为开发机直播水稻田高效安全的封闭除草剂，采用大田试验，比较了不同时期应用含有乙氧磺隆成分的除草剂对阔叶草和莎草科杂草的防除效果。结果发现，播种时同步喷施五氟·乙氧或混配乙氧磺隆与其他除草剂能够有效抑制机直播稻田阔叶草和莎草科杂草的萌发和生长，且对水稻出苗安全。机直播后10 d或15 d施用对阔叶草防效下降，但播种15 d后撒施0.65%五氟·乙氧控释颗粒剂97.5 g/hm²对杂草防效较好，密度防效达到90%以上。表明采用五氟·乙氧或混配乙氧磺隆与其他除草剂防除机直播稻田阔叶草，越早施药效果越好。但如果因气候条件或其他因素影响错过施药窗口期时，撒施0.65%五氟·乙氧控释颗粒剂97.5 g/hm²或喷施30%氰氟草酯112.5 g/hm²+30%五氟·乙氧90 g/hm²也可以防控绝大部分直播田杂草。

To develop the efficient and safe soil-applied herbicides in direct-seeded rice fields, a field test was conducted to evaluate the control efficiency of ethoxysulfuron on broadleaf weeds and sedge family weeds at different dates after sowing. The results showed that the germination and growth of broadleaf grass and sedge family weeds were effectively inhibited with weed control measure of synchronous seeding and spraying herbicides of ethoxysulfuron. And there was no negative influence on the rice seedling emergence rate after ethoxysulfuron treatment. However, the control effect on broadleaf grass decreased variedly when herbicides treatments containing of ethoxysulfuron were applied at 10 days or 15 days after sowing. All of poaceae weeds, sedge family weeds and broadleaf weed could be effectively controlled after treatment of 97.5 g a.i./hm² 0.65% penoxsulam·ethoxysulfuron controlled-release granules at 15 days after rice sowing, and the control efficiency of plant number reached over 90%. All these results suggested that ethoxysulfuron, as a soil-applied herbicide, should be applied earlier after rice sowing. But if the recommended application window was missed due to bad weather or other uncontrollable factors, the application of 97.5 g a.i./hm² 0.65% penoxsulam·ethoxysulfuron controlled-release granules or 112.5 g a.i./hm² 30% cyhalofop-butyl combined with 90 g a.i./hm² 30% penoxsulam·ethoxysulfuron treatment could also be a better choice to control most weeds in mechanized direct-seeded rice fields.