Uso de microrganismos e metabólitos no desempenho do feijoeiro comum e no controle do tombamento (Rhizoctonia solani)

Abstract

Damp-off, caused by the fungus Rhizoctonia solani, is one of the most important soil diseases affecting common bean production. This research aimed to verify the agronomic performance of microorganisms, metabolites of isolated forms and in combination via commercial formulation in the efficiency for culture and control of R. solani in the common bean crop. The experiments were carried out under field conditions at the Experimental Station of Agroteste Pesquisa e Desenvolvimento, in the municipality of Lavras, Minas Gerais, Mato Dentro community, under the coordinates 21º 12' 51.87" S, 45º 03' 26.3" W and 898 m of altitude, in the 2020/2021 harvest. The following determinations were made for the common bean crop with the action of soil conditioner and growth promoter, in the field, plant height, plant fresh and dry mass, root fresh mass, root dry mass, leaf nutrient analysis and components of crop production and productivity. R. solani pathogen control assays, in vitro, were conducted at the Biological Control Laboratory and in vivo assays in a greenhouse, belonging to the Department of Phytopathology (DFP) of the Federal University of Lavras, in the year 2022. In this way, in vitro biocontrol performance experiments of microorganisms, metabolites, isolated and in combination on mycelial growth, number and weight of microsclerotia of R. solani were established; In vivo biocontrol performance of microorganisms, metabolites, isolated and in combination on damping-off and severity of R. solani. The data obtained from the evaluations were submitted to analysis of variance (Test F), with the test of homogeneity, and the means of the treatments, when significant, were compared by the Tukey test at 5% probability in the statistical software R Studio. The results of the studies indicate that: The agronomic use of the products SPA (Bacillus spp.), SPR (Bacillus + Trichoderma spp.) and SPT (Trichoderma spp.), is favorable to the normal development of the culture under study. Bacillus spp.; Trichoderma spp. and the combination of these biological control agents are efficient in the in vitro control of mycelial growth and sclerotia formation of R. solani; Bacillus spp. provides greater plant height, fresh and dry root mass and positively influences the productivity of the common bean crop. Through the data obtained, it can indicate a high ability to control metabolites, microorganisms, isolated or in combination, with high potential for use in an integrated management system for diseases of cultivated plants. The antagonistic microorganisms applied via the sowing furrow, with metabolites, isolated microorganisms and in combination interfered in the vegetative parameters of common bean plants without the presence of inoculum under field conditions. The treatments with Bacillus, Trichoderma, isolated and in combination via application of metabolites and microorganisms, significantly interfered in the increase of productivity of the bean crop. The performance of the evaluated products is different according to the considered variable and fraction of the metabolite.