STUDY OF PROCYMIDONE AND PROPARGITE RESIDUE LEVELS RESULTING FROM APPLICATION TO GREENHOUSE TOMATOES

Levels of procymidone and propargite residues were studied in an experiment in greenhouse tomatoes. The pesticides were applied according to recommended application procedures in Greece. Tomatoes received six sprayings with procymidone, at 10-day intervals, at rate of application 62.5 g of ai/100 L and a single spraying with propargite, at rate of 60 g of ai/100 L. In separate experimental plots double doses were applied, according to the same scheme. Residues were determined with a simple gas chromatographic method; the recovery of procymidone from tomatoes was 85-104% and of propargite 94-107%; the limits of determination were 0.005 mg/kg for procymidone and 0.01 mg/kg for propargite. Procymidone residues were very persistent, and a detectable decline was observed only 35 days after the last application. Repeated applications of procymidone showed a significant residue accumulation effect in tomatoes. Propargite residues were found to decline slowly with time. The results show that the recommended preharvest interval in Greece, which is 3 days for both pesticides should be reconsidered in the case of procymidone with repeated applications.