Difference of Chlorpyrifos Residue in Fruits of Various Apple Cultivars and Bagging Effect on the Residue

Apple is one of important fruits exported in China. The pesticide residue in apple fruit directly impacts the export trade of agricultural products and safety of consumer. Chlorpyrifos is one of organophosphorous pesticides permitted to be used in apple production. In order to evaluate the difference of chlorpyrifos residue in fruits of various apple cultivars and effects of fruit bagging on fruit chlorpyrifos residue, chlorpyrifos residue quantity in different tissues of fruit of various apple cultivars was determined with gas chromatography(GC- FPD). The results showed that there was a significant difference among apple cultivars in chlorpyrifos residue in the fruit, Red Fuji belonged to the cultivar with high pesticide residues, while Gala, Red General and 83-1-70-3 to the cultivars with low pesticide residues. Chlorpyrifos residues showed significant difference in different fruit tissues of apple, the final residue of pesticide in the pericarp was the highest, followed in the whole fruit, lowest in the pulp. Chlorpyrifos residue in apple fruit was significantly decreased with bagging. Regardless of the pesticide concentration applied, and sampling time, pesticide residue in bagged apple fruit reduced by 33% as compared with that in fruit without being bagged.