http://bdtd.unoeste.br:8080/jspui/handle/tede/1 Pró Reitoria de Pesquisa e Pós-Graduação 2026-10-20T21:28:26Z http://bdtd.unoeste.br:8080/jspui/handle/jspui/1803 Título: Qualidade fisiológica de sementes de Megathyrsus ma-ximus produzidas sob diferentes condições edafoclimáticas, de manejo e armazenamento Autor: OLIVEIRA, Gilson da Silva Primeiro orientador: MACHADO NETO, Nelson Barbosa Abstract: The physiological quality of tropical forage crop seeds is important for pasture esta-blishment and productivity. The objective of this study was to evaluate the physiolo-gical quality of Megathyrsus maximus seeds produced in different fields and subjec-ted to various storage conditions, taking into account soil, climate, and management variables. Batches of the M. maximus × M. infestum hybrid and the cultivars ‘Mas-sai,’ ‘MG-12 Paredão,’ ‘Miyagui,’ and ‘Mombaça’ were analyzed. Physical purity was determined upon receipt of the samples. Other evaluations included moisture con-tent, viability by the tetrazolium test, germination, germination rate index, thousand-seed weight, electrical conductivity, hydrogen peroxide content, and crude protein. The samples were evaluated at the initial stage and after six months of storage at room temperature and under refrigeration. The data were analyzed using analysis of variance and multivariate analyses. Variability was observed among the lots, along with distinct responses to storage conditions. In some lots, germination increased after storage, particularly in ‘Massai’ and ‘Mombaça,’ while refrigerated storage was associated with better maintenance of viability in some of the samples. Multivariate analyses revealed associations between physiological attributes, environmental va-riables, and management practices, with patterns that varied across the evaluated fields. Since these analyses identify associations, they do not allow for the attributi-on of an isolated causal effect to these factors. The results indicate that seed quality should be evaluated by considering both the production environment and storage conditions together. Instituição: Universidade do Oeste Paulista Tipo do documento: Tese 2026-09-29T00:00:00Z http://bdtd.unoeste.br:8080/jspui/handle/jspui/1802 Título: Correlação entre locais de produção e a qualidade de sementes de urochloa spp. (sin. Brachiaria spp.) em função do manejo e armazenamento Autor: LORENÇONI, Pedro Henrique Lopes Primeiro orientador: CUSTÓDIO, Ceci Castilho Abstract: As tropical forage seeds are not subject to intensive genetic improvement by humans and exhibit long and variable flowering periods depending on the species or cultivar, assessing the longevity of seed lots harvested in different production areas is an essential tool for seed companies. The present study aimed to collect and evaluate information from different production fields of five (5) Brachiaria cultivars: Urochloa brizantha cv. BRS Piatã, Urochloa brizantha cv. Marandu, Urochloa brizantha cv. MG-5 Vitória, Urochloa humidicola cv. Tully, and Urochloa ruziziensis cv. Kennedy. Samples obtained from each production field were physically and physiologically evaluated at three distinct time points and storage conditions: initially; after six months of storage under ambient conditions; and after six months of storage under short-term germplasm storage conditions (10 °C / 30% RH). Following the collection of the results, correlations were established between the parameters observed in the production fields and selected analytical parameters and the performance of the seed lots after the storage period. The results demonstrated that seed physiological quality and seed storage potential are determined by the interaction between weather conditions and crop management. Overall, higher solar radiation and suitable thermal conditions favored seed vigor, whereas high altitude, dry periods, and temperatures outside the optimal range reduced seed quality. Balanced nutrient management, combined with soil correction, was a crucial factor for better results, whereas unbalanced management practices, particularly for nitrogen utilization, impaired physiological quality. Regional differences were evident, with better performance of Urochloa brizantha cultivars produced in Mato Grosso do Sul, Urochloa humidicola in Minas Gerais, and Urochloa ruziziensis in the municipality of Jaborandi, Bahia. The conclusion is that seed quality and longevity depend on integrated management adapted to the environment and genetic material, making it essential to jointly consider field conditions and physiological attributes to optimize the production, storage, and commercialization of seed lots. Instituição: Universidade do Oeste Paulista Tipo do documento: Dissertação 2026-09-25T00:00:00Z http://bdtd.unoeste.br:8080/jspui/handle/jspui/1801 Título: Utilização de fertilizante de eficiência aumentada em pastagem sob sistema de integração lavoura-pecuária em solo arenoso Autor: OLIVEIRA, Clayton Baravelli Luís de Primeiro orientador: MORO, Edemar Abstract: The growing demand for food production poses significant challenges to sustainable agricultural practices. Integrated crop-livestock (ICL) systems have emerged as diversified approaches to address these challenges. Pasture management in these systems plays a crucial role in optimizing forage production and efficiently utilizing resources to enhance overall productivity. This study investigates the use of technologically advanced nitrogen fertilizers, specifically NBPT + Duromide-coated urea and formaldehyde-coated urea, aiming to reduce nitrogen (N) losses, particularly through ammonia volatilization (NH3-N), and consequently mitigate carbon dioxide emissions in sandy soil within the ICL system. Evaluations spanned three agricultural years (2020-21, 2021-22, and 2022-23), utilizing Urochloa Brizhanta cv. marandu pasture and NS-6828 and NS-6700 soybeans. The soil, characterized as dystrofic Ultisol, exhibited a sandy texture. Employing a randomized complete block design with four replications in a 3x4 factorial scheme, treatments included three N sources: conventional urea (UrConv), slowrelease formaldehyde-coated urea (UrForm), and urea with urease inhibitor and Duromide technology (UrDuromide), each with four doses (0, 100, 200, and 400 kg ha-1 of N). Analysis of carbon dioxide (CO2) emissions and total organic carbon (TOC) involved testing for dose × source interaction using Statistical Analysis System software. Nonlinear regression, employing a logistic model, was applied to NH3-N volatilization data. Nitrogen losses varied with dose and fertilizer, reaching up to 33% with UrConv. UrDuromide exhibited declining efficiency over the evaluation period, resulting in losses reduced by 52% in the first year, 46% in the second, and only 5% in the third. UrFormaldehyde demonstrated less variability, with reductions in NH3-N losses ranging from 57% to 45%. Trends in TOC and CO2 emissions mirrored each other, with UrConv contributing to the highest CO2 emissions and TOC accumulation. UrDuromide showed a promising up to 6% reduction compared to UrConv in greenhouse gas emissions and, consequently, lower TOC accumulation. In conclusion, the use of technology to enhance nitrogen fertilizer efficiency presents a promising avenue for reducing greenhouse gas emissions, providing a viable alternative in comparison to conventional urea sources. Instituição: Universidade do Oeste Paulista Tipo do documento: Tese 2024-04-01T00:00:00Z http://bdtd.unoeste.br:8080/jspui/handle/jspui/1800 Título: Efeito do níquel na mitigação da fitotoxidez de glufosinato aplicado em pós-emergência da soja IPRO RR2 Autor: Scabeni, Eduardo Verdi Primeiro orientador: Volf, Marcelo Raphael Abstract: New soybean cultivars tolerant to glufosinate ammonium enable more efficient weed management. However, herbicide drift can adversely affect susceptible crops. Nickel (Ni) nutrition has been studied as a potential strategy to mitigate herbicide-induced phytotoxicity, as several studies highlight its role in enhancing tolerance to environmental stresses, including toxicity in annual crops. This study evaluated the effect of foliar Ni application in mitigating phytotoxicity induced by glufosinate ammonium in the susceptible soybean cultivar Intacta RR2 PRO® (IPRO). The experiment was conducted in two locations: Area 1 (LRV) in the municipality of Lucas do Rio Verde and Area 2 (NMT) in the municipality of Nova Mutum. Herbicide applications were performed at the V6 phenological stage (sixth node of the main stem with fully developed leaves), followed by Ni application 120 hours later. Five doses of glufosinate ammonium (0%, 15%, 25%, 50%, and 100% of the maximum recommended dose) and two Ni doses (0% and 100%, equivalent to 60.0 g ha⁻¹) were tested. Phytotoxicity symptoms were assessed through visual observation at 7, 14, and 21 days after application using a standardized phytotoxicity rating scale. At the R8 stage, plant height and yield components were evaluated, including grain yield, thousand-grain weight (TGW), and total pod number (TPN). The results suggest that foliar Ni application partially mitigated the phytotoxic effects of glufosinate ammonium. This mitigating effect was evidenced by its influence on plant height, pod number, and grain yield, as well as by a reduction in visual phytotoxicity symptoms. Therefore, Ni supplementation may represent a promising strategy for alleviating glufosinate ammonium-induced phytotoxicity in soybean cultivation. Instituição: Universidade do Oeste Paulista Tipo do documento: Dissertação 2026-04-25T00:00:00Z