EVALUATION OF ANTAGONISTIC POTENTIAL OF TRICHODERMA ISOLATES AGAINST SELECTED PHYTOPATHOGENIC FUNGI

Abstract

Phytopthogen are simply an organism parasitic on a plant host resulting the serious problems regarding crop losses in agriculture sector. To facing such a threat, it is very wise to use Biological Control Agents (BCA’s) like Trichoderma, a soil-borne filamentous fungi that are capable of parasitizing several plant pathogenic fungi. It is a potential fungal BCA’s against a range of plant pest and pathogens. Unfortunately, popularization of bio-pesticides is very slow as compared to chemicals and only 0.035% bio-pesticides are available in pesticides market share of Nepal as of 2011/12. Trichoderma harzanium and Trichoderma viride have curved a niche for themselves in Nepal as important BCA’s for management of various diseases. In this study, Trichoderma and phytopathogens were isolated from soil samples and diseased plant parts using soil dilution plating methods and tissue culture techniques respectively. Thereafter, antagonistics properties of eight T-isolates coded as Tar, T22, I2, I3, TV, T-gel, TH3 and Dar were evaluated against fourteen phytopathogenic fungi (Acremonium spp., Alternaria brassisicola, Exsirohilum turcicum, Fusarium spp., Macrophomina phaseolina, Penicillium spp., Rhizoctonia solani, Sclerotium rolfsii) tested in vitro study using dual culture techniques volatile and non-volatile compounds methods whereas in vivo study includes germination percentage and percentage increased or decreased of diseases severity over control. In dual culture techniques and non-volatile compound effects, it is found that T-isolates has maximum growth inhibition of R. solani (as much as 100% overgrowth) whereas M. phaseolina has lowest effect on it. Generally volatile organic compounds of T-isolates shows moderate and similar effect on phytopathogen except M. phaseolina which has almost no effect on them. Study conducted on vivo trail gives satisfactory results to proof T- isolates as a very potent BCA’s. Overall results analysis shows Trichoderma isolates Tar and I2 are very potent BCA’s and could be recommended for mass production of Trichoderma based biopesticides from them. Present study concludes the uses of Trichoderma and assessment of their suitability as bio-pesticides for control of selective fungal phytopathogen.