Residues in pasture following application of a granular heptachlor preparation

摘要

Abstract An established pasture was treated with technical heptachlor at five different rates (?, ?, 1, 2, and 4 lb per acre) as a 16/25 mesh “prill” type formulation. Residues of heptachlor and heptachlor epoxide were found in fresh grass 9 to 12 months later even after several mowings. At the lowest three rates of treatment (?, ?, and 1 lb per acre) 0.1-p.p.m. of heptachlor epoxide was stir present in the grass after 15, 35, and 50 weeks. Heptachlor residues had fallen to this level after 10, 30, and 40 weeks.