APLICAÇÃO FOLIAR DE SILÍCIO E COBRE SOBRE DESEMPENHO FISIOLÓGICO E PRODUTIVO DA SOJA

Abstract

The search for nutritional strategies that improve the physiological and productive performance of soybean has gained prominence due to the need to maximize the metabolic efficiency of the crop. This study aimed to evaluate the effects of isolated and combined foliar application of silicon (Si) and copper (Cu) on the physiological and productive performance of soybean (Glycine max L.). The experiment was conducted in the experimental area of the Federal University of Mato Grosso do Sul (UFMS), Chapadão do Sul Campus, during the 2024/2025 growing season. The experimental design used was a Randomized Complete Block Design (RCBD), with six treatments and four replications, including different combinations of silicon and copper doses: T1 (absolute control), T2 (Si 0.60 g L-1 and Cu 0.0 g ha-1), T3 (Si 0.0 g L-1 and Cu 164 g ha 1), T4 (Si 0.60 g L-1 and Cu 164 g ha-1), T5 (Si 0.0 g L-1 and Cu 328 g ha-1) and T6 (Si 0.60 g L-1 and Cu 328 g ha-1), with potassium silicate and copper chelate as sources. Foliar applications were carried out at three reproductive stages of soybean: R3, R5.1 and R6. Foliar copper, silicon, and proline levels were evaluated, as well as grain yield and canonical discriminant analysis of nutritional and productive variables. Normality and homogeneity tests were applied, followed by ANOVA with Scott-Knott (5%). Canonical discriminant analysis assessed the combined behavior of the variables. The results indicated that the combined application of Cu and Si (Si 0.60 g L-1 and Cu 164 g ha-1) provided better physiological balance and higher productivity, demonstrating a synergistic effect between the elements. The treatment with the highest dose of copper (328 g ha-1) increased foliar levels of the nutrient, but without significant productive gains, while isolated silicon contributed to the metabolic stability of the plants. Thus, the association between Cu and Si proved to be a promising strategy for the nutritional management of soybeans, enhancing the physiological and productive performance of the crop. Keywords: micronutrient, beneficial element, foliar fertilization, proline, (Glycine max L.).