砜吡草唑对玉米田杂草的除草活性及其安全性评价

采用生物测定方法研究新型除草剂砜吡草唑对玉米田主要禾本科杂草马唐、牛筋草、稗草、狗尾草的除草活性,通过安全性测定评价砜吡草唑对玉米等作物的安全性。结果表明,砜吡草唑土壤封闭处理对马唐、稗草、牛筋草、狗尾草均具有良好的生物活性。砜吡草唑处理剂量(有效成分)为120 g/hm~2时,对马唐、稗草、牛筋草、狗尾草的鲜重抑制率分别为98.76%、97.77%、100%、100%,对四种杂草的鲜重GR90(有效成分)分别为120、73.30、13.88、20.72 g/hm~2。砜吡草唑对玉米的安全性最高,对高粱和谷子的安全性较差,对玉米的鲜重GR10(有效成分)为602.01 g/hm~2。砜吡草唑在玉米和四种杂草间的鲜重选择性指数不小于8.21。砜吡草唑可作为玉米田理想的土壤封闭处理剂。

Herbicidal Activity and Safety Evaluation of Pyroxasulfone Against Corn Fields Weeds

The whole-plant bioassay method was conducted to study the herbicidal activity of pyroxasulfone against the main gramineous weeds in the corn fields, such as Digitaria sanguinalis, Eleusine indica, Echinochloa crusgalli and Setaria viridis. Furthermore, the safety of pyroxasulfone to corn, sorghum and millet was also evaluated. The results showed that the soil treatment of pyroxasulfone had good control effects on Digitaria sanguinalis, Eleusine indica, Echinochloa crusgalli and Setaria viridis. When the application dosage was 120 g a.i/ha, the fresh weight inhibition rates of pyroxasulfone to the four weeds were 98.76%, 97.77%, 100% and 100%, respectively. The GR₉₀ values of Digitaria sanguinalis, Eleusine indica, Echinochloa crusgalli and Setaria viridis were 120, 73.30, 13.88, 20.72 g a.i./ha, respectively. Pyroxasulfone had good safety to corn, but the bad safety to sorghum and millet. The fresh weight GR₁₀ of corn was 602.01 g a.i/ha. The fresh weight selectivity index of pyroxasulfone was not less than 8.21 between maize and four weeds. Pyroxasulfone can be used as an ideal soil treatment herbicide in corn field, and also can be further registered and popularized.