Malathion, Methyl Parathion, Diazinon, and Endosulfan Residues in Sunflower Seeds1

Sunflowers were sprayed 2, 3, and 4 times during the growing season with either malathion at 1.25 lb per acre, or methyl parathion, diazinon, or endosulfan at 1.0 lb per acre. Mature seeds contained 0.01 ppm malathion and methyl parathion, 0.03 ppm diazinon, and 0.06 ppm endosulfan when the plants were sprayed twice, 48 and 41 days before harvest. Residues in the seeds were approximately the same after a third spray was applied 28 days prior to harvest. Seeds from plants treated a fourth time 14 days before harvest contained 0.01 ppm malathion, 0.04 ppm methyl parathion, 0.07 ppm diazinon, and 0.13 ppm endosulfan.