Grain, oil, and protein production on soybean stems and branches under reduced densities

Abstract

The reduction of sowing density is a strategy that aims to reduce production costs with no losses in grain yield. This study aimed to evaluate the yield components and contents of protein and oil in grains from branches and stems of two soybean cultivars as a function of the reduction in sowing density. The experiments were conducted in two growing seasons (2016/17 and 2017/18) in Londrina, PR, Brazil. Two soybean cultivars were evaluated: BRS 1010 IPRO and NS 5959 IPRO. The experimental design was completely randomized blocks in a split-plot scheme, with five replications. Plots consisted of five sowing densities (100, 80, 60, 40, and 20% of that indicated by the cultivar breeder) and subplots consisted of two plant strata (branches and stems). The number of pods m?2 and grain, protein, and oil yield increased in the branches and decreased in the stems with a decrease in sowing density. The number of grains per pod is higher in the stems than in the branches, regardless of the cultivar. The protein content in the grains is higher in the branches than in the stems for the cultivar BRS 1010 IPRO and decreased with a reduction in sowing density. The thousand-grain weight of the cultivar NS 5959 IPRO decreased with a reduction in sowing density. The oil content in the grains was not influenced by the studied factors.