Bio-efficacy of entomopathogenic fungi against mealy bug, Maconellicoccus hirsutus (Green) infesting custard apple in Junagadh

Abstract

Effectiveness of different doses of entomopathogenic fungi alone and its combination with two insecticides against mealy bug, Maconellicoccus hirsutus (Green) revealed that the Lecanicillium lecanii @ 2.0 gm/l + profenophos 50 EC 0.025% and L. lecanii @ 2.0 gm/l + flonicamid 50 WG 0.0125% were found to be the most effective for reducing the population of mealy bug on custard apple both in laboratory condition as well as in field condition. The difference in fruit yield recorded in various combinations of entomopathogenic fungi and insecticide was found statistically higher yield compared to control and all other treatments. However, treatment combination of (T7) L. lecanni @ 2.0 g/l + profenophos 50 EC 0.025% recorded the highest fruit yield of custard apple i.e. 4648 kg/ha which was found statistically at par with (T8) L. lecanni @ 2.0 g/l + flonicamid 50 WG 0.0125% (4499 kg/ha). The CBR of different treatments were worked out. Among the different treatments, the highest CBR i.e. 1:11.12 was recorded in the treatment of (T7) L. lecanni 2.0 g/l + profenophos 50 EC 0.025% whereas, the lowest CBR was observed in the treatment of (T10) flonicamid 50 WG 0.025% (1:5.96).