Antagonistic Potential of Biocontrol Agents against Macrophomina phaseolina in Green Gram

Abstract

Macrophomina blight caused by Macrophomina phaseolina, is one of the most destructive diseases affecting green gram (Vigna radiata L.) particularly under drought and high-temperature conditions. The ability of the pathogen to persist in the soil and rapidly colonize host tissues makes management difficult through conventional means. In an effort to identify effective biological alternatives an in vitro study was conducted to evaluate the antagonistic performance of selected fungal and bacterial bioagents against M. phaseolina. The experiment involved six biocontrol agents four fungal species from the Trichoderma genus and two bacterial strains, Bacillus subtilis and Pseudomonas fluorescens. Dual culture and streak plate techniques were employed on PDA medium to assess their efficacy. Results revealed significant variation in pathogen suppression, with Trichoderma harzianum exhibiting the highest growth inhibition at 87.77%, followed by Trichoderma hamatum and Trichoderma asperellum. In contrast, the bacterial antagonists showed comparatively lower inhibition levels. The outcomes of this study highlight the potential of Trichoderma harzianum as a promising biocontrol agent for managing Macrophomina blight in green gram under eco-friendly disease management practices.