Compatibility of Metarhizium anisopliae (Metsch.) Sorokin with pesticides used in Tea cultivation of Assam

Metarhizium anisopliae is one of the facultative insect pathogens with significant host range. Mycelial growth and conidial survibility may be effected by environmental factors or by chemical used to protect crop plants. In the present study, compatibility of M. anisopliae with 17 pesticides including 10 insecticides, 5 fungicides and 2 herbicides was assessed in vitro by poisoned food technique. The formulations of pesticides were tested at two different concentrations (lethal dose & sub lethal dose). All the fungicides viz., captan 50% WP at 0.25%, carbendazim 12% + mancozeb 63%, carbendazim 50% WP, metalaxyl-M 4% + mancozeb 64%, mancozeb 75% WP at both the concentrations were found to be highly toxic to the fungus. Herbicides like glyphosate 41% SL at 0.3% and paraquate dichloride 24% SL 0.15% and 0.3% were also found to be detrimental inhibiting the fungal growth. Insecticides, deltamethrin 2.8% EC at 0.014%, inhibited the growth of the fungus to an extent of 85.4%. Insecticides like thiamethoxam 25% WG, methomyl 40%W/W at 0.04%, diafenthiuron 50% at 0.04% and imidacloprid 17.8% at 0.2% and 0.1% were safe showing higher mycelial growth. Similarly, propargite 57% EC at 0.2% was found to be compatible with less detrimental effects (35.62%).