氰氟草酯和精噁唑禾草灵对三叶浮萍的毒性效应

为了正确评价精噁唑禾草灵·氰氟草酯混配制剂的生态环境效应，采用水培实验的方法研究了精噁唑禾草灵和氰氟草酯对三叶浮萍（Lemma Paucicostata）的单一毒性和联合毒性效应。结果表明，精噁唑禾草灵和氰氟草酯对三叶浮萍96h的IC50分别为3.33mg/L和5.04mg/L，精噁唑禾草灵·氰氟草酯混合处理液对三叶浮萍96h的IC50为3.14mg/L，对联合毒性进行评价，显示出明显的协同效应。精噁唑禾草灵、氰氟草酯及其联合处理均不同程度地减少了浮萍体内的叶绿素a、叶绿素b的含量,影响作用呈良好的浓度（剂量）-效应关系。

Toxicity of Fenoxaprop-ethy and Cyhalofop-butyl l on Lemma Paucicostata

In order to assess the bioenvironmental effect of a mixed herbicide which composed by Fenoxaprop-ethyl and Cyhalofop-butyl correctly, the single toxic and joint toxic effects of them on Lemma Paucicostata were studied. The results showed that the IC50 of Fenoxaprop-ethyl and Cyhalofop-butyl to Lemma Paucicostata for 96 h were 3.33 and 5.04 mg/L respectively, the IC50 of joint toxicity of them for 96 h to Lemma Paucicostata was 3.14 mg/L. The additive index (AI) was 1.566, the combined toxicities were the synergism action. The content of chlorophyll a and chlorophyll b of Lemma Paucicostata both affected by the single and joint toxicity of Fenoxaprop-ethyl and Cyhalofop-butyl with the concentration increased.