Downwind Spray Drift Assessment for Airblast Sprayer Applications in a Modern Apple Orchard System

2021 ◽  
Vol 64 (2) ◽  
pp. 601-613
Author(s):  
Anura P. Rathnayake ◽  
Lav R. Khot ◽  
Gwen A. Hoheisel ◽  
Harold W. Thistle ◽  
Milt E. Teske ◽  
...  
Keyword(s):  
Spray Deposition ◽  
Mechanistic Model ◽  
Apple Orchard ◽  
Growth Stages ◽  
List Type ◽  
Spray Drift ◽  
Worst Case ◽  
Dormant Stage ◽  
Drift Potential ◽  
Spray Applications

HighlightsAirblast sprayer drift potential was evaluated up to 183 m (600 ft) downwind from an orchard edge.A central leader apple orchard was sprayed at dormant and full canopy stage.Higher drift at full canopy stage was likely due to higher wind speeds and lower humidity.String and artificial foliage samplers had higher collection efficiencies than Mylar cards.Abstract. Risk assessment of orchard pesticide spraying is currently based on spray drift estimation using a worst-case scenario (dormant stage). However, most spray applications are conducted during non-dormant canopy growth stages. Such overestimation leads to restrictive operational regulations in pest management activities. Therefore, field data were generated and studied for a mechanistic model that will predict spray drift from airblast spray applications in tree fruit orchards. Spray trials were conducted at dormant and full canopy growth stages in a central leader trained apple orchard. An axial-fan airblast sprayer sprayed fluorescent tracer in the third row from the orchard’s downwind edge, with four passes being one run. A total of 20 runs, i.e., 17 spray runs and three blanks, were performed during each of the two crop growth stages. Mylar cards, artificial foliage (AF), and horizontal strings (HS) were used to quantify drifting spray deposition up to 183 m (600 ft) downwind. Within the orchard, the deposition on card samplers 3 m upwind of the sprayed row was 21.94% ±4.63% (mean ± standard deviation) of applied dose (AD) at dormant stage and 16.02% ±2.86% AD at full canopy stage. Deposition downwind and adjacent (-3 m) to the sprayed row was 17.92% ±2.70% AD and 7.15% ±1.78% AD at dormant and full canopy stages, respectively. Spray drift decreased substantially at the orchard edge to 3.18% ±1.30% AD at dormant stage and 2.30% ±1.16% AD at full canopy stage. Spray drift was very low at 183 m (600 ft) downwind of the orchard, with deposition of 0.002% ±0.003% AD at dormant stage and 0.003% ±0.004% AD at full canopy stage. Deposition data collected at common sampler locations showed that HS and AF samplers collected significantly (p < 0.05) more drifting spray than card samplers. Downwind speeds had a strong linear relationship with spray drift at both growth stages (dormant: R2= 0.80, full canopy: R2= 0.86), while the influence of temperature and humidity could not be directly observed from the collected data. Keywords: Airblast spraying, Deposit samplers, Dormant and full canopy, Drift, Modern orchard systems.

Field Performance of a Solid Set Canopy Delivery System Configured for High-Density Tall Spindle Architecture Trained Apple Canopies

2021 ◽  
Vol 64 (6) ◽  
pp. 1735-1745
Author(s):  
Rajeev Sinha ◽  
Lav Khot ◽  
Gwen Hoheisel ◽  
Matthew Grieshop
Keyword(s):  
Delivery System ◽  
Spray Deposition ◽  
Low Cost ◽  
Vertical Plane ◽  
Apple Orchard ◽  
High Density ◽  
Growth Stages ◽  
List Type ◽  
Hollow Cone ◽  
Leaf Surfaces

HighlightsVariants of a solid set canopy delivery system were evaluated in a high-density apple orchard.A pair of hollow-cone nozzles installed in three tiers had optimum spray performance for studied crop growth stages.A shower-down arrangement of emitters was the simplest design but had lesser deposition on abaxial leaf surfaces.Abstract. Optimally configured solid set canopy delivery system (SSCDS) based spraying has potential to improve tree-fruit crop pest and disease management by reducing application time and eliminating dependence on ground conditions. In such an effort, this study attempted to optimize SSCDS variants. Four different emitter types (E1 to E4) installed in different mounting configurations (C1 to C4) were evaluated for spray deposition and coverage in a high-density apple orchard trained in tall spindle architecture. Emitters E1, E2, and E4 had full circle spray patterns, and E3 had a hollow-cone pattern. Configuration C1 had a pair of E1 emitters spraying in a vertical plane and installed between two trees at 1.5 m above ground level (AGL). Another E1 emitter spraying in a horizontal plane was mounted atop each tree at 3.3 m AGL. Configurations C2 and C4 had emitters (E2 and E4, respectively) mounted atop each tree at 3.3 m AGL, and C3 had a pair of E3 emitters installed in a three-tier arrangement between two trees in the crop row. During field trials, a tree canopy about 3.0 m tall was divided into three zones (0 to 1.4 m, >1.4 to 2.2 m, and >2.2 to 3.0 m AGL) as bottom, middle, and top canopy zones, respectively. Mylar cards were used to quantify spray deposition using fluorometry, and water-sensitive papers (WSPs) were used to quantify coverage using image processing. Configuration C3 with 80° hollow-cone nozzles in a twin-emitter, three-tier arrangement had the highest overall spray deposition (581.1 ±77.8 ng cm-2, mean ± standard error) and coverage (18.4% ±4.1%). Moreover, C3 also had a significantly higher coverage on the abaxial surfaces of leaves compared to the other configurations. Configurations C1 was non-optimal because it lacked abaxial surface coverage as the canopy grew in the middle and late growth stages. Moreover, significant spray runoff from leaf surfaces was observed visually in the middle zone for C1 during the middle and late stages. This may be attributed to canopy growth around the emitters. Configurations C2 and C4, with emitters in a shower-down arrangement, had the highest deposition and coverage in the top canopy zone compared to the middle and bottom zones. Configurations C2 and C4 also had significantly higher spray coverage on the adaxial surfaces of leaves compared to the abaxial surfaces. Overall, despite the complex design of configuration C3 with six emitters per tree, it may be the most ideal arrangement for agrochemical application in an apple orchard trained in tall spindle architecture. For commercial feasibility, we recommend exploring this three-tier SSCDS configuration with low-cost emitter alternatives. Pertinent continuing efforts have been published by our group in which we successfully modified low-cost irrigation emitters, and the resulting three-tier SSCDS configurations had improved spray performance over expensive hollow-cone nozzles. Keywords: Fixed spray system, High-density apple orchard, Solid set canopy delivery system, Spray coverage, Spray deposition, SSCDS.

Assessment of Spray Deposition and Losses in an Apple Orchard with an Unmanned Agricultural Aircraft System in China

2020 ◽  
Vol 63 (3) ◽  
pp. 619-627
Author(s):  
Yang Liu ◽  
Longlong Li ◽  
Yajia Liu ◽  
Xiongkui He ◽  
Jianli Song ◽  
...  
Keyword(s):  
Pest Control ◽  
Plant Protection ◽  
Spray Deposition ◽  
Apple Orchard ◽  
Tree Canopy ◽  
List Type ◽  
Spray Drift ◽  
Reduced Pressure ◽  
External Contamination ◽  
Aircraft System

Highlights Field tests were performed in an orchard to evaluate spray performance of an unmanned agricultural aircraft system. A conventional air-assisted orchard sprayer was applied as a reference for comparing the feasibility of UAAS. The canopy deposition, airborne drift, loss to ground, and sprayer external contamination were tested. Field test results can provide a reference for the application of UAAS for pest control in orchards. Abstract. Unmanned agricultural aircraft system (UAAS) technology has developed rapidly in China in recent years. Due to their high application efficiency, all-terrain operation, and low-volume spraying, UAASs have been widely used for pest management in field crops, achieving good pest control and reduced pressure on farmers. In this study, the applicability of UAAS for orchard protection was tested in an apple orchard by spraying with a four-rotor UAAS and a conventional air-assisted orchard sprayer. The spray characteristics of both sprayers, including canopy deposition, drift in the air, loss to the ground, and external contamination on the sprayer, were measured and compared. The field results showed that the effective spray swath width of the UAAS was 2.23 m, and the maximum droplet density was 132 droplets cm -2 in the center of the flight line. The actual deposition in the tree canopy was lower with the UAAS than with the air-assisted sprayer, but the normalized deposition of the UAAS was equivalent to that of the air-assisted sprayer, and the coefficient of variation for deposition in all parts of the canopy was obviously higher for the UAAS than for the air-assisted sprayer. Due to the airflow produced by the high-speed rotors, the spray drift in the air was much higher with the UAAS than with the air-assisted sprayer, whereas the ground loss of the UAAS was 1/5 that of the air-assisted sprayer. Moreover, the rotor airflow of the UAAS caused a large amount of droplets to attach to the sprayer fuselage, causing the external contamination on the UAAS to be five times that of the air-assisted sprayer. Results showed that the use of a multirotor UAAS for plant protection in an orchard had considerable influence on the spray drift and external contamination of the spray equipment. Based on the results, the following recommendations can be made: (1) plant protection with a UAAS should be attained by spraying at a reasonable height to reduce the drift in the air, and (2) UAAS manufacturers should develop adequate spraying systems as well as appropriate UAAS designs for plant protection. Keywords: Air-assisted orchard sprayer, Apple orchard, Spray deposition, Spray loss, UAAS.

scholarly journals Lack of Effects On Bumblebee (Bombus Terrestris) Colony Development And Drone And Queen Production Due To The Insecticide Chlorantraniliprole

2021 ◽  
Author(s):  
Axel Dinter ◽  
Olaf Klein ◽  
Lea Franke
Keyword(s):  
Bombus Terrestris ◽  
Larval Mortality ◽  
Larval Survival ◽  
Flight Activity ◽  
Colony Development ◽  
Growth Stages ◽  
Monitoring Site ◽  
Worst Case ◽  
Set Up ◽  
Spray Applications

Abstract The aim of the study was to investigate the potential impact of the insecticide chlorantraniliprole on queen-right bumblebee (Bombus terrestris) colonies under semi-field conditions in Phacelia tanacetifolia. The P. tanacetifolia crop was grown in soil treated with modelled worst-case 20-year plateau concentration of chlorantraniliprole in the top 20 cm of soil (equivalent to 0.088 mg a.s./kg). Additionally, two chlorantraniliprole spray applications at 60 g a.s./ha were made. In treatment T1 both spray applications took place before P. tanacetifolia flowering at growth stages BBCH 51–55 and BBCH 55–59. In T2 one spray application was conducted before P. tanacetifolia flowering at BBCH 55–59 and one application during P. tanacetifolia flowering and during daily bee flight at BBCH 61–62. The application in the control (C) and reference item treatment (R) (400 g dimethoate a.s./ha) was carried out during full P. tanacetifolia flowering and bumblebee flight. The bumblebee colonies were exposed to the treated flowering P. tanacetifolia crop for 20 days in the tunnels and afterwards the colonies were kept on a monitoring site. Results of this study indicate no significant differences between the chlorantraniliprole groups T1 and T2 and the control regarding all parameters assessed (i.e. adult and larval mortality, flight activity at the hive entrance, colony weight development, condition of the colonies and production of young queens and males). Overall, no effects of chlorantraniliprole on B. terrestris colonies including queen/male production, adult and larval survival, colony development and forager flight activity were found in this worst-case exposure set-up.

scholarly journals Drift measurements for conditions of hydrogen cyanamide spraying in kiwifruit

2018 ◽  
Vol 71 ◽  
pp. 19-24
Author(s):  
Robert Connell ◽  
Scott Post ◽  
Mark Ledebuhr ◽  
Brian Moorhead ◽  
Andrew Hewitt
Keyword(s):  
Spray Deposition ◽  
Late Winter ◽  
Spray Drift ◽  
Bud Burst ◽  
Spray Application ◽  
Hydrogen Cyanamide ◽  
Adjuvant System ◽  
Drift Potential ◽  
Downwind Side ◽  
Time Of Year

Kiwifruit are sprayed in late winter with hydrogen cyanamide to enhance with bud burst. The trellis layout of kiwifruit vines in combination with the canopy dormancy at that time of year means that a higher portion of the spray is able to drift away from the canopy. A spray application field study was conducted in a kiwifruit orchard to investigate spray drift potential, with particular focus for conditions relevant to hydrogen cyanamide applications. Spray application with conventional airblast-sprayer hollow-cone nozzles/adjuvant was compared with air-induction (AI) nozzles/drift-reducing adjuvant. Spray was applied every second row in the orchard with spray drift sampling conducted by measuring vertical distribution of spray deposition on both sides of the downwind shelterbelt. The trial showed that airborne drift carried to a height of at least 15 m to the downwind edge of the orchard, which was the height of the vertical sampling towers. The air-induction nozzle/drift-reducing adjuvant system reduced the drift intercepted at 15 m height on the downwind side of the shelterbelt by approximately 78% compared to the standard nozzle/adjuvant system.

Technical Note: Model Physics and Collection Efficiency in Estimates of Pesticide Spray Drift Model Performance

2020 ◽  
Vol 63 (6) ◽  
pp. 1939-1945
Author(s):  
Harold W. Thistle ◽  
Milton E. Teske ◽  
Brian Richardson ◽  
Tara M. Strand
Keyword(s):  
Forest Canopy ◽  
Collection Efficiency ◽  
Spray Deposition ◽  
Model Performance ◽  
Technical Note ◽  
Large Field ◽  
List Type ◽  
Spray Drift ◽  
Wind Fields ◽  
Data Limitations

HighlightsRecent large field programs are re-examined in the context of model development.Details of plant canopy wind fields are discussed.Collection efficiency of rotorods is discussed in detail, and the theory is used to re-examine field data.The approach used in the AGDISP model to simulate canopy wind fields is discussed in detail.Abstract. Recent field studies provided data to evaluate the performance of the aerial spray deposition algorithm in AGDISP. Those studies provided data for forest canopy settings that are either outside the stated domain of AGDISP or where assumptions in the model greatly impact the model performance. The two data sets were collected with the intention of providing input to drive model upgrades, but data limitations restricted that objective. Rather, this technical note shows that collection efficiency (CE) must always be considered (the model currently adjusts for CE only if the modeled output is canopy capture). One of the previous studies showed that the model substantially overpredicted droplet flux 65 m downwind of the spray line. Consideration of CE resolves some of this overprediction, but the model physics employed in AGDISP remain a substantial simplification of the complex flows that transport droplets in the atmospheric boundary layer near and in deep, three-dimensionally varying forest canopies. Keywords: Aerial application, AGDISP, Model, Spray drift.

Development and Performance Evaluation of a Pneumatic Solid Set Canopy Delivery System for High-Density Apple Orchards

2020 ◽  
Vol 63 (1) ◽  
pp. 37-48 ◽  
Author(s):  
Rajeev Sinha ◽  
Rakesh Ranjan ◽  
Haitham Y. Bahlol ◽  
Lav R. Khot ◽  
Gwen-Alyn Hoheisel ◽  
...  
Keyword(s):  
Delivery System ◽  
Large Scale ◽  
Spray Deposition ◽  
Apple Orchard ◽  
High Density ◽  
Growth Stages ◽  
Operating Pressure ◽  
Apple Orchards ◽  
Crop Growth Stages ◽  
And Performance

Abstract. Solid set canopy delivery systems (SSCDS) are fixed spray systems that consist of a network of permanently plumbed emitters in high-density tree-fruit orchard canopies. Most of the previously configured SSCDS worked on the principle of hydraulic spray delivery (HSD), which may not be suitable for large-scale installation due to the drop in operating pressure caused by frictional losses in the spray lines. Therefore, a pneumatic spray delivery (PSD) based SSCDS was developed in this study for potentially achieving uniform spray application at all locations along the spray lines. A reservoir subsystem was developed to contain a precisely metered amount of spray liquid. Once filled, compressed air pushed through the spray lines can pressurize the reservoir to help deliver uniform spray into the canopy through emitters. In this study, HSD and PSD systems of 91 m set length were installed in a high-density apple orchard. Both systems were evaluated for variations in operating pressure, spray output, and spray performance. Spray performance was quantified during the middle (BBCH 75) and late (BBCH 85) apple (cv. WA-38 on tall spindle architecture) crop growth stages. Deposition and coverage in three canopy zones and on both sides of leaves were evaluated using Mylar cards and water-sensitive papers (WSP) as samplers, respectively. The Mylar cards and WSP were respectively analyzed using fluorometry and image processing. Statistically similar operating pressure (p > 0.05) was observed for the HSD and PSD systems at 3 m (286.1 and 284.1 kPa, respectively), 33 m (268.4 and 270.5 kPa), 60 m (260.6 and 268.9 kPa), and 87 m (255.3 and 257.9 kPa) from the row inlet. Despite the operating pressure drop, the PSD system had uniform spray output along the 91 m spray line. Compared to the HSD system, about 4%, 3%, 5%, and 20% higher spray output was delivered with the PSD system at 3, 33, 60, and 87 m, respectively, along the spray line. Overall, the PSD system had significantly higher mean spray deposition (p < 0.01) compared to the HSD system during the middle (521 and 382 ng cm-2, respectively) and late (631 and 409 ng cm-2, respectively) growth stages. The PSD system also had numerically higher spray deposition compared to the HSD system for all the canopy zones and on either side of leaf surfaces. Spray coverage trends were similar to deposition; however, the differences were not significant. Overall, the PSD-based SSCDS shows potential for large-scale installation, with additional refinements, for uniform spray applications in high-density apple orchards. Keywords: Hydraulic spray delivery, Pneumatic spray delivery, Solid set canopy delivery system, Spray coverage, Spray deposition.

scholarly journals UAV-Based Heating Requirement Determination for Frost Management in Apple Orchard

2021 ◽  
Vol 13 (2) ◽  
pp. 273
Author(s):  
Wenan Yuan ◽  
Daeun Choi
Keyword(s):  
Apple Orchard ◽  
Growth Stages ◽  
Flower Bud ◽  
Critical Temperatures ◽  
Mapping Algorithm ◽  
Aerial Vehicle ◽  
Bud Growth ◽  
Frost Protection ◽  
Map Resolution ◽  
Temperature Maps

Frost is a natural disaster that can cause catastrophic damages in agriculture, while traditional temperature monitoring in orchards has disadvantages such as being imprecise and laborious, which can lead to inadequate or wasteful frost protection treatments. In this article, we presented a heating requirement assessment methodology for frost protection in an apple orchard utilizing unmanned aerial vehicle (UAV)-based thermal and RGB cameras. A thermal image stitching algorithm using the BRISK feature was developed for creating georeferenced orchard temperature maps, which attained a sub-centimeter map resolution and a stitching speed of 100 thermal images within 30 s. YOLOv4 classifiers for six apple flower bud growth stages in various network sizes were trained based on 5040 RGB images, and the best model achieved a 71.57% mAP for a test dataset consisted of 360 images. A flower bud mapping algorithm was developed to map classifier detection results into dense growth stage maps utilizing RGB image geoinformation. Heating requirement maps were created using artificial flower bud critical temperatures to simulate orchard heating demands during frost events. The results demonstrated the feasibility of the proposed orchard heating requirement determination methodology, which has the potential to be a critical component of an autonomous, precise frost management system in future studies.

Chemical Concentration and Spatial Uniformity of a Premixing In-Line Injection System Attached to a Variable-Rate Orchard Sprayer

2021 ◽  
Vol 64 (6) ◽  
pp. 1977-1987
Author(s):  
Zhihong Zhang ◽  
Heping Zhu ◽  
Zhiming Wei ◽  
Ramon Salcedo
Keyword(s):  
Spatial Distribution ◽  
Duty Cycle ◽  
Spray Deposition ◽  
Injection System ◽  
List Type ◽  
Variable Rate ◽  
Chemical Concentration ◽  
Fluorescent Tracer ◽  
Distribution Uniformity ◽  
The Mean

HighlightsA newly developed premixing in-line injection system attached to a variable-rate orchard sprayer was evaluated.Tests were conducted to verify the in-line injection system performance using a vertical spray patternator.Concentration accuracy and spatial distribution uniformity were determined with a fluorescent tracer.Uniform spray mixtures were obtained for different spray viscosities and duty cycle combinations.Abstract. Pesticide spray application efficiency is highly dependent on the chemical concentration accuracy and spatial distribution uniformity. In this study, the performance of a newly developed premixing in-line injection system was evaluated when it was attached to a laser-guided, pulse width modulated (PWM), variable-rate orchard sprayer. The chemical concentration accuracy was determined with respect to spray deposition with a fluorescent tracer, and the spatial distribution uniformity was determined with spray deposits at different heights on a vertical spray patternator. Outdoor tests were conducted with 27 combinations of target chemical concentration (1.0%, 1.5%, and 2.0%), viscosity of the simulated pesticide (1.0, 12.0, and 24.0 mPa·s), and various spray outputs manipulated with PWM duty cycles. For each injection loop, the amounts of the chemical concentrate and water discharged into the mixing line were measured separately in response to preset target concentrations. The results showed that the measured concentrations were consistent across the patternator heights, spray viscosities, and duty cycle combinations. For all treatments, the mean absolute percentage error (MAPE) of the measured concentration was 6.96%, indicating that the concentration accuracy of the system was acceptable. The mean coefficient of variation was 3.35%, indicating that the spatial distribution uniformity of the system was in the desirable range. In addition, there was little variation in chemical concentration for spray mixtures collected at different heights on the patternator. Thus, the premixing in-line injection system could adequately dispense chemical concentrate and water to produce accurate concentrations and uniform spray mixtures for variable-rate nozzles to discharge to targets. Keywords: Environment protection, Precision pesticide application, Laser-guided sprayer, Tank mixture disposal, Specialty crop.

An Open-Sourced Web Application for Aerial Applicators to Avoid Spray Drift Caused by Temperature Inversion

2021 ◽  
Vol 37 (1) ◽  
pp. 77-84
Author(s):  
Yanbo Huang ◽  
D. K. Fisher
Keyword(s):  
Open Source ◽  
Web Application ◽  
Mississippi Delta ◽  
Temperature Inversion ◽  
Weather Data ◽  
List Type ◽  
Spray Drift ◽  
Atmospheric Conditions ◽  
Weather Stations ◽  
Open Source Hardware

HighlightsA web application for guiding data calculated from distributed weather data through open-source cloud service.A design scheme of portable weather stations built from inexpensive open-source electronics.Integration of open-source hardware and software for online guiding data to avoid drift caused by temperature inversion.Abstract. It is important for agricultural chemical applicators to follow proper spray procedures to prevent susceptible crops, animals, people, or other living organisms from being injured far downwind. Spraying during stable atmospheric conditions should be avoided to prevent surface-temperature inversion-induced off-target drift of crop protection materials. Previous statistical analysis determined times of high likelihood of stable atmospheric conditions, which are unfavorable for spraying, during the day under clear and cloudy conditions in hot summer months in the Mississippi Delta. Results validated the thresholds of temperature increase in the morning and temperature drop in the afternoon with wind speeds and the transition between stable and unstable atmospheric conditions. With this information, an algorithm was developed to calculate if atmospheric conditions were favorable for spraying based on field temperature and wind speed at any instant. With this algorithm, a web application was built to provide real-time determination of atmospheric stability and hourly online recommendation of whether aerial applications were appropriate for a location and time in the Mississippi Delta. This study further developed another web application specifically for Stoneville, Mississippi, with data measured from weather stations constructed from inexpensive open-source electronics, accessories, and software for more accurate online guidance for site-specific drift management. The web application is adapted for accessing on mobile terminals, such as smartphones and tablets, and provides timely guidance for aerial applicators and producers to avoid spray drift and air quality issues long distances downwind in the area. Keywords: Open-source hardware, Open-source software, Spray drift, Temperature inversion, Web application.

scholarly journals Spray Drift Generated in Vineyard during Under-Row Weed Control and Suckering: Evaluation of Direct and Indirect Drift-Reducing Techniques

2020 ◽  
Vol 12 (12) ◽  
pp. 5068 ◽  
Author(s):  
Marco Grella ◽  
Paolo Marucco ◽  
Athanasios T. Balafoutis ◽  
Paolo Balsari
Keyword(s):  
Weed Control ◽  
Experimental Work ◽  
Environmental Issues ◽  
Buffer Zone ◽  
Optimum Combination ◽  
Spray Drift ◽  
Spray Application ◽  
Herbicide Application ◽  
Spray Applications

The most widespread method for weed control and suckering in vineyards is under-row band herbicide application. It could be performed for weed control only (WC) or weed control and suckering (WSC) simultaneously. During herbicide application, spray drift is one of the most important environmental issues. The objective of this experimental work was to evaluate the performance of specific Spray Drift Reducing Techniques (SDRTs) used either for WC or WSC spray applications. Furthermore, spray drift reduction achieved by buffer zone adoption was investigated. All spray drift measurements were conducted according to ISO22866:2005 protocol. Sixteen configurations deriving from four nozzle types (two conventional and two air-induction—AI) combined with or without a semi-shielded boom at two different heights (0.25 m for WC and 0.50 m for WSC) were tested. A fully-shielded boom was also tested in combination with conventional nozzles at 0.25 m height for WC. Ground spray drift profiles were obtained, from which corresponding Drift Values (DVs) were calculated. Then, the related drift reduction was calculated based on ISO22369-1:2006. It was revealed that WC spray applications generate lower spray drift than WSC applications. In all cases, using AI nozzles and semi-shielded boom significantly reduced DVs; the optimum combination of SDRTs decreased spray drift by up to 78% and 95% for WC and WSC spray application, respectively. The fully-shielded boom allowed reducing nearly 100% of spray drift generation. Finally, the adoption of a cropped buffer zone that includes the two outermost vineyard rows lowered the total spray drift up to 97%. The first 90th percentile model for the spray drift generated during herbicide application in vineyards was also obtained.

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