特丁净与3种封闭除草剂混配对多花黑麦草的协同作用

Synergistic effect of terbutryn in combination with 3 pre-emergence herbicides on Italian ryegrass(Lolium multiflorum)

[目的]为评估特丁净与吡氟酰草胺、砜吡草唑、二氯异草酮3种封闭除草剂混用对多花黑麦草的除草效果与混用效应,寻找高效防治多花黑麦草的混配药剂。[方法]通过室内盆栽试验及田间试验评估3种封闭除草剂与特丁净混用对多花黑麦草的防除效果,利用孙云沛联合作用系数法评估不同除草剂混用效应。[结果]室内盆栽试验结果表明,特丁净、吡氟酰草胺、砜吡草唑、二氯异草酮对多花黑麦草的ED50值分别为120.10、42.67、4.89、8.19 g a.i./hm^(2)。吡氟酰草胺与特丁净混配比例为1∶5、1∶6、1∶7、1∶8时,表现出拮抗作用,而1∶4的比例有增效作用;砜吡草唑和特丁净混配比例为1∶6、1∶8、1∶10、1∶12、1∶14时均表现出增效作用,其中1∶12的比例下的增效作用最佳;二氯异草酮与特丁净配比为1∶2、1∶4、1∶6、1∶8、1∶10时均表现出增效作用,其中1∶8的比例下的增效作用最佳。田间小区试验结果表明,砜吡草唑与特丁净在剂量为112.5+1125 g a.i./hm^(2)和105+1260 g a.i./hm^(2)处理下,对多花黑麦草的鲜质量防效分别为94.97%、99.38%。二氯异草酮+特丁净在剂量为189+756 g a.i./hm^(2)和189+1134 g a.i./hm^(2)处理下对多花黑麦草的鲜质量防效分别为87.1%、84.83%。[结论]二氯异草酮、砜吡草唑与特丁净混用对防治多花黑麦草有增效作用,且二氯异草酮与特丁净在1∶4(162 g a.i./hm^(2)二氯异草酮+648 g a.i./hm^(2)特丁净)和砜吡草唑与特丁净在1∶10(112.5 g a.i./hm^(2)砜吡草唑+1125 g a.i./hm^(2)特丁净)、1∶12(105 g a.i./hm^(2)砜吡草唑+1260 g a.i./hm^(2)特丁净)比例下对多花黑麦草的防除效果很好,有较好应用前景。

[Aims]To evaluate the herbicidal and synergistic effects of terbutryn in combination with diflufenican,pyroxasulfone or bixlozone on Lolium multiflorum,aiming to identify an effective combination herbicides for controlling L.multiflorum.[Methods]The efficacy of 3 pre-emergence herbicides in combination with terbutryn on L.multiflorum was assessed through both laboratory bioactivity tests and field trials,while the combined effects of different herbicides were evaluated using the Sun Yunpei co-toxicity coefficient method.[Results]The results of laboratory bioactivity tests showed that the ED50 values for terbutryn,diflufenican,pyroxasulfone and bixlozone on L.multiflorum were 120.10,42.67,4.89 and 8.19 g a.i./ha respectively.When the ratios of diflufenican:tebutryn were 1∶5,1∶6,1∶8 and 1∶10,the compositions showed antagonistic effect,while it was synergistic with the ratio of 1∶4.When the ratios of pyroxasulfone:terbutryn were 1∶6,1∶8,1∶10,1∶12 and 1∶14,the compositions showed synergistic effects,and the optimal ratio was 1∶12.Bixlozone and terbutryn at the ratios of 1∶2,1∶4,1∶6,1∶8 and 1∶10 showed synergistic effects,and the optimal ratio was 1∶8.The results of the field plot trial showed that soil application with pyroxasulfone+terbutryn at 112.5+1125 g a.i./ha and 105+1260 g a.i./ha achieved fresh weight control efficacy of 94.97%and 99.38%for L.multiflorum,respectively.The fresh weight control efficacy was 87.1%and 84.83%under the treatments with bixlozone+terbutryn at 189+756 and 189+1134 g a.i./ha.[Conclusions]The mixture of bixlozone and tebutryn,as well as the mixture of pyroxasulfone and terbutryn,exhibits synergistic effects in controlling L.multiflorum.Additionally,the combination of bixlozone and terbutryn at a ratio of 1∶4(bixlozone162 g a.i./ha+tebutryn 648 g a.i./ha),along with pyroxasulfone and terbutryn at a ratio of 1∶10(pyroxasulfone 112.5 g a.i./ha+terbutryn 1125 g a.i./ha)or 1∶12(pyroxasulfone 105 g a.i./ha+terbutryn 1260 g a.i./ha),demonstrates effective control against L.multiflorum,so they have good application prospect.