Study on degradation dynamics of Z- and E-isomers of dimethomorph in soils

The degradation of dimethomorph in three kinds of soils including Jilin black soil,Henan cinnamon soil and Jiangxi red soil were investigated in laboratory conditions.The results indicated that the degradation half-life of dimethomorph were 69 d,69 d and 462 d in Jilin black soil,Henan cinnamon soil and Jiangxi red soil,respectively.Dimethomorph was classified into middle or difficultly degradation of pesticide.The degradation half-life in Jilin black soil,Henan cinnamon soil and Jiangxi red soil were 89 d,126 d and 533 d for Z-isomer and 53 d,29 d and 408 d for E-isomer.The degradation rates of Z-isomer are slower than E-isomer in all three kinds of soils tested.The ratios of E-isomer to Z-isomer changed obviously during degradation process in Henan cinnamon soil.The degradation rate of dimethomorph in laboratory condition is lower than that of in field condition abviously.