Department of Microbiology, College of Basic Sciences and Humanities, G. B. Pant University of Agriculture and Technology, Pantnagar, Nainital, U.P., 263 145
*Department of Entomology, College of Agriculture, GBPUAT, Pantnagar, 263 145
Effect of quinalphos (0,0-diethyl-0-quinoxalyl-2-phosphorothioate), benzene hexachloride and carbofuran (2,3-dihydro-2,2-dimethyl-7-benzofuranyl methyl carbamate) was studied on Azotobacter vinelandii and Pseudomonas stutzeri after inoculating these organisms in sterilized soil. The cell population was determined periodically as total viable count (TVC) per gram of soil. Population of A. vinelandii and P. stutzeri was not affected by quinalphos and benzene hexachloride. An initial bacteriostatic influence followed by subsequent stimulatory effect on Azotobacter population and continuous increase in Pseudomonas population were recorded in carbofuran treated soils.
Insecticides, soil microbe interaction, nitrogen fixation, denitrification
