ISOLATION OF SOIL MICROORGANISMS FOR BIOLOGICAL CONTROL OF CITRUS PHYTOPATHOGENS

Abstract

: Citriculture is one of the most representative sectors of Brazilian agribusiness, however it faces adversities generated by diseases and pests that are responsible for significant production losses. In Citrus cultivation, more than fifty phytopathologies are attributed to fungi. Control measures occur through the application of pesticides, however, environmental issues highlight biological control as an alternative to chemical control, also constituting a capital-saving technology. In view of the above, this work aimed to isolate microorganisms from the soil of a Laranja Pêra orchard, where the isolates were subjected to an in vitro paired culture test in order to determine the percentage of inhibition of the growth of citrus phytopathogens: Geotrichum citri-aurantii  and Alternaria alternata. Three fungi were isolated from the soil sample, which were subjected to area growth assessment, and subsequently to statistical analysis using the ANOVA test at 5% probability. It was possible to identify inhibition potential in all isolates with statistically significant differences in all replicates. The isolates interfere with the growth of pathogens in different ways, but they still demonstrate the inhibitory and antagonistic nature of the isolates and their biologically active metabolites.