Interação entre Bacillus aryabhattai e Azospirilum brasílense no desempenho produtivo da soja

Abstract

Soybean is a crop of great importance in brazilian agribusiness, characterized by its adaptability to all regions of the country. The demand for technological solutions that increase crop productivity is constant, mainly due to the high frequency of extreme weather events, such as drought and high temperatures. The use of biostimulants is one of these solutions, as these products act positively on the plant's physiological processes and promote stress tolerance. This study aimed to evaluate the efficiency of biostimulants based on the rhizobacteria Bacillus aryabhattai and Azospirillum brasilense, applied via seed treatment, alone or in interaction, on soybean crops. Two experiments were carried out under field conditions in the municipality of Lucas do Rio Verde - MT, during the 2023/2024 harvest. The design used was randomized blocks, with four treatments and five replications. The treatments were: T1 = control, T2 = seed treatment with A. brasilense (5 ml for 2.5 kg of seeds), T3 = seed treatment with B. aryabhattai (5 ml for 2.5 kg of seeds) and T4 = seed treatment with A. brasilense + B. aryabhattai. The variables analyzed were divided into biochemical analyses (total soluble carbohydrates, total phenolic compounds and total flavonoids) and biometric and production evaluations (plant height, distance between nodes, plant density, number of pods per plant, number of grains per pod, thousand-grain weight and productivity). Significant changes were observed in the leaf contents of total phenolic and flavonoid compounds, suggesting that the microorganisms used acted on the antioxidant system of soybean plants. However, in relation to the biometric and production parameters, there was no significant difference between the treatments, indicating that the applied doses of B. aryabhattai and A. brasilense may not have been sufficient to optimize the physiological processes of soybean and increase crop productivity under the conditions analyzed.