明确上海、浙江、江苏、安徽、湖北、湖南、江西、黑龙江 8 个省市采集的56 个稻田稗草种群对氰氟草酯和(噁)唑酰草胺的抗性情况.采用室内整株生物测定法,于稗草 3～4 叶期茎叶喷雾处理,氰氟草酯在 150、600 g a.i./hm2剂量下,(噁)唑酰草胺在105、420 g a.i./hm2剂量下测定56个稗草种群对氰氟草酯和(噁)唑酰草胺的敏感性;选择2个相对敏感种群及在低剂量下防效低于 60%的疑似抗性种群进行抗性水平测定.56个稗草种群中有 5个(8.93%)种群对氰氟草酯敏感、26 个(46.43%)种群对(噁)唑酰草胺敏感;有 51 个(91.07%)种群对氰氟草酯有抗性、30 个(53.57%)种群对(噁)唑酰草胺有抗性.对氰氟草酯敏感的5个稗草种群对(噁)唑酰草胺也敏感,对(噁)唑酰草胺有抗性的30 个稗草种群对氰氟草酯也有抗性.采自上海、浙江、江苏、安徽、湖北、湖南、江西、黑龙江水稻田稗草种群对氰氟草酯已产生不同程度抗性,对(噁)唑酰草胺的抗性频率低于氰氟草酯,部分稗草种群对氰氟草酯和(噁)唑酰草胺有交互抗性.
This study aimed to explore the effect of 5％ tembotrione oil dispersion (OD)-38％ atrazine suspension concentrate (SC) tank mixture on the weeds in spring maize fields and the safety of the mixture. To be specific, randomized block design was adopted for the field experiments. The results showed that the application of tank-mixture of 5％ tembotrione OD at 90 g a.i./hm2 and 38％ atrazine SC at 570 g a.i./hm2 and the mixture of 5％ tembotrione OD at 90 g a.i./hm2 and 38％ atrazine SC at 1140 g a.i./hm2 respectively controlled 94.7％～96.3％ and 94.0％～96.3％ of the grass weeds, 94.7％～96.0％ and 93.7％～95.7％ fresh weight of grass weeds, 95.3％～96.3％ and 93.3％～97.3％ of broadleaf weeds, and 94.7％～96.0％ and 93.3％～96.3％ fresh weight of broadleaf weeds. The efficacy was better than that of the 5％ tembotrione alone and the control herbicide and no phytotoxicity of the mixtures was identified. The tank mixture of tembotrione and atrazine should be promoted in the spring maize field for weed control and the recommended dosages were 90 g a.i./hm2 for 5％ tembotrione and 570 g a.i./hm2 for 38％ atrazine.
为指导田间科学合理用药,采用罩笼喷药法监测了2014—2018年吡蚜酮推荐剂量对浏阳第六(4)代褐飞虱的防治效果.结果表明:2014—2018年期间,药后3 d,130、220 mg/L吡蚜酮处理对褐飞虱的防治效果分别为36.66％～51.07％、45.70％～56.12％;药后7 d,130、220 mg/L吡蚜酮处理对褐飞虱的防治效果分别为72.59％～86.85％、83.97％～92.56％;药后14 d,130、220 mg/L吡蚜酮处理对褐飞虱的防治效果分别为89.32％～100％、92.95％以上.整体来看,吡蚜酮对浏阳褐飞虱依然具有较好的防治效果,可以作为浏阳褐飞虱化学防控的主要药剂,但鉴于其他省份褐飞虱对吡蚜酮抗性水平的上升,大田应用方面应适当选择其他作用机理的化学药剂交替使用.
