No abstract

The soybean presents great economic expression and high impact in the Brazilian agribusiness. The productive potential of a cultivar is expressed according to the genetic constitution and the environment. The sowing time exerts influence on the agronomic traits of the soybean, impacting the yield of grains. The objective of this study was to evaluate the influence of the sowing season on the productive potential and the agronomic traits of soybean. The work was conducted at the Capim Branco experimental farm, belonging to the Federal University of Uberlândia. Twelve cultivars (UFUS 6901, UFUS 7415, BRSMG 68, TMG 801, TMG 7062 IPRO, TMG 2158 IPRO, BRS 7270 IPRO, NA 5909 RR, NS 6909 RR, CD 2737 RR, P98Y30 RR e BRASMAX Desafio RR) and four sowing seasons (October 22, November 5, December 22, 2016 and January 5, 2017) were used. The experimental design was a randomized block design with four replicates. The evaluated characters were: number of days for flowering and maturity, plant height at maturity, insertion height for the first pod, number of nodes at maturity, total number of pods, number of tainted pods and productivity. The sowing carried out in October and November contributed to obtain a larger number of nodes and a greater height of plants at maturity, which are agronomic traits favorable to higher productivity. Sowing delay seriously affected soybean yield and in the Uberlândia MG region the ideal sowing time was October 22, before the beginning of November. In the late sowing in December and January, the cultivars that had their productions less affected were the conventional cultivars BRSMG 68 and TMG 801.

Ao professor Dr. Osvaldo Toshiyuki Hamawaki, pela orientação e por ter disponibilizado os recursos necessários para a realização do trabalho. À Professora Dr a. Ana Paula Oliveira Nogueira, pela coorientação, pelo tempo, paciência e sabedoria dedicados para realização do trabalho. Aos alunos membros do programa de melhoramento genético de soja da Universidade Federal de Uberlândia, pela colaboração na condução dos experimentos. Aos membros da Banca Examinadora, Dr a. Flávia Aparecida Amorim e Dr a. Jacqueline Siqueira Glasenapp, por aceitarem o convite de avaliar esta dissertação. À minha família, principalmente minha mãe Eremita, avô Érico e avó Aparecida, por todo apoio durante toda minha vida. Aos meus amigos que me ajudaram durante os experimentos e participaram dessa trajetória,

Soy is one of the main cultivated species in the world with great economic expression and high impact on Brazilian agribusiness. The productive potential is expressed due to the genetic constitution of the cultivar and the environment in which it is exposed. The market demands for bean production require the ideal handling of the culture in order to optimize the yield potential of the plant. In this context, the handling of the culture is essential to achieve success when cultivating soy. Plant population influences the agronomic characters and consequently in the grain yield. Thus, this factor needs particular studies for each cultivar. The objective in this study was evaluating the influence of the plant population on the productive potential and agronomic characters in soy, in Uberlandia, Minas Gerais. The experiment was performed in Capim Branco Farm, which belongs to the Federal University of Uberlandia. The study was composed by 15 treatments in a 3x5 factorial scheme, constituted by three cultivars (UFUS 7415, UFUS 7401 and UFUS 6901) and five plant populations (200, 240, 280, 320 and 360 thousand plants ha-1). It was adopted the experimental outlining of randomized complete blocks, with five repetitions. The evaluated characters were: number of days to flowering and maturity (NDF and NDM), plant height at flowering and maturity (APF and APM), number of nodes at flowering and maturity (NNF and NNM), insertion height for the first pod (APV), total number of pods (NVT), thousand grain weight (P1000G) and productivity (PROD). It was noted that plant population didn’t interfere in the soy cycle, number of nodes and thousand grain weight. The cultivars UFUS 6901, UFUS 7415 and UFUS 7401 presented better yields in populations of 240, 280 and 320 thousand plants ha-1 respectively.