivum L.) mais eficientes na utilização desse nutriente, e a identificação de manejos que intensifiquem o aproveitamento do N. Para as cultivares e condições climáticas do Brasil, existem poucos estudos que tenham quantificado como o arranjo espacial de plantas afeta a eficiência de uso do N. O objetivo deste estudo foi avaliar o efeito de diferentes arranjos espaciais (combinação entre densidades de semeadura e espaçamento entre linhas) no desempenho agronômico e aproveitamento do N mineral aplicado. O experimento foi conduzido em Pato Branco, nas safras agrícolas de 2014 e 2015, em delineamento em blocos ao acaso, em modelo fatorial, com três repetições. Dois cultivares de trigo (CD 150 e Ametista) foram submetidos a quatro densidades de semeadura (150, 300, 450 e 600 sementes m-2), duas doses de N (20 e 120 Kg ha-1) e dois espaçamentos entrelinhas (0,17 e 0,25 m). As maiores produtividades de grãos foram alcançadas no menor espaçamento entrelinhas e alta dose de N, para ambos os cultivares e anos avaliados. As densidades, para máxima eficiência técnica, de 400 sementes m-2 para a cultivar CD 150 e 425 sementes m-2 para a cultivar Ametista proporciona os maiores rendimento de grãos, ambas para o menor espaçamento. A eficiência de uso, de absorção e de utilização do N foram superiores nas condições com menor nível de N. Em ambos os espaçamentos utilizados, a eficiência de uso do N foi favorecida no menor espaçamento, bem como a eficiência de absorção do N. Os resultados permitem concluir que o teor de N proveniente da mineralização da matéria orgânica deve ser empregado como parâmetro para aplicação de N em cobertura. Com isso, evitar o uso excessivo do mesmo e otimizar tanto o rendimento de grãos quanto os parâmetros da eficiência de uso do N.
An alternative to minimize Nitrogen (N) losses, beyond use of more efficient wheat (Triticum aestivum L.) varieties on the use of this nutrient, is the identification of managements to intensify the use of N. For the varieties and climatic conditions of Brazil, there are few studies that have quantified how the spatial arrangement of plants affects the N-use efficiency. The objective of this study was to evaluate the effect of different spatial arrangements (combination between seeding rates and row spacing) on agronomic performance and utilization of the applied mineral nitrogen. The experiment was conducted in Pato Branco in the crops year 2014 and 2015, in a randomized block design, a factorial model, with three replications. Two wheat cultivars (CD 150 and Ametista) were submitted to four seeding densities (150, 300, 450 and 600 seeds m-2), two N doses (20 to 120 kg ha-1) and two row spacings (0.17 and 0.25 m). The highest grain yields were reached at the lowest line spacing and high nitrogen dose for cultivars and evaluated years. The densities, for maximum technical efficiency, of 400 seeds m-2 for the cultivar CD 150 and 425 seeds m-2 for the cultivar Ametista provides highest grain yield, for both cultivars and years evaluated. The N-use efficiency, N-uptake efficiency and N-utilization efficiency were higher in the conditions with lower level of N. In both spacings used, N-use efficiency was favored in the least spacing, as well as N-uptake efficiency. The results showed that the N content from the mineralization of organic matter should be used as a parameter for N application in the cover. Thus, avoiding excessive use of it and optimize both the grain yield as the N-use efficiency parameters.
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Mooleki, Siyambango Patrick. "Synchronization of nitrogen availability and plant nitrogen demand, nitrogen and non-nitrogen effects of lentil to subsequent wheat crops." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape2/PQDD_0029/NQ63902.pdf.
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Ottman, M. J., and S. H. Husman. "Nitrogen Fertilizer Movement in Wheat Production, Higley." College of Agriculture, University of Arizona (Tucson, AZ), 1994. http://hdl.handle.net/10150/201420.
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Ottman, M. J., and S. H. Husman. "Nitrogen Fertilizer Movement in Wheat Production, Yuma." College of Agriculture, University of Arizona (Tucson, AZ), 1994. http://hdl.handle.net/10150/201421.
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Ottman, M. J., and B. R. Tickes. "Nitrogen Fertilizer Movement in Wheat Production, Roll." College of Agriculture, University of Arizona (Tucson, AZ), 1994. http://hdl.handle.net/10150/201429.
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Labeled nitrogen fertilizer (N-15) was applied to wheat to determine fertilizer nitrogen movement in the soil at harvest. Most of the labeled fertilizer recovered in the soil was found in the surface few feet. The amount of nitrogen fertilizer detected below S feet was minimal.
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Bhogal, Anne. "Effect of long-term nitrogen applications on nitrogen cycling under continuous wheat." Thesis, University of Nottingham, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.294731.
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Dick, G., J. Harper, L. Moore, and M. Ottman. "Effect of Russian Wheat Aphid on Durum Wheat Yield." College of Agriculture, University of Arizona (Tucson, AZ), 1988. http://hdl.handle.net/10150/200817.
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Doerge, Thomas, and Mike Ottman. "Predicting the Nitrogen Needs of Wheat Using Stem Nitrate Analysis." College of Agriculture, University of Arizona (Tucson, AZ), 1986. http://hdl.handle.net/10150/200546.
Full textAbstract:
The high yielding spring wheats grown in Arizona usually require applications of fertilizer nitrogen (N) to achieve optimum yields and acceptable quality. The University of Arizona's currently recommended procedure of preplant soil plus periodic stem tissue analysis for NO₃-N to predict the N needs of wheat is not widely used by Arizona growers. A nitrogen fertility trial was conducted at the Maricopa Agricultural Center during the 1985-86 crop year to evaluate the accuracy and practicality of the currently recommended procedure for predicting the optimum N rate for 'Aldura' durum wheat grown on a sandy soil low in residual N. Five rates of N from 0 to 500 lbs N/a were applied in four split applications. Three additional N treatments were made using equivalent amounts of three different N sources (urea, ammonium nitrate, and calcium nitrate) as indicated by the current UA procedure. Maximum grain yields of over 6500 lbs/a and protein levels above 13% were attained with the application of 215 to 250 lbs Nia. The amount of N predicted by the UA procedure (215 lbs N/a) did attain maximum grain yield and resulted in the most favorable adjusted economic return of all the fertilizer treatments used in the trial. Though additional work is needed, the stem NO₃-N tissue test was practical to use and proved quite accurate in predicting the N needs of durum wheat.
20
Zhou, Maoqian 1961. "Nitrogen fixation by alfalfa as affected by salt stress and nitrogen levels." Thesis, The University of Arizona, 1989. http://hdl.handle.net/10150/277231.
Full textAbstract:
The growth and Nitrogen fixation by one low salt tolerant alfalfa (Medicago sativa L.) and two germination salt tolerant selections inoculated with were investigated at two salt levels (0, -0.6 Mpa) and two N rates (1, 5ppm) using a system which automatically recirculates a nutrient solution. The high level of salinity (-0.6 Mpa osmotic potential of culture solution) resulted in substantial reduction in the N fixation percentage and total fixed N. The effect of salinity was more pronounced for later cuttings than for the earlier cutting. The N fixation percentages were substantially decreased by increasing N level and the reduction was enhanced by time. The N treatment levels did not exhibit a significant effect on total fixed N. Cultivars did not differ in either growth or N fixation. However, the interaction of N and salinity significantly decreased the percentage and amount of N fixation.
21
Ottman, M. J., and N. Vigorito. "Nitrogen Fertilizer Movement in the Soil as Influenced by Nitrogen Rate and Timing in Wheat Production, 1991." College of Agriculture, University of Arizona (Tucson, AZ), 1994. http://hdl.handle.net/10150/201430.
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Ottman, M. J., and N. Vigorito. "Nitrogen Fertilizer Movement in the Soil as Influenced by Nitrogen Rate and Timing in Wheat Production, 1992." College of Agriculture, University of Arizona (Tucson, AZ), 1994. http://hdl.handle.net/10150/201431.
Full textAbstract:
Durum wheat was grown with deficient, adequate, and excessive rates of ¹⁵N-labeled nitrogen fertilizer in order to document fertilizer nitrogen movement in the soil with differing nitrogen management. Crop water use increased with nitrogen rate due to increased vegetative growth. The amount of excess water applied increased with a decrease in nitrogen rate. Soil bromide concentrations at harvest suggest that the maximum potential depth of leaching was 3 to 6 feet. Most of the fertilizer applied in this study was recovered in the top 2 to 3 feet of soil. Fertilizer nitrogen rate and timing resulted in some differences in recovery of labeled fertilizer in the soil and plant, but did not contribute significantly to the depth of fertilizer nitrogen leaching.
23
Ottman, M. J. "Nitrogen Fertilizer Requirement of Feed and Malting Barley Compared to Wheat, 2011." College of Agriculture, University of Arizona (Tucson, AZ), 2012. http://hdl.handle.net/10150/211153.
Full textAbstract:
Barley is generally thought to require less nitrogen fertilizer than wheat, but how much less has not been clearly documented. The purpose of this study is to compare the nitrogen fertilizer requirements of barley and wheat. A study was conducted at the Maricopa Agricultural Center testing the response of 2 durum wheats (Kronos and Havasu), 2 bread wheats (Yecora Rojo and Joaquin), 2 feed barleys (Baretta and Nebula), and 2 malting barleys (Conrad and Moravian 69) to 7 rates of nitrogen fertilizer (0, 30, 60, 90, 120, 150, and 180 lbs N/acre). The surface soil was relatively high in nitrate at planting (19 ppm NO₃-N) contributing an estimated 76 lbs N/acre. Maximum yield was obtained at 156 (durum), 147 (wheat), 137 (feed barley), and 127 (malting barley) lbs N/acre. However, since the yield of durum and bread wheat was higher than feed and malting barley, the nitrogen fertilizer per 100 pounds of grain yield was similar for these crop types (~2.37 lbs N per 100 lbs of grain). If the 76 lbs N/a of nitrogen estimated to be available from the surface soil were included, then about 3.62 lbs of N would have been required per 100 lbs of grain for both wheat and barley. The N requirement reported in this study does not include the extra N potentially needed for wheat to obtain acceptable protein levels. In conclusion, wheat required more nitrogen fertilizer than barley to obtain maximum yield in our study, but the amount of nitrogen fertilizer required per 100 pounds of grain was similar.
24
Clark, Lee J., and Keller F. Ellsworth. "Durum wheat response to nitrogen fertilization at Safford Agricultural Center, 2004." College of Agriculture, University of Arizona (Tucson, AZ), 2004. http://hdl.handle.net/10150/203827.
Full textAbstract:
This study was initiated in 2003 in response to a push by one of the grain buying companies to produce more durum wheat for export from Arizona. The export market required a minimum of 13% protein and other quality constraints. A nitrogen timing regime was established by the University to provide the crop with this nutrient according to its physiological development. This study had four nitrogen application treatments addressing different ways to provide the crop with its nitrogen needs. This second year of the study showed statistically different yields from the treatments applied and different inferences from the first year of the study. An economic analysis is included to show the profitability of nitrogen applications for this year and an economic summary for the last four years of nitrogen studies on durum wheat.
25
Clark, Lee J., and Keller F. Ellsworth. "Durum wheat response to nitrogen fertilization at Safford Agricultural Center, 2003." College of Agriculture, University of Arizona (Tucson, AZ), 2003. http://hdl.handle.net/10150/205401.
Full textAbstract:
This study was initiated in response to a push by one of the grain buying companies to produce more durum wheat for export from Arizona. The export market required a minimum of 13% protein and other quality constraints. A nitrogen timing regime was established by the University to provide the crop with this nutrient according to its physiological development. This study had four nitrogen application treatments addressing different ways to provide the crop with its nitrogen needs. No significant differences were seen in yields but slight differences in percent protein were observed. An economic analysis is included to show the profitability of nitrogen applications.
26
Ottman, M. J. "Solum Barley Nitrogen and Phosphorous Fertilizer Trial." College of Agriculture, University of Arizona (Tucson, AZ), 1995. http://hdl.handle.net/10150/201446.
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27
Jamjod, Sansanee. "Genetics of boron tolerance in durum wheat." Title page, contents and abstract only, 1996. http://web4.library.adelaide.edu.au/theses/09PH/09phj324.pdf.
Full textAbstract:
Bibliography: leaves 234-256. Genetic studies of tolerance of durum wheat (Triticum turgidum L. var durum) to high concentrations of boron (B) were undertaken to identify genetic variation in response to B, the mode of gene action, number of genes and chromosomal locations of genes controlling tolerance. Results demonstrated that tolerance to B is under simple genetic control as observed in bread wheat. High levels of tolerance can be transferred into sensitive commercial varieties via backcrossing and selection can be performed during seedling growth at early generations.
28
Doerge, T., T. Knowles, and M. Ottman. "Evaluation of the Accuracy of a Wheat Stem Nitrate Test in Predicting Nitrogen Requirements of Irrigated Durum Wheat." College of Agriculture, University of Arizona (Tucson, AZ), 1988. http://hdl.handle.net/10150/200815.
Full textAbstract:
The procedure currently recommended by the University of Arizona for predicting the nitrogen (N) requirements of durum wheat has proven to be quite accurate at sites where grain yields exceeded 5,400 lbs/acre. However, the method slightly overestimated N needs when the yield possibility was below that level. Additional information on the relationships between N rates, stem NO₃⁻N levels and grain yields are needed for the wide range of agronomic conditions found in Arizona. Three N fertility trials were conducted at the Maricopa Agricultural Center to: 1) document the accuracy of the currently recommended soil + stem NO₃⁻N testing procedure in predicting the N needs of durum wheat on soils of varying residual N content and grain yield potentials; and 2) to evaluate the use of the current stem testing procedure on two durum varieties 'Aldura' and 'Westbred -881. The University of Arizona procedure was found to accurately predict the minimum amount of N required for optimum production of durum wheat on two sites where yield potentials were 5,400 and 4300 lbs. grain /A, but it slightly overpredicted N rates on two sites with maximum yield levels of 5,400 lbs /a. 'Aldura' consistently out yielded 'Westbred -881' by about 12 % but 'Aldura' also averaged 0.78 %lower in grain protein content. Little statistical or practical differences were observed in the quantities of NO₃⁻N contained in the stem tissue of these two varieties, which should simplify the interpretation of stem NO₃⁻N values for various wheat cultivars. The currently recommended procedure for predicting optimum N rates in durum wheat production has proven to be accurate when yield levels exceed 5,400 lbs. grain /A. A slight modification of the procedure may be needed to more closely predict N requirements on lower yielding sites.
29
Barczys, Cathleen. "THE EFFECT OF AUDIBLE SOUND FREQUENCY ON THE GROWTH RATE OF YOUNG WHEAT PLANTS." Thesis, The University of Arizona, 1985. http://hdl.handle.net/10150/275379.
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Roth, Bob, Bryant Gardner, and Barry Tickes. "Barley Response to Water and Nitrogen Levels." College of Agriculture, University of Arizona (Tucson, AZ), 1987. http://hdl.handle.net/10150/203803.
Full textAbstract:
Results from one year's data show that yields of more than five tons per acre are feasible for Fiesta, Gustoe and NKX -1558 barley cultivars. The cultivar Barcott is a shorter season variety; yields were reduced by approximately one ton per acre, compared to the other cultivars. Additional data needs to be collected to verify the amounts of water and nitrogen required for obtaining optimum production.
31
Ottman, M. J. "Effect of Planting Date on Wheat Yield in Yuma, 2013." College of Agriculture and Life Sciences, University of Arizona (Tucson, AZ), 2013. http://hdl.handle.net/10150/312151.
Full textAbstract:
Planting dates are known to affect wheat yields. Previous research has shown that the optimum planting date in Yuma is December 15 to January 15. Wheat is sometimes sown later than this in the Yuma area, and earlier planting dates have not been tested. To test a wide range of planting dates, six varieties(Duraking, Havasu, Joaquin, Kronos, WB-Mead, and Yecora Rojo) were planted at two seeding rates (160 and 240 lbs/A) and six planting dates at the beginning of each month from November through April at the Yuma Valley Agricultural Center. Grain yield averaged 6517 (Nov 4), 6339 (Dec 6), 6096(Jan 4), 5712 (Feb 1), 4962(Mar 1), and 3590(Apr 5). The late-flowering varieties performed relatively better at the earlier planting dates. Seeding rates of 160 and 240 lbs/A had no measureable effect on yield overall.
32
Clark, Lee J., and E. W. Carpenter. "Wheat and Barley Response to Nitrogen Fertilization at Safford Agricultural Center, 2000." College of Agriculture, University of Arizona (Tucson, AZ), 2000. http://hdl.handle.net/10150/204097.
Full textAbstract:
Yields of both wheat and barley were increased with the addition of nitrogen and the largest gain was seen when it was applied at the initiation of growth or at boot stage. Effects of applied nitrogen were somewhat masked by the addition of nitrogen through the use of well water. Nitrogen level in the well water added 21 pounds of nitrogen per acre foot of irrigation, adding 48 pounds of nitrogen throughout the growing season. With the low value of grain and the given cost of nitrogen fertilizer, added nitrogen did not increase profitability for the producer.
33
Clark, Lee J., and E. W. Carpenter. "Wheat and barley response to nitrogen fertilization at Safford Agricultural Center, 2001-02." College of Agriculture, University of Arizona (Tucson, AZ), 2002. http://hdl.handle.net/10150/203857.
Full textAbstract:
This study is a follow-up on a study initiated three years ago with an emphasis on the timing of application of nitrogen (N) fertilizer. The times targeted in this study were: at planting, at initiation of growth and at boot stage. A nitrogen starter fertilizer at planting increased yields over 100 pounds of grain per acre for both wheat and barley compared with plots which did not receive the added nitrogen at planting. No difference was seen between applying 46 or 92 pounds of N per acre as a starter fertilizer. Amount of N added at boot stage seemed to increase barley yields slightly but had no effect on wheat yield nor protein content. An economic analysis is included to show the profitability of nitrogen applications.
34
Doerge, T., T. Knowles, M. Ottman, and L. Clark. "Comparison of Residual Nitrate and Fertilizer Nitrogen Efficiency in Basin Irrigated Wheat." College of Agriculture, University of Arizona (Tucson, AZ), 1988. http://hdl.handle.net/10150/200816.
Full textAbstract:
The relative efficiencies of residual soil NO₃⁻N and fertilizer Nin basin - irrigated wheat production are not well defined. A two-year field study was conducted at the Safford Agricultural Center to investigate what these N efficiencies are under optimum yielding conditions. 'Aldura' durum wheat was grown on the same field site two years in succession. In 1987 a wide range of fertilizer N (0 to 419 lbs /A) applications resulted in residual NO₃⁻N accumulations of 36 to 140 lbs /A in the surface four feet of soil. Residual N plots were split in 1988 with one subplot receiving no additional N while the other was treated with 145 lbs of fertilizer N /A. Grain yield response curves for the –N and +N subplots were used to estimate the marginal rate of substitution (MRS) of soil NO₃⁻N for fertilizer N. The marginal efficiency of residual NO₃⁻N was a constant 16.7 lbs. grain produced /lb. of N across the range of profile N values in this study, while the marginal efficiency of fertilizer N varied from over 17 to below 6 lbs. grain /lb. N. When basin- irrigated wheat is supplied with adequate, but not excessive N, the MRS of soil vs. fertilizer N is about 1:1 although absolute N efficiencies under basin irrigation are considerably lower than those achieved in other grain production systems.
35
Husman, S. H., and M. J. Ottman. "Nitrogen Fertilization of Durum Based on Stem Nitrate, Buckeye, 1996." College of Agriculture, University of Arizona (Tucson, AZ), 1996. http://hdl.handle.net/10150/202441.
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Doerge, Thomas, Tim Knowles, and Mike Ottman. "Inproved Nitrogen Management in Irrigated Wheat Production Using Stem Nitrate Analysis." College of Agriculture, University of Arizona (Tucson, AZ), 1987. http://hdl.handle.net/10150/203766.
Full textAbstract:
The method for predicting the nitrogen (N) requirements of irrigated wheat that is recommended by the University of Arizona requires preplant soil, plus mid-season stem nitrate analysis. Additional information on the relationships between N rates, stem NO₃-N levels and grain yields are needed for the wide range of agronomic conditions typical of Arizona's wheat growing areas. Three N fertility trials were conducted at the Maricopa Agricultural Center to, 1) measure the accuracy of the current University of Arizona procedure on soils of contrasting texture; 2) to evaluate the use of the current stem testing procedure on two durum varieties, "Aldura" and "Westbred-881"; and 3) to evaluate the effect of various N forms on the levels of NO₃-N in stem tissue for wheat grown in a clay loam soil. The University of Arizona procedure was found to over predict slightly the amount of N required for optimum economic return on sandy soils where the maximum yields obtained did not exceed 5100 lbs. grain/a which is considerably below the expected yield possibility for these sites. The procedure accurately predicted the amount of N required for optimum production on a clay loam soil (175 lbs. N/a)at a maximum yield of 6000 lbs. grain /acre. "Aldura" and "Westbred-881" were remarkably similar in their response to a wide range of N applications. There was no significant difference in the yields of these two varieties, but "Westbred-881" did contain somewhat higher protein levels. Little statistical or practical differences were observed in the quantities of N contained in the stem tissue of these two varieties; this should help simplify the interpretation of stem NO₃-N values for various wheat cultivars. The chemical form of N applied to wheat grown in a clay loam soil had no significant effect on the quantity of NO₃-N measured in stem tissue at any time during the growing season. The currently recommended procedure for predicting optimum N fertilization rates in wheat productions shows considerable promise but needs further evaluation, particularly under high - yielding conditions.
37
Doerge, T. A., and M. J. Ottman. "Predicting Late Season Nitrogen Fertilizer Requirements of Irrigated Durum Wheat Using Stem Nitrate Analyses." College of Agriculture, University of Arizona (Tucson, AZ), 1990. http://hdl.handle.net/10150/201347.
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A field experiment was conducted on a Casa Grande sandy loam at the Maricopa Agricultural Center to 1) determine the optimum rates of late season N needed to achieve optimum yield and quality of irrigated dumm wheat in conjunction with varying rates of early season N, and 2) to evaluate the usefulness of stem NO₃⁻N analysis in predicting the late season N rates which optimize grain production but minimize the potential for nitrate pollution of groundwater. The application of 80, 195 and 350 lbs. N/a during vegetative growth resulted in wheat with deficient, sufficient and excessive N status at the boot stage as indicated by stem NO₃⁻N analysis. The application of 60 lbs. N/a at heading to N-deficient wheat and 15 lbs. N/a to N-sufficient wheat resulted in grain protein levels above 14% but had little effect on grain yield. Applications of N at heading to wheat which had previously received excessive N did not affect grain yield or quality. The use of stem NO₃⁻N analysis appears to be a useful tool in predicting the minimum N rate to be applied during the early reproductive period to insure acceptable levels of grain protein at harvest.
38
Riley, E. A., T. L. Thompson, S. A. White, and M. J. Ottman. "Tissue Testing Guidelines for Nitrogen Management in Malting Barley, Maricopa, 1998." College of Agriculture, University of Arizona (Tucson, AZ), 1998. http://hdl.handle.net/10150/208274.
Full textAbstract:
Malting barley is not a widely planted crop in the Southwest, due to grain protein contents that can sometimes exceed the industry standard of 11.4 %. To achieve < 11.4% grain protein, careful nitrogen (N) management is needed. Tissue testing guidelines for N management for reduced grain protein and acceptable yields have not yet been determined for malting barley in the Southwest. The objectives of this study were to: (i) correlate NO₃-N in dried stem tissue with sap NO₃-N, and (ii) develop stem NO₃-N guidelines for N management in malting barley. In November 1997 two varieties of malting barley, Morex and Crystal, were planted at the Maricopa Agricultural Center. Five N rates (0, 60, 120, 180, and 240 lbs/acre) were applied in four split applications. Each treatment was replicated three times in a randomized complete block design. Samples were collected from lower stems at the 3-4 leaf 2 node, and flag leaf visible growth stages. Grain yields ranged from 1765 lbs/A to 3439 lbs/A for Morex and 2104 lbs/A to 4274 lbs/A for Crystal. Grain protein ranged from 7.6- 10.5% (Morex) and 7.0- 10.7% (Crystal). Correlation coefficients between stem NO₃-N and sap NO₃-N were 0.80 for Morex and 0.84 for Crystal. For Morex and Crystal, grain protein was within the malting industry grain protein range of 10.5- 11.4% at 240 lbs N/A, and yield was optimized at 180 lbs N/A. Sap NO₃ analysis can be a useful tool for determining N status of malting barley. Stem NO₃-N concentrations at 180 lbs N/A were generally within the optimum range for NO₃-N in small grains.
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Roth, B., B. Gardner, and B. Tickes. "Barley Response to Water and Nitrogen, 1988." College of Agriculture, University of Arizona (Tucson, AZ), 1988. http://hdl.handle.net/10150/200813.
Full textAbstract:
Results from 1988 show that yields of 3.9 and 3.7 tons per acre are feasible for Gustoe and NKX -1558 barley cultivars. The short season cultivar Barcott yielded about one ton less. The predicted optimum amounts of water and nitrogen were approximately 30 inches and 150 pounds per acre, respectively.
40
Migner, Pierre. "The effect of seeding density and nitrogen fertility on the yield and quality of a hard red spring wheat in Quebec /." Thesis, McGill University, 1992. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=56675.
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An experiment was conducted for two years to determine the effect of seeding rate, and nitrogen fertility on the yield and quality of hard red spring wheat (Triticum aestivum L.) in Quebec. The experiment was conducted on a Ste-Rosalie series soil (humic gleysol), in the St-Hyacinthe region, 50 km east of Montreal. The design of the experiment was a split-plot design. The treatments in the main plots were the plant densities while the nitrogen treatments (rate of nitrogen, number and timing of the applications and formulation of fertilizer nitrogen) were applied to the sub-plots. Nitrogen had a significant effect on yields in 1987, but not in 1986. Maximum yield was 6838 kg ha$ sp{-1}$ in 1986 and 3807 kg ha$ sp{-1}$ in 1987. Protein concentration was increased by higher nitrogen rates in both years. The yield and protein concentration were affected by low precipitation in 1987. Applying the nitrogen later in the season increased the protein concentration in both seasons. It also decreased yield in 1987, but this was caused by lack of water in late June and July 1987. Formulation of nitrogen fertilizer did not have an effect on yield and protein content of the crop.
41
Cepeda, Jose de los Angeles 1955. "Nitrogen fixation by alfalfa as affected by osmotic potentials and measured by nitrogen-15 techniques." Thesis, The University of Arizona, 1987. http://hdl.handle.net/10150/276591.
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One low salt tolerant alfalfa (Medicago sativa L.) cultivar and two germination salt tolerant alfalfa selections were compared for growth and N fixation at four salinity levels (0, -0.3, -0.6 and -1.2 Mpa). In the first experiment a Hoagland's solution at 5 ppm-N was used; in the second experiment the solution had a 1 ppm-N concentration and supplemental light was used. No significant differences were found among the cultivars. This provides additional support that germination salt tolerance is not necessarily related to salt tolerance for growth. Nitrogen fixed to the first harvest was 61, 48, 49, and 27% of the total shoot N for plants in the control, -0.3, -0.6, and -1.2 Mpa solutions, respectively. At the second harvest, N fixation percentages were 94, 89, 80, and 57% for the corresponding salinity levels which showed significant reduction in N fixation at -0.3 Mpa. The evaluation of N fixation was by 15N techniques.
42
Papadopoulos, Anastasios K. "Nitrogen and moisture distributions under subirrigated soybeans." Thesis, McGill University, 1994. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=55520.
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A field lysimeter experiment was conducted on a sandy loam soil during the 1990 and 1991 growing seasons. The experiment tested the effects of different watertables on soybean yields, and on moisture distribution and nitrogen concentration of the soil profile. The watertable depths were 40, 60, 80, and 100 centimeters (cm).Yields were measured in terms of number of beans per plant, number of pods per plant, number of beans per pod, and seed protein content at harvest.
Soil samples collected at depths of 30 and 70 cm from the soil surface were analyzed for moisture content and NO$ sb3 sp-$-N and NH$ sb4 sp+$-N concentrations.
The experimental results showed that controlled watertable management increased the yield and decreased soil NO$ sb3 sp-$-N levels. The best results from the watertables tested were found to be at 60 and 80 cm. This is suggested as the range of watertable depths that should be maintained for optimum soybean production.
43
Ayub, Najma. "The effect of VAM inoculation on interplant ¹⁵N transfer." Thesis, University of Aberdeen, 1991. http://digitool.abdn.ac.uk/R?func=search-advanced-go&find_code1=WSN&request1=AAIU546184.
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This thesis reports a study carried out to investigate the involvement of VA mycorrhizas in interplant 15N transfer in a model pasture system and in a model agroforestry system. Two pot experiments were designed to investigate the effect of VAM inoculation on 15N transfer from clover to rye grass in sterile (in the first experiment the sterilisation was by autoclaving and in the second, by gamma-irradiation) and fresh soil. A third pot experiment was designed to investigate the effect of VAM inoculation on 15N transfer from grass and clover to wild cherry seedlings in fresh soil. For these pot experiments donor plant seedlings were labelled with 15N by growing in Hoaglands solution containing K 15NO3 (5 atom % 15N). To study 15 N transfer and its possible mechanisms, plants and soil samples were analysed for 15N, total N (14N + 15N) and P concentrations. Rates of soil nitrogen mineralisation and nitrification, as well as 15N enrichment of available N were also determined to investigate N transfer through soil. There was transfer of 15N from donor to receiver in the simulated pasture system as well as in simulated agroforestry system. The transfer of 15N was increased by VAM inoculation. The transfer of 15N was small in relation to plant nutrition and was not associated with an increase in total N in the receiver plants although P concentrations were generally increased. There was no increase in the soil N fluxes of mineralisation and nitrification associated with enhanced 15N transfer from donor to receiver in the VAM inoculated system. In addition, there was often no increase in the 15N concentration in the soil available N pool of VAM inoculated systems. There was no evidence, therefore, of increased transfer of 15N through the soil in VAM inoculated systems with enhanced 15N interplant transfer, suggesting the likely involvement of VAM fungal hyphae. There was no marked effect on plant growth due to VAM inoculation. The growth of cherry, however, was reduced when grown with grass and this may have been due to N competition between the root systems. The growth of cherry seedlings was reduced to a lesser extent when grown with clover compared to when grown with grass. The findings of this study suggest that VA mycorrhizal hyphae play a part in interplant transfer of nitrogen. Although the study did not demonstrate high rates of 15N transfer in VAM inoculated system, circumstances are discussed where VAM interplant transfer of nutrients may become significant at the single plant, community and ecosystem level. The benefits to man of VAM mediated N transfer may be best realised in land use systems such as pastures having legumes and non-legumes, in mixed cropping of legumes and non-legumes and in an agroforestry system with a legume component, particularly when the soil is deficient in nutrients such as nitrogen and phosphorus.
44
Salazar, Adriana Isabel Diaz. "Effect of nitrogen, sulfur, and potassium chloride fertilization on the baking quality of soft red winter wheat." Thesis, This resource online, 1990. http://scholar.lib.vt.edu/theses/available/etd-03242009-040439/.
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Yousfi, Salima. "Salinidad y trigo duro: Firmas isotópicas, actividad enzimática y expresión génica." Doctoral thesis, Universitat de Barcelona, 2012. http://hdl.handle.net/10803/83604.
Full textAbstract:
La salinidad y el estrés hídrico son los factores más importantes que limitan la producción de trigo duro, sobre todo en regiones áridas y semiáridas, como la región Mediterránea. El trigo duro es uno de los principales cultivos en el sur y este de la Cuenca Mediterránea, donde se cultiva frecuentemente en condiciones de secano y si es posible con riego deficitario, a menudo con agua de poca calidad, que junto a una elevada evapotranspiración, puede provocar una progresiva salinización del terreno.
En este sentido, la mejora genética de trigo duro para una mejor adaptación a estas condiciones de estrés es una de las pocas alternativas viables. El objetivo general de esta Tesis es estudiar las bases fisiológicas y moleculares de las diferencias genotípicas en crecimiento potencial y tolerancia a la salinidad y el estrés hídrico. En un primer estudio (Experimento 1) publicado en “Functional Plant Biology” se investigó qué criterio fenotípico de selección era el más adecuado para seleccionar genotipos de trigo duro que crecieran mejor en condiciones de salinidad continuada. De esta forma se determinó la importancia de los isótopos estables como criterios eficientes para seleccionar genotipos tolerantes y susceptibles a la salinidad. Posteriormente, se realizó un segundo estudio (Experimento 2) donde se evaluó el efecto de la salinidad en la composición isotópica del carbono (δ13C) y el nitrógeno (δ15N) de genotipos de trigo duro y de dos amfiploides (un tritordeo y un triticale). Este trabajo está publicado en la revista “Journal of Experimental Botany”. En este segundo ensayo, la salinidad se aplicó durante la floración y el llenado del grano durante unas pocas semanas. Los resultados de este trabajo representaron la puesta a punto del estudio del comportamiento fisiológico del trigo duro durante la fase reproductiva y bajo diferentes combinaciones de salinidad y riego. Como continuación de los dos Experimentos (1 y 2) y en vista de los resultados obtenidos en el uso de las firmas isotópicas como criterio de evaluación bajo condiciones salinas, se planteó evaluar el uso combinado de la composición isotópica del carbono (δ13C), oxígeno (δ18O) y el nitrógeno (δ15N) en materia seca para observar las respuestas genotípicas de plantas de trigo duro sometidas a diferentes combinaciones de salinidad. Como contribución original, se elaboró un modelo conceptual de las tres firmas isotópicas juntas (δ13C, δ18O, δ15N) junto con características del metabolismo nitrogenado para explicar las diferencias genotípicas en tolerancia a distintas condiciones de salinidad y estrés hídrico. También se evaluaron las características fotosintéticas en relación con las firmas isotópicas y las actividades de enzimas clave del metabolismo nitrogenado. (Trabajo Publicado en la revista “New Phytologist”). Además de los resultados anteriores obtenidos, en esta Tesis se comparó la eficiencia de las firmas isotópicas del carbono, oxígeno y nitrógeno mediante dos vías: muestras de materia seca y muestras de fracción soluble en genotipos de trigo duro para la evaluación de diferencias genotípicas en tolerancia a diferentes condiciones de salinidad y regimenes hídricos. Posteriormente se analizó la respuesta genética de plantas de trigo duro a la salinidad evaluando el nivel de transcripción de genes específicos asociados a tolerancia a salinidad y estrés hídrico, junto a otros que codifican para enzimas claves del metabolismo nitrogenado. También se han estudiado las relaciones entre estas tasas de transcripción, las diferencias genotípicas en crecimiento, firmas isotópicas y actividades de enzimas del metabolismo nitrogenado. El trabajo ha mostrado la eficacia de los isótopos estables de carbono y del nitrógeno como herramientas de evaluación de la respuesta del trigo duro frente a la salinidad.Inadequate irrigation for long term and under conditions of high evapotranspiration demand, combined with the use of poor water quality and the lack of adequate drainage frequently induces the salinization of arable land causing a significant increase in the area affected by salinity. Salinity is an environmental factor that limits in a remarkable manner the production of crops in many parts of the world, but especially in arid and semiarid regions like the Mediterranean. Under these conditions, which is often grown durum wheat improvement for tolerance to salinity under irrigation deficit may be one of the strategies to alleviate this problem. This Thesis shows that isotope compositions of carbon (δ13C), oxygen (δ18O), and nitrogen (δ15N) and the concentration of nitrogen in dry matter are potentially and effective criteria for discriminating between different growing conditions and between genotypes tolerant or susceptible to salt. Furthermore, the results of this study reflect the importance of nitrogen metabolism in tolerance to salinity. Additionally, this thesis develops a model relating genotypic tolerance to different conditions of salinity and drought with the signatures of the three isotopes (C, O, N), together with photosynthetic and transpiration exchanges and parameters key of nitrogen metabolism such as nitrogen concentration and activities of the glutamine synthetase and nitrate reductase. Finally, we study the relationship between the expression of genes potentially key in the tolerance to salinity and drought and genotypic variability in response to different combinations of these stresses.
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Ottman, M. J., T. C. Knowles, and S. H. Husman. "Late Season Nitrogen Fertilizer for Durum at Buckey, Casa Grande, and Vicksburg, 1996-97." College of Agriculture, University of Arizona (Tucson, AZ), 1997. http://hdl.handle.net/10150/202472.
Full textAbstract:
Research conducted recently suggested that application of nitrogen fertilizer from flowering until the dough stage could increase grain protein concentration in durum even if nitrogen applications earlier in the season were adequate for optimum yield. We tested the ability of late season nitrogen application to increase protein at commercial farms in Buckeye, Casa Grande, and Vicksburg. Late season nitrogen increased protein by nearly two percentage points in two out of the three locations. No response was measured at the third location possibly due to high rates or nitrogen earlier in the season. The cost of the late season fertilizer at 35 to 50 lbs N /acre was about $15 /acre. The fertilizer was paid for at the two location where a response was obtained by 1) the slight yield increase of 310 lbs /acre which was worth about $23 /acre and 2) the difference in dockage or premiums paid for protein which was worth about $38 /acre. It is possible that lower stem nitrate levels could be used to determine whether or late applications of nitrogen will increase protein, but we currently do not have a method to determine if protein will be over the critical level of 13% or if HVAC will be over the critical level of 90 %.
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Knowles, Tim C., Michael J. Ottman, and Rock Cramer. "Influence of Nitrogen Fertilizer Applied at Flowering on Durum Wheat Grain Yield and Quality." College of Agriculture, University of Arizona (Tucson, AZ), 1996. http://hdl.handle.net/10150/202440.
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Application of nitrogen (N) fertilizer in conjunction with the irrigation event occurring closest to the flowering stage is effective in reducing the incidence of yellowberry and boosting grain protein levels of durum wheat. However, N applications at this time normally do not increase grain yield, except perhaps on very sandy soils. A field experiment was conducted to determine the profitability of applying 35 pounds of N per acre at flowering to durum wheat to avoid dockage for poor grain quality. Two treatments consisted of a check plot with no N applied at flowering and UAN 32 water run at a rate of 35 lbs. N /acre to basin irrigated durum wheat grown on a loamy sand soil. Maximum durum wheat grain yield (6157 lbs. /acre), protein concentration (13.7 %), and corrected income per acre ($480.31) was obtained with the N fertilizer application. In fact, N fertilization at flowering on this sandy soil increased durum wheat grain yield by 255 lbs. /acre compared to the unfertilized plot.
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Saberi, Hossein Khabaz. "Manganese efficiency in durum wheat (Triticum targidum L. var durum)." Title page, contents and summary only, 1999. http://web4.library.adelaide.edu.au/theses/09APSP/09apsps115.pdf.
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Bibliography: leaves 203-212. This study investigated the genetic diversity for tolerance of durum wheat (Triticum turgidum L. var durum) to micronutrient deficient soils with an emphasis on manganese. 69 genotypes were studied under field conditions at Marion Bay (Lower Eyre Peninsula) and Coonalpyn. Durum genotypes, notably Stojocri, were identified as having higher tolerance than commerical durum varieties.
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Ross, Delaney Meredith. "Effect of nitrogen rate and weed density on spring wheat yield at two landscape positions." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2001. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp05/MQ62837.pdf.
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Koenig, Karen. "The effect of nitrogen fertilization on protein content and bread baking properties of wheat flour." Diss., Virginia Polytechnic Institute and State University, 1988. http://hdl.handle.net/10919/53557.
Full textAbstract:
The effects of variation in nitrogen application during two growing seasons to Coker 916, a soft red winter wheat, on wheat grain and flour protein content and bread baking properties were examined. Nitrogen fertilization regimens tested included the single spring application of 168 kg/ha in growth stages 25 or 30, the split spring application of 224 kg/ha in growth stages 25 and 30, and no nitrogen application either in growth stages 25 and 30.
Variation in rate of nitrogen application had a more consistent effect on grain and flour protein than did variation in timing. Grain and flour protein content increased with increased nitrogen fertilization. The gliadin to glutenin protein ratio of the flour was reduced as the rate of grain nitrogen application increased. Significant differences were found in the flour gliadin percent protein with variation in spring nitrogen management. Fractionation and resolution of gliadin and glutenin components using SDS-PAGE revealed changes in the relative quantities present of two high molecular weight glutenin subunits (108,000 and 91,000 daltons), one low molecular weight glutenin subunit (40,500 daltons) and the ω-gliadin (44,000 daltons) fraction of experimental flours.
Differences in dough rheological properties and baking characteristics of the flour were associated with variation in nitrogen management. Increased nitrogen fertilization resulted in a stronger, more extensible dough with improved mixing tolerance and dough handling characteristics. Increased flour protein was associated with larger bread loaf volume and darker crust color. Sensory panelists found significant differences in the bread crust color, texture and taste, bread aroma, crumb texture and chewiness. This experiment demonstrated that a change in nitrogen management of Coker 916 wheat resulted in a distinct change in protein composition and bread baking properties of experimentally milled flour.Ph. D.