Vol. 9, Special Issue 11, Part P (2025)

The compatibility of Trichoderma koningii, a widely used biocontrol agent, with selected systemic fungicides was evaluated to support integrated disease management strategies. The study was conducted during 2024-2025 at the Department of Plant Pathology, Dr. Sharadchandra Pawar College of Agriculture, Baramati, following a Completely Randomized Design (CRD). Seven systemic fungicides—Fosetyl-Al 80% WP, Tebuconazole 25.9% EC, Fluxapyroxad 333 g/L FS, Difenoconazole 25% EC, Kresoxim-methyl 44.3% SC, Propiconazole 25% EC, and Hexaconazole 5% EC—were tested using the poisoned food technique at both full and half of the recommended doses. The results demonstrated that Fluxapyroxad and Kresoxim-methyl were highly compatible with T. koningii, allowing over 90% radial growth even at the full recommended dose. Fosetyl-Al showed moderate compatibility, with 63.33% and 68.89% growth inhibition at half and full doses, respectively. In contrast, Tebuconazole, Difenoconazole, Propiconazole and Hexaconazole exhibited strong inhibitory effects, with 90-94.44% suppression, indicating incompatibility with the biocontrol fungus. The results indicate that T. koningii can be successfully used in combination with compatible fungicides like Fluxapyroxad and Kresoxim-methyl to improve crop protection, whereas fungicides that strongly inhibit its growth should be used with caution or avoided. This study highlights the need to evaluate fungicide compatibility to maximize the effectiveness of biocontrol agents and promote sustainable disease management.