Toximetric Studies on Some Major Bamboo Pathogens

Nigrospora oryzae was found to be an important causal agent of leaf spot disease on Bambusa nutan, Fusarium oxysporum on B. balcooa with more than 50% severity and F. verticilliodes on Dendrocalamus asper as the causal agents for emerging and growing culm rot with 100% severity in some areas. Bio- control study was conducted to know the antagonistic activity of six Trichoderma species namely T. hamatum, T. harzianum, T. viride, T. virens, T.koningii and T. pseudokoningii and the anti-fungal activity of leaf and bark extracts of Cleistanthus collinus and Prosopis juliflora against the fungal pathogens was tested. Highest inhibition was obtained with T. harzianum for all test pathogens. Though both bark and leaf extract of C. collinus and P. juliflora exhibited inhibition against test pathogens. Highly significant growth inhibition (>95%) was achieved by both leaf and bark extract of P. juliflora against N. oryzae. Even lowest concentration of leaf extract (0.01%) showed discernible effect. The effectiveness of plant extract for F. oxysporum and F. verticilliodes were between 50-65%.