Ação mitigadora da associação de fungos micorrízicos arbusculares e silício na soja sob condições de estresse hídrico

Abstract

Soybean cultivation in tropical areas is affected by various types of stress, including drought, which affects productivity. In this sense, it is necessary to create alternatives to mitigate water stress. Arbuscular mycorrhizal fungi (FMA) have characteristics that can alleviate drought. The aim of this research was to study alternatives to mitigate the effects of water deficit in soybean plants using silicon associated with inoculation with FMA and its effects on metabolic and productive aspects. Different levels of irrigation were applied, with 40% and 70% being the levels that characterized water stress. The experiment was laid out in a causalized block design in a 2 x 2 x 4 triple factorial arrangement, with 4 replications FMA (absence and presence), Si (absence and presence) and irrigation rates (40%, 70%, 100% and 130%). Agronomic characters such as plant height, number of nodes, root volume and yield were assessed. Photosynthetic rate, transpiration, stomatal conductance, intercellular CO2 concentration and SPAD index were evaluated for physiological parameters. With the increase in irrigation, it was possible to see an increase in all the variables analyzed in the soybean. Si promoted a significant increase in plant height, number of nodes, root volume and productivity, photosynthetic rate, transpiration, stomatal conductance, intercellular CO2 concentration and SPAD index at the levels that characterized severe water stress (40% and 70% irrigation). The research concluded that increased irrigation increased root production, plant height, gas exchange, SPAD index and productivity. For the lowest irrigation rates, drought stress was mitigated, resulting in an increase in root yield, plant height, gas exchange and soybean productivity.