几种除草剂对科尔沁沙地苜蓿杂草的防控效果

Control Effect of Several Herbicides on Weeds of Alfalfa Fields in Horqin Sandy Land

在苜蓿三个叶龄期施用除草剂研究其对苜蓿产量和杂草防控效果的影响,结果表明:咪唑乙烟酸对燕麦的防效随苜蓿叶期增加而降低,株防效和鲜重防效均为四叶期>五叶期>六叶期;咪唑乙烟酸和高效氟吡甲禾灵混用可以显著提高对燕麦的防效,苜蓿产量提高100～1000kg/hm2;辛酰溴苯腈与高效氟吡甲禾灵混用会降低对反枝苋的防效,但可提升对燕麦的防效,同时显著提升苜蓿产量1000～2000kg/hm2。综合考虑除草剂对苜蓿的安全性、产量以及对燕麦、反枝苋的防控效果,科尔沁沙地苜蓿苗期化学除草可在苜蓿四叶期、五叶期选用咪唑乙烟酸1200ml/hm2+高效氟吡甲禾灵660ml/hm2或咪唑乙烟酸1800ml/hm2+高效氟吡甲禾灵660ml/hm2,也可采用辛酰溴苯腈1050ml/hm2+高效氟吡甲禾灵660ml/hm2和辛酰溴苯腈1500ml/hm2+高效氟吡甲禾灵660ml/hm2。

The present study evaluated the effects of herbicide application on alfalfa yield and weed control at three leaf stages.Results showed that the control effect of imazethapyr on oats as the leaves aged.The control effect of plant and fresh weight on oat was higher when applied at the four-leaf stage than at the five-leaf stage,and much better than at the six-leaf stage;The mixture of imazethapyr and haloxyfopr-methyl significantly improved the control effect on oats and increased alfalfa yield by 100~1000kg/hm2.The combination of bromoxynil octanoate and haloxyfop-r-methyl could reduce the control effect on amaranthus retroflexus,but it increased the control effect on oats and significantly increased the yield of alfalfa by 1000 to 2000kg/hm2.With the comprehensive consideration of the safety of the herbicides,the increase in alfalfa yield,and the control effect of weeds,the herbicides of weed control seedling stage of alfalfa in the Horqin sandy land,should be the mixture of imazethapyr 1200ml/hm2+haloxyfop-r-methyl 660ml/hm2 or imazethapyr 1800ml/hm2+haloxyfop-r-methyl 660ml/hm2 at the four-and the five-leaf stages.The combination of bromoxynil octanoate 1050ml/hm2+haloxyfop-r-methyl 660ml/hm2 or bromoxynil octanoate 1500ml/hm2+haloxyfop-r-methyl 660ml/hm2 was also recommended to achieve the similar increase in alfalfa yield at the four-and the five-leaf stage.