Abstract
BACKGROUND: Azoxystrobin and kresoxim‐methyl are strobilurin fungicides widely used in vegetable cultivation in southeastern Spain. The dissipation of these fungicides in peppers was evaluated in a study carried out in a greenhouse and under cold‐storage conditions. Pepper samples were collected during a 5‐week period in which two successive applications of these pesticides were performed. Gas chromatography (GC) with nitrogen–phosphorus detection (NPD) was used to study the disappearance of these compounds in peppers.
RESULTS: The disappearance rates of azoxystrobin and kresoxim‐methyl on peppers were described as pseudo‐first‐order kinetics (r between 0.950 and 0.992) and half‐life in the range of 10.28–15.21 days. These fungicides showed similar behaviour because they are structurally similar. After 21 days under cold and darkness storage conditions, dissipation of azoxystrobin and kresoxim‐methyl were not observed.
CONCLUSION: The pre‐harvest times established by Spanish law for these fungicides are correct since the residue levels were below the legal limit after two applications at the maximum recommended doses. Pepper storage or transport under refrigerated and darkness conditions do not contribute to dissipation of azoxystrobin or kresoxim‐methyl residues. Copyright © 2008 Society of Chemical Industry