除草剂烯草酮的应用技术研究

在温室及田间条件下对烯草酮的作用特点、施药时期等进行了试验研究。温室试验结果表明，烯草酮的除草活性明显高于12．5％稀禾啶机油乳油，二者对稗草的ED90分别为36．2g／hm^2(有效成分，下同)和72.8g／hm^2；对大豆、棉花、花生、油菜等阔叶作物高度安全；烯草酮的最佳施药时期为禾本科杂草2～5叶期；烯草酮具有较好的耐雨水冲刷性，且明显好于稀禾啶；不同种类的禾本科杂草对烯草酮的敏感性不同，其中黑麦草对烯草酮最敏感，野燕麦较敏感，稗草中等敏感，狗尾草、马唐、牛筋草和看麦娘的敏感性略差。多点田间小区试验结果表明，烯草酮对大豆、油菜田发生的稗草、狗尾草、看麦娘、早熟禾等主要禾本科杂草均有较好的防除效果，处理后大豆、油菜无任何药害症状产生，应用剂量以72～108g／hm^2为宜，在此剂量范围内药后30～60d以上述杂草的鲜重防效可达85．1％～100％。

Utilization Technology for the Herbicide Clethodim

Greenhouse and field studies were conducted to investigate weed control and crop safety with clethodim. Ingreenhouse experiments, clethodim activity was much higher than that of a sethoxydim 12.5% EC; barnyardgrass(Echinochloa crus-galli) ED90s were 36.2 and 72.8 g/ha, respectively. Clethodim showed a high degree of safety tosoybeans (Glycine max), cotton (Gosspium hirsutum), peanuts (Arachis hpogaea), and oilseed rape (Brassicacampestris). The best application timing for clethodim was the 2-5 leaf stage of grasses. Clethodim was more rainfastthan sethoxydim. Different grass species showed different susceptibility to clethodim, with ryegrass (Lolium perenne)being the most susceptible, followed by wild oats (Avena fatua) (relatively susceptible), barnyardgrass (moderatesusceptibility), green foxtail (Setaria viridis), large crabgrass (Digitaria sanguinalis), goosegrass (Eleusine indica), andshortawn foxtail (Alopecurus aequalis) (susceptibility somewhat low). Clethodim at 72-108 g/ha in small plot field studiesat several locations provided 85.1-100% control (fresh weights) of barnyardgrass, green foxtail, shortawn foxtail, and annualbluegrass 30 to 60 d after application in soybeans and oilseed rape, with no symptoms of herbicide injury.