The Screening Of Formula And Application Of Flufenacet Mixture For Weed Control In Soybean Field

Flufenacet is a broad-spectrum herbicide.It can be applied as both pre-emergence soil treatment and post-emergence foliage treatment.It is mainly used to control annual grass weeds,and some broad-leaved weeds in dryland crop fields.In this paper,the mixture ratio of flufenacet and flumioxazin,flumetsulam and metribuzin respectively were screened by soil spay method in pot experiment.The interaction of mixture was discussed by Gowing method.The combined action and optimum proportion of flufenacet and three herbicides respectively were determined.The field trials were also carried out for each formula.The main results are as follows:The significant synergistic effect of flufenacet and flumioxazin was observed on Abutilon theophrasti.The combined actions of fluthiachlor(10-40)g a.i./hm2 + fluoroacetylene(10-20)g a.i./hm2 on Abutilon theophrasti were synergistic and additive to other weeds.The combination of flufenacet and flumioxazin had the greatest synergistic effect on Abutilon theophrasti at(30+10)g a.i./hm2,and the synergistic effect on total of weeds,while the other mixtures showed additive effect.Therefore,the optimum ratio of flufenacet and flumioxazin was determined with 3:1.The combined effects of flufenacet and flumetsulam on the broadleaf weeds were additive.The combination of flufenacet and flumetsulam showed synergistic effect on grass weeds at(20 +5)g a.i./hm2 and(30 + 10)g a.i./hm2.When flufenacet and flumetsulam was applied at(30 + 10)g a.i./hm 2,the synergistic effect on total of weeds was observed,and the interaction of other mixture was additive.Thus,the optimum ratio of flufenacet mixed with flumetsulam was determined with(3:1).The combination of flufenacet and metribuzin showed additive effects on grass weeds.Five mixed combinations of flufenacet and metribuzin showed synergistic effects on broad-leaved weeds at((10-40)+50),((10-40)+150),(30+150)g a.i./hm 2 respectively,while the other mixed combinations showed additive effects.The synergistic effect of flufenacet and metribuzin on total of weeds was synergistic when the dosage of mixture was((10-40)+50),((20-40)+100)g a.i./hm 2.The ratio range of flufenacet mixed with metribuzin was in 1:(1.25-5).The results of field experiment showed that when the mixture of flufenacet and flumioxazin(3:1)was used to control weeds in soybean field,the total dosage of flufenacet and flumioxazin was 100 g a.i./hm2,the individual efficacy on grasses was by 77.27%,and the fresh weight efficacy was by 83.98%,the Individual efficacy on broad-leaved weeds was by 93.72%,and the fresh weight efficacy was by 97.70%.At the same time,the mixture of herbicides had no effect on soybean growth.Therefore,it is recommended that field doses should reach 100-150 g a.i./hm2.When the mixture of flufenacet and flumetsulam(3:1)was used to control weeds in soybean fields,the dosage of the mixture active ingredient was 80 g a.i./hm2,the individual efficacy of the mixture was by 80.91%,and the fresh weight control effect was 86.28%on grass weeds,the individual efficacy on broad-leaved weeds was 84.64%,and the fresh weight control effect was 92.91%.Soybean growth was nomal after herbicide mixtures treatment.So,it is recommended that the herbicide dosage in the field is 80-150 g a.i./hm2.When the dosage of flufenace,metribuzin mixture active ingredients was 180 g a.i./hm2,the individual efficacy was 82.62%,and the fresh weight control effect was 89.61%on grass weeds,broad-leaved weed individual efficacy was 93.00%,and the fresh weight control effect was 92.97%.The mixture of herbicides had no effect on soybean growth.Therefore,it is recommended that field doses should reach 180-240 g a.i./hm2.