In-vitro compatibility of entomopathogenic fungi with plant extracts: a potential tool for insect pest management

In-vitro compatibility of leaf extracts of Azadirachta indica A. Juss, Datura stramonium L., Eucalyptus tereticornis L., Parthenium hysterophorus, Cannabis sativa L. with entomopathogenic fungi (Beauveria bassiana, Metarhizium anisopliae) was evaluated by incorporating leaf extracts at three different concentrations (0.15, 1.5 and 15%) into the culture media (PDA + S). Leaf extracts of A. indica in the tested concentrations was found more compatible with B. bassiana and M. anisopliae as compared to other botanicals as maximum spore viability 87.67 & 86.33%, respectively was observed in A. indica leaf extract treated media at a concentration of 0.15%. However, maximum linear growth of B. bassiana (5.07 and 5.70 cm) and M. anisopliae (5.07 and 6.00 cm) was recorded in the media treated with eucalyptus leaf extract at the concentrations of 1.5% and 0.15%, respectively than observed in the A. indica leaf extract treated media. But spore viability of these two entomopathogens (83.33 and 85.67%, respectively) was lesser in eucalyptus leaf extract treated media than A. indica. It indicated that A. indica leaf extract has more positive interaction with tested entomopathogens. Maximum inhibitory effect against B. bassiana, M. anisopliae was shown by Datura leaf extracts (28.41 and 28.93%, respectively) followed by Parthenium (24.49 and 23.49%, respectively).