AVALIAÇÃO DO EFEITO DA INOCULAÇÃO DE MICROORGANISMOS NOS PROCESSOS FISIOLÓGICOS DE SOJA SUBMETIDAS À SECA

Abstract

Soybean (Glycine max L. Merrill) is currently the world's leading legume crop in terms of energy and food security issues. Although Brazil is currently the largest soybean producer in the world, Brazilian production is often compromised by the frequent occurrence of dry spells. In this context, climate instability and the frequency of dry spells can aggravate and compromise soybean planting. Thus, the use of multi-strain biodefensives is a new alternative and has been showing great effectiveness in establishing sustainable solutions, tolerance to biotic and abiotic stresses and in crop improvement. For this, this study used the bacterium Bacillus amyloliquefaciens BV03 (NO-NEMA) and the fungus Trichoderma asperellum BV10 (TRICHO-TURBO), as well as the interaction of these combined microorganisms, since good results have already been obtained from those applied separately, and the form of application, whether inoculated in the seeds before planting or combined with foliar application, was carried out in a greenhouse at Instituto Goiano, Campus Rio Verde. The seeds used were of the Neo680 cultivar, planted in soil+sand in a 2:1 ratio, autoclaved and soaked in a preparation containing approximately 6 ml of syrup in 1 kg of seeds and delineated as follows: T1 – Control (plants continuously irrigated; T2 - water deficit (30% of water available in the soil); T3 - Drought+BV03 inoculated in seeds (Standard Dose); T4 - Drought+BV03 inoculated in seeds + foliar application (Standard Dose); T5 - Drought+BV03+BV10 , both inoculated in the seeds (Standard Dose); and T6 - Dry+ BV03+BV10, both inoculated in the seeds and both applied in the leaves. Physiological parameters were evaluated, such as: Water potential in the morning (Ѱam) and at noon (Ѱmd), water changes gaseous (A, gs, E, Ci, ϕFSII and ϕFSII/CO2), concentration of photosynthetic pigments (Chl a Chl b and total Chl) and electrolyte leakage (EE). It was observed that the plants inoculated with the microorganisms were able to mitigate the effects of drought, attenuating the damage, maintaining a good Ѱw, with gas exchange values close to that of T1, in addition to guaranteeing a good rate of EE, guaranteeing the integrity of the membrane. It is concluded that BV03+BV10 managed to mitigate the damage caused by drought, where the form of application manages to increase this protection.