25%双环磺草酮悬浮剂对不同叶龄期水稻品种的安全性评价

双环磺草酮是在我国取得水稻田使用登记许可的HPPD抑制剂类除草剂，杀草谱广，尤其对抗性千金子、杂草稻等恶性杂草表现出良好的防除效果。为进一步探索双环磺草酮在直播稻田的应用前景和应用技术，采用盆栽试验法，开展了25%双环磺草酮悬浮剂 (SC) 对不同叶龄期水稻品种的安全性评价。结果表明:在水稻1~2叶期、2~3叶期和3~4叶期浅水层条件和水稻1~2叶期湿润条件下，按有效成分150~375 g/hm2剂量施用25%双环磺草酮SC，对上海地区主栽的3个常规粳稻品种南粳46、沪软1212和松香粳1018 以及申优26杂交粳稻品种生长均安全，对水稻株高、植株地上部分鲜重、根长、根系鲜重等生长指标均无显著影响。表明双环磺草酮对水稻粳稻品种安全，待进一步明确应用技术后，有望成为直播稻田优秀的除草剂品种。

Safety evaluation of benzobicyclon 25% SC on rice varieties at different leaf stages

Benzobicyclon is a 4-hydroxyphenylpyruvate dioxygenase (HPPD)-inhibiting herbicide that was registered in Chinese rice production. It has a wide herbicidal spectrum, especially good control efficacy on malignant weeds such as resistant Chinese sprangletop (Leptochloa chinensis), weedy rice (Oryza sativa f. spontanea), and so on. In order to explore the application prospect and technology of benzobicyclon in the direct seeding rice field, the safety evaluation of benzobicyclon 25% SC on various rice varieties at different leaf stages was studied by the pot-culture experiment. The results showed that: Under whether the condition of shallow water at 1-2 leaf stage, 2-3 leaf stage, and 3-4 leaf stage of rice, or the wet condition at the 1-2 leaf stage of rice, the application of 150-375 g a.i./hm2 of benzobicyclon 25% SC was safe to the three conventional Japonica varieties Nanjing 46, Huruan1212, Songxiangjing1018 and the hybrid Japonica varieties Shenyou 26, which were mainly planted in Shanghai, and had no significant effect on the growth indices including plant height, aboveground fresh weight, root length, and root fresh weight. The results indicate that benzobicyclon is safe for Japonica rice varieties, and is expected to become an excellent herbicide variety in the direct seeding rice fields with the updated application technology.