Gaur, NeetaShashikala, M.2021-11-112021-11-112021-09https://krishikosh.egranth.ac.in/handle/1/5810178027Chickpea (Cicer arietinum L.) is one of the major rabi pulse consumed and cultivated in the world. Chickpea severely suffers from infestation of Gram pod borer (Helicoverpa armigera) in all the cultivated areas of the world including India. It has been recorded 56 to100 per cent yield loss due to infestation of chickpea pod borer. The continuous prevalence of this pest makes its management most important during chickpea cultivation. In the present investigation efforts were made to study the compatibility between Bacillus thuringiensis, entomopathogenic bacterium and insecticides at different lethal and sublethal concentrations (R, R/2, R/4, R/8 and R/16) under in-vitro conditions. Further field efficacy of Bt, insecticides and different combinations were evaluated against H. armigera infesting chickpea. Incremental Cost benefit ratio(ICBR) was also calculated. Compatibility study showed that as the concentration of the insecticides increased bacterial growth decreased indicating reduced compatibility over increased concentration. Bt was significantly highly compatible (compatibility index 1) with chlorantraniliprole 18.5 SC at all the tested concentrations as compared to other treatments. Maximum per cent inhibition was observed at recommended dose (46 ppm) of chlorantraniliprole 18.5 SC (21.663) followed by emamectin benzoate 5 SG which showed compatibility index 2 with 27.401 per cent inhibition. However, lambda cyhalothrin 5 EC, ethion 50 EC and neem 10000 ppm were found non compatible with Bt at all the concentrations with compatibility index 3. In field efficacy combination of Bt with insecticides was found more effective as compared Bt or insecticides alone against gram pod borer. Among different combinations Bt + half dose of chlorantraniliprole 18.5 SC with significantly minimum larval population was recorded (0.20) with per cent reduction (93.11) followed by Bt + emamectin benzoate 5 SG while minimum was in Bt alone against H. armigera infesting Chickpea. The incremental cost benefit ratio (ICBR) was calculated on the basis of grain yield obtained. The net returns in treatment Bt + chlorantraniliprole was found higher followed by chlorantraniliprole alone among all the treatments. Maximum B:C ratio was in Bt + chlorantraniliprole (1.65:1) followed by chlorantraniliprole alone and Bt + emamectin benzoate while minimum was in neem alone as compared to control (0.66). The present investigation revealed that combination of Bt + half dose of chlorantraniliprole 18.5 SC was significantly effective against gram pod borer. A need based integrated strategy can be formulated by use of this combination for the management of chickpea pod borer.EnglishThesis