Residue and Risk Assessment of Chlorothalonil,Myclobutanil and Pyraclostrobin in Greenhouse Strawberry

The dietary risk may be introduced by using chlorothalonil,myclobutanil and pyraclostrobin in strawberry picking period.The dietary exposure and risk assessment were conducted based on the field trial data.Under greenhouse conditions,chlorothalonil at a rate of 1 250 g(ai)/hm2,myclobutanil at a rate of 66.7 g(ai)/hm2 and pyraclostrobin at a rate of 166.7 g(ai)/hm2 were applied on the strawberry,with residues 2 h after application in strawberry fruits of 39.2,3.4 and 3.8 mg/kg and with half-life of 3.76,3.39 and 4.06 d,respectively.Risk quotient showed that the risk of chlorothalonil for 2-4 age children within 7 d PHI(preharvest interval) and for 18-30 age women in 1 d PHI can not be accepted(the risk quotient ranges were 1.2-4.6);however the risk of myclobutanil and pyraclostrobin for the people age of 2-4,18-30 and 60-70 were very low within 7 d PHI(the risk quotient ranges were 0.003-0.07 and 0.02-0.36,respectively).Maximum residue limit at 2 mg/kg and PHI at 3 d were recommended for myclobutanil and pyraclostrobin in strawberry.Chlorothalonil was notrecommenended to be used in strawberry picking period.