Comparative Field Efficacy of Different Entomopathogens against White Grubs Infesting Green Gram, Vigna radiata (L.)

Green gram (Vigna radiata) a major pulse crop worldwide, is often constrained in its production by white grubs such as Anomala sp. which feed on the roots. A field experiment was conducted at the Instructional-Cum-Research Farm, Assam Agricultural University, Jorhat to evaluate the efficacy of different entomopathogenic microbes against such white grub infestation. Treatments included entomopathogenic fungi like Metarhizium anisopliae, Beauveria bassiana and B. brongniartii and entomopathogenic nematodes such as Heterorhabditis bacteriophora and Steinernema thermophilum. All microbial treatments significantly reduced grub population and plant mortality as compared to untreated control. Among them, H. bacteriophora proved most effective, recording the lowest grub population (2.00) and highest yield (11.95 q/ha) followed by M. anisopliae with 2.25 number of grubs per sq.m and 10.86 q/ha of green gram yield. The study demonstrates the potential of entomopathogenic microbes as ecofriendly alternative for sustainable management of white grubs in green gram.