DISSIPATION OF CYHALOTHRIN RESIDUES ON APPLE FOLIAGE AND APPLES AT HARVEST

A method to quantify cyhalothrin (Karate) residues by gas chromatography on apple foliage and fruit is described in detail. Two models are proposed to describe the dissipation pattern on foliage. According to these models, cyhalothrin residues would be half their initial concentration 10 days following a treatment. When two treatments are carried out, there is some carry-over and accumulation of residues from the first treatment to the second. Thirty-nine days past treatment, residues could not be detected in the pulp, but very low levels were detected in the peel and a whole apple at harvest. In high-density dwarf apple orchards spray drift from one row to the other can be completely eliminated with the use of a screen, mounted on a trailer and pulled along by a second tractor, running parallel to the sprayer in the adjacent passageway.