A Special Synergist For Ultra-low Capacity Spray Application And Its Preparation Method And Application

Traditional spray equipment,such as hand-held sprayer,has the disadvantages of time-consuming,laborious and inefficient pollution,which leads to serious food safety,especially agricultural products and environmental pollution.With the development of high-efficiency spray equipment,a new type ultra-low-capacity spray equipment represented by unmanned aerial vehicles has emerged.Such spray equipment can improve the effective utilization rate of pesticides and reduce the use of pesticides through accurate spraying,so as to achieve the best prevention and control effect and reduce the pollution of the environment.In this paper,a special synergist for ultra-low capacity spray application was developed,and its distribution and control effects were studied.The main results are as follows:1 Studies on surface tension,HLB value,critical micelle concentration,droplet size and distribution of surfactants,and preliminary screeningThe surface tension,droplet size and distribution of different surfactants were measured,and the critical micelle concentration of each surfactant was estimated.The surface tension of 1000 times of different surfactants and its HLB value were moderately correlated at the level of P=0.05,and there was no significant correlation between the critical micelle concentration and droplet size;there is a significant correlation between the size and distribution of droplets.There was a linear negative correlation between VAD(volume-weighted average particle size)and R.S(sample dispersion coefficient),R.S(sample dispersion coefficient)and 60-90um fog droplet proportion.There was a linear positive correlation between VAD(volume-weighted average particle size)and the droplet ratio of 60-90um.16 kinds of surfactants were preliminarily screened out:JFC,K T,MOA-7,LAE-9,OP-9,OP-10,A-110,EL-40,O-20,T-20,600#,TX-5,TX-7,TX-9,TX-10,and TX-13.2 Study on wettability and filtration of surfactantThe wetting infiltration time was measured with standard round canvas sheet.The test results showed that the wetting infiltration performance was related to the type of surfactant and the concentration of aqueous solution;the wetting infiltration time of surfactant is obviously shortened with the increase of the concentration of aqueous solution,and finally tends to be stable.Four kinds of surfactants with good wettability were screened out:JFC,JFC-2,JFC-E and KT,which were selected as the screening objects of the next water evaporation inhibitors.3 Screening water evaporation inhibitorsWeighing in 40?water bath pot 24 h inhibition rate of evaporation to determine water evaporation,the combination of surfactant JFC and A-110 and isoctanol were selected as components of water evaporation inhibitors by considering various factors.The water evaporation inhibition rate of three substances with different concentration ratio was determined by orthogonal design,and then the effect between themes was verified and the orthogonal test effect curve was drawn.The experimental results show that the effects of the three on water evaporation inhibitors were isooctyl>A-110>JFC.The components of water evaporation inhibitors were 1.2%isoctanol,0.6%JFC,0.8%A-110.When 0.02%xanthan gum,0.02%magnesium silicate aluminum,0.02%film forming agent and 0.1%coagulant nuclear substance are added into the water evaporation inhibitors,the common dosage of pesticide additives,the water evaporation inhibition rate is not changed much.4 Sample processing and parameter determinationThe specific formulation of synergist was determined:24%isoctanol,12%JFC,16%A-110,0.4%film forming agent,0.4%xanthan gum,2%nucleated substance,0.5%magnesium silicate aluminum,22.35%methyl oleate,22.35%paraffin oil.After grinding,the quality of samples was tested according to the quality control index of pesticide oil suspension.After adding synergist to suspension and emulsions of benzole procyclazole,water dispersible granule and microemulsion of micropyrimidacloprid,the surface tension of the liquid was significantly decreased,the wetting infiltration time was significantly shortened,the wetting infiltration performance of the liquid was significantly improved,and the moisture evaporation inhibition rate was significantly increased.After adding synergist to suspension and emulsions of benzole procyclazole,the droplet size and distribution can be improved.5 Field spray distribution and control effect of synergist5.1 Distribution and control effect of synergist on fog drops in riceThe experimental results of droplet distribution show that adding synergistic agent to improve the uav paddy fields in commodity medicine spray droplets distribution effect is best,the number of droplets per unit area is the largest,for 52/cm~2,Particle diameter is 51microns,center distance is minimum,fog drops are most densely distributed the number of droplets detected per leaf area was 2.6 times higher than that of the commercial drug control.Experimental results of prevention and control effect show that Under the condition of constant pesticide,the average protective effect was the highest after adding synergist,which was 71.81%.Different additives have obvious effects on the thermal fogger and uav,but not on the antifogging effect of the mist sprayer and the electric sprayer;The effect of synergistic agent on reduction of rice curvaceous disease was not obvious,the average defense effect was 67.21%with 10%reduction,50.37%with 20%reduction,and 48.45%with 30%reduction.5.2 Distribution and control effect of synergist on fog drops on maizeThe experimental results of droplet distribution show that after the addition of synergist and adjuvant E(fog and fog stabilizer)to commercial drugs,the number of fog drops at treatment points 10m and 15m away decreased successively in the upper,middle and lower parts of maize leaves,droplet diameter increases successively,center distance increases successively,droplet distribution becomes sparse.As the application distance increases,the number of droplets decreases,the diameter of droplets decreases,the central distance increases,and the distribution of droplets becomes sparse.When applying on corn with hot mist machine,the addition of synergist was better than that of assistant E.Experimental results of prevention and control effect show that when electric sprayer and hot fogger are used to prevent and control maize speckle disease,under the condition of constant pesticide,the anti-effect without auxiliary agent is 84.67%,and the anti-effect of electric sprayer after adding synergist is 87.35%.The prevention and control effect of the heat fog machine is 89.17%,and the prevention and control effect is obviously improved.The protective effect was best when the synergist was added to the treatment with constant and reduced dosage.The synergistic agent has no obvious effect on the amount of corn speckle disease after reducing 10%and reducing 20%.