Componentes de rendimento e produtividade em função da densidade populacional de cultivares de soja em terras baixas

Abstract

The soybean (Glycine max L. Merrill) stands out as one of the main agricultural crops in the national and world scenario. The development of soybean depends on many factors, among which the most important are meteorological ones such as: humidity, temperature and photoperiod. Among the new management practices, different plant arrangements have been studied, either by the variation in the plant population, or by the spacing between rows, in which the area and the shape of the available area for each plant is altered, reflecting in differentiated intraspecific competition . The objective of this work was to evaluate the variation of yield and yield components in different population densities of soybean cultivars in the lowlands. Seeds of the cultivars TEC 7849 I PRO (maturation group 7.8), TMG7062 (maturation group 6.2), and NS 4823 (maturation group 4.8) were used. Population densities were established in five treatment levels: 40, 80, 160, 240 and 320 thousand ha-¹ plants. Plant height, number of nodes, number of secondary stems, number of pods, number of grains per pod, number of seeds per plant, weight of 1000 seeds were collected for 2 m² for the analyzes, productivity. Changes in the spatial arrangement of soybean plants can positively influence grain yield and its components. The use of the smaller population promoted the insertion of the first legume, presenting an increasing behavior as the population of plants increased, as opposed to the number of nodes, where the smallest population showed a decrease in the number of nodes per plant. The number of secondary stems, number of vegetables per plant and number of seeds per plant, expressed lower values of these variables as the population increased. For the mass of 1000 seeds the variable presented smaller values as the population increased. Cultivation productivity was positively expressed in the largest populations of this study.