Herbicidal activity of pyroxasulfone 40％SC on weeds and its safety evaluation on peanuts
To determine the feasibility of the pyroxasulfone applying in peanut field,the herbicidal activity of pyroxasulfone 40％SC on Digitaria sanguinalis,Pennisetum alopecuroides,Echinochloa crus-galli,Chenopodium album,Amaranthus retroflexus and Portulaca oleracea was determined by whole plant assay,and the safety of the pesticide on peanut was evaluated through field trail.The results showed that pyroxasulfone 40％SC showed very high activity against the six tested weeds,with GR50 value of 0.76-2.90 g/hm2 and control efficacy of 100％at 13.32 g/hm2.Toxicity of pyroxasulfone 40％SC to three gramineous weeds and three broadleaf weeds was 5.60-9.30 times and 22.16-25.24 times of S-metolachlor 960 g/L EC,respectively.GR10 values of pyroxasulfone 40％SC were 212.03 g/hm2 and 87.68 g/hm2,respectively under the two watering methods,watering by bottom infiltration and spraying above the basin.The higher the dose,the more obvious the growth inhibition,indicating relatively poor safety of pyroxasulfone to peanut.Even so,the selectivity index of pyroxasulfone was 29.45 to 142.30 between peanuts and weeds under the way of watering by bottom infiltration.Field trail showed that weed control efficacy was more than 92.6％when pyroxasulfone 40％SC at dose of 120-240 g/hm2,and the yield increase rate of peanut was 21.09％-22.71％.The weed control efficacy and peanut yield were significantly higher than that of S-mctolachlor at dose of 720 g/hm2,and no crop injury was observed in all treatments.In conclusion,pyroxasulfone 40％SC can be used as an alternative herbicide for weed control in peanut fields,but it is necessary to pay attention to the peanut safety issues caused by excessive application of pyroxasulfone and rainfall water accumulation.
peanutpyroxasulfoneselectivitycrop safetyweed control efficacy
万方数据
维普
