Study of Imidacloprid, Azoxystrobin and Difenoconazole Residues and their Biochemical effects on Cucumber

Abstract

Cucumber plants at the fruiting stage were sprayed on June 2021 in a private field at El-Tahra village, Zagazig-district, Sharkia-Governorate, Egypt with imidacloprid Avenue 70% WG and azoxystrobin 20%+difenoconazole 12.5% mixture in commercial formulation Decent 32.5% SC to determine their persistence in cucumber-leaves and fruits, also to estimate their biochemical effects on cucumber-fruits. QuEChERS method was used for extraction and clean-up and analyzed using HPLC. Results revealed that, initial amounts of each-pesticide in leaves were much higher-than cucumber fruits. Loss percentages in residues were higher in cucumber fruits than leaves. The t½ values for investigated pesticides in cucumber-fruits (peel and whole-fruits) and leaves, were (1.88, 2.02, 2.47), (1.72, 1.81, 3.2) and (1.77, 2.10, 2.45 days) for imidacloprid, azoxystrobin and difenoconazole, respectively. Residue amounts of tested-pesticides were more greatly detected in the peel than that pulp. Cucumber fruits could be used safely for human-consumption at any time after spraying to the end of the experimental-period (12-days) after peeling. The pickling process removed in great amounts from initial deposits of investigated pesticides. Levels of total soluble sugar%, glucose mg/kg, acidity%, total soluble solids (T.S.S.), % ascorbic-acid mg/kg, β-carotene%, dry matter% and protein% as well as elements N%, P%, K%, Fe mg/kg, Mn mg/kg, Ca%, Zn mg/kg, on treated cucumber-fruits were significantly reduced during tested-periods (3 and 6-days after application). Data revealed that reduction of each quality attributes and elements was more pronounced with Decent than imidacloprid. This finding may be due-to presence of two-fungicide mixture in decent formulation (azoxystrobin+difenoconazole).