BIOCONTROL POTENTIAL OF TRICHODERMA HARZIANUM SPECIES AGAINST SEED-BORNE FUNGI OF FIFTEEN VEGETABLES USING DUAL CULTURE ASSAY

Abstract

Seed-borne fungi varied significantly across vegetables, with Fusarium spp. emerging as the most dominant pathogen, particularly in chilli, cucumber, apple gourd, and bottle gourd. Alternaria and Aspergillus spp. also showed crop-specific prevalence, while Cladosporium, Penicillium, and Rhizoctonia solani were minor contributors. Diversity analysis revealed that Tomato, Bitter Gourd, and Red Chilli harbored the highest fungal diversity, whereas Pumpkin and Apple Gourd recorded the lowest. Percentage occurrence data further confirmed Fusarium as the primary seed-borne threat, followed by Alternaria and Aspergillus. Antagonism assays demonstrated that Trichoderma harzianum significantly suppressed the radial growth of Fusarium oxysporum, Alternaria solani, and Aspergillus flavus, while its effect on Aspergillus niger was limited. Overall, the study highlights Fusarium as the most serious seed-borne pathogen, with T. harzianum proving to be an effective biocontrol agent against major fungi, though its efficacy is species-specific.