Characterization of Antagonistic Potential of Trichoderma Spp. against some Soil Borne Plant Pathogens

Ten isolates of Trichoderma spp. isolated from rhizosphere of different crops were evaluated for their antagonistic potential against five soil borne plant pathogens, viz., Rliizoctonia solani, Fusarium oxysporum f sp radicis-lycopersici, Macrophomina phaseolina and Sclerotium rolfsii using dual culture technique and production of volatile and non-volatile antibiotics. Sclerotial antagonism by the biocontrol strains was tested with R. solani and S. rolfsii. The isolate T₂, T₄ and T₇ against ^Pythium sp., T₁, T₇ and T₁₀ against F. oxysporum f. sp radicislycopersici, T₃ and T₉ against R. solani, T₇ against S. rolfsii and T₆ against M. phaseolina were the most efficient. The highest percentage inhibition of respective pathogen through the production of certain metabolites of Trichoderma isolates was recorded with T₇ against Pythium sp, and Fusarium oxysporum sp. radicis-lycopersici, T₁ against R. solani, T₅ and T₆ against S. rolfsii and T₉ isolate against M. phaseolina. Trichoderma isolate T₉ and T₂ were most effective in inhibition of sclerotia formation, production and germination of sclerotia of R. solani and S. rolfsii, respectively.