Ação do bioestimulante (FH Attivus) na mitigação do estresse hídrico em diferentes estádios da soja.

Abstract

The present study aimed to evaluate the effect of FH Attivus biostimulant on mitigation of negative effects generated by the water deficit in soybean plants, seeking to understand which physiological and morphological mechanisms participate in the increase in soybean tolerance under such conditions. The experiment was developed in a completely randomized design, in a 4x2 factorial scheme, consisting in four dosages and two application seasons, with one extra control sample, amounting nine treatments, in a greenhouse located in the experimental area of the agrarian sciences center of the Federal University of Ceará, Campus do Pici, Fortaleza - CE. It was possible to observe an increase in plant height and relative chlorophyll index (SPAD) when applied 0.100 kg.ha-1 before the imposition of water deficit. Regarding the physiological variables net photosynthesis, stomatal conductance, transpiration and carboxylation efficiency, it can be seen that when 0.250 kg.ha-1 was applied before the imposition of water deficit, there was an increase in the variables. When evaluating water potential, it was possible to observe that, when applied 0.100 kg.ha-1 before or 0.250 kg.ha-1 after the imposition of the water deficit, there were lower values of potential, lower even than observed in the control sample, showing that the plants were turged. Regarding the leakage of electrolytes, it was necessary usage of 0.500 kg.ha-1 before imposing the water deficit to reduce the occurrence of free radicals and, consequently, damage to the membrane. In general, the evaluation of the biostimulant FH Attivus demonstrated a positive effect, since the application of this product attenuated the effects of water stress for most variables, especially when applied before the imposition of stress.