1. Non-volatile and volatile metabolites of antagonistic trichoderma against collar rot pathogen of mentha arvensis

Mentha arvensis L. is an aromatic perennial herb, is commercially cultivated for its oil. The crop is severely affected by collar-rot disease. The disease caused by Sclerotium rolfsii Sacc (Saccardo) is a soil borne plant pathogen and it has wide host range. Trichoderma species were identified as significantly and potentially effective antagonists against the pathogen. Invitro conformation test like dual plate can be coupled to extracellular enzyme and protein analysis because they play a importent role in inactivation of fungal plant pathogens. Twelve isolates were tested for the production of volatile and Non volatile metabolites. The results indicated that Trichoderma isolates were not produced any volatile metabolites. All antagonists produced non-volatile metabolite/s and inhibiting the mycelial growth of Sclerotium rolfsii. T. konigiopsis (M32, M33), T. neokoningii (M6), T. harzianum (21), T. gamsii (M11, 15) were more aggressive in inhibiting the mycelial growth of the S. rolfsii and formation of sclerotial bodies. The other isolates were partially inhibiting the growth rate of S. rolfsii.