双唑草腈的除草活性及对不同水稻品种和后茬作物的安全性

双唑草腈(pyraclonil)为原卟啉原氧化酶(PPO)抑制剂,为明确其在水稻田的应用前景,采用室内生物测定法研究了双唑草腈的除草活性及对不同水稻品种的安全性,通过大田试验作了进一步验证,并评价了双唑草腈对水稻及后茬作物的安全性。结果表明,双唑草腈对水稻田禾本科杂草稗草、阔叶杂草鸭舌草均有很好的除草活性。在室内试验中,该药剂对稻田稗草和鸭舌草的ED50分别为11.50g/hm~2和8.22g/hm~2,均高于对照药剂丙草胺对稗草和鸭舌草的活性;双唑草腈在3种水稻和稗草之间的选择性指数分别为4.15、3.44和3.73,高于对照药剂;田间试验结果显示,1.8%双唑草腈颗粒剂162、216、324g/hm~2处理在药后20、40d对稗草、鸭舌草、节节菜及异型莎草的株防效均在98%以上,显著优于对照药剂80%丙炔噁草酮可湿性粉剂和50%丙草胺乳油;双唑草腈对水稻以及三种主要后茬作物小麦、油菜和小白菜安全。研究表明双唑草腈具有很好的应用前景。

Evaluation of herbicidal activity of pyraclonil and its safety to rice and following crops

Pyraclonil belonged to protoporphurinogen oxidase inhibitor. In order to evaluate the application potential of pyraclonil in rice field in China, the herbicidal activity and safety to three rice varieties were investigated in the laboratory and the safety to rice and following crops were determined by field experiments. The results indicated that pyraclonil had high herbicidal activity to gramineous weeds Echinochloa crusgalli (barnyardgrass) and broadleaf weeds Monochoria vaginalis. In the bioassay test, pyraclonil had high herbicidal activity to E. crusgalli and M. vaginalis with the ED50 value of 11.50 g /hm2 and 8.22 g /hm2, respectively, significantly higher than that of the control herbicide pretilachlor. The selectivity coefficients of pyraclonil among three rice varieties and barnyardgrass were 4.15, 3.44 and 3.73 for barnyardgrass, respectively, significantly higher than those of pretilachlor. The field experiments showed that the control efficacies against E. crusgalli, M. vaginalis, Rotala indica and Cyperus difformis were all above 98% when using 1.8% pyraclonil granules at 162, 216 and 324 g/hm2 after treatment for 20 and 40 days, significantly higher than those of 50% pretilachlor emulsifiable concentrates and 80% oxadiargyl wettable powder. Pyraclonil is safe to rice and three main following crops, including wheat, rape and Brassica chinensis, therefore, it has an excellent application prospect in rice fields