Pesticide Application Technology Research Articles

Numerical Simulation and Experimental Verification of Rotor Airflow Field Based on Finite Volume Method and Lattice Boltzmann Method

The primary focus of research in agricultural unmanned aerial vehicle (UAV) pesticide application technology is the investigation of droplet drift and deposition. The influence of the rotor airflow on droplets is particularly significant, making numerical simulations a crucial tool for airflow field analysis. Among existing numerical simulation methods, the Finite Volume Method (FVM) and the Lattice Boltzmann Method (LBM) are commonly used, but there is limited research that compares the two approaches. Therefore, this paper conducts numerical simulations of the rotor airflow of an agricultural UAV using Fluent, representing the FVM, and XFlow, representing the LBM. This research aims to reveal the distribution patterns of airflow field numerical simulations under different theoretical methods, validate them through practical experiments, and select the optimal method for simulating rotor airflow. The ultimate goal is to establish an effective airflow field model to enhance the precision of pesticide application by an agricultural UAV. The results indicate that the lift error calculated by XFlow in this paper is 2.57% smaller than that by Fluent. The wind field of Fluent entered the “stable state” earlier than XFlow, and the speed value of Fluent was smaller than that of XFlow. The difference between the two speed values became larger and larger as the distance from the rotor was longer. Compared with XFlow, Fluent changes more obviously in the core region, and the center region gradually disappears with the distance from the rotor. However, in the velocity field calculated by XFlow, there are still more turbulent flows outside the core region, indicating that the transient calculation method based on the LBM can better show the details of fluid flow than the steady-state calculation method based on the FVM. Through comparison with the actual test data, it is found that the relative error of the velocity value of XFlow at 0.2 m and 0.4 m is small, while that of Fluent at 0 and 0.2 m is small. It shows that XFlow simulation has higher accuracy for external turbulent flow, while Fluent simulation has higher accuracy for steady laminar flow. The research results provide data comparison and a basis for further analysis of the wind field model of the rotor wing of the plant protection UAV, and they lay a foundation for further research on precision application technology.

Spray performance simulation and experiment analysis of a greenhouse fixed-pipe twin-fluid cold fogger with different nozzle settings.

High-efficient pesticide application equipment for protected cultivation is scarce. In response, a fixed-pipe twin-fluid clod fogger (FTCF) was proposed as a potential solution. To investigate the optimal nozzle layout and spray performance, a computational fluid dynamics (CFD) model was used to study the airflow distribution and spray deposition of a FTCF with different nozzle settings using the Euler-Lagrange approach. Specifically, two piping configurations, middle-cross-inverted (MCI) and bilateral-malposed-opposite (BMO), were combined with three nozzle spacings (2 m, 3 m, 4 m) resulting in six nozzle settings. Additionally, a greenhouse spray trial was conducted to test the performance of FTCF with the selected nozzle settings and to validate the model. The simulation results revealed that MCI piping configuration exhibited a stronger airflow disturbance compared to BMO configuration, indicating a more significant air-guided effect in the MCI configuration. Combining this finding with the ground droplet distribution analysis of MCI piping configuration, it was observed that MCI-2 m had the lowest coefficient of variation (CV) for ground deposition (20.56%). Consequently, MCI-2 m was determined as the most optimal nozzle setting. Verification results demonstrated a high consistency between experimental and simulated spray deposition results. The FTCF system effectively generated a three-dimensional airflow field throughout the greenhouse environment. Furthermore, jet flow produced by FTCF disrupted the overall airflow pattern within the greenhouse space which facilitated droplet suspension and dispersion. This study provides valuable insights and innovative ideas for enhancing pesticide application technologies in protected cultivations. © 2024 Society of Chemical Industry.

DEVELOPMENT OF THE DERMAL EFFECT OF PESTICIDES ON PROFESSIONAL CONTINGENTS USING INNOVATIVE 3RIVE 3D TECHNOLOGY

The skin is the most vulnerable organ when spraying pesticides on fields. Farmers are also exposed to pesticides during mixing, loading of pesticides, and when cleaning equipment and disposing of empty containers. The aim. To study and analyze the features of the risk of pesticides dermal exposure to professional contingents during treatments using the innovative 3RIVE 3D pesticide application technology. Materials and methods. The 3RIVE 3D innovative technological system of introducing was used to applicate Brigade 3Rive 3D, SC formulation. Field experiments on the study of working conditions when using the pesticide were conducted in various soil and climatic regions of Eastern Europe. Statistical processing of the results was carried out using a package of licensed statistical programs IBM SPSS StatisticsBase v.22 and MS Excel. Research results and discussion. During the conducted research, no bifenthrin contamination was found on the open skin of the operator and the tractor driver, who were processing corn crops with the Brigade 3Rive 3D, SC formulation. However, the operator's gloves were found to contain 0.025 mg of bifenthrin. Calculation of the unitless CASd value on the possibility of skin acute effects when applying the formulation showed that bifenthrin and the Brigade 3Rive 3D, SC formulation based on it are characterized by sufficient selectivity of action on the target object (CASd – 645 and 162, respectively, i.e. > 100) and a low level of danger acute dermal toxic effects for workers, which is due to low values of effective consumption rates. The real dermal risk of bifenthrin exposure when using the Brigade 3Rive3D, SC formulation was significantly lower compared to the risk of workers involved in “traditional” air treatment and treatment with unmanned aerial vehicles (UAVs) (p=0.009-0.048 according to Wilcoxon's W-criterion); in comparison with rod and fan processing – it is non-significantly lower (р=0.262-1.000). There was a similar picture in comparison with the dermal aggravated risk – significantly lower in comparison with the risk of workers involved in “traditional” air treatment and processing with the help of UAVs (p=0.009 according to Wilcoxon's W-criterion); in comparison with rod and fan treatment – non-significantly lower (р=0.262-1.000). Conclusion. It was established that the studied active substance bifenthrin and the Brigade 3Rive 3D, SC formulation based on it are characterized by sufficient selectivity of dermal action on the target object and a low probability of acute dermal effects. A higher probability of acute inhalation poisoning than dermal exposure was revealed.

Mechanical Analysis of Rice Canopy Using Explicit Dynamics and Practical Applications of Canopy Opener

Open-canopy pesticide application technology is not affected by the canopy structure and can substantially increase droplet penetration and deposition in the middle and lower rice canopy. However, the optimal working position of the canopy opener is difficult to determine. The purpose of this study was to examine the characteristics of rice canopy disturbances under the action of a canopy opener, verify simulation results using high-speed photography tests, and identify the spraying effect of the optimal operating parameters of a canopy opener through spray tests. The mechanical characteristic parameters of the rice heading stage were determined through experiments, and the canopy-opening process was simulated based on the finite element method of explicit dynamics. The simulation results show that when the speed of the canopy opener is 1.2 m s−1 and the height is 0.6 m, the rice canopy is the most disturbed. The spray experiment results show that under this condition, the overall coverage rate of the rice canopy is relatively high, and the coverage rates of the upper, middle, and lower layers of rice are 92.18%, 66.43%, and 52.84%, respectively.

A Review: Development of Plant Protection Methods and Advances in Pesticide Application Technology in Agro-Forestry Production

In this review, through reviewing the history of the struggle between human beings and plant diseases, insects and weeds, more specifically thoughts on plant protection in ancient Chinese agricultural books, the recognition of plant pests as a target and six types of plant protection methods and 36 subdivision measures are summarized. Then, we focus on the development overview of pesticide application technology and conduct a systematic review by combining the development timeline of pesticide application and key technologies including performance measurement and the simulation and modeling of pesticide-spraying systems. Finally, three suggestions for further research are proposed from the perspectives of human beings’ and environmental health, sustainable and eco-friendly application media and efficient application equipment systems in plant protection.

Multivariate Analysis Applied to the Ground Application of Pesticides in the Corn Crop

Including the correct combination of factors for the application technology of pesticides can improve their distribution on their targets. The aim of this work was to use multivariate analysis to study the effect size and the order of influence of three factors that interfere with pesticide application technology in corn crops. A 2 × 2 × 3 factorial experiment was conducted with two droplet size classes (fine and coarse), two application rates (80 and 150 L ha−1), and the presence of adjuvants (mineral oil one and two, and no adjuvant). A knapsack boom sprayer was used for the applications. Droplet deposition on the corn leaves was evaluated by detecting a tracer added to the spray via spectrophotometry and the droplet spectrum by analyzing water-sensitive papers. Univariate and multivariate statistical analyses were performed to integrate the variables analyzed. Droplet size has proven to be the most important factor in spraying planning, and the second factor is the application rate. With the association between fine droplets and higher application rates, a better performance was obtained in coverage, droplet density, and droplet deposition.

Research and experiment of electrostatic spraying system for agricultural plant protection unmanned vehicle

IntroductionThe traditional spraying system is not suitable for agricultural plant protection in small plots due to its disadvantages of weak droplet refining ability, small spraying area, large pesticide consumption, and high manual spraying cost. At present, spraying pesticide is the main way to resist crop diseases and insect pests. The utilization rate of pesticide is only 38.8% in China, which leads to serious waste and serious environmental pollution. It is necessary to develop advanced plant protection equipment and pesticide application technology to solve the problem. The combination of agricultural plant protection vehicle and electrostatic spray technology may solve the problems of spraying efficiency, droplet adsorption rate and evenness. It is of great significance to improve the efficiency of plant protection and pesticide utilization.MethodsIn this paper, the principle of droplet charging is described, an electrostatic spraying system is designed and tested, and the effects of charging voltage and pump pressure on the droplet charge ratio and droplet size are analyzed.Results and discussionThis study has shown that electrostatic spraying systems are suitable for agricultural plant protection unmanned vehicles.

Leaf Sample Size for Pesticide Application Technology Trials in Coffee Crops

Plot size, sample sufficiency, and number of repetitions are factors that affect the experimental errors or residuals and the expression of true differences among treatments. The objective of this study was to determine, using statistical models, the appropriate sample size for application technology experiments in coffee crops through the evaluation of foliar spray deposition and soil runoff in the ground-based application of pesticides. In the first stage, we determined the quantity of leaves per set and the volume of the solution for washing the leaves and extracting the tracer. We analyzed the variability between the coefficients of variation (CVs) of the amount of tracer extracted in two droplet classes (fine and coarse), for the different parts of the plants, and for the different quantities of leaves per set that were organized into intervals of five leaves (1-5, 6-10, 11-15, and 16-20). Less variability was found in the intervals with 10 leaves per set and using 100 mL of extraction solution. In the second stage, a field experiment was conducted using an entirely randomized design with 20 plots: 10 sprayed with fine droplets and 10 with coarse droplets. In each plot, 10 sets (samples) with 10 leaves each were collected from the upper and lower canopy of the coffee trees. Moreover, 10 Petri dishes were placed per plot and collected after application. Based on the results of the spray deposition (mass of tracer extracted per cm2 of leaf), we determined the optimal sample size using the maximum curvature and maximum curvature of the coefficient of variation methods. Higher variabilities were related to the targets that are more difficult to reach. Thus, this study determined an optimal sample size between five and eight sets of leaves for spray deposition, and four to five Petri dishes for soil runoff.

Sphenophorus levis Behavior Studies: Evaluating Insect Attractiveness or Repellency to One Insecticide Treatment and Assessing Nocturnal Insect Activity and Location Pattern

Sphenophorus levis Vaurie, 1978 (Coleoptera: Curculionidae). is a difficult to control pest in sugarcane that causes great damage to the subterranean part of the plant. Low insect control is the result of the pesticide application technology adopted but also a consequence of the lack of studies regarding the pest's behavior. This research aimed to examine the attractiveness and repellency of one labelled insecticide dose to S. levis adults and to evaluate the activity and location behavior of S. levis adults under hourly observations over 24 h. Repellency and attractiveness studies were conducted in free-choice tests with treated soil with an insecticide product composed of lambda-cyhalothrin + thiamethoxam active ingredients and untreated soil. Insect activity and location behavior studies were assessed by conducting hourly observations of S. levis adults in containers with soil and sugarcane plant. The results indicate that S. levis adults are not repelled nor attracted to soil treated with the labelled dose of lambda-cyhalothrin + thiamethoxam in sugarcane. Additionally, insects presented nocturnal behavior for most activities (walking, digging and mating) starting at 6:00 p.m. until 2:00 a.m. An average of 21% of insects were out of the soil at night while the majority, 79%, remained inside the soil. During the day, most insects, 95%, remained hidden in the soil. Exposed insects were primarily located on the soil surface. According to these results, nocturnal insecticide applications may improve S. levis adult control due to greater insect activity and exposure at night.

Comparison between Drift Test Bench and Other Techniques in Spray Drift Evaluation of an Eight-Rotor Unmanned Aerial Spraying System: The Influence of Meteorological Parameters and Nozzle Types

In the past decade, an unmanned aerial spraying system (UASS) was applied more and more widely for low-volume aerial pesticides spraying operations in China. However, UASS have a higher drift risk due to more fine droplets sprayed with a higher working height and a faster driving speed than ground sprayers. Study on UASS spray drift is a new hot spot within the field of pesticide application technology. The field test bench was originally designed and applied for the measurement of the spray drift potential of ground sprayers. No methodology using the test bench for UASS drift evaluation was reported. Based on our previous study, field drift measurements of an eight-rotor UASS were conducted using three techniques (test bench, ground petri dish, and airborne collection frame) in this study, and the effects of meteorological parameters and nozzle types were investigated, to explore the applicability and the feasibility of the test bench used in UASS field drift evaluation. The test bench is proven promising for direct drift determination of UASS and the described methodology enabled classification of different UASS configurations. Higher wind speeds and finer droplets produced higher drift values. The faster the wind speed and the lower the humidity, the more the spray drift. The test bench can reduce the site requirements and improve the efficiency of the field drift test.

CFD Simulation of Circulating-Airflow Distribution Inside Canopy From Novel Air-Assisted Sprayer in Orchard

HIGHLIGHTS A CFD model was developed to simulate airflow movements from circulating air-assisted sprayer. The CFD model can simulate airflow distribution inside the pear canopy with good accuracy. Simulation identifies the preferred parameters for circulating air-assisted spraying. An excessive adjustment of the airflow angle resulted in the formation of an eddy. ABSTRACT. Circulating air-assisted (CAA) spraying involves a negative pressure suction (NPS) created by a fan placed over the top of a canopy to change the airflow direction twice, i.e., first from the outside of the canopy to its inside and then from the bottom up, which can increase the airflow velocity inside the canopy. However, this new pesticide application technology has not been adequately investigated. In particular, the effects of the inlet and outlet airflow parameters of CAA spraying technology on the airflow distribution inside a canopy are yet to be determined. In this study, a computational fluid dynamics (CFD) model is developed and validated to simulate the interactions between the airflow ejected by a CAA sprayer and the canopy of a fruit tree. In the computational domain, the fruit tree is considered a porous medium. The model is validated based on three fruit trees of different sizes, leaf-area densities (LAD). The root mean square error and the mean relative square error are 1.44, 1.43, 2.22 m/s, and 24.9%, 24.7%, and 36.4%, respectively. This suggests that the CFD model can predict the interactions between the airflow field generated by a CAA sprayer and the canopy of a fruit tree. The validated CFD model is employed to analyze the airflow distribution patterns inside a canopy under different combinations of inlet and outlet airflow parameters. A reasonable combination of inlet and airflow parameters is obtained for CAA spraying technology. For example, the suitable outlet airflow velocity, top NPS, and bottom outlet angle for seven-year-old crown pear trees (average height: 2.0 m; average canopy diameter: 1.2 m; average trunk height: 0.62 m; average LAD: 2.96) selected in this study from a farm in southern China are 15 m/s, 200 Pa, and 10°, respectively. The results of this study can facilitate the parametric adjustment of CAA sprayers and enhance plant protection in orchards. Keywords: Circulating air-assisted spraying, Fruit-tree canopy, Inlet and outlet airflow parameters, Simulation.

Fungicide smoke generated by electrical heating effectively controls gray mold of Chinese chives and reduces residue risk through adequate environmental sterilization.

Labor-saving pesticide application technology is eagerly pursued in the planting system of Chinese chives. In this study, we developed a set of application approaches by turning fungicides into smoke to achieve this goal. The fungicides fludioxonil, fluopyram, boscalid, procymidone, and prochloraz could be vaporized into smoke at temperatures below 300 °C. The SFR (smoke formation rate) decreased with the increasing temperature. At 300 °C, the SFR of fludioxonil, fluopyram, boscalid and procymidone were all higher than 80%. At 300 °C and 600 °C, there were no significant differences in the smoke particle state of these five fungicides. However, the inhibition rate of these five fungicides against the growth of Botrytis squamosa generally decreased with the temperature. At 600 °C, only fludioxonil and boscalid had inhibition rates higher than 80%. The deposition uniformity of fungicide smoke increased with the increasing amounts of NH4 Cl. When the amount of NH4 Cl reached 80% of the total content, the smoke of fungicide was uniformly deposited throughout each glass slide. In the greenhouse experiment, the control efficacy of fungicide application by smoke was significantly better than that of spraying application, whereas its residue was much lower. It is feasible to control air-borne disease through the vaporization of fungicides into smoke by electrical heating. Smoke application would effectively inhibit the spores in the air and would not increase the humidity of the environment. These findings indicate that smoke application is a labor-saving pesticide application technology viable in production. © 2022 Society of Chemical Industry.

Survey of pesticide application practices and technologies in Georgia agronomic crops

AbstractPesticide regulations and application technologies are changing rapidly due to rising concerns around off-target movement of pesticides and increased focus on improving the efficiency of pesticide applications. In order to conduct relevant applied research and develop educational programs related to pesticide application, it is necessary to understand the common application practices and technologies that growers use. A survey was conducted to assess common pesticide application practices and technologies used by Georgia growers. Both online and printed survey copies were distributed by county agricultural extension agents to growers in all 159 counties. A total of 186 responses representing agronomic crops in 65 counties were received and analyzed for results. Main results of this survey indicated that 1) 72% of respondents produced ≥200 ha of crops; 2) 29% of respondents received their information from university Extension personnel; 3) 42% of respondents used a separate sprayer for applications of dicamba, 2,4-D, or 2,4-DB; 4) 46% of respondents used sprayers with boom lengths ≥18.3 m; 5) 65% of respondents used ≥121 L/ha to apply pesticides; 6) 53% of respondents used three or more different nozzles on their spray booms throughout the season; 7) 68% of respondents used TeeJet® nozzles; 8) 65% of respondents used global positioning systems and rate controllers on their application equipment; 9) 66% of respondents recorded their pesticide application data on a notepad or diary; and 10) 39% of respondents reported that application accuracy is the biggest advantage of new spray technologies. Respondents also reported that weather, timing, and pesticide drift/regulations were their biggest application challenges and that more research is needed on topics such as rates, carrier volumes, pest control, chemicals and adjuvants. Information from this survey provides useful insights into the current application practices, technologies, and research needs of Georgia growers and will be used for developing appropriate research and educational efforts.

Research on the Influence of Education of Farmers' Cooperatives on the Adoption of Green Prevention and Control Technologies by Members: Evidence from Rural China.

The study explores the impact of education of farmers’ cooperatives on members’ green production behavior. The Probit, Oprobit model and the mediation effect model are used to analyze the influence mechanism of the cooperative’s education on the members’ adoption of four types of green prevention and control technologies and the overall adoption rate, and the instrumental variable method is used for endogeneity treatment and robustness test. The results show that: (1) The education of cooperatives have a significant positive impact on the members’ physical pest control technology, biological pesticide application technology, water and fertilizer integration technology, scientific pesticides reduction technology, and the overall adoption rate plays a critical role. As a result, there is a certain degree of heterogeneity in different intergenerational member groups. (2) The education of cooperatives can significantly enhance members’ cognition of green prevention and control. (3) Through on-the-spot demonstration and general meetings of the members to carry out education, members are more likely to adopt green prevention and control technologies. These findings shed light on the mechanisms by which cooperative’s education affect the green production behavior of cooperative members and provide important policy implications for green agricultural development.

MOBILE APPLICATION FOR ADJUSTING AIR-BLAST SPRAYERS IN COFFEE PLANTATION

Mobile application development advances, particularly for smartphones and tablets, have allowed farmers to make decisions more assertively in their agrobusiness management. This article addresses the development and evaluation of an app aimed at people who deal with the pesticide application technology in coffee farming, more specifically, adjustment and calibration of sprayers. This mobile app provides the main data necessary for a correct calibration of air-blast sprayers to apply pesticides in coffee planting. Its functionalities include calculation of the application rate for each situation (L ha-1) based on data obtained in the field, such as canopy volume. The app, called SprayCafé, was developed for the Android platform using the Java programming language in the integrated development environment Android Studio. After the development, the application was evaluated, based on a questionnaire answered by 139 users, who ranked the following requirements: ease of use, loading time, adequacy of screen resolution, data relevance, sequence of information, and applicability, among others. The system proved to be simple and robust; it was thus assessed as adequate to the field and to be of great value for coffee planting, especially because it allows safer and more adequate pesticide application. The graphical user interface is interactive and easy to use.

Influence of surfactant‐humectant adjuvants on physical properties, droplet size, and efficacy of glufosinate formulations

AbstractGlufosinate efficacy is inconsistent among weed species and under environmental conditions that favor rapid droplet drying. Surfactant‐humectant adjuvants could maximize glufosinate efficacy by increasing wetting and penetration into the leaf surface while decreasing evaporation rate (ER). However, there is a lack of information in the literature about the interaction of surfactant‐humectants adjuvants with glufosinate. The objective of this study was to investigate the influence of surfactant‐humectant adjuvants on the physical properties, droplet size, and efficacy of two glufosinate formulations. Laboratory, greenhouse, and field studies were conducted at the Pesticide Application Technology Laboratory of the University of Nebraska‐Lincoln. Treatment design was a 2 × 5 factorial with two glufosinate formulations combined with five adjuvant treatments plus an untreated control. Density and viscosity of glufosinate solutions mostly increased with the addition of adjuvants. However, the influence of the adjuvants on dynamic surface tension (dST), static contact angle (sCA), and evaporation rate (ER) varied by glufosinate formulation, adjuvant, and relative humidity (RH). Under greenhouse conditions, an improvement in efficacy by adding adjuvants was mainly observed for Interline solutions. The addition of adjuvants to Interline solutions increased biomass reduction up to 19 and 35% for common lambsquarters (Chenopodium album L.) and kochia [Bassia scoparia (L.) A. J. Scott], respectively. Also, some of the adjuvants presented null or antagonistic influence on herbicide efficacy. No increase in control, biomass reduction, and mortality of horseweed (Erigeron canadensis L.) and Palmer amaranth (Amaranthus palmeri S. Watson) was observed with the use of adjuvants under field conditions. Herbicide‐adjuvant‐plant‐environment interaction is complex. Thus, the use of surfactant‐humectant adjuvants may not increase herbicide efficacy.

Design and Development of an Indoor Testing Facility for Downwash and Spray Distribution Evaluations of Agricultural UAV

The usage of UAV as a pesticide application technology is becoming a common practice in South East Asia with a very significant proportion of agricultural areas have now being treated using such method. Up to date, about more than 169 of various designs and configurations of UAV have been produced to cater the demand, however it is in doubt whether all these available models were optimally integrated with the spray systems to give the required spraying qualities. Despite of each UAV configuration has their own unique aerodynamic effects, it is crucial to determine their downwash airflow patterns, the spray distributions and the effective application parameters that could give high spraying quality. This research outlines the development of an indoor testing facility and its standardised testing procedure for evaluating the spraying performances of any model UAVs that are used in agricultural applications. The testing facility was developed to imitate the UAV in the actual field spraying operation. With 23 m travel length, the developed testing facility was designed to carry the test UAV up to 100 kg, adjust the test UAV at three levels of spraying heights (1.5, 2.5, and 3.5 m), and moves the test UAV up to a maximum travelling speed of 10 m/s. The 6x6 m sampling platform structure for the pressure sensors and water sensitive papers was built underneath the rail support structure to measure and collect data for spraying distributions and downwash 3D profile spectrum. With the availability of this indoor UAV Testing Facility, it is expected that any efforts to increase the spraying efficiency using UAV could be tested repeatedly with same standard protocols, so that proper recommendations could be made on the flying requirements of the UAV in order to achieve an efficient agricultural chemical spraying operation.

Canopy spray application technology in specialty crops: a slowly evolving landscape.

Many specialty crops are susceptible to insects and diseases, and as such are reliant on regular canopy pesticide applications to achieve quality attributes required for salability. The majority of specialty crop producers continue to use antiquated pesticide application technologies for directed canopy spraying such as the radial air blast sprayer that has been associated with chemical wastage and off-target drift of around 40% and 15% of total applied spray volume, respectively. However, precision sprayers are available that result in remarkable improvements to these parameters. The wide-scale adoption of precision sprayers by specialty crop producers remains low. Reasons for the continued dominance of old technologies include risk averseness of farmers and regulatory bottlenecks. However, as farm labor becomes more expensive, less available, and consumers and regulations favor sustainably produced products, motivations to improve spray application efficiency are increasing. While there are many opportunities and future directions application technology may take, sensor-controlled sprayer technology that applies a proportionate amount of spray will likely be the primary technology of precision sprayers going into the future. © 2020 Society of Chemical Industry.

Spray drift characteristics test of unmanned aerial vehicle spray unit under wind tunnel conditions

Since the 2010s, unmanned aerial vehicle (UAV) sprayer was applied more and more widely for low-volume aerial pesticides spraying operations in China. However, droplets from the UAV sprayer have a higher drift risk due to more fine droplets sprayed and a higher flight height than ground sprayers. Study on UAV spray drift has been a new hot spot within the field of pesticide application technology. Most of previous studies used direct field methods for spray drift, but the meteorological conditions in field were unstable and uncontrollable, and drift research under an actual operation state in wind tunnel has not been reported. Therefore, 25 treatments of wind tunnel measurements and droplets spectrum tests of 10 models of nozzles were conducted to explore the influence factor on spray drift characteristics of UAV chemicals application in this study. A spray unit with a rotor of UAV was innovatively installed in wind tunnel, and the airstream from the wind tunnel was regarded as the relative moving natural wind to simulate the flight status. The airborne and the sediment spray drift was measured to study the effects of the nozzle type and size (flat fan, hollow cone and air-inclusion nozzles), flight speed, adjuvant (DRS-60, Y-20079, MF and G-611) and meteorological parameters (20°C & 40%, 20°C & 80%, 30°C & 40% and 30°C & 60%). The drift potential (DP) and the drift potential reduction percentage (DPRP) in vertical and horizontal directions were obtained for each test. Both nozzle type and size had an impact on the spray drift potential obviously by affecting the droplet size and the ratio of fine droplets, and the regression linear models between DPRPV/DPRPH and DV50, V75 were established (R2=0.934/0.925). Flight speed also had a significant effect on the spray drift characteristics, and reducing the flight speed could increase the DP effectively. Adding spray adjuvants could affect the DP under experimental meteorological parameters, and the anti-drift performance ranked in the order of DRS-60>MF>Y-20079>G-611. Recommendations were proposed in order to reduce the spray drift for UAV sprayer’s operation. These findings can contribute to provide guidelines and technical support for the wind tunnel spray drift tests of UAV and the field operation regulation of unmanned aerial PPP application. Keywords: unmanned aerial vehicle (UAV) sprayer, wind tunnel, spray drift potential, nozzle, adjuvant DOI: 10.25165/j.ijabe.20201303.5716 Citation: Wang C L, Zeng A J, He X K, Song J L, Herbst A, et al. Spray drift characteristics test of unmanned aerial vehicle spray unit under wind tunnel conditions. Int J Agric & Biol Eng, 2020; 13(3): 13–21.

Basis and Recent Trend in Pesticide Formulation and Application Technology

Basis and Recent Trend in Pesticide Formulation and Application Technology