Comparative Persistence of Thiacloprid in Bt-Transgenic Cabbage (Brassica oleracea cv. capitata) vis-à-vis Non-Transgenic Crop and its Decontamination

Thiacloprid is a systemic neonicotinoid. The study hypothesized that difference may be seen in the rate of dissipation of thiacloprid when applied on non-transgenic and transgenic cabbage. Thiacloprid was estimated by HPLC. Half life of thiacloprid in transgenic as well as in normal cabbage ranged between 12.3–13.1 days in two doses of application. Under field condition, after 15 days, 59.2 % and 54.3 % dissipation was recorded at lower and higher rates of application in transgenic cabbage, where as the insecticide dissipated 57.5 % and 59.1 % for single dose and double dose application, respectively in non-transgenic cabbage. The study establishes that there is no significant difference in dissipation of a systemic pesticide in transgenic versus non-transgenic cabbage. Decontamination of thiacloprid contaminated cabbage was carried out by different chemical treatments. The application of 0.5 % NaHCO 3 (an edible alkali) may be recommended for decontamination. Thiacloprid residues in the day-3 field samples of cabbage could be reduced below Japanese MRL (1.0 mg kg −1 ) by treating with 0.5 % NaHCO 3 solution for 1 h.