Seleção in vitro de isolados de Trichoderma sp. Antagonistas a Macrophomina sp., patógeno do FEIJÃO-CAUPI

Abstract

The main objective of this work is to select, under laboratory conditions, isolates of the fungus Trichoderma sp. that demonstrate high antagonistic capacity against the phytopathogenic fungus Macrophomina phaseolina, the causal agent of ash-gray rot disease, which is one of the main diseases affecting cowpea (Vigna unguiculata L.). The central methodology established is the dual culture method (or direct confrontation), where Trichoderma (the biological control agent) and Macrophomina (the pathogen) are inoculated on opposite sides of a Petri dish using a culture medium, such as PDA (Potato Dextrose Agar). The success of the antagonism is evaluated by the inhibition of the pathogen's radial growth due to the antagonistic capability of Trichoderma. We obtained relevant results in the isolates TM44, TM45, TM58, and TM15, with more than 50% suppression of the Macrophomina phaseolina colony. The relevance of this study lies in identifying a sustainable and ecologically correct biological control alternative for the management of this important disease in cowpea cultivation.