Efeito da densidade de plantas sobre caracteres agronômicos de cultivares de soja com diferentes padrões de engalhamento

Abstract

Soybeans (Glycine max (L.) Merrill) are one of the most economically significant agricultural commodities on the world market, with Brazil being the largest producer and exporter of the crop. In this sense, management techniques that increase productivity and reduce production costs are strategies to increase the efficiency of Brazilian grain production. Adjusting plant density is a management practice that can promote these improvements, since soybeans have the capacity to compensate for the smaller number of plants with greater individual production, however, this characteristic can be affected by the environment. The present study evaluated the behavior of soybean cultivars with different engalhamento capacities when subjected to variations in plant density. The experiment was conducted in the 2022/23 harvest, in three locations (Pato Branco/PR, Guarapuava/PR and Abelardo Luz/SC), consisting of five soybean cultivars (BMX Raio, BMX Zeus, BMX Ativa, DM57I52 and BMX Vênus) and they were subjected to five plant densities (-60%, -30%, ideal population, 30% and 60%), with three replications and in a randomized block experimental design. Were evalueted five plants per plot to determine grain yield and agronomic characters: weight of a thousand grains, number of branches, number of pods, number of grains, number of grains per pod, number of productive nodes, plant height and Internode distance, per plant and individually for main stem and branches. The data were subjected to joint three-factor analysis, being analyzed through analysis of variance using the F test (α=5%). When a significant three-factor interaction was verified, polynomial regression was applied, while, in cases of significant two-factor interaction or for isolated factors, means were compared using the Tukey test. Furthermore, the data were evalueted on R software. The results indicate that the increase 30 and 60% in plant density presents higher grain yield, regardless of the cultivation potential of the cultivars and cultivation locations. At high densities the genotypes, there was a greater participation of the stem in grain yield, while the number of branches was reduced. As well as, even with lower production of pods and grains per plant, the increase in population density increased the weight of the grains, so that the yield increased as a result of the greater weight of a thousand grains and the greater productivity of the agronomic components per area.