Characterization and growth response of bacteria in soil following application of carbofuran

Abstract Enhanced biodegradation of carbofuran (2, 3‐dihydro‐2, 2 dimethyl‐7‐benzofuranyl methyl carbamate) is an economically significant, but poorly understood, mlcrobial phenomenon in soil. A series of experiments was conducted to examine short term changes in soil bacterial populations stimulated by carbofuran application at field rates. In the field experiment, commercially formulated carbofuran and butylate (S‐ethyl diisobutyl carbamothioate) were applied at 5.6 kg al ha‐1 and 8.4 kg ai ha‐1, respectively, on a soil (Putnam silt loam) exhibiting enhanced degradation of caibofuran. In laboratory studies, technical grade carbofuran (20 mg kg‐1 soil) was applied to samples of the field soil. Bacterial populations were estimated using non‐selective (tryptic soy agar) and selective media containing carbofuran or butylate. Largest population increases in pesticide‐treated soil were observed between 7 and 15 days after treatment (DAT) compared to populations in non‐treated soil. Significant increases (P<0....