五氟磺草胺等6种除草剂对直播稻田高龄稗草的生物活性及田间控制效果

为筛选防治高龄稗草的有效药剂，用室内盆栽法测定了6种除草剂对高龄稗草的生物活性，并通过大田试验作了进一步验证。盆栽法测得五氟磺草胺和双草醚对高龄稗草的活性最高，其ED50值均为9.3 g/hm2，而噁唑酰草胺和氰氟草酯对高龄稗草活性最低，ED50 分别为28.7、28.6 g/hm2。其余2种除草剂嘧啶肟草醚和氟吡磺隆对高龄稗草的活性介于以上两者之间，ED50为10.1 g/hm2和11.4 g/hm2。田间试验结果显示，2.5%五氟磺草胺油悬浮剂30、37.5 g/hm2和10%噁唑酰草胺乳油 150、180 g/hm2 4个处理对高龄稗草防效优良，处理后20、40 d防效均在93.0%以上；处理后40 d，10%双草醚悬浮剂3种浓度处理和5%嘧啶肟草醚乳油 80 g/hm2的防效均在91.4%以上；10％氟吡磺隆水分散粒剂和10%氰氟草酯乳油对高龄稗草防效均不理想，药后20、40 d各处理的株防效均不到80%。

Biological activity and control effect of six herbicides to large Echinochloa crusgalli (L.) Beauv. in direct seeding rice field

Control efficacy of six herbicides against the large Echinochloa crusgalli (L.) Beauv. was determined by pot and field experiments. The results showed that biological activity of penoxsulam and bispyribac-sodium was the highest, and the effective concentration of herbicide causing 50% inhibition on fresh weight?(ED50)?was 9.3?g/hm2. Metamifop and cyhalofop-butyl demonstrated the lowest activity to E. crusgalli with the ED50?value of 28.7 and 28.6 g/hm2,?respectively. The ED50?value of pyribenzoxim and flucetosulfuron were 10.1 and 11.4 g/hm2,?respectively. Field trial demonstrated that 2.5% penoxsulam OF and 10% metamifop EC had good control effect on the weed, with the efficacy of over 93% after 40 days.Control efficacy of 10% bispyribac-sodium SC and 5% pyribenzoxim EC80 g/hm2?was more than 91.4%,?but that of 10% flucetosulfuron WG and 10% cyhalofop-butyl EC was below 80%.