Uptake and Metabolism of Phorate by Mustard

Following soil application of a granular formulation of phorate @ 1 and 4 kg a.i./ha, its residues were determined in the soil and mustard. In the soil, phorate, underwent rapid transformation to-form phorate sulfoxide and phorate sulfone and the parent compound was not detected beyond 30 days of application even when applied @ 4 kg a.i./ha. Eight weeks after application, phorate residues in the soil disappeared almost completely. Residues in greens of mustard mainly comprised of phorate sulfoxide and phorate sulfone, though phorate, phorate sulfoxide and phorate sulfone were also detected. It is concluded that the application of phorate at the dosage of 1 kg a.i./ha were unlikely to lead to unacceptable residues in the harvested mustard seeds.