Residues of Endosulfan and its Metabolites in a Rice Field of Madurai, India

Thirty-day-old rice seedlings, IR-20 variety were transplanted into the experimental plots and were sprayed with endosulfan (35% EC) after 52 days at the rate of 0.64 kg a.i/ha. Residues of endosulfan in the plant, soil, and water were found to decrease steadily upto 15 days. A second application of the pesticide was made on the 31st day and the plant was harvested on 56th day after the first application. The residue level on hay and grains was 0.7 ${\mu}g/g$. This level is seven times higher than FAO/WHO-prescribed tolerance level of 0.1 ${\mu}g/g$. Metabolites of endosulfan were traced out in plants, soil, and water during the pre- and post-harvest period.