评价5种常用茎叶处理除草剂对直播稻田不同叶龄稗、千金子、马唐和牛筋草等4种禾本科杂草的室内活性和田间防效，为直播稻田禾本科杂草的防控提供理论依据。【方法】在4种禾本科杂草稗、千金子、马唐和牛筋草分别处于2～3、4～5及6～7叶龄时，采用定量喷雾法测定其在5种茎叶处理除草剂（50%二氯喹啉酸可湿性粉剂、25 g/L五氟磺草胺可分散油悬浮剂、100 g/L双草醚悬浮剂、100 g/L氰氟草酯乳油和10%噁唑酰草胺乳油）高推荐剂量下的死亡率和鲜重抑制率，并选取2种表现较好的除草剂开展田间试验，验证其田间防效及安全性。【结果】在推荐剂量上限处理下，50%二氯喹啉酸可湿性粉剂（375 g a.i/ha）可防除各叶龄稗和2～3叶龄马唐，对其他杂草的防效较差;25 g/L五氟磺草胺可分散油悬浮剂（30 g a.i/ha）可防除2～3叶龄稗，100 g/L双草醚悬浮剂（45 g a.i/ha）可防除各叶龄稗，两者对其余杂草生长仅有一定抑制作用;100 g/L氰氟草酯乳油（120 g a.i/ha）除对6～7叶龄稗和马唐的防效稍低外可有效防除其余杂草，杂草的死亡率和鲜重抑制率分别为82.5%～100.0%和85.4%～100.0%;10%噁唑酰草胺乳油（120 g a.i/ha）除对6～7叶龄马唐的防效偏低外，对其余杂草的防效均较高，杂草的死亡率和鲜重抑制率分别为90.0%～100.0%和92.1%～100.0%。田间试验结果显示，100 g/L氰氟草酯乳油和10%噁唑酰草胺乳油在有效成分用量90～240 g a.i/ha内对4种禾本科雜草的总体防效均在90.0%以上，且对水稻安全，增产效果显著。【结论】50%二氯喹啉酸可湿性粉剂、100 g/L双草醚悬浮剂和25 g/L五氟磺草胺可分散油悬浮剂可用于防除直播稻田稗，但不适于防除千金子、马唐和牛筋草，100 g/L氰氟草酯乳油和10%噁唑酰草胺乳油可用于防除稗、千金子、马唐和牛筋草。应尽量在杂草出苗后早期（2～3叶龄）用药，以提高除草效果。
关键词： 直播稻田;禾本科杂草;除草剂;叶龄;氰氟草酯;噁唑酰草胺
中图分类号： S482.4 文献标志码： A 文章编号：2095-1191（2019）06-1240-07
Abstract：【Objective】The herbicidal activity and field control effects of five post-emergenceherbicides to Echinochloa crusgalli， Leptochloa chinensis， Digitaria sanguinalis and Eleusine indica in direct seeding rice field at different leaf stages were evaluated and compared in order to provide theoretical guidance for controlling grass weeds in direct seeding rice fields. 【Method】When E. crusgalli， L. chinensis， D. sanguinalis and E. indica were at 2-3， 4-5 and 6-7 leaf stages respectively，the mortality and fresh weight inhibition rates under the upper recommended rates of five post-emergence herbicides（50% quinclorac WP， 25 g/L penoxsulam OD， 100 g/L bispyribac-sodium SC， 100 g/L cyhalofop-butyl EC and 10% metamifop EC） were determined by metered-dose spray method， and then two herbicides with better performances were chosen to investigate its field control effect and safety to rice. 【Result】At the upper limit of recommended field rate， 50% quinclorac WP（375 g a.i/ha） effectively controlled E. crusgalli at all leaf stages and D. sanguinalis at 2-3 leaf stage， but provided poor control to other weeds. 25 g/L penoxsulam OD（30 g a.i/ha） controlled E. crusgalli at 2-3 leaf stage and 100 g/L bispyribac-sodium SC（45 g a.i/ha） controlled E. crusgalli at all leaf stages， however， these two herbicides merely inhibited the growth of all the other weeds rather than killed them. Except E. crusgalli and D. sanguinalis at 6-7 leaf stage， 100 g/L cyhalofop-butyl EC（120 g a.i/ha） effectively controlled all the other weeds， and morality and fresh weight inhibition rate were 82.5%-100.0% and 85.4%-100.0% respectively. Similarly， except D. sanguinalis at 6-7 leaf stage， 10% metamifop EC（120 g a.i/ha） effectively controlled all the other weeds， and morality and fresh weight inhibition rate were 90.0%-100.0% and 92.1%-100.0% respectively. Field trial results showed that， when used at 90-240 g a.i/ha， 100 g/L cyhalofop-butyl EC and 10% metamifop EC displayed ideal field control efficacies（>90.0%） to these four grass weeds， with high safety to rice and remarkable increases of rice yield. 【Conclusion】50% quinclorac WP， 100g/L bispyribac-sodium SC and 25 g/L penoxsulam OD can be used to control E. crusgalli in direct-seed rice field， but they are not suita-ble for controlling L. chinensis， D. sanguinalis and E. indica. 100 g/L cyhalofop-butyl EC and 100% metamifop EC are available for controlling all these four grass weeds and should be applied at the early stage（2-3 leaf stage） after emergence to increase the control effects.
相关热词搜索： 禾本科 除草剂 除草 田间 稻田