1Department of Agricultural Chemistry, College of Agriculture, Vellayani, P.O., Thiruvananthapuram, Kerala-695 522, India
2,3Division of Agricultural Chemicals, Indian Agriculture Research Institute, New Delhi-110 012, India.
The deposition and translocation of residues of lindane and deltamethrin on different components of cotton boll were assessed by following foliar application of 14C labelled materials at various maturation stages of cotton boll. A 2 mL spray solution with a known specific activity was sprayed on each boll and samples were collected after 2, 9 and 15 d of spraying. The results showed that contamination of cottonseeds was the least when the bolls were closed and maximum when they were partially open. Maximum deposition of these pesticides on the lint was observed in the case of fully open bolls. The deposition of pesticides on partially open bolls was 10–18 times higher than that on unopened bolls. The percentage deposition of residues on seeds in partially open bolls was 7.4–14.3% while that on fully open bolls was 3.1–4.5%. Thus the ultimate contamination of cotton seeds and hence oil could be the result of cumulative contribution from various sprays received after the boll opening.
Insecticides, lindane, deltamethrin, residues, contamination, cotton boll, seed, lint
