Study On The Mechanism And Application Effect Of The Adjuvants For Aviation Plant Protection

The adjuvants for aviation plant protection plays an important role in the promotion of UAV(Unmanned Aerial Vehicle).Currently,there are few registered adjuvants for aviation plant protection,and there are more types of traditional spray adjuvants,but not all of them are suitable for the operation of uavs.It is very effectively to increase the adhesion and spreading of the pesticide and reduce droplet drift by using adjuvants for aviation plant protection reasonably in the operation of UAV,and it plays a significant role in improving the pesticide utilization efficiency and quality and efficiency of UAV.However,improper use of adjuvants for aviation plant protection may causes problems such as nozzle blockage and poor operation quality.Therefore,the evaluation and screening are very important for the promotion and application of adjuvants for aviation plant protection.The screening and application of adjuvants for aviation plant protection involve many disciplines such as physical chemistry,biochemistry and biology.The main purpose of the study is to evaluate and screen 14 kinds of adjuvants for aviation plant protection,including Beibeijia,Beidatong,Chengpijingyou,Feishoubao,Huameirunnong,Hongyuyan,Kesheng,Mate 320,Nongboshi,Nongjianfei,Qigong,Quanfeng,Tiannongsen and Zhushaxianfeng.Providing theoretical basis and scientific guidance for the improvement of deposition effect and control effect by adding adjuvants for aviation plant protection.The main research and achievement of the research are as follows:(1)In the experiment of the effect of 14 adjuvants on the physicochemical properties of pesticide dosage forms(WG,SC,ULV),the surface tension,viscosity,wetting area,contact angle and evaporation rate was measured by a surface tensiometer,a rotational viscometer,pesticide droplet wettability test cards,a contact angle meter.The results are as follows:(a)Wetting and spreading ability:It is the most significantly to improve its wetting and spreading ability by adding Quanfeng adjuvants to WG and SC formulation,and at the same time,the surface tension of the original solution are reduced by 43.77%and 40.16%respectively,the wetting areas are increased to 105 and 116.0 and the contact angle approaches to 0?The surface tension of the ULV formulation is low,and the ULV formulation can be almost completely wetted and spread on the leaf surface of rice and corn.(b)Adhesiveness:Compared with the original solution,the viscosity of WG formulation increased 85.11%when adding Chengpijingyou adjuvant,the viscosity of SC formulation increased 16.81%when adding Feishoubao adjuvant,the viscosity of SC formulation increased 16.81%when adding Feishoubao adjuvant,the viscosity of ULV formulation increased 10.55%when adding Huameirunnong adjuvant.(c)Anti-evaporation ability:Compared with the original solution,the anti-evaporation ability of WG formulation increased and the evaporation rate decreased by 19.69%when adding Quanfeng adjuvant,the anti-evaporation ability of SC formulation increased and the evaporation rate decreased by 7.65%when adding Tiannongshen adjuvant,the ULV formulation has excellent anti-evaporation ability because of its formulation is methyl oleate.(2)The particle size and droplet deposition were measured by Laser Particle Size Analyzers and Polyethylene Collecting Line in the wind tunnel laboratory.The results are as follows:(a)Adjuvants and nozzle types both have significant influences on the characteristics of droplets deposition(P=0.000).(b)When using the pressure nozzle,the minimum value of D_v50 is the Qigong adjuvant(100.58?m)and the largest is Mate 320 adjuvant(138.22?m).When using the centrifugal nozzle,the minimum value of D_v50is Quanfeng adjuvant(134.24?m),and the largest value is Beibeijia adjuvant(175.16?m).(c)When using the pressure nozzle,the minimum value of?_Vol<150?m is Mate 320(55.6%).When using the centrifugal nozzle,the minimum value of?_Vol<150?m is a multiplier additive(20.0%).When using the pressure nozzle,the minimum value of?_Vol<150?m is Mate 320(55.6%).(d)When using the pressure nozzle,the minimum value of RSF is Qigong adjuvant 0.64).When using the centrifugal nozzle,the minimum value of RSF is Beibeijia adjuvant(55.6%).(e)Droplets in the horizontal direction are mainly concentrated at 7?11m by using centrifugal nozzle,and droplets are concentrated at 2?6m by using the pressure nozzle.Droplets in the vertical direction are mainly concentrated near the nozzle by using centrifugal nozzle,and droplets are mainly concentrated near the ground by using the pressure nozzle.(f)For the pressure nozzle,the solution with the least drift loss is the one with Mate 320 adjuvant,and the total deposition in the horizontal direction of 2?11m is 92.1%.For the centrifugal nozzle,the solution with the least drift loss is the one with Beibeijia adjuvant,and the total deposition in the horizontal direction of 2?11m is 56.8%.(g)A spray drift model was established for the droplet size and total deposition along the horizontal direction of two nozzles.It can be seen from the model that reducing the number of small droplets and increasing the droplet size can effectively reduce drift loss.(3)Trough the above tests,Beibeijia and Feishoubao adjuvants with better anti-drift ability and ULV formulation with better anti-evaporation ability were selected to spray cotton defoliant with UAV in Xinjiang where has high temperature,dryness and high wind speed climate,so as to achieve better defoliation effect.Quanfeng,Nongjianfei and Qigong adjuvants with good wetting and spreading ability were selected to spray corn insecticide with UAV in Guangdong,so as to achieve better control effect.YR-GSF06 four-rotors UAV and HY-B-15L single rotor UAV were used for spraying cotton defoliant test.The results are as follows:The defoliation rate and coverage rate,the amount of acres(A)and additives(B)and type(C type)three factors influencing the importance of sequence was ABC,the amount of acres had significant effects on leaf removal effect(P=0.045<0.05),other factors had no significant effect on the removal rate of leaf and boll opening rate..When the optimal level of the three factors is A3(15 L/ha),B1(Hongyuyan)and C1(single rotor UAV),the maximum defoliation rate can be obtained.When the spray volume of ULV formulation is7.5 L/ha,the ideal defoliation effect(the defoliation rate was 90.63%.)can be achieved with appropriate operating parameters and adjuvants,and meet the requirement of machine pick up cotton.P20 four-rotors UAV was used for spraying cotton defoliant test.The results are as follows:Adding Hongyuyan,Kesheng,Beibeijia,Feishoubao adjuvants to ULV formulation can increase the deposition density of drops by 24.74%,15.62%,109.05%,31.12%respectively;increase the defoliation rate by 11.63%,11.63%,23.62%,21.70%respectively;increase the boll opening rate by 23.01%,17.42%,38.72%,25.91%respectively.The prediction models of droplet size,deposition density,defoliation rate and boll opening rate were established.The droplet deposition density can be predicted by Dv50.Cotton defoliation rate and boll opening rate can be predicted by droplet deposition density,Therefore,the droplet size can be changed by adding adjuvants to change the efficacy.When the spray valume is 6 L/ha,the defoliation rate and boll opening rate of ULV formulation are63.96%and 67.74%respectively,the defoliation rate and boll opening rate of SC formulation are 54.58%and 44.68%respectively.Compared with the traditional water-based formulation,ULV formulation has a great application space in cotton defoliation due to its good wetting and spreading ability and strong anti-evaporation ability and other characteristics.(4)Through the above tests,Quanfeng,Nongjianfei and Qigong adjuvants with better wetting and spreading ability are selected to spray corn pesticides on UAV in Guangdong area in order to achieve better control effect.P20 was used to spray WG and ULV insecticides for spraying corn insecticide test.The results are as follows:During operation,adding Quanfeng adjuvant to WG formulation and adding Nongjianfei adjuvant to ULV formulation both can improve the deposition effect of droplets.For WG formulation,D_v50,fraction coverage,droplet density and droplet rate were increased by 24.46%?152.39%?53.11%?66.67%?27.47%respectively.For ULV formulation,Dv50,fraction coverage,droplet density and droplet rate were increased by 27.06%?75.86%?21.71%?50.00%?22.77%respectively.At the same dosage,compared with the formulation without adjuvants,the control effect of WG formulation with adjuvant were improved by 45.22%and 27.58%after 3 and 7 days respectively,and the control effect of ULV formulation was improved by 7.32%and 9.09%.When using UAV to spray insecticide to control corn borer,the control effect of most treatments can reach the control effect of high-clearance sprayerr(77.8%)and knapsack sprayer(75.5%),and the control effect of ULV formulation is better than that of WG formulation.MG-1P was used for spraying corn insecticide test.The results are as follows:In the operation,the addition of three adjuvants can improve the droplet deposition results to varying degrees.Adding Quanfeng adjuvant,D_v50,fraction coverage,droplet density and droplet rate were increased by 1.19%,250.00%,18.53%,430.33%respectively;Adding Nongjianfei adjuvant,D_v50,fraction coverage,droplet density and droplet rate were increased by 74.75%,167.65%,300.00%,10.15%respectively;Adding Qigong adjuvant,D_v50,fraction coverage,droplet density and droplet rate were increased by 19.31%,35.67%,66.67%,8.08%respectively.The results of spraying cotton defoliant and corn insecticide on UAV show that the effect and quality of UAV can be improved by adding adjuvant,and the screening of adjuvant for aviation plant protection plays an important role in promoting the development of UAV.