Five Trichoderma strains such as T. virens IMI-392430, T. pseudokoningii IMI-392431, T.
harzianum IMI-392432, T. harzianum IMI-392433, T. harzianum IMI-392434 were tested for efficacy to
inhibit and overgrowth of mycelia of Fusarium solani, a causal agent of root rot of Ashwagandha on
potato dextrose agar (PDA) medium. Duel culture technique showed that all Trichoderma strains
effectively inhibited and overgrew mycelia of the pathogen, especially T. harzianum IMI-392432
providing the highest percent of inhibition of radial growth (PIRG) (69.32 %) and overgrowth mycelia
(59.28 %). Liquid culture filtrates having 75% concentration extracted from 30-day-old T. harzianum
IMI-392432 showed the highest percent inhibition of mycelia growth (PIMG) value of 76.23% by using
normal poison agar technique. Further, highest percent inhibition of conidial germination (PICG) (82.86
%) of the pathogen was exhibited by T. harzianum IMI-392432 at same culture and concentrations. In this
study it was observed that different Trichoderma strains have good antagonistic effect on Mycelial growth
and conidial germination of F. solani. In each case, T. harzianum IMI-392432 performed the best
bio-control agent against F. solani causing root rot disease of Ashwagandha.