| In this paper,the best volume fraction of JZ-12 was 0.5%by pot culture in greenhouse One aspect of JZ-12 synergistic mechanism is to change the wetting property of JZ-12 by measuring the surface tension,distribution and analyzing the wettability of the mixed solution of JZ-12 tank-mixed adjuvant and medicine solution.The solubilization of the waxy layer on the leaf surface was detected by scanning electron microscope,and the leaf surface retention and residue were determined by Spectramax 190 and HPLC-MS/MS,the enhancement mechanism of JZ-12 on leaf epidermis of target plant was determined.The mechanism of JZ12 synergism to herbicides was explained preliminarily in this paper,which can provide a theoretical basis for the rational compatibility of tank-mixed adjuvants witn postemergence herbicides.Through the potted seedling experiment in greenhouse,it was determined that the best volume fraction of JZ-12 combined with 25%Quinclorac SC,40%Cyhalofop-butyl OD and 10%Metamifop EC was 0.5%.At this dosage,187.50 g a.i./hm2 Quinclorac plant control effect could reach 96.7%and 89.5%for fresh weight.Same as 60.00 g a.i./hm2,the control effect of plant and fresh weight was equal to the control level of commercial tank-mixed adjuvant,the control effect of fresh weight was 87.2%and 90.2%,respectively.Same as 60.00 g a.i./hm2,the fresh weight control effects of Metamifop were 86.8%and 92.9%,respectively.Therefore,JZ12 mixed with 25%Quinclorac suspension has the best synergistic effect.In addition,tankmixed adjuvant itself does not have any medicine effect,only exists for the pesticide synergism,occasionally exists spraying clear water with tank-mixed adjuvant mixed liquid test group,it was not concluded that the addition of tank-mixed adjuvant could promote the growth of Echinochloa oryzoides.Through the real-time state test of droplet distribution,and compared with the Commercial tank-mixed adjuvant Zhengyuan,the tank-mixed adjuvant JZ-12 can significantly reduce the value of dynamic contact angle,and with the increase of the volume fraction,the distribution effect of droplet on the glass slide is better,under the same time condition,it is more able to carry on the effective bonding with the surface.For the three herbicides,JZ-12 had the best effect on reducing the dynamic contact angle of 40%Cyhalofop-butyl OD.When 0.5%volume fraction was added equally,the dynamic contact angle decreased by 46.5%compared with the single agent solution,the dynamic contact angles of 10%Metamifop EC and 25%Quinclorac SC decreased by 30.3%and 21.13%,respectively.The effect of JZ-12 on the static surface tension of three herbicides was the same,the effect of JZ-12 on reducing the static surface tension was 4%～8%,and the effect of JZ-12 on static surface tension of three herbicides was the same as that of Zhengyuan tank-mixed adjuvant.In addition,with the same volume fraction of 0.5%,JZ-12 can reduce the static surface tension of tap water by 69.76%,and with the same volume fraction of Zhengyuan auxiliaries,which can reduce the static surface tension by 66.45%.The wettability of JZ-12 to the droplets of three herbicides was slightly different under the condition of the same addition of 0.5%volume fraction tank-mixed adjuvant.After adding 0.5%volume fraction JZ-12,the adhesion work of the three herbicides decreased by 17.67%,6.16%and 9.97%respectively,the adhesion tension decreased by 18.30%,8.86%and 21.19%respectively,and the spreading coefficient increased by 53.89%,77.93%and 40.40%respectively.Compared with the same volume fraction of Zhengyuan auxiliaries experiment,the adhesion work of three herbicides decreased by 17.09%,4.42%and 6.09%,the adhesive tension decreased by 18.31%,5.74%and 8.83%,and the spreading coefficient increased by 51.23%,2.10%and 37.42%,respectively.In addition,with the addition of 0.5%of the same volume fraction,JZ-12 can reduce the adhesion work and adhesion tension of tap water by 69.13%and 68.42%respectively,and increase the spreading coefficient by 90.41%;Zhengyuan can reduce the adhesion work and adhesion tension decreased by 65.28%and 63.95%respectively,and the spreading coefficient increased by 84.51%.Then,combined with the above analysis,JZ-12 has a better synergistic effect on the characteristics of liquid drops than commercial tank-mixed adjuvant.The optimum volume fraction of JZ-12 is 0.5%.The synergistic effect of JZ-12 is related to the type of herbicide preparation.Through the experiment of determining the retention of the mixture solution on the leaf epidermis,the retention of the mixture solution with 0.5%volume fraction JZ-12 compared with the single agent treatment,which could be increased by 6.1μg/cm2,6.20 μg/cm2,9.55μg/cm2,respectively.It was concluded that JZ-12 had the best synergistic effect on the retention of 10%Metamifop EC.At the same time,when 0.5%volume fraction Zhengyuan was added,the retention was 4.13 μg/cm2,1.21 μg/cm2 and 2.16 μg/cm2,respectively.It can be seen that the effect of JZ-12 on retention is better than that of the commercial additive,which is the same maximum dosage with 0.5%volume fraction tank-mixed adjuvant,JZ-12 increased drug retention per unit area by 32.30%,80.48%and 77.79%,respectively,compared with Zhengyuan.Compared with the control,JZ-12 had a significant effect on the dissolution of three herbicides in the epicuticular wax layer of the target plant.The Waxy lamellae of the epidermis of each cell are visibly polymerized and condensed into sheets or aggregates.The whole epidermis was observed by scanning electron microscope(SEM).The wax around the stomata and other cells were dissolved and softened.The wax of the epidermis was adhered to the wall,the topology of the chip collapses,and the chemical penetrates into the plant.The addition of JZ-12 significantly increased the contents of 25%Quinclorac SC,40%cyhalofop-butyl OD and 10%Metamifop EC on the surface of target plants.At the same maximum dosage,the concentration of eluate increased by 103.01%,100.00%and 4.50%,respectively,compared with single-agent treatment.It was found that the permeation rate of 0-6h was the fastest,and the absorption rate of 6-48h was gradually slow and tended to be flat.The results showed that the addition of JZ12 could rapidly and largely assist drug penetrate into the plant in a short time.The results showed that JZ-12 had better synergistic effect than the commercial tankmixed adjuvant in many aspects.The optimum volume fractions of JZ-12 with 25%Quinclorac SC,40%cyhalofop-butyl OD and 10%Metamifop EC were all 0.5%.Its efficiency-increasing mechanism is mainly in two aspects:1.For the improvement of droplet characteristics;2.Effect on plant epidermis:Increase leaf surface retention,dissolve waxy layer of plant epidermis,and increase osmotic efficiency. |
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