Field Evaluation of Beauveria bassiana and Metarhizium anisopliae against the White Grub, Holotrichia longipennis Damaging Soybean in Uttarakhand Hills

Field experiments were conducted at Crop Research Center, College of Forestry and Hill Agriculture, GBPUA&T, Ranichauri during 2006-2009 to evaluate the effectiveness of entomopathogenic fungi, Beauveria bassiana and Metarhizium anisopliae with few insecticides against white grub, Holotrichia longipennis damaging soybean. On the basis of average cumulative plant mortality during the study, M. anisopliae (5.0×10¹³ spores g^-1) was found to be superior compared to other bio-agents by recording lowest plant mortality (21.83%) and 61.58% decrease in grub population followed by B. bassiana (5.0×10¹³ spores g^-1) where the plant mortality and decrease in grub population was 25.18% and 54.75%, respectively, compared to control. Highest percentage of yield increase (113.41%) was also recorded with M. anisopliae. However, among all the treatments, imidacloprid was found to be the most effective in reducing the grub population (82.28%) and thereby increasing the yield 206.86% over control.