The variation in the activity of the three antioxidant enzymes catalase, peroxidase and polyphenol oxidase in cabbage (Brassica oleracea L. var. capitata) leaf induced by foliar application of imidacloprid was evaluated. Studies carried out upto 35 days after application (DAA) of the insecticide indicated that there was a continuous increase in the activity of catalase with increasing dose and also with elapse of time. In case of peroxidase the activity was found to remain higher at normal and double of normal doses over control throughout the duration of study and the difference with control reached maximum on 7th DAA. Polyphenol oxidase activity at double dose showed to remain higher than that of control and normal doses all through the period of investigation, the difference being maximum on 14th and 28th DAA.
