scholarly journals Spray drift and droplet spectrum from dicamba sprayed alone or mixed with adjuvants using air-induction nozzles

2018 ◽  
Vol 53 (6) ◽  
pp. 693-702 ◽  
Author(s):  
Guilherme Sousa Alves ◽  
Greg Robert Kruger ◽  
João Paulo Arantes Rodrigues da Cunha
Keyword(s):  
Wind Speed ◽  
Wind Tunnel ◽  
Ammonium Sulfate ◽  
Droplet Size ◽  
Vegetable Oil ◽  
Wind Direction ◽  
Laser Diffraction ◽  
Spray Drift ◽  
Fluorescent Tracer ◽  
Nozzle Type

Abstract: The objective of this work was to evaluate the spray drift and droplet spectrum of dicamba applied alone or with potential drift-reducing adjuvants, using air-induction flat fan nozzles. Standard (XR and TT) and air-induction (AIXR and TTI) nozzles were evaluated in a wind tunnel. The adjuvants used were polymer, ammonium sulfate, vegetable oil, and phosphatidylcholine. The applications were conducted at 276 kPa pressure and 3.5 m s-1 wind speed. The droplet spectrum was measured using a laser diffraction system. Round strings were used as drift collectors, positioned perpendicularly to the wind direction, at 2, 3, 4, 5, 6, 7, and 12 m from the nozzle. Drift was calculated by quantifying, through fluorimetry, a fluorescent tracer added to each solution at 1 g L-1. Droplet spectrum and dicamba drift depend on the interaction between spray composition and nozzle type. Air-induction nozzles are more recommended for dicamba applications, especially the TTI nozzle. Polymer and ammonium sulfate increase droplet size in all nozzle types, which may reduce drift to nearby crops.

Spray Drift from Dicamba and Glyphosate Applications in a Wind Tunnel

2017 ◽  
Vol 31 (3) ◽  
pp. 387-395 ◽  
Author(s):  
Guilherme Sousa Alves ◽  
Greg R. Kruger ◽  
João Paulo A. R. da Cunha ◽  
Bruno C. Vieira ◽  
Ryan S. Henry ◽  
...  
Keyword(s):  
Wind Speed ◽  
Wind Tunnel ◽  
Laser Diffraction ◽  
Spray Drift ◽  
Downwind Distance ◽  
Fluorescent Tracer ◽  
Drift Potential ◽  
Herbicide Treatments ◽  
Low Speed Wind Tunnel ◽  
Nozzle Type

With the recent introductions of glyphosate- and dicamba-tolerant crops, such as soybean and cotton, there will be an increase in POST-applied tank-mixtures of these two herbicides. However, few studies have been conducted to evaluate drift from dicamba applications. This study aimed to evaluate the effects of dicamba with and without glyphosate sprayed through standard and air induction flat-fan nozzles on droplet spectrum and drift potential in a low-speed wind tunnel. Two standard (XR and TT) and two air induction (AIXR and TTI) 110015 nozzles were used. The applications were made at 276 kPa pressure in a 2.2 ms−1 wind speed. Herbicide treatments evaluated included dicamba alone at 560 gaeha−1 and dicamba+glyphosate at 560+1,260 gaeha−1. The droplet spectrum was measured using a laser diffraction system. Artificial targets were used as drift collectors, positioned in a wind tunnel from 2 to 12 m downwind from the nozzle. Drift potential was determined using a fluorescent tracer added to solutions, quantified by fluorimetry. Dicamba droplet spectrum and drift depended on the association between herbicide solution and nozzle type. Dicamba alone produced coarser droplets than dicamba+glyphosate when sprayed through air induction nozzles. Drift decreased exponentially as downwind distance increased and it was reduced using air induction nozzles for both herbicide solutions.

Dicamba Spray Drift as Influenced by Wind Speed and Nozzle Type

2017 ◽  
Vol 31 (5) ◽  
pp. 724-731 ◽  
Author(s):  
Guilherme Sousa Alves ◽  
Greg R. Kruger ◽  
João Paulo A. R. da Cunha ◽  
Denise G. de Santana ◽  
Luís André T. Pinto ◽  
...  
Keyword(s):  
Wind Speed ◽  
Wind Tunnel ◽  
Environmental Conditions ◽  
Laser Diffraction ◽  
Spray Drift ◽  
Fluorescent Tracer ◽  
Volume Percentage ◽  
Wind Speeds ◽  
Drift Potential ◽  
Nozzle Type

With the release of dicamba-resistant crops, it is necessary to understand how technical and environmental conditions affect the application of dicamba. This study sought to evaluate drift from dicamba applications through flat-fan nozzles, under several wind speeds in a wind tunnel. Dicamba applications were performed through two standard (XR and TT) and two air induction (AIXR and TTI) 110015 nozzles at 0.9, 2.2, 3.6 and 4.9 ms−1 wind speeds. The applications were made at 276 kPa pressure and the dicamba rate was 561 g ae ha-1. The droplet spectrum was measured using a laser diffraction system. Artificial targets were used as drift collectors, positioned in a wind tunnel from 2 to 12 m downwind from the nozzles. Drift potential was determined using a fluorescent tracer added to solutions, quantified by fluorimetry. The air induction TTI nozzle produced the lowest percentage of dicamba drift at 2.2, 3.6 and 4.9 ms−1 wind speeds at all distances. Dicamba spray drift from XR, TT and AIXR nozzles increased exponentially as wind speed increased, whereas from TTI nozzle drift increased linearly as wind speed increased. Drift did not increase linearly as the volume percentage of droplets smaller than 100 µm and wind speed increased.

Effect of Nozzle Type on Spray Drift in Banding Application

2013 ◽  
Vol 465-466 ◽  
pp. 520-525
Author(s):  
Nasir Salim Hassen ◽  
Nor Azwadi Che Sidik ◽  
Jamaluddin Md Sheriff
Keyword(s):  
Wind Speed ◽  
Wind Tunnel ◽  
Air Flow ◽  
Spray Drift ◽  
Application Process ◽  
Nozzle Height ◽  
Wind Speeds ◽  
Nozzle Type

The most important problem that faces spraying application process in the field is spray losses as result to spray drift to non target areas by action of air flow. Spray drift from conventional TeeJet even flat nozzle TPE and Drift Guard Even flat nozzle DGE (pre orifice nozzle) for banding application was investigated and compared under wind tunnel conditions. This paper examined effect nozzle heights 50 and 60 cm on spray drift. To determine the effect of wind speed on spray drift, wind tunnel was used to product three cross wind speeds 1, 2 and 3m/s. According to the results from this study, nozzle type affected significantly the spray drift. Increasing wind speeds had a high significant effect on increasing the spray drift. Nozzle height affected significantly the spray drift, the closer the nozzle is to the ground, the more the likelihood of spray drift is minimized. This study supports the use of nozzle type DGE as a means for minimizing spray drift.

Effect of Nozzle Angleson Spray Losses Reduction

2014 ◽  
Vol 564 ◽  
pp. 216-221
Author(s):  
Nasir S. Hassen ◽  
Nor Azwadi Che Sidik ◽  
Jamaluddin Md Sheriff
Keyword(s):  
Wind Speed ◽  
Wind Tunnel ◽  
Mean Value ◽  
The Other ◽  
Spray Drift ◽  
Spray Application ◽  
Application Process ◽  
Nozzle Height ◽  
Wind Speeds ◽  
Flat Fan Nozzle

Spray losses are the most important problem that is faced in the spray application process as result of spray drift to non target areas by the action of air flow.This paper investigated the spray drift for banding applicationusing even flat-fan nozzle TPEunder wind tunnel conditions.In addition, this paper also examined the effect of different spray fan angles 65°, 80° and 95° on spray drift particularly where there is need to make the nozzle operate at the optimum heights above the ground or plant level.In addition, three cross wind speeds 1, 2 and 3m/swere produced to determine the effect of wind speed on total spray drift.According to the results from this study, the nozzle anglehas a significant effect on the total spray drift. The nozzle angle 65° gave the highest drift reduction compared to the other nozzle angles. The maximum driftfor all nozzles was found at nozzle height of 60 cm. The minimum mean value of the drift was found at wind speed of 1 m/s. This study supports the use of nozzle angles of less than 95° on heights more than 0.5m and on wind speeds more than 1m/s as a means for minimizing spray drift.

Herbicide Formulation, Spray Nozzle Design, and Operating Pressure Affects the Droplet Size Spectra of Agricultural Sprays

2019 ◽  
pp. 1-7 ◽  
Author(s):  
Joshua A. McGinty ◽  
Gaylon D. Morgan ◽  
Peter A. Dotray ◽  
Paul A. Baumann
Keyword(s):  
Wind Tunnel ◽  
Droplet Size ◽  
The United States ◽  
Spray Drift ◽  
Operating Pressure ◽  
Spray Nozzle ◽  
Spray Droplet ◽  
Size Spectra ◽  
Drift Potential ◽  
Spray Droplets

Aims: Determine the droplet size spectra of agricultural sprays as affected by herbicide formulations, spray nozzle designs, and operating pressures. Place and Duration of Study: This study was conducted in April 2014 at the United States Department of Agriculture Agricultural Research Service Aerial Application Technology Research Unit Facility in College Station, Texas. Methodology: The spray droplet size spectra of six herbicide formulations as well as water alone and water with nonionic surfactant were evaluated in a low-speed wind tunnel. These spray solutions were conducted with five different flat-fan spray nozzle designs, producing a wide range of spray droplet sizes. The wind tunnel was equipped with a laser diffraction sensor to analyze spray droplet size. All combinations of spray solution and nozzle were operated at 207 and 414 kPa and replicated three times. Results: Many differences in droplet size spectra were detected among the spray solutions, nozzle designs, and pressures tested. Solutions of Liberty 280 SL exhibited the smallest median droplet size and the greatest proportion of spray volume contained in droplets 100 µm or less in size.  Solutions of Enlist Duo resulted in smaller median droplet size than many of the solutions tested, but also exhibited some of the smallest production of fine spray droplets. Median droplet size was found to vary greatly among nozzle designs, with the greatest droplet size and smallest drift-prone fine droplet production observed with air-inclusion designs utilizing a pre-orifice. Increasing the operating pressure from 207 to 414 kPa resulted in a decrease in median droplet size and an increase in the production of droplets 100 µm or less in size. Conclusion: Herbicide formulations and spray nozzle designs tested varied widely in droplet size spectra and thus the potential for spray drift. Increasing operating pressure resulted in decreased droplet size and an increase in the production of drift-prone droplets. Additionally, median droplet size alone should not be used to compare spray drift potential among spray solutions but should include relative span and V100 values to better predict the potential for spray drift due to drift-prone spray droplets.

Wind tunnel tests on the characteristics of wind fields over a simplified gorge

2016 ◽  
Vol 20 (10) ◽  
pp. 1599-1611 ◽  
Author(s):  
Peng Hu ◽  
Yongle Li ◽  
Yan Han ◽  
CS Cai ◽  
Guoji Xu
Keyword(s):  
Wind Speed ◽  
Wind Tunnel ◽  
Wind Direction ◽  
Wind Field ◽  
Small Range ◽  
Wind Fields ◽  
Wind Speeds ◽  
Mean Wind Speed ◽  
Wind Characteristics ◽  
The Mean

Characteristics of wind fields over the gorge or valley terrains are becoming more and more important to the structural wind engineering. However, the studies on this topic are very limited. To obtain the fundamental characteristics information about the wind fields over a typical gorge terrain, a V-shaped simplified gorge, which was abstracted from some real deep-cutting gorges where long-span bridges usually straddle, was introduced in the present wind tunnel studies. Then, the wind characteristics including the mean wind speed, turbulence intensity, integral length scale, and the wind power spectrum over the simplified gorge were studied in a simulated atmospheric boundary layer. Furthermore, the effects of the oncoming wind field type and oncoming wind direction on these wind characteristics were also investigated. The results show that compared with the oncoming wind, the wind speeds at the gorge center become larger, but the turbulence intensities and the longitudinal integral length scales become smaller. Generally, the wind fields over the gorge terrain can be approximately divided into two layers, that is, the gorge inner layer and the gorge outer layer. The different oncoming wind field types have remarkable effects on the mean wind speed ratios near the ground. When the angle between the oncoming wind and the axis of the gorge is in a certain small range, such as smaller than 10°, the wind fields are very close to those associated with the wind direction of 0°. However, when the angle is in a larger range, such as larger than 20°, the wind fields in the gorge will significantly change. The research conclusions can provide some references for civil engineering practices regarding the characteristics of wind fields over the real gorge terrains.

scholarly journals Effect of working pressure at different spray nozzles on drift quantification in wind tunnel

2014 ◽  
Vol 34 (1) ◽  
pp. 66-73 ◽  
Author(s):  
Marco A. Gandolfo ◽  
Fernando K. Carvalho ◽  
Rodolfo G. Chechetto ◽  
Ulisses D. Gandolfo ◽  
Eder D. de Moraes
Keyword(s):  
Wind Speed ◽  
Wind Tunnel ◽  
Agricultural Production ◽  
Large Scale ◽  
Spray Drift ◽  
Application Technology ◽  
Working Pressure ◽  
Spray Solution ◽  
Tunnel Floor

Each year, there is an increase in pesticide consumption and in its importance of use in the large-scale agricultural production, being fundamental the knowledge of application technology to the activity success. The objective of the present study was to evaluate the influence of working pressure on the drift generated by different spray nozzles, assessed in wind tunnel. The treatments were composed of two spray nozzles AXI 110015 and AXI 11002 with pressure levels of 276 and 414 kPa. The spray solution was composed by water and NaCl at 10%. The applications were conducted at wind speed of 2.0 m s-1, being the drift collected at 5.0; 10.0 and 15.0 m away from the spray boom and at heights of 0.2; 0.4; 0.6; 0.8 e 1.0 m from the tunnel floor. To both spray nozzles, the greatest drift was collected at the smallest distance to the spray-boom and at the lowest height. The AXI 11002 nozzle gave a smaller drift relative to the AXI 110015 nozzle for the two tested pressures and for all the collection points. Regardless of the nozzle, a rise in the working pressure increases the spray drift percentage at all distances in the wind tunnel.

scholarly journals Drift Evaluation of a Quadrotor Unmanned Aerial Vehicle (UAV) Sprayer: Effect of Liquid Pressure and Wind Speed on Drift Potential Based on Wind Tunnel Test

2021 ◽  
Vol 11 (16) ◽  
pp. 7258
Author(s):  
Qi Liu ◽  
Shengde Chen ◽  
Guobin Wang ◽  
Yubin Lan
Keyword(s):  
Wind Speed ◽  
Wind Tunnel ◽  
High Efficiency ◽  
Plant Protection ◽  
Spray Drift ◽  
Liquid Pressure ◽  
Agricultural Plant ◽  
Wind Speeds ◽  
Drift Potential ◽  
Test Platform

Background: Unmanned Aerial Vehicles (UAVs) applied to agricultural plant protection is widely used, and the field of operation is expanding due to their high efficiency and pesticide application reduction. However, the work on pesticide drift lags behind the development of the UAV spraying device. Methods: We compared the spray drift potential at four liquid pressures of 2, 3, 4, and 5 bar ejected from the hydraulic nozzles mounted on a UAV test platform exposed to different wind speeds of 2, 4, and 6 m/s produced by a wind tunnel. The combination of the wind tunnel and the UAV test platform was used to obtain strict test conditions. The droplet size distribution under spray drift pressures was measured by a laser diffraction instrument. Results: Increasing the pressure leads to smaller droplet volume diameters and produced fine droplets of less than 100 µm. The deposition in the drift area was elevated at most of the sampling locations by setting higher pressure and faster wind speed. The deposition ratios were all higher than the flow ratios under three wind speeds after the adjustment of pressures. For most samples within a short drift distance (2–8 m), the drift with the rotor motor off was more than an order of magnitude higher than that with the rotor motor on at a pressure of 3 bar. Conclusions: In this study, the wind speed and liquid pressure all had a significant effect on the UAV spray drift, and the rotor wind significantly inhibited a large number of droplets from drifting further.

Influence of Airspeed and Adjuvants on Droplet Size Distribution in Aerial Applications of Glyphosate

2018 ◽  
Vol 34 (3) ◽  
pp. 507-513 ◽  
Author(s):  
Bruno C Vieira ◽  
Guilherme S Alves ◽  
Fernando K Carvalho ◽  
João Paulo AR Da Cunha ◽  
Ulisses R Antuniassi ◽  
...  
Keyword(s):  
Wind Tunnel ◽  
Size Distribution ◽  
Droplet Size ◽  
High Speed ◽  
Droplet Size Distribution ◽  
Laser Diffraction ◽  
Flight Speed ◽  
Central Research ◽  
Operating Pressure ◽  
Size Spectra

Abstract. Drift is one of the most hazardous consequences of an improper aerial application of glyphosate. Wind, droplet size, application height, and distance to sensitive areas are the most important factors for drift. Droplet size is affected by nozzle, operating pressure, flight speed, deflection angle, and physicochemical properties of the spray solution. The objective of this study was to evaluate the effect of flight speed and the use of adjuvants on droplet size spectra in aerial applications of glyphosate. The study was conducted in a high-speed wind tunnel at the Pesticide Application Technology Laboratory (University of Nebraska-Lincoln, West Central Research and Extension Center, North Platte, Neb.). Aerial applications were simulated with four different airspeeds (44.4, 52.8, 61.1, and 69.4 m/s) and glyphosate combined with adjuvants (high surfactant oil concentrate, microemulsion drift reduction agent, nonionic and acidifier surfactant, polyvinyl polymer, and glyphosate alone). Droplet size spectra were evaluated using a Sympatec Helos laser diffraction instrument measuring 90 cm from the nozzle tip (CP11-4015). The volumetric droplet size distribution parameters (VMD, DV0.1, and DV0.9) and the percentage of droplets smaller than 100 µm were reported. The relative span was calculated to indicate the droplet size homogeneity [(DV0.9 - DV0.1) / DV0.5]. Glyphosate solutions with adjuvants had a larger VMD than the glyphosate alone solution at 44.4 m/s wind speed. At 69.4 m/s only the glyphosate solution with polymer had a larger VMD. Conversely, the glyphosate with polymer had the smallest DV0.1, and the greatest relative span and percentage of droplets smaller than 100 µm. Generally, adjuvants influence on droplet size was diminished or muted as the airspeed was increased. The polymer tested in this study failed as a drift agent reduction agent, especially at higher airspeeds. While not all polymers were tested, cautions should be taken if using these types of adjuvants in aerial applications. The interaction of airspeed and adjuvants influencing droplet size distribution in aerial applications of glyphosate should be considered by applicators in order to mitigate glyphosate drift to the surrounding environment. Further studies are necessary to better understand the interaction between solution viscosity and air shear effect on the atomization process and droplet size distribution, as well as confirm that trends hold true for other adjuvants in the polymer class. Although applicators tend to operate aircrafts with increased flight speeds in order to optimize the application time efficiency, this practice can reduce or mute adjuvants effects, decrease the droplet size distribution, and increase drift potential in aerial applications of glyphosate. Keywords: Drift reduction technologies, Flight speed, High-speed wind tunnel, Laser diffraction.

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