Effect of carbofuran on enzymatic activities and growth of tomato plants in natural, fertilized and vermicompost-amended soils

The effects of carbofuran, a widely used carbamate pesticide, on soil enzymatic activities such as fluorescein diacetate hydrolysis (FDAH), dehydrogenase, and acid and alkaline phosphatases were studied at different time intervals in unamended soil and soil amended with inorganic fertilizers and vermicompost, cropped with tomato plants. The results showed that all enzymatic activities varied with carbofuran application rates and increased significantly up to 1.0 kg active ingredient (a.i.) ha(-1) dose of carbofuran. The most significant increase was observed at 0.20 kg a.i. ha(-1) dose both in unamended and amended soils. This showed that carbofuran was not toxic to all enzymatic activities studied upto 1.0 kg a.i. ha(-1) dose of carbofuran in both systems. A significant decrease in all enzymatic activites were observed at higher dose of carbofuran both in unamended and amended soils relative to their respective controls. Highest enzymatic activities were observed in vermicompost amended soil and minimum in fertilized soil compared to control. The results indicated that the growth of tomato plants was significantly higher at 0.20 kg a.i. ha(-1) dose of carbofuran in all the cases and followed the order: fertilized soil > vermicompost amended soil > natural soil and was positively correlated with the enzyme activities.