氟噻草胺与二甲戊灵混配对多花黑麦草的协同控制作用及对小麦的安全性

为探讨麦田恶性杂草多花黑麦草的防治措施,通过室内试验测定了氟噻草胺与二甲戊灵混用对小麦及多花黑麦草的抑制活性。液体培养法测定表明,氟噻草胺、二甲戊灵对多花黑麦草的生长抑制中剂量(ED_(50))分别为0.13 mg/L、0.16 mg/L。氟噻草胺与二甲戊灵以1∶1、1∶2、2∶1混配,对多花黑麦草的ED_(50)值为0.12 mg/L、0.04 mg/L、0.24 mg/L,共毒系数(CTC)分别为123.8、346.7、59.8,表明氟噻草胺与二甲戊灵以1∶1、1∶2混配对多花黑麦草防治有增效作用,尤其以1∶2混配增效显著。盆栽试验结果显示,在播后3 d、苗后5 d、苗后15 d,喷施氟噻草胺∶二甲戊灵为1∶2的混合药剂对多花黑麦草与小麦的选择性指数分别为1.15、0.24、0.28,表明在播后苗前施药对多花黑麦草的选择性最高,能一定程度控制多花黑麦草的发生和生长,而苗后施药对多花黑麦草选择性相对较差。

Synergistic Effect on Lolium multiflorum Lamk.and Security to Wheat of Flufenacet and Pendimethalin

To explore the controlling measure of Lolium multiflorum Lamk.in wheat fields,the inhibitory activities of flufenacet and pendimethalin on wheat and Lolium multiflorum Lamk.were investigated indoor.Hydroponics results of Lolium multiflorum Lamk.showed that the median effective doses(ED50)of flufenacet,pendimethalin were 0.13 mg/L,0.16 mg/L,respectively.When flufenacet and pendimethalin were applied mixedly in the ratio of 1∶1,1∶2,2∶1,the ED50 values were 0.12 mg/L,0.04 mg/L,0.24 mg/L,respectively,and the co-toxicity coefficients (CTC) were 123.8,346.7,59.8,respectively,which showed that mixed use of flufenacet and pendimethalin in the ratio of 1∶1,1∶2 could enhance weed control effect,especially the later.Pot-experiment results showed that the selective coefficients between Lolium multiflorum Lamk.and wheat were 1.15,0.24,0.28,respectively,at 3 days after sowing(pre-emergence),5 days after germination and 15 days after germination when the two herbicides were mixedly applied in the ratio of 1∶2,revealing that the selective coefficient was the highest when the herbicides were sprayed after sowing and before emergence,which could control the occurrence and growth of Lolium multiflorum Lamk.to some extent,while the selectivity was relatively poor when the herbicides were sprayed post emergence.