In vitro study on the effect of bhendi varieties on the infectivity of Beauveria bassiana (Bals.) Vuill to Spodoptera litura Fab

Laboratory experiments on the evaluation of infectivity of Beauveria bassiana (Bals.) Vuill. to tobacco caterpillar Spodoptera litura Fab. as influenced by two okra varieties. Infectivity of B. bassiana at three concentrations viz. 0.1, 1.0 and 3.0 per cent was evaluated by contaminated food bioassay method. In comparison, topical bioassay method was also made. Statistically significant variation between the two okra varieties was observed with regard to the mortality of S. litura. When the leaf extract of the bhendi variety P 7 was amended to the culture medium of B. bassiana, the maximum conidial germination, sporulation and mycelial growth were recorded as against the minimum with the variety Pusa Sawani. Hence, it is concluded that plant factors influence infectivity of the entomopathogenic fungi B. bassiana.