Azinphos-ethyl residues on field grown tomatoes

Abstract

In a pilot investigation two formulations of azinphos—ethyl were applied to outdoor tomatoes at the rate of 1.1 lb a.i./ac. A second spray was applied after 3 weeks and residues were determined at intervals after each application.

Gross residues did not exceed 2 p.p.m. The bulk of these were external residues removable by hexane extraction or by peeling the fruit. Internal residues did not exceed 0.1 p.p.m. The rate of residue dissipation was fairly slow, the mean decline in external levels over 2 weeks being 57% with a maximum of 83% (1.97 to 0.33 p.p.m.). Weathering conditions were not extreme during the tests.