In vitro antagonism of three Trichoderma spp. against Sclerotium rolfsii Sacc., a collar-rot pathogen in elephant foot yam.

摘要

The present investigation focuses on the screening of potential biological control agents against the collar-rot pathogen Sclerotium rolfsii [Corticium rolfsii] on elephant foot yam (Amorphophallus paeoniifolius), an intercrop of coconut in Andhra Pradesh, India. Among the three antagonists isolated and screened, viz. Trichoderma viride, T. harzianum and T. hamatum, T. hamatum inhibited the radial growth of S. rolfsii to an extent of 52.22% followed by T. viride (44.11%) and T. harzianum (38.87%). All the three Trichoderma spp. were very effective in producing volatile and non-volatile metabolites that were suppressive to S. rolfsii. Viability tests on the sclerotia of S. rolfsii parasitized by Trichoderma spp. revealed complete colonization and replacement of sclerotial contents by 7th day of parasitization in case of T. hamatum and by 10th, day in case the of T. viride and T. harzianum..