Efficacy of Trichoderma against Sclerotium rolfsii causing collar rot disease of lentil under in vitro conditions

Three biocontrol agents viz., Trichoderma viride, T. virens and T. harzianum were evaluated to test the antagonism against Sclerotium rolfsii under in vitro conditions. All the three antagonists’ viz., T. viride, T. virens and T. harzianum have shown the potential of parasitizing the growth of Sclerotium rolfsii in vitro. The rate of inhibition was fastest in T. harzianum (63.60%) followed by T virens (51.5 %). Least inhibition was recorded in T. viride (50.85% ) after 72 hours of incubation. However, T. viride showed the highest (91.31%) reduction in sclerotia formation followed by T. harzianum (84.92%) and T. virens (84.29%) after 15 days of incubation. The volatile compounds from Trichoderma viride were found most effective in suppressing the mycelial growth (51.11%) and sclerotia production (95.90%) of the target pathogen. The culture filtrate from both T. harzianum and T. viride (15% concentration) was found very effective in inhibiting the radial growth (57.46 and 49.62%) and sclerotia formation (98.20 and 99.83%) of Sclerotium rolfsii. The antagonists such as T. harzianum and T. viride can be used as a bio-control agent against S. rolfsii under field condition.