除草剂对小麦田雀麦的生物活性测定

为筛选防除雀麦Bromus japonicus的高效除草剂,采用室内生物测定法研究了13种除草剂对雀麦的除草活性及5种除草剂的田间药效试验。结果表明,在田间推荐剂量的低剂量下,氟唑磺隆、啶磺草胺、氟噻草胺、甲基二磺隆、异丙隆、磺酰磺隆、丙苯磺隆7种除草剂对雀麦具有很高的防除效果,21 d鲜重抑制率分别为88.30%、86.32%、83.97%、78.47%、76.76%、72.83%、71.39%,高剂量下的21 d鲜重抑制率达98.57%、95.36%、91.58%、91.46%、89.47%、82.48%、82.20%;其中氟唑磺隆各剂量下的防效较其它除草剂高。而嘧啶肟草醚、苯唑草酮、炔草酯、吡氟酰草胺、唑啉草酯、精噁唑禾草灵6种除草剂对雀麦防效较差。氟唑磺隆、啶磺草胺、氟噻草胺、甲基二磺隆、异丙隆5种除草剂的田间药效试验表明,氟唑磺隆对雀麦防效最高,高剂量下20 d株防效达85.04%,药后40 d株防效和鲜重防效分别达83.94%和84.17%,未见小麦有明显药害症状,建议田间推荐用量为21.00~42.00 g(a.i.)/hm~2。表明雀麦对不同除草剂的敏感性存在差异,在供试的13种除草剂中氟唑磺隆对雀麦防效最高,较为安全,为防除雀麦的理想除草剂。

Biological activities of herbicides to japanese bromegrass Bromus japonicus in wheat fields

In order to select the efficient herbicide to control Bromus japonicus, dose-response experiments were carried out to determine the weed control effect of 13 herbicides in glasshouses, and field experiments were conducted with five herbicides. The results showed that seven herbicides, including flucarbazone-Na, pyroxsulam, flufenacet, mesosulfuron-methyl, isoproturon, sulfosulfuron and propoxycarbazone-sodium, controlled B. japonicus very well at the test doses:the fresh weight inhibition rates after 21 days were 88.30%, 86.32%, 83.97%, 78.47%, 76.76%, 72.83%, and 71.39%, and the inhibition rates of fresh weight at the high doses after 21 days were 98.57%, 95.36%, 91.58%, 91.46%, 89.47%, 82.48% and 82.20%, respectively, among which flucarbazone-Na had the highest inhibition rate. On the contrary, the other six herbicides (pyribenzoxim, topramezone, clodinafop-propargyl, diflufenican, pinoxaden and fenoxaprop-p-ethyl) could not control B. japonicus very well at different doses. Field experiments with flucarbazone-Na, pyroxsulam, flufenacet, mesosulfuron-methyl and isoproturon showed that the herbicides were safe to wheat at the proposed dosage; flucarbazone-Na had a best control effect to B. japonicus:the plant control effect of flucarbazone-Na at the 20th day after treatment was 85.04%, and the plant control effect and the fresh weight control effect of flucarbazone-Na at the 40th day after treatment were 83.94% and 84.17%, respectively, with a recommended dose of 21.00-42.00 g (a.i.)/hm². B. japonicus had different sensitivities to different herbicides. Among the 13 herbicides tested, flucarbazone-Na had the best control effect to B. japonicus, and it was safe to wheat, so it was the efficient herbicide for controlling B. japonicas.