Study On The Synergistic Mechanism And Application Of Spray Adjuvants To Three Kinds Of Pesticides

Improve the effective utilization rate of pesticides and reduce the use of pesticides is a hot spot in the field of agrochemical research.Therefore,this article compares the reduction and synergistic effects of six kinds of spray adjuvants on three kinds of commonly used pesticides,and screens out three kinds of spray adjuvants with the strongest synergistic effects,and discusses their synergistic mechanism for the three kinds of commonly used pesticides.The toxicity bioassay and field efficacy trials of these three kinds of pesticides added with three kinds of spray adjuvants were tested for Bemisia tabaci.Using Ponceau-G as a tracer,the room simulated the rain erosion resistance of imidacloprid and added with three spray adjuvants.Combining indoor simulation tests and using response surface method to analyze the ability of the three spray additives to resist rain erosion of the imidacloprid,and finally optimize the best rain erosion resistance conditions in order to reveal the spray adjuvants to improve the utilization of pesticides and the synergistic mechanism,so as to provide a certain theoretical basis for the comprehensive prevention and control of Bemisia tabaci.The major tests in this paper are listed as follows:1.Effect of spray adjuvant on surface tension and contact angle of three kinds of pesticides.Six kinds of spary adjuvants(Qiangliyuan,Roushuitong,Organosilicone,Apudun,Huainongte,Beichuang),and three kinds of pesticides(70%imidacloprid WG,5%abamectin EC,1.3%matrine AS)were mixed respectively.The changes of the surface tension and contact angle of these mixtures were measured.The relationship between the surface tension and the cosine value of the contact angle of these mixtures was analyzed.It was shown that addition of six kinds of spray adjuvants could reduce the surface tension and contact angle under different concentrations.Among them,Organosilicon,Qianliyuan,and Huainongte have the best effect in reducing the surface tension and contact angle of the three kinds of pesticides.The regression results showed that there was a significant(P<0.05)negative correlation between the surface tension and the cosine value of the contact angle.2.The influence of spray adjuvants on the drying time,expansion diameter and maximum retention of three kinds of pesticides.The effects of three spray adjuvants on the drying time,expansion diameter and maximum retention on tomato leaves of the three pesticides were analyzed.The results show that the three spray adjuvants(Qiangliyuan,Organosilicone,Huainongte)could increase the expansion diameter of the pesticides,shorten the drying time,and increase the retention of the pesticides.With the increase in the concentration of spray adjuvants,the expansion diameter and the retention of the pesticides on the tomato leaves continue to increase,and the drying time of the pesticides continues to shorten.3.Response surface method to optimize the rain erosion resistance of three spray adjuvants.The Box-Behnken design method in the response surface method was used to optimize the factors affecting the rain erosion resistance of the pesticides.The effect of the pesticides against rain erosion of horizontal inclination angle of the glass slide,the vertical distance between the outlet of the acid burette and the sample to be washed on the leaf and the water drop rate were further explored.The best conditions for the imidacloprid with Qiangliyuan to resist rain erosion are:the horizontal inclination of the slide glass is 26.90°,the vertical distance between the outlet of the acid burette and the sample to be washed on the leaf is 2.89 cm,and the water drop rate is 1.27 d/s,the predicted value of Ponceau-G is 0.001 mg;The best conditions for the imidacloprid with Organosilicone to resist rain erosion are:the horizontal inclination of the slide is 71.09°,the vertical distance between the outlet of the acid burette and the sample to be washed on the leaf is 1.34 cm,and the water drop rate is 1.87 d/s,the predicted value of Ponceau-G is 0.002 mg;The best conditions for the imidacloprid with Huainongte resist rain erosion are:the horizontal inclination angle of the slide is 69.45°,the vertical distance between the outlet of the acid burette and the sample to be washed on the leaf is 3.80 cm,and the water drop rate is 1.50 d/s,the predicted value of Ponceau-G is 0.002 mg.After five more parallel experiments were verified,the washouts of Ponceau-G were 0.0032,0.0014,0.0023,and 0.0019 mg,which were roughly in line with the predicted values,indicating that the model has good prediction accuracy.4、Reduction and synergistic effect of spray adjuvants mixed with three kinds of pesticides against Bemisia tabaci.The toxicity bioassay and field efficacy trials were carried out.The results showed that the synergistic effect of the three spray adjuvants on the three pesticides were from high to low were as follows:Qiangliyuan>Organosilicone>Huainongte.Field effi cacy trials showed that the three kinds of pesticides reduced by 20%and 30%added with three kinds of spray adjuvants were significantly higher than the control effect of three kinds of pesticides.The control effect of the three kinds of pesticides reduced by 40%added Qiangliyuan and Organosilicone were significantly higher than that of each pesticide against Bemisia tabaci,and the addition of Huainongte was slightly higher or the same as that of each pesticide.The control effects of each treatment on Bemisia tabaci were the highest after three days application,and the control effects were as high as 97.11%,90.83% and 88.17%.