Study On Synergistic Effect And Synergistic Mechanism Of Spray Adjvant On Herbicide

For many years,it has been difficult to control weeds,high density,long time and other problems,resulting in crop production,threatening food security.Chemical weeding has become the main means of weed control in the field at present because of its advantages of strong practicability,economical convenience,time-saving and labor-saving,fast and efficient,and the amount of herbicide is increasing year by year.Over the years,the abuse of herbicides has led to the increase of weed resistance,serious agricultural residues,serious farmland environmental pollution,frequent crop drug damage and many other problems^[1].On the basis of reducing the dosage,spray adjuvant can improve the utilization rate of herbicide,solve the problem of farmland environment deterioration,and achieve the expected control effect^[2].However,the synergistic mechanisms of different adjuvants are different,and the synergistic mechanisms of different agents and different target plants are different.Therefore,it is of great practical significance to study the synergistic mechanism and synergistic effect of spray adjuvants on herbicides,so as to achieve herbicide reduction and synergistic effect and solve soil and environmental pollution.In this paper,using the methods of instrumental analysis,laboratory bioactivity measurement and field experiment,surface tension,contact Angle,spread diameter,wettability,drying time,evaporation performance and maximum liquid holdup of leaves as evaluation indexes,the synergies of four kinds of spray adjuvants on the high efficiency herbicides of corn and soybean fields were studied.The synergies of adjuvants on herbicides in corn and soybean fields were studied by greenhouse pot method and field experiment,and the effects of four kinds of spray adjuvants on herbicide absorption in weed leaves were further clarified.Thus,theoretical support was provided for the establishment of scientific and effective herbicide reduction and efficiency enhancement technology in corn and soybean fields.The main research results of this paper are as follows:（1）The greenhouse pot method was used to determine the effects of GY-Tmax,Jijian,Ann Gro and Jiexiaoli on the efficacy of herbicide in corn and soybean fields.The effects of GY-Tmax,Jijian,Ann Gro and Jiexiaoli on herbicide activity in corn and soybean fields were determined by pot pot method in greenhouse.The experimental results show that:Nicosulfuron 42g a.i./hm²,mesotrione 135 g a.i./hm²,atrazine 1425 g a.i./hm²,methyl·nitrosulfuron·atrazine 450 g a.i./hm²,clomazone 576 g a.i./hm²,quizalofop-P-ethyl 37.5 g a.i./hm²,fomesafen 359 g a.i./hm²and clomazone·quizalofop-P-ethyl·fomesafen 525 g a.i./hm²,Adding GY-Tmax 0.1%（v/v）increased the fresh weight control efficiency of Amaranthus retroflexus L.and Echinochloa crusgalli（L.）Beauv.by 30.05%～34.94%and 29.03～34.54%,adding Jijian 0.1%（v/v）increased the fresh weight control efficiency of Amaranthus retroflexus L.and Echinochloa crusgalli（L.）Beauv.by 24.83%～27.29%and 22.68%～31.04%.Adding Ann Gro 0.1%（v/v）increased the fresh weight control efficiency of Amaranthus retroflexus L.and Echinochloa crusgalli（L.）Beauv.by27.27%～28.29%and 22.68%～32.71%,adding Jiexiaoli 0.05%（v/v）increased the fresh weight control efficiency Amaranthus retroflexus L.and Echinochloa crusgalli（L.）Beauv.by28.32%～30.61%and 26.78%～32.29%.（2）)The effects of GY-Tmax,Jijian,Ann Gro and Jiexiaoli on herbicide activity in corn and soybean fields were determined by pot pot method in greenhouse.The experimental results show that:Nicosulfuron 42 g a.i./hm²,mesotrione 135 g a.i./hm²,atrazine 1425 g a.i./hm²,methyl·nitrosulfuron·atrazine 450 g a.i./hm²,clomazone 576 g a.i./hm²,quizalofop-P-ethyl 37.5 g a.i./hm²,fomesafen 359 g a.i./hm²and clomazone·quizalofop-P-ethyl·fomesafen 525 g a.i./hm²,Adding GY-Tmax 0.1%（v/v）increased the fresh weight control efficiency of Amaranthus retroflexus L.and Echinochloa crusgalli（L.）Beauv.by 28.72%～32.94%and 28.36%～32.21%,and adding Jijian 0.1%（v/v）increased the fresh weight control efficiency of Amaranthus retroflexus L.and Echinochloa crusgalli（L.）Beauv.L.by 24.01%～29.16%and 23.01%～26.71%.Adding Ann Gro 0.1%（v/v）increased the fresh weight control efficiency of Amaranthus retroflexus L.and Echinochloa crusgalli（L.）Beauv.L.by 25.83%～30.37%and 25.16%～28.38%,and adding Jiexiaoli 0.05%（v/v）increased the fresh weight control efficiency of Amaranthus retroflexus L.and Echinochloa crusgalli（L.）Beauv.by 27.24%～31.10%and 26.44%～30.95%%.（3）The effects of GY-Tmax,Jijian,Ann Gro and Jiexiaoli on the synergistic mechanism of herbicide were determined by laboratory instrument analysis.Automatic interfacial tensimeter was used to determine the critical micellar dose（CMC）of each adjuvant and determine the dosage of four spray adjuvants.Automatic interfacial tensiometer,contact Angle instrument and other instruments were used to investigate the effects of different dosages of GY-Tmax,Jijian,Ann Gro and Jiexiaoli spray adjuvants on the surface tension,contact Angle,expanded diameter and wettability of herbicide liquid.The results showed that the surface tension of the herbicide was reduced by 4.21%～19.48%,2.76%～14.86%,1.99%～12.5%and 25.35%～47.78%,respectively,when reaching the CMC value.Make solution contact Angle by 17.53%～33.32%,14.26%and30.78%,10.58%to 23.45%,41.60%to 60.49%;Make the extension diameter increased by 21.31%-37.66%,17.36%and 30.80%,12.29%to 24.42%,31.92%to 59.53%;The wetting time is shortened by 0.86～2.01min,0.55～1.55min,0.45～1.26min,2.59～3.26min.GY-Tmax,Jijian and Ann Gro could prolong the drying time of liquid medicine by 35.08%～64.24%,30.56～52.74%,21.52%～41.19%,and Jiexiaoli could shorten the drying time by 9.49%～66.38%.GY-Tmax,Jijian,Ann Gro and Jiexiaoli can increase the transpiration time of drug liquid on Echinochloa crusgalli（L.）Beauv.leaves by 25.9%～62.4%,17.9%～55.0%,9.5%～45.0%,respectively.The transpiration time of liquid on Amaranthus retroflexus L.was increased by 11.5%～59.4%,6.6%～49.5%,5.6%～19.9%;The adjuvant could increase the maximum holdup of weed killer in Echinochloa crusgalli（L.）Beauv.and Amaranthus retroflexus L.by 105.3%～132.8%and 81.8%～103.5%.