3种稻田除草剂对克氏原螯虾的急性毒性效应

Acute toxic effects of three rice field herbicides on Procambarus clarkii

为探明稻田常用除草剂对克氏原螯虾(Procambarus clarkii)的急性毒性效应,采用半静态试验方法,研究氢氟草酯(茎叶除草剂)、五氟磺草胺(芽前除草剂)和氟酮磺草胺(芽前除草剂)3种除草剂商品制剂对克氏原螯虾幼虾的急性毒性效应。结果表明:氢氟草酯、五氟磺草胺对克氏原螯虾幼虾的96 h半致死浓度(LC50)分别为0.602 5 mg∕L、40.622 5 mg∕L,氟酮磺草胺对克氏原螯虾的96 h半致死浓度大于100 mg∕L。3种农药对克氏原螯虾幼虾的毒性大小依次为:氢氟草酯>五氟磺草胺>氟酮磺草胺,其中氢氟草酯对克氏原螯虾幼虾的毒性等级为高毒,五氟磺草胺和氟酮磺草胺对克氏原螯虾幼虾均为低毒。研究认为,五氟磺草胺和氟酮磺草胺可在稻-虾共作生产中按常规剂量使用,而氢氟草酯按常规剂量(推荐使用最高剂量为0.209 9 mg∕L)使用可能存在较大的风险,应注意施用方法和对施用剂量的控制。

In order to explore the acute toxic effects of herbicides commonly used in paddy fields on Procambarus clarkii,the acute toxicity of three herbicide commercial preparations,Cyhalofop-butyl(stem and leaf herbicide),Penoxsulam(pre bud herbicide)and Triafamone(pre bud herbicide),to Procambarus clarkii was studied by semi-static test method.The results showed that the 96 h-LC50 values of Cyhalofop-butyl and Penoxsulam on juvenile Procambarus clarkii were 0.6025 mg∕L and 40.6225 mg∕L respectively,and the 96 h half lethal concentration of Triafamone on Procambarus clarkii was more than 100 mg∕L.The sensitivity of Procambarus clarkii to the three herbicides from high to low was:Cyhalofop-butyl>Penoxsulam>Triafamone.The toxicity grade of Cyhalofop-butyl to Procambarus clarkii was high,and Penoxsulam and Triafamone were low to Procambarus clarkii.The research and analysis showed that Penoxsulam and Triafamone could be used at the conventional dose in rice-crayfish co-culture production,while there might be a great risk in the use of Cyhalofopbutyl at the conventional dose(the recommended maximum dose was 0.2099 mg∕L).Attention should be paid to the control of application dose and application method.