Efeitos do boro na nutrição e na produtividade da soja.

Abstract

The application of different sources and doses of boron can significantly improve agronomic traits in soybean crops, contributing to an increase in the agronomic and economic return of the crop. The aim of this study was to evaluate the impact of the application of sources and doses on productivity and agronomic factors of soybean, in order to determine their effectiveness in meeting the nutritional demands of the crop and improving the agronomic and economic return of the crop. Thus, the objective of this study was to evaluate the effect of sources and doses of boron applied pre-sowing to soybean on growth traits, production components and grain productivity. The experiment was carried out in an experimental area of the Federal University of Mato Grosso do Sul, Chapadão do Sul campus. The experimental design was randomized blocks, with seven treatments and four replications. The treatments were formed by the use of two boron sources, ulexite with 10% boron and durabor with 9.8% boron, a controlled release source for 180 days and three doses (Table 1). Each plot consisted of 5 rows of 5 meters in length spaced 0.5 m apart. The evaluations were made during the period from installation to harvest of the crop, considering the following variables: plant height (ALT), height of the insertion of the first pod (ALT - IPV), number of branches on the main stem (No. RHP), number of nodes on the main stem (No. NHP), number of pods per plant (No. VP), number of grains per pod (No. GP), mass of a thousand grains (PROD g), productivity in kg (PROD kg), relative chlorophyll index (IRC), boron content in the leaf and soil pigments: chlorophyll and carotenoids. The data obtained were subjected to analysis of variance and the means were compared by the Scott Knott test at a 5% probability level, using the Sisvar software. The use of Durabor 20 kg ha-1 may be a recommended strategy to maximize several agronomic factors of soybeans, increasing soil levels and improving growth characteristics, production components and productivity, indicating that this dose may be ideal to meet the nutritional demands of the crop and improve the agronomic and economic return of the crop. Keywords: Glycine max L., micronutrient, plant nutritio