25%丙草胺CS对水稻直播田杂草的防除效果和作物安全性评价

Evaluation of the control effect of pretilachlor 25%CS on weeds in direct-seeded rice fields and crop safety

为评价新制备的25%丙草胺微囊悬浮剂(CS)的应用效果,参照农药田间药效试验准则开展了水稻直播田杂草的防除及安全性试验。试验结果表明25%丙草胺CS以施用剂量450~877.5 g a.i./hm^(2)进行喷雾处理,其对水稻直播田稗草、鸭舌草等杂草表现出较好的防治效果和持效性,且其对水稻的成苗数、株高、根长、株鲜重、根鲜重等生长指标无明显影响,这一结果为除草剂的合理使用提供了良好的借鉴作用,建议推荐剂量为450~877.5 g a.i./hm^(2),于播种后2 d水稻立针期和杂草未出苗时喷施。

In order to evaluate the application effect of the newly prepared pretilachlor 25%microcapsule suspension(CS),the control and safety test of weeds in rice direct-seeded fields was carried out according to the guidelines for field efficacy tests of pesticides.The test results showed that pretilachlor 25%CS,when sprayed at a dosage of 450-877.5 g a.i./ha,showed good control and persistence of weeds such as Echinochloa crusgalli and Monochoria vaginalis in rice directseeded fields,and had no significant effect on the growth indicators of rice such as the number of seedlings,plant height,root length,plant fresh weight,and root fresh weight.This result provides a good reference for the rational use of herbicides.The recommended dosage is 450-877.5 g a.i./ha,which should be sprayed at the rice needle-standing stage 2 days after sowing and when the weeds have not yet emerged.