Vol. 9, Issue 11, Part B (2025)

The escalating concerns over synthetic fungicide use necessitate the development of sustainable alternatives for managing fungal foliar diseases in vegetable crops. This study investigated the in-vitro antagonistic potential of five entomopathogenic fungi (EPF) and Trichoderma viride against two significant phytopathogens: Drechslera bicolor (from brinjal) and Curvularia lunata (from spinach). The bioagents—Beauveria bassiana, Nomuraea rileyi, Metarhizium anisopliae, Verticillium lecanii, and Trichoderma viride—were evaluated using a dual culture technique, with Carbendazim 50 WP (0.1%) and an untreated control as benchmarks.

All bioagents significantly inhibited the mycelial growth of both pathogens compared to the control, though none matched the complete inhibition achieved by Carbendazim. Against D. bicolor, Nomuraea rileyi and Metarhizium anisopliae were the most effective, showing the highest percent inhibition (54.22% and 52.28%, respectively) and the lowest pathogen growth rates. Against C. lunata, Nomuraea rileyi again emerged as the most potent antagonist (50.28% inhibition), followed by Metarhizium anisopliae and Trichoderma viride. Beauveria bassiana and Verticillium lecanii demonstrated comparatively lower efficacy. The formation of inhibition zones indicated antibiosis as a key mode of action for T. viride, N. rileyi, and M. anisopliae.

The results demonstrate that EPF, particularly Nomuraea rileyi and Metarhizium anisopliae, possess significant antagonistic activity against foliar pathogens. The efficacy was bioagent-and pathogen-specific, highlighting the importance of targeted selection. This study provides a foundational basis for incorporating these entomopathogenic fungi into integrated disease management strategies as eco-friendly biocontrol agents.