Effects of two different formulations of metalaxyl on their residues in cucumber.

Abstract

Investigations were carried out on the presence of metalaxyl residues in field grown cucumbers. In one experiment, cucumber plants underwent once and twice sprayings by Ridomil-MZ 72 WP at 2.5 g/litre. In another, single and double applications of metalaxyl granule (5G) were carried out at 5 g/m2. Fungicide application performed every 14 days. Samples were taken at different time intervals and metalaxyl level was determined by HPLC. The results showed variable dissipation rates of metalaxyl residues in cucumber. In samples from single and double sprayed plots, the residues were 0.19 and 0.08 mg/kg 14 days after treatment respectively. In single granulated plots, the residues increased during the first 7 days and then decreased to 0.85 mg/kg, 14 days after granule application. However, in double granulated plots, the residues decreased to 0.02 mg/kg after the same period of time. In all treatments except single granulated plots, the residues declined below the MRL (0.5 mg/kg), 7 days after application. These experiments showed that two times spraying and granule applications did not cause the fungicide accumulation in cucumber.