BIOEFFICACY OF LIQUID FORMULATION OF BACILLUS THURINGIENSIS BTIII AGAINST HELICOVERPA ARMIGERA UNDER FIELD CONDITION IN DIFFERENT FIELDS

Abstract

Bacillus thuringiensis is a promising agent to control a number of insect pests of order Lepidoptera. A formulation of potential Bacillus thuringiensis strain would be beneficial for controlling Helicoverpa armigera (a major pest in various crops) larvae. A formulation with high efficacy and low cost would add to the characteristic features of Bacillus thuringiensis. In the present study, liquid formulations of B. thuringiensis were prepared by using five different types of stabilizers: glycerol, groundnut oil, mustard oil, mineral oil, and sunflower oil. Persistence of Bt cells was monitored at weekly interval. It was found that glycerol supported maximum persistence of Bt cells when formulations were stored at room temperature. Glycerol based formulation showed minimum decline in cell number and could be used to control H. armigera larvae for two months.