Tratamento de sementes de soja com produtos à base de Bacillus spp.: análise bibliométrica, qualidade fisiológica e efeito bioestimulante

Abstract

Due to adverse environmental effects and the variable efficacy of chemical control methods, there has been a growing development of products derived from biocontrol agents for plant health management, with particular emphasis on growth-promoting rhizobacteria of the Bacillus genus. Accordingly, the objective of this study was to investigate the use of Bacillus as a management strategy for soybean seed treatment through a bibliometric analysis, and to evaluate the physiological potential of soybean seeds and the biostimulant effects of commercial formulations based on Bacillus spp. in relation to storage duration and environmental conditions. For this purpose, an exploratory bibliometric analysis was conducted over a 25-year period (2000 to 2024) on the topic of soybean seed treatment with Bacillus spp., and experimental trials were carried out with five seed treatments (B. amyloliquefaciens PTA 4838; B. subtilis CNPSo 2657; B. firmus I1582; abamectin; imidacloprid + thiodicarb) plus a control, under two storage durations (initial analysis and 180 days). For the latter period, the effects of storage in a chamber under controlled conditions (10°C and 40% relative humidity) and under uncontrolled conditions were analyzed. The results of the bibliometric analysis revealed a diversification of applications starting in 2014, with a growing trend in the use of these microorganisms for the management of fungal diseases and nematodes, with B. subtilis being the most extensively studied species. Regarding the second line of investigation, the application of commercial products based on Bacillus spp. resulted in significant reductions in the incidence of Aspergillus spp., improved final seedling germination, germination speed index, laboratory emergence speed, and biostimulant effects, including increases in root system length and dry matter of both shoots and roots, across both storage periods and under controlled environmental conditions. Moreover, under simulated water deficit conditions, Bacillus spp. was able to maintain the physiological potential of seeds in terms of germination variables and root system length. Temperature and humidity control were decisive factors in preserving the physiological potential of the seeds. The information regarding the effects of Bacillus spp.-based products on seed physiological performance may support integrated management programs in achieving better seedling development outcomes while aligning with the environmental requirements of sustainable production systems.