In vitro bio efficacy of microbial antagonists against fusarium oxysporum f.sp. vasinfectum

The bio efficacy of T. viride and P. fluorescens isolates were tested in in vitro against Fusarium oxysporum f. sp. vasinfectum causing wilt of cotton. Among the T. viride isolates, Tv7 and P.fluorescens isolates, Pf5 significantly inhibited the growth of F. oxysporum f.sp. vasinfectum tested by the dual culture technique than the control. Similarly, the culture filtrate of Tv7 and Pf5 isolates were significantly inhibits the growth of F. oxysporum f.sp. vasinfectum. The reduction of mycelial growth of fungus was directly correlated with the concentration of Tv7 and Pf5 culture filtrates in poisoned food technique. The combination of culture filtrate of T. viride (Tv3) and P. fluorescens (Pf7) recorded the maximum germination percentage of 95.75% and increased the shoot and root length to the maximum of 14.10 and 20.29 cm, respectively and recorded a higher vigour index of 3292.84 in roll towel method.