Determination and safety evaluation of difenoconazole residues in apples and soils.

Difenoconazole was a triazole fungicide with proven bio-efficacy which leads to morphological and functional changes in the fungal cell membrane. In this work, field trials were conducted in three apple orchards. Sampling methods were improved in both the terminal residual and dissipation experiments. Residual data were analyzed and results showed that, at both recommended rates with 3 times applications and 1.5-folds of recommended rates with 4 times applications, the preharvest intervals (PHIs) of difenoconazole in apples were 6-7 days. The DT₅₀ of difenoconazole in apples and soils were 6.3-10.2 and 9.6-68.4 days, respectively. The DT₉₀ them were 26.2-40.6 and 45.6-216.3 days, respectively.