Objective] To figure out different the security of 10% Metamifop EC of different dosages on direct sowing rice, and their efficiency in controlling such gramineous weeds as Echinochloa crusgalli (L.) Beauv., Leptochloa chinen-sis (L.) Nees and Digitaria sanguinalis (L.) Scop., and define the optimal safe dosage. [Method] From the 4-leaf and 1-heart stage to the 5-leaf stage of rice, apply 10% Metamifop EC of different dosages, observe growth conditions of rice, calculate plant control efficiency, and fresh weight control efficency 20 days after application. [Result] 10%Metamifop EC (1 050-2 400 ml/hm2) is safe for direct sowing rice, and effective in controlling vicious gramineous grasses from 5-leaf to 5-leaf and 1-heart stage, and it takes effect fast. [Conclusion] Con-sidering the cost and control efficiency, the recommended dosage is 1 500-1 800 ml/hm2 in from 5-leaf to 5-leaf and 1-heart stage of gramineous grasses; and after this stage, raise the dosage to 1,800 ml/hm2 and above. The study provides references for the large-scale application of 10%Metamifop EC.%[目的]明确噁唑酰草胺10%EC不同剂量对直播水稻生长的安全性，以及对稻田稗、千金子、马唐等禾本科杂草的防除效果，找出最佳安全使用剂量。[方法]在水稻4叶1心至5叶期喷施不同剂量的噁唑酰草胺10%EC，观察水稻生长状况并计算株防效和药后20 d 鲜重防效。[结果]10%噁唑酰草胺EC 1050~2400 ml/hm2对直播水稻安全性好，对处于5叶至5叶1心期的稗、千金子等恶性禾本科杂草防除效果好、作用速度较快。[结论]从使用成本、除草效果等方面综合考虑，禾草5叶至5叶1心期使用，推荐剂量为1500~1800 ml/hm2；超过5叶1心期以后，建议加大施药剂量至1800 ml/hm2以上。为噁唑酰草胺10%EC的大面积推广应用提供了依据。
展开▼
