Effect of root absorption properties of tea plant on pesticide residues in tea

The effect of root uptake of pesticides by plant from soil on the pesticide residues in tea was investigated in field conditions. After 7 months of incubation, no detectable amount of dimethoate and cyhalothrin both in soil and tea was found,and the concentration of ethion and dicofol was 2.81 mg/kg and 3.98 mg/kg in soil,whereas the concentration of ethion and dicofol in tea was 0.08 mg/kg and 0.15 mg/kg,respectively,while the initial concentration of each pesticide in soil was 10 mg/kg, The amount of ethion and dicofol found in tea increased with the increasing concentration in soil,which suggested that the pesticides in soil might contribute to the pesticide residues in tea.