Field evaluation of bio-pesticide for control of chickpea pod borer helicoverpa armigera,a major pest of chickpea crop

Studies conducted on application of biological insecticide (with and without adjuvants) revealed that bacillus thuringiensis (bt) field tests conducted over 3 successive chickpea seasons indicated consistently a significant (p<0.05) increase in yield between the dipel 2x® alone/dipel® + adjuvant treatments and control (.in the 1st year trial the calculated grain yield in karate and dipel 2x® + pottasium carbonate (k2co3) treatments were 1822.0 kg/ha-1 (the highest) and 1535.0 kg/ha-1,respectively. the grain yield was noted to be 2.0 to 2.5 times higher in all the dipel 2x® + adjuvants treatments as compared to the grain yield (591.0 kg/ha-1) of control,in 2nd year trial,the highest calculated grain yield (1157.0 kg/ha-1) and (1022.0 kg/ha-1) were noted in chemical insecticide and dipel 2x®+ powder milk (p. milk) treatments,respectively. application of dipel 2x® with adjuvants significantly increased grain yield 4-6 times as compared to control plot yield (171.0 kg/ha-1),and in 3rd year trial,the overall calculated grain yield obtained in chemical insecticide (karate®) and dipel 2x® + k2co3 were 934.0 and 693.0 kg/ha-1,respectively being 3 to 4 times higher than the control grain yield (206.0 kg/ha-1). the grain yield in all the bt treatments was at least 2 to 3 times higher than control plot yield. the application of microbial insecticide (dipel 2x®) @ 1.6 kg ha-1 (51.2 biu ha-1) alone or with adjuvants costs more than the cost of chemical insecticides application in sub-tropical climate at temperature ranges between 16 to 34°c. the objective behind the use of adjuvant (heavy organic matters other than k2co3) was to increase the b.t. persistency. bt field test results indicated that microbial insecticides can be used (with and without adjuvants) for management of h. armigera populations infesting chickpea and their use would reduce reliance on toxic chemical released into the agro-ecosystem of pakistan. this study in providing an alternate tool with eco-friendly approach as part of an integrated insect pest management (iimp) programmes. copyright © 2012 zoological society of pakistan.