Dissipation study of ten insecticides in apples under field conditions

Apples are among the most widely cultivated fruits in temperate climate zone. Given the potential of pests and diseases to cause significant damage to fruit production, orchardists rely on using insecticides and fungicides in infested orchards to protect apple yields. In this study, the dissipation of ten insecticides was monitored under field conditions in two apple varieties (Rosana and Selena) in an apple orchard. Pesticide residues in apples were determined using the QuEChERS extraction method followed by ultrahigh-performance liquid chromatography coupled to tandem mass spectrometry.

The dissipation rate of all insecticides applied more than 80 days before harvest followed first-order kinetics. Mean dissipation half-lives were calculated ranging from 4.5 days (spinosad) to 66.4 days (flonicamid, sum in accordance with residue definition). At the end of the preharvest interval, all analytes tested were found at concentrations below 30% of the established maximum residue levels, except flonicamid (sum) and pirimicarb. As metabolites of flonicamid and spirotetramat (i.e., TFNA, TFNG and spirotetramat-enol) were included in the residue definition, changes in their levels were also monitored. In the case of flupyradifurone, a statistically significant difference in dissipation rate between apple varieties was found.

The results provided a better understanding of the fate of insecticides in apples in apple orchards and thus the potential risks associated with their use. The results of this study also provide a scientific basis for the appropriate selection and use of pesticides for the integrated pest management practices in apple orchards. © 2025 The Author(s). Journal of the Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.