pubmed-article:17390775 | pubmed:abstractText | An experiment was carried out to investigate the residues of pymetrozin in cucumber under field conditions. Plots of cucumber (cv. Daminus) were sprayed with pymetrozine (Chess, WG50) at two different rates; 0.5 and 1.0 kg/ha. Samples were collected 2 hours and 1, 2, 3, and 4 days after spraying and pymetrozin residues were determined using high performance liquid chromatography with UV detector. Two hours after spraying, the residues was 0.326 mg/kg for 0.5 kg/ha treatment. The residues decreased to 0.013 mg/kg on the third day and no residue was detected four days after spraying. In 1.0 kg/ha treatment, the residue was 0.627 mg/kg, two hours after spraying, which decreased to 0.028 mg/kg, on the third day, but no residues was found in samples which collected four days after spraying. In farm plots which received 0.5 kg/ha pymetrozine, the residues in peels and peeled cucumber were 0.359 and 0.308 mg/kg respectively, two hours after spraying, but in plots which sprayed at 1.0 kg/ha, the residues were 0.648 and 0.609 mg/kg respectively. Furthermore the residues in peels showed a significant difference with those of peeled and unpeeled cucumber under field conditions. | lld:pubmed |