Residue behavior and consumer risk assessment of combination product of betacyfluthrin and imidacloprid on cucumber (Cucumis sativus L.)

Residue behavior and consumer risk assessment of combination of betacyfluthrin and imidacloprid at recommended dose (X) and double the recommended dose (2X) on cucumber crop were studied during kharif season, 2019. The combination product was applied thrice as foliar sprays at 7 days interval with first application at fruit initiation stage. Residues of betacyfluthrin and imidacloprid were detected using gas chromatography-electron capture detector and high pressure liquid chromatography, respectively, after the extraction and clean-up of samples with modified QuEChERS technique. The average initial deposits at X and 2X dose of betacyfluthrin were 0.69 and 1.41 mg kg⁻¹, which dissipated to half of its concentration in 1.51 and 1.73 days with a suggested safe waiting period of 5.73 and 8.34 days whereas, for imidacloprid, initial deposits were 0.84 and 1.56 mg kg⁻¹, which dissipated to half of its concentration in 1.29 and 1.51 days with a suggested safe waiting period of 5.24 and 7.49 days, respectively. Residues in soil samples collected at harvest were found to be below determination level for both components. Dietary risk assessment calculated as hazard quotient came out to be less than 1, thus establishing the safety of combination product of betacyfluthrin and imidacloprid for consumers when used following good agricultural practices.