Abstract: To clarify the feasibility of the mixture of imazapic and clethodimm in alfalfa (Medicago sativa) fields,the control efficacy of the mixture of imazapic and clethodim and its effect on the growth of alfalfa were tested in the field in 2019. The results showed that 14 days after treatment,the mixture of imazapic and clethodim inhibited the plant height,branch number,aboveground fresh weight,but the inhibition rate was lower than that of imazapic alone;28 days after treatment,the mixture of imazapic and clethodim reduced the inhibition rate of alfalfa plant height. The branch number,aboveground fresh weight,and yield of the alfalfa treated with a mixture of imazapic and clethodim were significantly higher than that of the control and the two single-dose treatments (P<0.05),but there is no difference in the quality. Compared with the single use of imazapic and clethodim,the mixture of imazapic and clethodim significantly improved the control efficacy of Digitaria sanguinalis,Echinochloa hispidula, and other gramineous weeds (P<0.05),and the control efficacy was higher than 90%. Alfalfa had a significant yield increase by more than 13%. In summary,the mixture of imazapic (86.4~100.8 g·hm^-2) and clethodim (54.0~108.0 g·hm^-2) effectively controls weeds and the inhibitory effects of these herbicides on alfalfa growthcould be alleviated in the later stage,thus,the mixure of these herbicides increases alfalfa yield and has good application prospects and value.

Key words: Imazapic, Clethodim, Alfalfa, Weeds, Control efficacy

摘要： 为明确甲咪唑烟酸与烯草酮混配应用于紫花苜蓿(Medicago sativa)田的可行性，2019年在田间测定甲咪唑烟酸与烯草酮不同混配的除草效果及对紫花苜蓿生长的影响。结果表明：药后14 d，混配处理对紫花苜蓿株高、分枝数、地上部鲜重均有抑制，但抑制率低于甲咪唑烟酸处理；药后28 d，混配处理对株高的抑制率降低，而分枝数、地上部鲜重、产量显著高于对照组和两种单剂处理(P<0.05)，对品质无影响；与甲咪唑烟酸、烯草酮单用相比，混配处理显著提高马唐、旱稗等禾本科杂草的防效(P<0.05)，杂草总防效90%以上，增产率13%以上，增产效果显著。综上所述，甲咪唑烟酸(86.4～100.8 g·hm^-2)与烯草酮(54.0～108.0 g·hm^-2)混配对紫花苜蓿的抑制作用在后期得到缓解，有效防除杂草，提高紫花苜蓿产量，具有良好的应用前景和价值。

关键词: 甲咪唑烟酸, 烯草酮, 紫花苜蓿, 杂草, 防效