Compatibilities of Metarhizium anisopliae with Four Botanical Pesticides

The compatibilities of Metarhizium anisopliae with 4 botanical pesticides were investigated. Impacts of matrine, tubatoxin, azadirachtin, and pyrethrin applications on the spore germination, hyphal growth, and conidia production of M. anisopliaeMa 41 were determined. The results indicated pyrethrin to be most compatible with the fungus among these pesticides. At a concentration commonly used, pyrethrin exerted an inhibition rate on the fungal conidial germination at 51.95% and that on sporulation at 44.50%. However, when the applied concentration was at a sub-lethal or low-sub-lethal level, the inhibition effects by pyrethrin on the fungal conidial germination, hyphal growth, and sporulation were not significant. Another pesticide, matrine66.08% and 55.84%, respectively. But, there were only slight inhibition effects on the conidial germination and hyphal growth of the fungus under the 3 concentrations tested. In contrast, tubatoxin and azadirachtin were found hardly compatible with M. anisopliae., demonstrated a moderate compatibility with the fungus. Under a commonly applied concentration or a sub-lethal dosage, the inhibition rates on the fungal conidial germination and the sporulation by the pesticide were