Compatibility of Selected Pesticides with Three Entomopathogenic Fungi of Sugarcane Pests

Abstract

Compatibility of selected insecticides, fungicides and weedicides, commonly used in sugarcane, with Beanveria bassiana (Balsamo-Criv.) Vuill. Beauveria brongniarlii (Sacc.) fetch and Metarhizium anisopliae (Metschnikoff) Sorukin, the entomopathogenic fungi that occur naturally on several pests of the crop, was evaluated in in vitro assays. Radial growth, biomass and spore production used as parameters did not show consistent trend for the five insecticides tested. On the basis of per cent reduction in spore production, however, chlorpyriphos (0.04%) was most toxic to all three fungi (100%); lindane (0.04%) was most toxic to B. brongniartii (100%) but least toxic to B. bassiana (26.3%) and M. anisopliae (17.1%); monocrotophos (0.036%) was moderately toxic to B. bassiana (43.0%) and M, anisopliae (35.2%), and least toxic to B. brongniartii (13.4%); malathion (0.10%) was most toxic to M. anisopliae (88.2%) and B. brongniartii (69.1%), and moderately toxic to B. bassiana (43.0%); endosulfan (0.035%) was moderately toxic to all three species (49.5-58.1%). Carhendazim (0.05%) was completely toxic to all three fuugi (100%); maneozeb 0.08% was also equally toxic to all three fungi (69.5-100.0%). Glyphosate (0.205%) was most toxic (88.1%) to B. bassiana and moderately toxic to B. brongniartii (39.3%) and M. anisopliae (58.2%); atrazine (0.35%) was moderately toxic (40.5-55.7%) to all three fungi; 2.4-D (0.20%) was moderately toxic to B. bassiana (45.9%) and B. brongniartii (63.3%), and least toxic (17.7%) to M. anisopliae. The implications of the results in sugarcane pest management involving entomopathogenic fungi are discussed.