20%双草醚悬浮剂防除水稻直播田杂草的药效

Efficacy of Bispyribac-Sodium 20% SC in Direct-Seeded Rice Fields

为有效控制水稻直播田草害,研究20%双草醚悬浮剂的防除效果、适宜用量和应用安全性.本研究中防除对象为水稻直播田稗草、马唐、莎草、鸭跖草等1年生杂草,以10%双草醚悬浮剂为对照药剂,以清水为空白对照,试验测定4种浓度(有效成分22.5,30.0,37.5,60.0g/hm^2)的20%双草醚悬浮剂的防效,同时跟踪其使用安全性及水稻产量变化.试验结果发现,20%双草醚悬浮剂对目标杂草具有良好的防除效果,优于对照药剂10%双草醚悬浮剂;20%双草醚悬浮剂有效成分60g/hm^2处理的防效显著高于其他3个低浓度处理.对杂草总数量的防效在药后1个月内保持在72%以上,药后45d降至44.91%~62.74%,但对杂草总质量的防效仍达72.33%~89.29%.20%双草醚悬浮剂在水稻直播田具备使用安全性,水稻增产率(与人工除草相比)为-2.70%^-10.81%,所以为水稻直播田理想除草剂,推荐使用剂量为有效成分22.5~37.5g/hm^2.

In order to effectively controlweed damagein direct-seeded rice fields,we studied the efficacy,appropriate dosage and application safety of bispyribac-sodium 20% SC.The control targets in this study were annual weeds such as Echinochloa crusgalli(L.)Beauv.,Digitaria sanguinalis(L.)Scop.,Cyperus rotundus L.and Commelina communis L.in direct-seeded rice fields.The control effect of four concentrations of bispyribac-sodium 20% SC was tested with 10% SC as control,andits use safety and the rice yield increase were also tracked.The results showedthat bispyribac-sodium 20% SC was notably effective,which was superior to bispyribac-sodium 10% SC.The treatment effect of active ingredient 60 g/hawas significantly higher than that of the other three lower-concentration treatments.Efficacy on the total amount of weeds remained above 72% within one month after treatment,and decreased to 44.91%~62.74%at 45 days,but the control effect on the total weight of weeds was as high as 72.33%~89.29%.In this study,bispyribac-sodium 20% SC appeared to be safe to use in direct-seeded rice fieldswith a yield increase of-2.70%^-10.81%.In conclusion,bispyribac-sodium 20% SC is an ideal herbicide for directseeded rice fields and its recommended dosage is 22.5~37.5 g a.i./ha.