双环磺草酮与氯氟吡啶酯复配的联合除草活性及对水稻的安全性评价

双环磺草酮是一种新型的对羟基苯丙酮酸双加氧酶抑制剂类除草剂,为明确其除草活性以及其与合成激素类除草剂氯氟吡啶酯复配后的除草效果,采用温室盆栽法研究了二者复配的联合作用类型,以及复配药剂在水稻与杂草之间的选择性,并进行了田间药效评价。温室盆栽试验结果表明:双环磺草酮与氯氟吡啶酯复配后使用,对供试杂草稗草、千金子、异型莎草及鸭舌草均呈现加成或增效作用;其中二者按照质量比5:1复配后的除草活性高于双环磺草酮单剂;复配药剂在供试水稻品种与杂草之间的选择性指数在28.72~54.81之间,与两种单剂相比,复配药剂对水稻的安全性均有提高。田间药效试验结果表明:双环磺草酮与氯氟吡啶酯复配扩大了杀草谱,对稗草、千金子、异型莎草及雨久花的株防效和鲜重防效在93.4%~100%之间,且对水稻安全;其中,田间复配用量为双环磺草酮有效成分120 g/hm^2、氯氟吡啶酯有效成分18 g/hm^2时效果最佳,对4种供试杂草的防效为97.1%~100%。

Evaluation of herbicidal activity and safety to rice of the combination of benzobicyclon and florpyrauxifen-benzyl

Benzobicyclon is a novel 4-hydroxyphenylpyruvate dioxygenase-inhibiting (HPPD) herbicide. The herbicidal activity and control efficacy of the combination of benzobicyclon and florpyrauxifen-benzyl were evaluated. Whole-plant dose-response experiments were conducted in greenhouse to evaluate the joint effect and the selectivity index of the mixtures between rice and weeds. Weed control efficacy and response of rice to the mixtures were also investigated in field experiments. The results of greenhouse experiments showed that the joint effect type was either additive or synergistic when benzobicyclon was mixed with florpyrauxifen-benzyl for the control of Echinochloa crus-galli, Leptochloa chinensis, Cyperus difformis and Monochoria vaginalis. When the mass ratio of benzobicyclon and florpyrauxifen-benzyl was 5:1, the weed control efficacy of the mixtures was higher than that treated only by benzobicyclon. The selectivity indexes between rice varieties and the tested weeds were in the range of 28.72-54.81, which demonstrated the safety of the mixtures to rice was improved compared with that of benzobicyclon and florpyrauxifen-benzyl used alone. The results of field efficacy test showed that the combination of benzobicyclon and florpyrauxifen-benzyl expanded the herbicidal spectrum. The fresh weight control effect against E. crus-galli,L. chinensis, C. difformis and Monochoria korsakowii was 93.4%-100% which was safe to rice. The recommended dosage applied in the field was 120 g a.i/hm2 for benzobicyclon and 18 g a.i/hm2 for florpyrauxifen-benzyl, and the control effect against weeds was between 97.1%-100%.