吉林中部地区紫花苜蓿地除草剂筛选试验

摘要

The slow growth of alfalfa (Medicago sativa)at seedlings stage results in the rapid growth of weeds, which severely affects the quantity and quality of alfalfa products.Six common herbicides with low toxicity and suitable for legume were selected for further evaluation.The results showed that 90% acetochlor with 2.0 L.hm-2 spraying in the soil after sowing had best effects which reached 93.81% of relative weeds prevention rate and did not affect yield although alfalfa seedlings grew slowly.Different herbicides should be selected ac-cording to different weed species when spraying on alfalfa leaves.The application of 40% bentazone with 3.0 L.hm-2 had 97.09% of relative prevention rate of Echinochloa phyllopogon which also had no harms to alfal-fa.The application of 15% fluazifop-p-butyl with 1.0 L.hm-2 effectively control Cirsium setosum and Meta-plexis japonica which had 93.63% and 100% of relative prevention rate,respectively.Herbicide was not rec-ommended for Chenopodium album,Portulaca oleracea,Abutilon theophrasti which should be prevented manually.%紫花苜蓿(Medicago sativa)苗期生长缓慢，导致杂草生长迅速，严重影响苜蓿草产品的产量和质量.为此，本研究选择市场上6种安全、低毒且适于豆科植物使用的除草剂进行筛选试验.结果表明，播后苗前土壤中施用剂量为2．0 L.hm－2的90％乙草胺除草效果最好，相对株防效达到93．81％，虽然紫花苜蓿幼苗生长缓慢，但不影响其产量形成.茎叶喷施时建议根据紫花苜蓿地杂草种类，选择不同的除草剂，对水稗(Echinochloa phyllopogon )进行杂草防除时，施用3．0 L.hm－2的40％灭草松，相对株防效达到97．09％，没有药害.施用1．0 L.hm－2的15％精吡氟禾草灵可有效防除小蓟(Cirsium setosum)和萝藦(Metaplexis japonica)，相对株防效分别达到93．63％和100％.而针对藜(Chenopo-dium album)、马齿苋(Portulaca oleracea)和苘麻(Abutilon theophrasti)，建议不严重时不要施用除草剂，而采取人工除草方式.