A aplicação de altas doses de nitrogênio (N) no cultivo do milho é prática rotineira em lavouras com altos índices de produtividade. Entretanto, são poucos conhecidos os efeitos de volumes de irrigação após a aplicação de altas doses de N em cobertura na dinâmica do N no perfil do solo. O objetivo desta pesquisa foi avaliar como o manejo da adubação nitrogenada em cobertura e os volumes de irrigação afetam o deslocamento do amônio, nitrato e cátions básicos no perfil do solo. Para isso, foi utilizado uma área experimental de 22 anos de duração em um Argissolo Vermelho Distrófico típico, em Eldorado do Sul, RS. O estudo foi conduzido no ano agrícola 2012/13, com a cultura do milho. Os tratamentos constaram da combinação de três manejos de N em cobertura e dois volumes de irrigação. Os manejos de nitrogênio em cobertura constaram de testemunha sem aplicação de nitrogênio em cobertura, aplicação única (300 kg N ha-1) e aplicações parceladas (150+150 kg N ha-1) na forma de ureia. A aplicação da dose única de N em cobertura foi realizada no estádio V5-6. O parcelamento da aplicação de 300 kg N ha-1 em cobertura foi realizado nos estádios V5-6 (150 kg N ha-1) e V11-12 (150 kg N ha-1). Os volumes de irrigação foram de 20 e 100 mm, aplicados aos nove dias após a primeira adubação nitrogenada de cobertura no estádio V7-8. O maior volume de irrigação (100 mm) aplicado nove dias após a aplicação da dose única de N (300 kg N ha-1) em cobertura aumentou os teores de nitrato nas camadas de 20-30 e 30-40 cm. Houve correlação positiva entre os teores de nitrato e os cátions básicos (cálcio e magnésio) nas camadas abaixo de 15 cm de profundidade, aos dez dias após a segunda adubação nitrogenada de cobertura. O parcelamento da adubação nitrogenada para altos rendimentos do milho é uma alternativa eficiente para diminuir os teores de nitrato nas camadas subsuperficiais do solo. Entretanto, isso não foi vantajoso quando comparado com a aplicação única de N em cobertura para rendimento de matéria seca e quantidade de nitrogênio acumulado na parte aérea no espigamento e rendimento de grãos, independentemente do volume de irrigação. / Application of high nitrogen (N) rates in corn is recommended practice to achieve high grain yield. However, little is known about N dynamics in soil profile after addition of high N rates combined with different irrigation volumes. Thus, the objective of this research was evaluate how management of N topdressing fertilization and irrigation volumes affect the movement of mineral N (N-NH4+ and N-NO3-) and basic cations in the soil profile. For this, a long-term trial (22 years), in Eldorado do Sul/RS, was used. The soil of the area is classified as an Ultisol (Rhodic Paleudult). The study was conducted in the agricultural year 2012/13, with cover crop (black-oat) in winter season and corn in summer season. The treatments consisted of three N topdressing managements combined with two volumes of simulated irrigation. The N topdressing managements were the control (without application), single application (300 kg N ha-1) and split application (150+150 kg N ha-1) in urea form. Single topdressing dose was applied at V5-6 stage. The split topdressing application was performed in stages V5-6 (150 kg N ha-1) and V11-12 (150 kg N ha-1). The irrigation volumes were 20 and 100mm, applied at nine days after the first N topdressing (V7-8 stage). The highest irrigation volume (100 mm) was applied nine days after the single application of 300 kg N ha-1 results in an increase of nitrate content in 20-30 and 30-40 cm soil layers. There was positive relationship between nitrate content and basic cations contents (calcium and magnesium) in soil layers below 15 cm depth, at ten days after the second N topdressing. The split of N topdressing fertilization for high corn yields is an efficient alternative to reduce the nitrate leaching in subsoil. However, it was not advantageous, when compared with single N topdressing application, for shoot dry matter yield, amount of accumulated N in shoots at silking and grain yield, regardless of irrigation volume.

A intensificação da agricultura está causando a degradação do ambiente agrícola, dos recursos hídricos e do solo. O manejo ecológico de solo e planta do Centro de Pesquisa Mokiti Okada (CPMO) tem como objetivo proporcionar ao agricultor, alternativas viáveis para atividade agrícola sustentável. Este sistema de manejo deve compensar a ausência dos insumos agrícolas - tradicionalmente utilizados na agricultura convencional - através da manutenção da qualidade física, química e microbiológica do solo. Esta pesquisa foi realizada no CPMO e no Sítio Camaquã, propriedade vizinha com solo de características similares. Os objetivos foram: i) caracterizar os atributos físico-hídricos do solo nos sistemas de manejo adotados; ii) verificar o efeito dos manejos nos atributos físico-hídricos do solo; iii) quantificar o rendimento do milho em cada sistema de manejo. Os tratamentos foram: manejo ecológico irrigado (MEI); manejo ecológico não irrigado (MENI) e manejo usual do Sítio Camaquã (MSQ). Cada tratamento foi composto por 8 parcelas com 54 m2 cada, para determinação da produtividade. Para determinação dos parâmetros físico-hídricos realizou-se amostragem do solo em duas épocas do ciclo do milho: 50 dias após a semeadura (50 DAS) e 140 DAS, ambas nas parcelas. Dentre os tratamentos com sistema de manejo ecológico, o MEI apresentou os melhores resultados: a densidade do solo diminuiu significativamente de 1,37 para 1,32 g.cm-3 e 1,26 para 1,22 g.cm-3 a 10 e 30 cm respectivamente da amostragem 50 para 140 DAS; a porosidade total aumentou significativamente de 51 para 55% e 54 para 57% a 10 e 30 cm respectivamente da amostragem 50 para 140 DAS. O tratamento MSQ se mostrou susceptível a processos de degradação devido ao manejo adotado, de elevada mobilização do solo: as médias de densidade, diâmetro médio geométrico, porosidade total e macroporosidade da amostragem 50 DAS para 140 DAS a 10 cm de profundidade variaram significativamente de 1,23 para 1,41 g.cm-3; 1,58 para 1,29 mm; 55 para 49% e 24 para 13% respectivamente. O rendimento do milho foi 5,0; 4,1 e 4,8 t.ha-1 nos tratamentos MEI, MENI e MSQ respectivamente. / The intensification of agriculture is causing the degradation of agricultural environment, water resources and soil. The soil and plant ecological management of Mokiti Okada Research Center (CPMO) has as a goal to provide viable alternatives of techniques for sustainable agriculture. This proposed management must compensate the no use of agricultural input, traditionally applied in a conventional model, through the maintenance of the soil physical, chemical and microbiological quality. This assay was performed in the CPMO experimental field and in an adjacent area, belonging to the neighbor Camaquã farm, whose soil characteristic is similar. The aims of this work were: i) to characterize soil physic-hydric attributes; ii) to survey the effect from crop system on the soil physic-hydric attributes; iii) to quantify the maize yield of the treatments. The treatments were: ecological crop system with irrigation (ECSI); ecological crop system without irrigation (ECSNI); conventional crop system (CCS) as usual in the Camaquã farm. Each treatment was comprised of 8 plots with 54 m2, where the grain yield was measured. Soil cores were sampled from the plots, at the two different growth stages, in order to survey the soil physics parameters: at 50 days after sowing (DAS) and 140 DAS. Among ecological crop system the ECSI treatment showed the best results. The soil bulk density decreased significantly from 50 to 140 DAS at 10 and 30 cm depth (1.37 to 1.32 g.cm-3 and 1.26 to 1.22 g.cm-3). The soil total porosity increased significantly at the same time and depth (51 to 55% and 54 to 57%). The soil of the CCS treatment showed it was susceptible to degradation pressures from usual high soil tillage management. At the 10 cm depth there were significantly differences between 50 to 140 DAS to bulk density (1.23 to 1.41 g.cm-3), mean geometric diameter (1.58 to 1.29 mm), total porosity (55 to 49%) and macro porosity (24 to 13%). The grain yields were: 5.0, 4.1 and 4.8 t.ha-1 to ECSI, CSNI and CCS treatments, respectively.

A aplicação de altas doses de nitrogênio (N) no cultivo do milho é prática rotineira em lavouras com altos índices de produtividade. Entretanto, são poucos conhecidos os efeitos de volumes de irrigação após a aplicação de altas doses de N em cobertura na dinâmica do N no perfil do solo. O objetivo desta pesquisa foi avaliar como o manejo da adubação nitrogenada em cobertura e os volumes de irrigação afetam o deslocamento do amônio, nitrato e cátions básicos no perfil do solo. Para isso, foi utilizado uma área experimental de 22 anos de duração em um Argissolo Vermelho Distrófico típico, em Eldorado do Sul, RS. O estudo foi conduzido no ano agrícola 2012/13, com a cultura do milho. Os tratamentos constaram da combinação de três manejos de N em cobertura e dois volumes de irrigação. Os manejos de nitrogênio em cobertura constaram de testemunha sem aplicação de nitrogênio em cobertura, aplicação única (300 kg N ha-1) e aplicações parceladas (150+150 kg N ha-1) na forma de ureia. A aplicação da dose única de N em cobertura foi realizada no estádio V5-6. O parcelamento da aplicação de 300 kg N ha-1 em cobertura foi realizado nos estádios V5-6 (150 kg N ha-1) e V11-12 (150 kg N ha-1). Os volumes de irrigação foram de 20 e 100 mm, aplicados aos nove dias após a primeira adubação nitrogenada de cobertura no estádio V7-8. O maior volume de irrigação (100 mm) aplicado nove dias após a aplicação da dose única de N (300 kg N ha-1) em cobertura aumentou os teores de nitrato nas camadas de 20-30 e 30-40 cm. Houve correlação positiva entre os teores de nitrato e os cátions básicos (cálcio e magnésio) nas camadas abaixo de 15 cm de profundidade, aos dez dias após a segunda adubação nitrogenada de cobertura. O parcelamento da adubação nitrogenada para altos rendimentos do milho é uma alternativa eficiente para diminuir os teores de nitrato nas camadas subsuperficiais do solo. Entretanto, isso não foi vantajoso quando comparado com a aplicação única de N em cobertura para rendimento de matéria seca e quantidade de nitrogênio acumulado na parte aérea no espigamento e rendimento de grãos, independentemente do volume de irrigação. / Application of high nitrogen (N) rates in corn is recommended practice to achieve high grain yield. However, little is known about N dynamics in soil profile after addition of high N rates combined with different irrigation volumes. Thus, the objective of this research was evaluate how management of N topdressing fertilization and irrigation volumes affect the movement of mineral N (N-NH4+ and N-NO3-) and basic cations in the soil profile. For this, a long-term trial (22 years), in Eldorado do Sul/RS, was used. The soil of the area is classified as an Ultisol (Rhodic Paleudult). The study was conducted in the agricultural year 2012/13, with cover crop (black-oat) in winter season and corn in summer season. The treatments consisted of three N topdressing managements combined with two volumes of simulated irrigation. The N topdressing managements were the control (without application), single application (300 kg N ha-1) and split application (150+150 kg N ha-1) in urea form. Single topdressing dose was applied at V5-6 stage. The split topdressing application was performed in stages V5-6 (150 kg N ha-1) and V11-12 (150 kg N ha-1). The irrigation volumes were 20 and 100mm, applied at nine days after the first N topdressing (V7-8 stage). The highest irrigation volume (100 mm) was applied nine days after the single application of 300 kg N ha-1 results in an increase of nitrate content in 20-30 and 30-40 cm soil layers. There was positive relationship between nitrate content and basic cations contents (calcium and magnesium) in soil layers below 15 cm depth, at ten days after the second N topdressing. The split of N topdressing fertilization for high corn yields is an efficient alternative to reduce the nitrate leaching in subsoil. However, it was not advantageous, when compared with single N topdressing application, for shoot dry matter yield, amount of accumulated N in shoots at silking and grain yield, regardless of irrigation volume.

CoordenaÃÃo de AperfeiÃoamento de Pessoal de NÃvel Superior / A mamoneira à uma planta oleaginosa arbustiva, e o Ãleo de suas sementes possui inÃmeras aplicaÃÃes industriais. Contudo, na atualidade tem-se dado Ãnfase ao seu emprego na produÃÃo de combustÃvel renovÃvel (biodiesel). O que reveste a cultura de grande importÃncia econÃmica e ambiental. Desse modo, foram conduzidos dois ensaios experimentais durante os anos de 2003, 2004 e 2005, com o objetivo de avaliar o comportamento da mamoneira cultivada em diferentes Ãpocas, espaÃamentos e sob condiÃÃes irrigadas e de sequeiro. Os trabalhos foram conduzidos na Fazenda Experimental Vale do Curu, que pertence ao Centro de CiÃncias AgrÃrias da Universidade Federal do CearÃ. No primeiro experimento a mamoneira cv. âBRS 149 Nordestinaâ foi semeada em quatro Ãpocas, combinadas com dois regimes de irrigaÃÃo. No segundo experimento, foram testadas duas cultivares (BRS 149 Nordestina e Mirante 10) semeadas em trÃs espaÃamentos e em duas Ãpocas distintas. Verificou-se que a antecipaÃÃo da semeadura para janeiro de 2004 com o uso da irrigaÃÃo promoveu incrementos na produtividade de grÃos e no nÃmero de racemos por planta, os quais possuem maior tamanho, peso e nÃmero de frutos. A suplementaÃÃo hÃdrica foi mais vantajosa no inÃcio do crescimento da cultura do que apÃs o tÃrmino da estaÃÃo chuvosa. As sementes dos racemos secundÃrios e terciÃrios possuem maior teor de Ãleo e massa de sementes. No experimento de 2005 foram obtidos os seguintes resultados: a Ãpoca de plantio associada à irrigaÃÃo promoveu aumentos da altura da planta, do nÃmero de ramos laterais e do nÃmero de internÃdios, alÃm de retardar o florescimento e aumentar a produtividade de grÃos. O nÃmero de racemos e de frutos por racemo reduziu com o plantio de sequeiro. Os racemos que mais contribuÃram com a produtividade total foram os secundÃrios seguidos dos terciÃrios. A cv. Nordestina apresentou maior massa e teor de Ãleo das sementes do que a cv. Mirante 10. Em mÃdia sob condiÃÃes irrigadas a massa das sementes aumentou, independente do espaÃamento ou da cultivar utilizada. Por outro lado, a antecipaÃÃo do plantio associada à irrigaÃÃo reduziu o teor de Ãleo das sementes. / The castor bean is an oil seed crop, and the oil present in the seeds has several industrial applications. Recently it has been suggested to be used as a renewable fuel (Biodiesel). As a consequence the crop has assumed a relevant ecological and economic importance. Two field studies were conducted in 2003, 2004 and 2005, with the objective of evaluating the behavior of castor bean grown at different times and spacing and under irrigated and rainfed conditions. The experiments were carried out at the "Fazenda Experimental do Vale do Curu", belonging to the Universidade Federal do CearÃ, Brazil. In the first experiment the castor plant cv. BRS 149 Nordestina was sown at four different times of planting combined with two irrigation regimes. In the second experiment, two cultivars were evaluated (BRS 149 Nordestina and Mirante 10) seeded in three plant spacing and two different times. Irrigation was more profitable at the beginning of the cycle, prior the rain season than at the end of the rain period, at the end of the plant growth cycle. The combination of the anticipation of the sowing in January of 2004 with the use of irrigation promoted increments in the seed yield and number of racemes for plant and higher weight and number of fruits per raceme. Irrigation yielded better results when was associated with the earliness of planting, as compared with application of water at the end of the raining season. The seeds of the secondary and tertiary racemes possessed greater oil content and seeds weigh. When sowed in December of 2003 the primary racemes produced very light seeds. In the experiment of 2005 the following results were observed: the combination of anticipation of sowing with irrigation promoted increases of the height of the plant, number of lateral branches and the number of internodes, delayed flowering and increased grain yield. Under rain red conditions the number the number of fruits per raceme was reduced. Secondary racemes were responsible for the higher proportion of total seed yield, followed by the tertiary racemes. The cv. BRS 149 Nordestina showed higher seed weigh and oil content. Under irrigation condition the weigh of the seeds increased, independent of the spacing or cultivar used. The early planting associated with the irrigation practice reduced the oil content of the seeds.

CoordenaÃÃo de AperfeiÃoamento de Pessoal de NÃvel Superior / A mamoneira à uma planta oleaginosa arbustiva, e o Ãleo de suas sementes possui inÃmeras aplicaÃÃes industriais. Contudo, na atualidade tem-se dado Ãnfase ao seu emprego na produÃÃo de combustÃvel renovÃvel (biodiesel). O que reveste a cultura de grande importÃncia econÃmica e ambiental. Desse modo, foram conduzidos dois ensaios experimentais durante os anos de 2003, 2004 e 2005, com o objetivo de avaliar o comportamento da mamoneira cultivada em diferentes Ãpocas, espaÃamentos e sob condiÃÃes irrigadas e de sequeiro. Os trabalhos foram conduzidos na Fazenda Experimental Vale do Curu, que pertence ao Centro de CiÃncias AgrÃrias da Universidade Federal do CearÃ. No primeiro experimento a mamoneira cv. âBRS 149 Nordestinaâ foi semeada em quatro Ãpocas, combinadas com dois regimes de irrigaÃÃo. No segundo experimento, foram testadas duas cultivares (BRS 149 Nordestina e Mirante 10) semeadas em trÃs espaÃamentos e em duas Ãpocas distintas. Verificou-se que a antecipaÃÃo da semeadura para janeiro de 2004 com o uso da irrigaÃÃo promoveu incrementos na produtividade de grÃos e no nÃmero de racemos por planta, os quais possuem maior tamanho, peso e nÃmero de frutos. A suplementaÃÃo hÃdrica foi mais vantajosa no inÃcio do crescimento da cultura do que apÃs o tÃrmino da estaÃÃo chuvosa. As sementes dos racemos secundÃrios e terciÃrios possuem maior teor de Ãleo e massa de sementes. No experimento de 2005 foram obtidos os seguintes resultados: a Ãpoca de plantio associada à irrigaÃÃo promoveu aumentos da altura da planta, do nÃmero de ramos laterais e do nÃmero de internÃdios, alÃm de retardar o florescimento e aumentar a produtividade de grÃos. O nÃmero de racemos e de frutos por racemo reduziu com o plantio de sequeiro. Os racemos que mais contribuÃram com a produtividade total foram os secundÃrios seguidos dos terciÃrios. A cv. Nordestina apresentou maior massa e teor de Ãleo das sementes do que a cv. Mirante 10. Em mÃdia sob condiÃÃes irrigadas a massa das sementes aumentou, independente do espaÃamento ou da cultivar utilizada. Por outro lado, a antecipaÃÃo do plantio associada à irrigaÃÃo reduziu o teor de Ãleo das sementes. / The castor bean is an oil seed crop, and the oil present in the seeds has several industrial applications. Recently it has been suggested to be used as a renewable fuel (Biodiesel). As a consequence the crop has assumed a relevant ecological and economic importance. Two field studies were conducted in 2003, 2004 and 2005, with the objective of evaluating the behavior of castor bean grown at different times and spacing and under irrigated and rainfed conditions. The experiments were carried out at the "Fazenda Experimental do Vale do Curu", belonging to the Universidade Federal do CearÃ, Brazil. In the first experiment the castor plant cv. BRS 149 Nordestina was sown at four different times of planting combined with two irrigation regimes. In the second experiment, two cultivars were evaluated (BRS 149 Nordestina and Mirante 10) seeded in three plant spacing and two different times. Irrigation was more profitable at the beginning of the cycle, prior the rain season than at the end of the rain period, at the end of the plant growth cycle. The combination of the anticipation of the sowing in January of 2004 with the use of irrigation promoted increments in the seed yield and number of racemes for plant and higher weight and number of fruits per raceme. Irrigation yielded better results when was associated with the earliness of planting, as compared with application of water at the end of the raining season. The seeds of the secondary and tertiary racemes possessed greater oil content and seeds weigh. When sowed in December of 2003 the primary racemes produced very light seeds. In the experiment of 2005 the following results were observed: the combination of anticipation of sowing with irrigation promoted increases of the height of the plant, number of lateral branches and the number of internodes, delayed flowering and increased grain yield. Under rain red conditions the number the number of fruits per raceme was reduced. Secondary racemes were responsible for the higher proportion of total seed yield, followed by the tertiary racemes. The cv. BRS 149 Nordestina showed higher seed weigh and oil content. Under irrigation condition the weigh of the seeds increased, independent of the spacing or cultivar used. The early planting associated with the irrigation practice reduced the oil content of the seeds.

Submitted by Marlene Santos (marlene.bc.ufg@gmail.com) on 2016-12-20T19:25:22Z No. of bitstreams: 2 Dissertação - João Augusto Vieira de Oliveira - 2015.pdf: 2197476 bytes, checksum: a0f442732e28ba900f7bc82946206efa (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2016-12-26T14:15:33Z (GMT) No. of bitstreams: 2 Dissertação - João Augusto Vieira de Oliveira - 2015.pdf: 2197476 bytes, checksum: a0f442732e28ba900f7bc82946206efa (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2016-12-26T14:15:33Z (GMT). No. of bitstreams: 2 Dissertação - João Augusto Vieira de Oliveira - 2015.pdf: 2197476 bytes, checksum: a0f442732e28ba900f7bc82946206efa (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2015-08-06 / Evidences indicate that by 2030 an increase in 40% of rice production is necessary so that it can meet the demand of the world population. The aim of this study was to quantify the expression of rice genes homologs to Arabidopsis genes previously related to yield (RUBISCO, AVP1, DA1 and TOR) by RT-qPCR analysis. The genotypes used in the study were the upland rice cultivars BRSMG Curinga and Primavera, and the old variety Douradão, which were evaluated in a yield experiment under two soil fertility levels, in a factorial scheme, in completely randomized design with two replications. Plant tissue samples were collected in vegetative and reproductive stages, which were used for total RNA isolation and subsequent cDNA syntheses. The cDNA was then subjected to RT-qPCR to evaluate the expression of four genes studied. Significant differences were observed in the expression of RUBISCO gene in leaves of upland rice plants in the vegetative stage, where there was a higher expression in high-level fertility in the soil, while in the reproductive stage, there was a higher expression in the low fertility treatment. DA1 that negatively regulates cell proliferation was less expressed in the vegetative stage in the treatment with high level of fertility, suggesting the suppression of this gene. AVP1 was more expressed in the reproductive stage, probably in order to increase the availability of P in a fundamental phase for the formation of the grain. TOR was the most expressed gene in this work, with a greater expression in adequate conditions of fertility, confirming its action under favorable conditions of cultivation. This study indicates that even two species that diverged over 120 million years have conserved productivity related metabolic routes. Thus, genes previously studied and validated in the model species Arabidopsis and that are of interest to economically important crops such as rice, may be the starting point for the development of cultivars with higher performance and better agronomic traits. / Evidências indicam que, até 2030, será necessário um aumento em 40% da produção de arroz para que ele possa atender a demanda da população mundial. O objetivo desse estudo foi quantificar a expressão de genes de arroz homólogos a genes de Arabidopsis anteriormente relacionados à produtividade (RUBISCO, AVP1, DA1 e TOR) por meio da análise de RT-qPCR. Os genótipos usados no estudo foram as cultivares de arroz de sequeiro BRSMG Curinga e Primavera, e a cultivar antiga Douradão, as quais foram avaliadas em um experimento de rendimento sob dois níveis de fertilidade do solo, em esquema fatorial, em delineamento experimental inteiramente casualizado, com duas repetições. Amostras de tecido foliar foram coletadas nas fases vegetativa e reprodutiva, que foram utilizadas para o isolamento de RNA total e posterior síntese de cDNA. O cDNA foi, em seguida, submetido à RT-qPCR para avaliar a expressão dos quatro genes estudados. Foram observadas diferenças significativas na expressão do gene RUBISCO (Ribulose bifosfato Carboxilase/Oxigenase) em folhas de plantas de arroz de terras altas no estádio vegetativo, em que houve uma maior expressão em solo com fertilidade recomendada, enquanto que na fase reprodutiva, houve uma maior expressão no tratamento de baixa fertilidade. DA1 (Receptor de Ubiquitina), que regula negativamente a proliferação celular foi menos expresso no estádio vegetativo, no tratamento com elevado nível de fertilidade, sugerindo a supressão deste gene. AVP1(Arabidopsis Vacuolar Pirofosfatase) foi mais expresso no estádio reprodutivo, provavelmente para aumentar a disponibilidade de P em uma fase fundamental para a formação do grão. TOR (Alvo de rapamicina) foi o gene com maior nível de expressão, principalmente no solo com maior nível de fertilidade, confirmando sua ação em condições favoráveis de cultivo. Esse estudo indica que mesmo duas espécies que divergiram mais de 120 milhões anos, como é o caso de Arabidopsis e arroz, têm conservadas rotas metabólicas relacionadas à produtividade. Assim, os genes previamente estudados e validados na espécie modelo Arabidopsis e que são de interesse para as culturas economicamente importantes, como o arroz, podem ser o ponto de partida para o desenvolvimento de cultivares com maior desempenho e melhores características agronômicas.

Submitted by Edineia Teixeira (edineia.teixeira@unioeste.br) on 2018-03-08T16:48:51Z No. of bitstreams: 2 Francisco_Guedes Junior2017.pdf: 1318457 bytes, checksum: 26ff578276db358f4f8a4282b249498e (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2018-03-08T16:48:51Z (GMT). No. of bitstreams: 2 Francisco_Guedes Junior2017.pdf: 1318457 bytes, checksum: 26ff578276db358f4f8a4282b249498e (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2017-02-10 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / The response to gypsum, as the root environment conditioner in depth has been observed for most annual crops. Such responses are attributed to better distribution of roots deep in crops in the soil by reducing chemical impediments caused by exchangeable aluminum and calcium deficiency in these layers, which provides the plants to take advantage of higher volume of water when dry spells occur. Thus, the aim of this study was to evaluate the effects of gypsum rates on root growth in yield of soybeans. The experiment was conducted at the Agronomic Institute of Paraná (IAPAR) in Santa Tereza do Oeste - PR. The soil was classified as Typic Harplortox (EMBRAPA, 2013) which comes without the managed under no-till 18 years. The experiment was conducted in randomized blocks in a factorial design with plaster 5 doses as treatments (0, 3, 6, 9 and 12 t ha-1) and six repetitions. For this statistical analysis we used the System for Analysis of Variance (SISVAR®) and ASSISTAT Version 7.7 beta (2016) regression analysis. The physical attributes soil density, total porosity, microporosity, macroporosity and saturated hydraulic conductivity soil did not differ significantly with the application of gypsum rates, but in the 0.1 - 0.2 m layer, by the concentration of pressure imposed by the machines and agricultural implements, it underwent deformation, providing differences of these attributes in this layer. There wasn't significant difference in grain yield and root growth of soybean. / A resposta ao gesso agrícola, como condicionador do ambiente radicular em profundidade, tem sido observada para a maioria das culturas anuais. Tais respostas são atribuídas à melhor distribuição das raízes das culturas em profundidade no solo pela redução de impedimentos químicos, causado pelo alumínio trocável e deficiência de cálcio nessas camadas, o que propicia às plantas o aproveitamento de maior volume de água quando ocorrem veranicos. Dessa maneira, o objetivo deste estudo foi avaliar o efeito de doses de gesso no crescimento radicular e no rendimento de grãos da soja. O experimento foi realizado no Instituto Agronômico do Paraná (IAPAR) no município de Santa Tereza do Oeste - PR. O solo foi classificado como Latossolo Vermelho distroférrico típico (EMBRAPA, 2013) o qual vem sendo manejado sob sistema plantio direto a 18 anos. O experimento foi conduzido em seis blocos ao acaso sob cinco doses de gesso com tratamentos (0; 3; 6; 9 e 12 t ha-1) e seis repetições. Para esta análise estatística utilizou-se o Sistema para Análise de Variância (SISVAR®) e ASSISTAT Versão 7.7 beta (2016) análise de regressão. Os atributos físicos densidade do solo, porosidade total, microporosidade, macroporosidade e condutividade hidráulica do solo saturado diferiram de forma significativa com a aplicação das doses de gesso apenas na camada de 0,1 - 0,2 m, devido à concentração da pressão impostas pelas máquinas e implementos agrícolas. Não ocorreu diferença significativa para o rendimento de grão e crescimento radicular da soja.

A soja é uma das culturas mais importantes do mundo, além de ser a principal comodity brasileira. Entretanto apesar dos ganhos crescentes de produtividade a base genética da cultura no país é estreita. Sendo assim, é importante a identificação e caracterização de fontes de variabilidade para os programas de melhoramento de soja. Dado o exposto, os objetivos deste estudo foram i) avaliação da produtividade de grãos e caracteres agronômicos correlacionados; ii) caracterização da diversidade fenotípica; iii) caracterização da diversidade genética e estrutura de populações; e iv) mapeamento associativo para produtividade de grãos. Os acessos foram fenotipados nos anos agrícolas de 2012/2013 e 2013/2014, em cinco ambientes. As características avaliadas foram: altura da planta na maturidade, período de granação, valor agronômico, acamamento, massa de cem sementes, número de dias para a maturidade, inserção da primeira vagem, altura da planta no florescimento, teor de óleo e produtividade de grãos. A análise dos dados fenotípicos foi feita pelo software SELEGEN utilizando modelos mistos, e a árvore de regressão para identificação dos caracteres correlacionados foi feita pelo software JMP SAS. A diversidade fenotípica foi feita a partir de todas as características avaliadas anteriormente utilizando três tipos de análises: os métodos de agrupamento de Ward e Average Linkage no software Power Marker, e pela análise de componentes principais no software JMP SAS. A genotipagem dos acessos foi realizada pelo Axiom&reg; Soybean Genotyping Array contendo 10017 SNPs polimórficos para os acessos genotipados. A partir dos dados de marcadores foi feita a caracterização da diversidade genética pelo software Power Marker. Além disso, foram realizadas análises de estrutura de população pelo software STRUCTURE e pelo pacote do R, adegenet. A análise de associação foi efetuada pelo software TASSEL, utilizando o modelo misto MLM (Q+K). Duas abordagens foram utilizadas na análise de associação, a primeira utilizando as médias fenotípicas ajustadas para BLUP dos cinco ambientes e a segunda utilizando apenas as médias de cada local individualmente. Na análise fenotípica os acessos Dowling, PI 417563, PI200526, PI 377573 e PI 159922, apresentaram boa produtividade de grãos nos cincos ambientes avaliados. A caracterização molecular e fenotípica da diversidade indicou a presença de variabilidade genética no painel de acessos avaliados. Além disso, foi possível a identificação de dois grupos (k=2) em ambas as análises de estrutura da população utilizadas. No mapeamento associativo, foram detectadas sete associações marcador-característica com p<0,001 e com correção para múltiplos testes q<0,1. Dentre estas, quatro foram significativas no modelo de análise conjunta dos cinco ambientes e para o ambiente dois. As demais associações foram significativas somente para este último local. / Soybean is one of the most important crops in the world, and is Brazil\'s main commodity. However despite growing yield gains the genetic basis of culture in the country is narrow. Therefore, the identification and characterization of sources of variability for soybean breeding programs is important. On this basis, the objectives of this study were i) assessment of grain yield and agronomic traits correlated; ii) characterization of the phenotypic diversity; iii) characterization of genetic diversity and population structure; and iv) associative mapping for grain yield. The inbred lines were phenotyped in the agricultural years of 2012/2013 and 2013/2014, in five environments. The traits evaluated were: plant height at maturity, fruit filling period, agronomic value, lodging, mass of hundred seeds, number of days to maturity, first pod, plant height at flowering, oil content and grain yield. The analysis of phenotypic data was made by SELEGEN software using mixed models, and regression tree for identification of correlated traits was made by JMP SAS software. The phenotypic diversity was made from all the features previously evaluated using three types of analysis: the Ward clustering methods and Average Linkage from the Power Marker software, and the principal component analysis in SAS JMP software. Genotyping was performed by Axiom&reg; Soybean Genotyping Array containing 10017 polymorphic SNPs genotyped for the soybean lines. From the markers data was taken the genetic diversity analysis by Power Marker software. In addition, population structure analysis was performed by Structure software and the R package, adegenet. The association analysis was performed by TASSEL software using the mixed model MLM (Q + K). Two approaches were used in the association analysis, the first using the phenotypic average adjusted to BLUP values for the five enviroments and the second one using only the means of each site individually. In the phenotypic analysis the lines: Dowling, PI 417563, PI200526, PI 377573 and PI 159922 showed good grain yield in the five evaluated environments. The molecular and phenotypic characterization of diversity indicated the presence of geneticvariability in the inbreed lines. Moreover, it was possible to identify two groups (k = 2) in both population structure analysis used. In the associative mapping, were detected seven markertrait associations with p <0.001 and with correction for multiple tests q <0.1. Among these, four were significant in the pooled analysis model with five environments and at the individually environment two. The other variables were significant only for the latter location.

MSCAGR (Plant Production) / Department of Plant Production / Chickpea (Cicer arietinum L) is adapted to cool-seasons and its organs are of high nutritive value and serve as cheap sources of protein, especially in developing countries. Chickpea crop is mainly grown for human consumption, animal feed and for medicinal purposes. The introduction and promotion of chickpea to especially small-scale South African crop farmers has multiple objectives including the improvement of soil fertility. Small-scale farmer’s flounder to afford Nfertilizers, coupled with the challenges faced by programmes aimed at assisting them about soil fertility in their cropping fields that are still without enough N concentration to meet N demand. It is therefore important that other alternatives that can help improve the N status of soils be explored. The shoot δ13C is an indicator of WUE in C3 plants. However, shoot-WUE is affected by a variety of factors including genotypes, phosphorus fertilizer application and availability of native or introduced rhizobial bacteria. However, not much is known on whether application of phosphate fertilizer, seed inoculation with rhizobial strain affect the shoot C/N ratio of chickpea genotypes in South Africa. Therefore, field experiments were established at Thohoyandou and Syferkuil in Limpopo to assess the role of phosphorus fertilization and rhizobial inoculation on C assimilation, C/N ratio and shoot-WUE of chickpea genotypes. Field experiments were conducted during winter season in 2016 and 2017 (April to August). Treatments consisted of a factorial combination of two rates of phosphorus fertilizer (0 and 90 kg P ha-1 ), four desi chickpea genotypes (ACC#1, ACC#2, ACC#3 and ACC#5) and two rhizobial inoculation levels (bradyrhizobium strain and without rhizobial strain. In Thohoyandou, ACC#1 showed greater grain yield in 2016 and 2017. Which was associated with more branches and greater plant height. Furthermore, the interaction between genotypes, phosphorus fertilizer and rhizobial inoculation had significant effect on grain yield in 2016. ACC#1, 3 and 5 of chickpea genotypes fixed the most N compared to that of ACC#2. In addition, ACC#5 had the highest soil N-uptake in both seasons followed by ACC#3, while ACC#1 had the least value of soil N-uptake in both seasons. Phosphorus fertilizer application increased the fixation of N by 36.8% (P≤0.01), and similarly in soil N-uptake by difference of 59.9% compared to control in 2016. Furthermore, rhizobial inoculation increased N-fixed in 2016 and soil N-uptake in both seasons. ACC#5 had the highest N fixed at phosphorus-fertilized with bradyrhizobuim across two locations in both seasons. ACC#5 depended more on soil N-uptake than fixing its own N as compared to ACC#1. N fixation differed across seasons; however, ACC#3 had greater N-fixed in both locations. Moreover, chickpea genotype that fixed more N had least δ15N. This finding indicates that N fixation is exhibited by the genotypes that depend less on δ15N, because N2 fixation is inhibited by high soil N concentration or δ15N. Furthermore, ACC#2 and ACC#3 had greater δ13C at Thohoyandou in 2017; chickpea genotypes had significant effect on δ13C at P≤0.05 at Thohoyandou, 2016. The results showed that ACC#1 with phosphorus fertilizer application and no bradyrhizobium strain showed greater δ13C. Also, δ13C increased with a decrease in N-fixed (r=.1000), this indicates that there was a functional relationship between plant WUE and N fixation in chickpea, probably because improved water use in legumes supports N fixation. / NRF

Thesis (M. Sc. Agriculture (Soil Science)) -- University of Limpopo, 2016. / Canola (Brassica napus) is an important oil crop which is not well grown in Limpopo Province. Planting date is identified as a critical management decision in canola production for enhanced biological and economic returns as it has direct influence on the growing condition at which the crop is exposed to. The objective of the study was to determine the impact of planting date on growth, grain yield, oil content and economic returns on canola production as a winter crop option in the province. The study was conducted at two climatically diverse locations; the University of Limpopo experimental farm at Syferkuil and an Ofcolaco farmers’ field in 2013 and 2014. Canola was planted at four different dates (April, May, June and July) and (March, April, May) during 2013 and 2014 growing seasons, respectively, in a randomised complete block design (RCBD) under four replications, using AG-Muster cultivar. Weather parameters were obtained from Agricultural Research Council and University of Limpopo experimental farm. Plant parameters measured were days to seedling emergence, flowering and physiological maturity, plant height, number of main and sub branches, dry matter at onset of flowering and crop residues after threshing, number of pods per plant, number of seeds per pod, unshelled and shelled weight, and grain yield. The results revealed that, days to seedling emergence responded significantly (P≤0.01) and (P≤0.05) to planting date at both locations and years except in 2014 at Syferkuil. Plant height was significantly influenced by planting date in 2013 at both locations but in 2014, the effect was significant at maturity and flowering at Syferkuil and Ofcolaco respectively. At Ofcolaco, planting date influenced days to 50% flowering, physiological maturity and plant height in both growing seasons. The influence of planting date on days to flowering and physiological maturity was significant (P≤0.01) at both locations and seasons. Canola dry matter accumulation at flowering responded significantly (P≤ 0.01) to planting date only at Syferkuil in 2013 across seasons and locations whereas residue after seed threshing responded significantly at both locations and seasons. Grain yield was significantly (P≤0.01) influenced by planting dates at all locations and seasons ranging from 292 to 2983 kg ha-1. At Syferkuil, planting canola not later than April resulted in higher grain yield whereas at Ofcolaco, planting between April and May produced the highest grain yield. The number of pods per 2 plant influenced grain yield more than the other yield components studied and regarding weather variables, minimum temperature was found to be most important in influencing growth and grain yield of canola. Oil yield ranged from 155 to 539 kg ha-1 at Syferkuil, in 2013 whilst in 2014, the range was 252 to 614 kg ha-1. At Ofcolaco, significant response of oil yield to planting dates was observed in both seasons. Economic returns at Syferkuil ranged from -R6213.00 to +R2130.00 whereas at Ofcolaco the range was +R793.00 to +R6555.00. The study revealed that Ofcolaco appeared to be better suited for canola production compared to Syferkuil due to higher grain yield and positive economic returns at the former. Keywords: canola; grain yield; oil yield; plant density, planting dates, weather parameters. / The National Research Foundation (NRF) through the Risk and Vulnerability Science Centre (RVSC). VLIR-IUC Programme.