3种农药对大型溞的急性毒性比较

采用"半静态法"测定了3种农药及其混剂对大型溞的24 h、48 h急性毒性,根据我国《化学农药环境安全评价实验准则》中的毒性等级标准,它们对大型溞的毒性等级如下:精甲霜灵悬浮种衣剂对大型溞的24 h、48 h-EC_(50)均大于10 a.i.mg·L~(-1),属"低毒"级,咯菌腈悬浮种衣剂对大型溞的24 h、48 h-EC_(50)分别是0.339 mg·L~(-1)、0.246 mg·L~(-1),根据0.1 a.i.mg·L~(-1)EC_(50)(48 h)≤1.0 a.i.mg·L~(-1)判断,属"高毒"级。嘧菌酯水分散粒剂对大型溞的24 h、48 h-EC_(50)分别是0.389 mg·L~(-1)、0.286 mg·L~(-1),根据0.1a.i.mg·L~(-1)EC_(50)(48 h)≤1.0 a.i.mg·L~(-1)判断,属"高毒"级。精甲霜灵·咯菌腈·嘧菌酯悬浮种衣剂对大型溞的24 h、48 h-EC_(50)分别是0.292 mg·L~(-1)、0.228 mg·L~(-1),根据0.1 a.i.mg·L~(-1)EC_(50)(48 h)≤1.0 a.i.mg·L~(-1)判断,属"高毒"级。精甲霜灵·咯菌腈·嘧菌酯悬浮种衣剂和嘧菌酯水分散粒剂都属"高毒",但比较具体数值,发现精甲霜灵·咯菌腈·嘧菌酯悬浮种衣剂毒性相对更大,原因是其中还含有"高毒"的咯菌腈。

The Toxicity of Three Pesticides of Mefenoxam, Fludioxonil, Azoxystrobin and Their Compounds to Daphnia magna Straus

Semi-static method was applied to determine the 24 h,48 h-EC50 values of three pesticides and their compounds to Daphnia magna Straus.And according to experimental criteria for environmental safety evaluation of chemical pesticides in China,the 24 h and 48 h-ECs0 values of mefenoxam seed coating agent are both above 10 a.i.mg· L-1 so it is of low toxicity.Fludioxonil seed coating agent is highly toxic because its 24 h and 48 h-EC50 values are 0.339 mg· L-1 and 0.246 mg· L-1 according to the standard of 0.1 a.i.mg· L-1 ＜EC50(48 h)≤ 1.0 a.i.mg·L-1.Azoxystrobin water dispersible granule is of high toxicity because its 24 h and 48 h-EC50 values are 0.389 mg·L-1 and 0.286 mg· L-1 according to the standard of 0.1 a.i.mg· L-1 ＜EC50(48 h) ≤ 1.0 a.i.mg· L-1.Mefenoxam-fludioxonil-azoxystrobin seed coating agent is of high toxicity because its 24 h and 48 h-ECs0 values are 0.292 mg· L-1 and 0.228 mg·L-1 according to the standard of 0.1 a.i.mg· L-1 ＜EC50(48 h)≤ 1.0 a.i.mg-L-1.Mefenoxam-fludioxonilazoxystrobin seed coating agent and azoxystrobin water dispersible granule are both of high toxicity.However,considering the EC50 values,mefenoxam-fludioxonil-azoxystrobin seed coating agent is more toxic because it contains fludioxonil besides azoxystrobin.