[Objective] The aim was to explore the factors affecting the herbicidal activity of pyrazosulfuron-ethyl against Sagittaria pygmaea in paddy soil.[Method] The bioassay method was carried out under greenhouse condition...[Objective] The aim was to explore the factors affecting the herbicidal activity of pyrazosulfuron-ethyl against Sagittaria pygmaea in paddy soil.[Method] The bioassay method was carried out under greenhouse conditions.[Result] The reduction of more than 80% in fresh weight was observed in S.pygmaea treated with 45 g/hm2 of pyrazosulfuron-ethyl for 7 d or more.Application of 60 g/hm2 at the sprouting stage of S.pygmaea suppressed completely the growth in fresh weight irrespective of tuber size.However,at 6 g/hm2 growth of the weed sustained less reduction with increasing tuber size.Differences in flooding water depth and temperature had no appreciable influence on the herbicidal activity.Growth inhibition of S.pygmaea by pre-emergence or 1.5-leaf stage applications under non-leaching conditions was significantly higher than that under water leaching conditions.Under non-leaching condition,there was no remarkable difference in this inhibition between preemergence and 1.5-leaf stage applications,while under water leaching conditions the growth reduction with the latter application was significantly larger.Growth inhibition of S.pygmaea planted at a depth of 2 cm was significantly higher than that planted deeper （5 cm） with the pre-emergence applications.[Conclusion] This study had provide basis for the further study on the inhibition effect of pyrazosulfuron-ethyl.展开更多
采用高效液相色谱-串联质谱法（HPLC-MS/MS）,建立了稻田水、土壤、水稻植株、稻秆、稻壳及糙米基质中吡嘧磺隆和苯噻酰草胺的残留分析方法。样品经20 m L V（乙腈）∶V（水）=70∶30的混合溶液提取,提取液用20 mg石墨化碳黑（GCB）与30...采用高效液相色谱-串联质谱法（HPLC-MS/MS）,建立了稻田水、土壤、水稻植株、稻秆、稻壳及糙米基质中吡嘧磺隆和苯噻酰草胺的残留分析方法。样品经20 m L V（乙腈）∶V（水）=70∶30的混合溶液提取,提取液用20 mg石墨化碳黑（GCB）与30 mg乙二氨基-N-丙基硅烷（PSA）净化,HPLC-M S/M S检测。吡嘧磺隆在上述各基质中的添加回收率在76%~107%之间,相对标准偏差（RSD）在1.5%~14%之间,定量限为0.004~0.01 mg/kg;苯噻酰草胺的添加回收率在77%~101%之间,RSD在2.4%~13%之间,定量限为0.001~0.01 mg/kg。实现了对两种除草剂同时简便、快速测定的要求。采用该方法测定了26%吡嘧磺隆·苯噻酰草胺水面扩展粒剂在稻田施用后,其有效成分吡嘧磺隆和苯噻酰草胺在实际样品中的残留量。结果表明,两种除草剂均属于易降解农药,在本试验条件下其在糙米中的残留量均低于我国最大残留限量（MRL）（吡嘧磺隆0.1 mg/kg;苯噻酰草胺0.05 mg/kg）。展开更多
基金Supported by the Science and Technology Innovation Platform Construction Project of Institution of Higher Education in Hunan Province(XCJZ2009-070)the Earmarked Fund for Mordern Agro-industry Technology Research System(CARS-19-E12)~~
文摘[Objective] The aim was to explore the factors affecting the herbicidal activity of pyrazosulfuron-ethyl against Sagittaria pygmaea in paddy soil.[Method] The bioassay method was carried out under greenhouse conditions.[Result] The reduction of more than 80% in fresh weight was observed in S.pygmaea treated with 45 g/hm2 of pyrazosulfuron-ethyl for 7 d or more.Application of 60 g/hm2 at the sprouting stage of S.pygmaea suppressed completely the growth in fresh weight irrespective of tuber size.However,at 6 g/hm2 growth of the weed sustained less reduction with increasing tuber size.Differences in flooding water depth and temperature had no appreciable influence on the herbicidal activity.Growth inhibition of S.pygmaea by pre-emergence or 1.5-leaf stage applications under non-leaching conditions was significantly higher than that under water leaching conditions.Under non-leaching condition,there was no remarkable difference in this inhibition between preemergence and 1.5-leaf stage applications,while under water leaching conditions the growth reduction with the latter application was significantly larger.Growth inhibition of S.pygmaea planted at a depth of 2 cm was significantly higher than that planted deeper （5 cm） with the pre-emergence applications.[Conclusion] This study had provide basis for the further study on the inhibition effect of pyrazosulfuron-ethyl.
