Bioactivity of Trichoderma asperellum against Colletotrichum asianum and Sclerotinia sclerotiorum

Anthracnose caused by Colletotrichum asianum and stem rot caused by Sclerotinia sclerotiorum are two important fungal plant diseases worldwide. This work reports potential biocontrol isolates of Trichoderma spp. against S. sclerotiorum and C. asianum. Antagonistic activity of 11 isolates of Trichoderma species was determined using dual culture technique. Potential isolates of Trichoderma secondary metabolites (500 to 5000 ppm) were tested against S. sclerotiorum and C. asianum, respectively using poisoned food technique. Antagonistic tests indicated that out of the 11 isolates of Trichoderma spp, Trichoderma asperellum [isolate-21] was the most effective against both the pathogens. Ethyl acetate (EA) crude extract of T.asperellum [isolate-21] exhibited the highest mycelial growth inhibition of S. sclerotiorum (93–99% at 2000–5000 ppm) and C. asianum (80–90% at 3000–5000 ppm).