The effects of spray application rate and droplet size on applications to control soybean rust

2008 ◽  
Author(s):  
Scott M Bretthauer ◽  
Tristan A Mueller ◽  
Richard C Derksen ◽  
Heping Zhu ◽  
Loren E Bode
Keyword(s):  
Droplet Size ◽  
Application Rate ◽  
Soybean Rust ◽  
Spray Application

scholarly journals Development of Drift-Reducing Spouts For Vineyard Pneumatic Sprayers: Measurement of Droplet Size Spectra Generated and Their Classification

2020 ◽  
Vol 10 (21) ◽  
pp. 7826
Author(s):  
Marco Grella ◽  
Antonio Miranda-Fuentes ◽  
Paolo Marucco ◽  
Paolo Balsari ◽  
Fabrizio Gioelli
Keyword(s):  
Droplet Size ◽  
Marked Reduction ◽  
Reduction Potential ◽  
Liquid Flow Rate ◽  
Spray Drift ◽  
Spray Application ◽  
Size Spectra ◽  
Wide Range ◽  
Environmental Requirements ◽  
Low Drift

Pneumatic spraying is especially sensitive to spray drift due to the production of small droplets that can be easily blown away from the treated field by the wind. Two prototypes of environmentally friendly pneumatic spouts were developed. The present work aims to check the effect of the spout modifications on the spray quality, to test the convenience of setting the liquid hose out of the spout in cannon-type and hand-type pneumatic nozzles and its effect on the droplet size, homogeneity and driftability in laboratory conditions. Laboratory trials simulating a real sprayer were conducted to test the influence of the hose insertion position (HP), including conventional (CP), alternative (AP), outer (OP) and extreme (XP), as well as the liquid flow rate (LFR) and the airflow speed (AS) on the droplet size (D50, D10 and D90), homogeneity and driftability (V100). Concurrently, the droplet size spectra obtained by the combination of aforementioned parameters (HP × LFR × AS) in both nozzles were also classified according to the ASABE S572.1. Results showed a marked reduction of AS outside the air spout, which led to droplet size increase. This hypothesis was confirmed by the droplet size spectra measured (D50, D10, D90 and V100). A clear influence of HP was found on every dependent variable, including those related with the droplet size. In both nozzles, the longer the distance to CP, the coarser the sprayed drops. Moreover, LFR and AS significantly increased and reduced droplet size, respectively. A higher heterogeneity in the generated drops was obtained in XP. This position yielded V100 values similar to those of the hydraulic low-drift nozzles, showing an effective drift reduction potential. The classification underlines that the variation of HP, alongside AS and LFR, allowed varying the spray quality from very fine to coarse/very coarse, providing farmers with a wide range of options to match the drift-reducing environmental requirements and the treatment specifications for every spray application.

Spray Application Efficiency from a Multi-Rotor Unmanned Aerial Vehicle Configured for Aerial Pesticide Application

2019 ◽  
Vol 62 (6) ◽  
pp. 1447-1453 ◽  
Author(s):  
Brian Richardson ◽  
Carol A. Rolando ◽  
Mark O. Kimberley ◽  
Tara M. Strand
Keyword(s):  
Wind Speed ◽  
Unmanned Aerial Vehicle ◽  
Droplet Size ◽  
Small Range ◽  
Surprising Result ◽  
Spray Application ◽  
Size Classes ◽  
Fine Droplet ◽  
Application Efficiency ◽  
Aerial Vehicle

HighlightsThe swath pattern was measured from an Agras MG-1 UAV spraying fine and extra-coarse droplet spectra.The recommended lane separation of 3.6 m did not differ for the two droplet size classes tested in this study.The applied spray deposited within the swath was higher with extra-coarse (>90%) than with fine (73%) droplets.There was potential for substantial downwind drift with fine droplets, even when flying close to the ground at low speed.Abstract. While there is increasing interest in the use of small, multi-rotor UAVs for application of agrichemicals, there is also uncertainty about their performance. Consequently, the purpose of this study was to quantify the performance of an Agras MG-1 with modified nozzle positions that, at the time of writing, was being used for commercial spraying in New Zealand. The approach was to release spray from the UAV along a single 50 m line. Spray deposits were measured using horizontal collectors placed on the ground in three 15 m transects centered on, and perpendicular to, the flight line. Airborne deposits were measured with a 10 m mast that supported spherical samplers at 1 m vertical intervals. Analysis of deposition data was undertaken to quantify factors influencing overall swath pattern variability, lane separation associated with a coefficient of variation (CV) of deposition of 30%, and spray application efficiency, which is the proportion of applied spray deposited within the swath. For two droplet size classes (extra-coarse and fine), the lane separation associated with a CV of 30% was about 3.6 m, with no significant effect of droplet size. This is a surprising result and may reflect the relatively small range of environmental conditions experienced during the field tests, including wind speed, which was relatively low for all tests. We speculate that this result may also be a consequence of the strong downwash. The swath width was positively correlated with wind speed. Spray efficiency was shown to be high (>90%) for the extra-coarse droplets but dropped significantly (73%) with the fine droplet spectrum. Combining in-swath deposition with the amount of airborne spray sampled in a 10 m vertical profile close to the edge of the swath accounted for 98.0% of the spray released with the extra-coarse spectrum but only 88.6% of the spray with the fine droplet spectrum. These results highlight that even with UAVs flying relatively close to the ground at a low forward speed, there is potential for substantial drift downwind of the swath when using smaller droplet size classes. Overall, the swath pattern was reasonably consistent across the two droplet size classes and for the narrow range of operational and meteorological conditions tested. Keywords: Aerial spraying, Pesticides, Spray application efficiency, Spray deposition, Swath pattern, UAV, Unmanned aerial vehicle.

scholarly journals Meeting droplet size specifications for aerial herbicide application to control wilding conifers

2020 ◽  
Vol 73 ◽  
pp. 13-23
Author(s):  
Brian Richardson ◽  
Carol Rolando ◽  
Andrew Hewitt ◽  
Mark Kimberley
Keyword(s):  
Droplet Size ◽  
Field Performance ◽  
The Other ◽  
Spray Drift ◽  
Spray Application ◽  
Herbicide Application ◽  
Water Control ◽  
Drift Potential ◽  
Droplet Sizes ◽  
Air Speed

Large areas of New Zealand are being aerially sprayed with herbicides to manage ‘wilding’ conifer spread. The purpose of the study was to obtain and analyse droplet spectra produced by nozzles commonly used for wilding conifer spraying to determine whether or not operational recommendations for a target droplet size class (~350 µm) are being met. Droplet spectra were measured in a wind tunnel for 27 nozzle x 3 operating condition (nozzle angle, air speed and pressure) combinations tested for each of three spray mixes. AGDISP, an aerial spray application simulation model, was used to quantify the field performance implications of changes to droplet spectra parameters. Only one nozzle, the CP-09, 0.078, 30°, met the target droplet size specification when used at 45° but not at 0°. However, under these conditions, this nozzle produced a large driftable fraction. All but one of the other scenarios tested produced much larger droplet sizes. Operational spray mixes tended to slightly increase the potential for spray drift compared with the water control. The CP-09, 0.078, 30° nozzle used at 45° met the operational droplet size specification but is more sensitive to changes to nozzle angle (0° versus 45°) than the other nozzles tested. None of the three Accu-FloTM nozzles tested met the target droplet size specification. However, the Accu-FloTM nozzles produced very few fine droplets making them good choices for reducing spray drift potential.

scholarly journals Advancing Sustainability in Tree Crop Pest Management: Refining Spray Application Rate with a Laser-guided Variable-rate Sprayer in Apple Orchards

HortScience ◽  
2020 ◽  
Vol 55 (9) ◽  
pp. 1522-1530
Author(s):  
Lauren Fessler ◽  
Amy Fulcher ◽  
Dave Lockwood ◽  
Wesley Wright ◽  
Heping Zhu
Keyword(s):  
Cost Savings ◽  
Application Rate ◽  
Variable Rate ◽  
Spray Application ◽  
Laser Rangefinder ◽  
Pesticide Application ◽  
Nontarget Organisms ◽  
Sensing Technology ◽  
Spray Rate ◽  
Deposit Density

Advanced variable-rate spray technology, which applies pesticides based on real-time scanning laser rangefinder measurements of plant presence, size, and density, was developed and retrofitted to existing sprayers. Experiments were conducted to characterize the application of four programmed spray rates (0.03, 0.05, 0.07, or 0.09 L·m−3 of crop geometric volume) when applied to Malus domestica Borkh. ‘Golden Delicious’ apple trees using this crop sensing technology. Water-sensitive cards (WSCs) were used as samplers to quantify spray coverage, deposits, and deposit density in the target and nontarget areas, and an overspray index based on a threshold of greater than 30% coverage was calculated. The application rate ranged from 262 L·ha−1 at the programmed spray rate of 0.03 L·m−3 to 638 L·ha−1 at the rate of 0.09 L·m−3. For a given WSC position, spray coverage and deposits increased as the spray rate increased. WSC positions 1 and 2 were oversprayed at all rates. The effect of spray rate on deposit density varied with WSC positions, with high densities achieved by low spray rates for WSCs closest to the sprayer but by high spray rates for WSCs positioned either deeper within or under the canopy. When coalescing deposits were accounted for, deposit densities met or exceeded the recommended pesticide application thresholds (insecticides 20–30 droplets/cm2; fungicides 50–70 droplets/cm2) at all WSC positions for each spray rate tested. The lowest spray rate reduced off-target loss to the orchard floor by 81% compared with the highest rate, dramatically reducing potential exposure to nontarget organisms, such as foraging pollinators, to come into contact with pesticide residues. Applying the lowest rate of 0.03 L·m−3 met deposit density efficacy levels while reducing spray volume by 83% compared with the orchard standard application of 1540 L·ha−1 and by 87% compared with the 1950 L·ha−1 application rate recommended when using the tree row volume method. Thus, there is potential for growers to refine pesticide application rates to further achieve significant pesticide cost savings. Producers of other woody crops, such as nursery, citrus, and grapes, who use air-assisted sprayers, may be able to achieve similar savings by refining pesticide applications through the use of laser rangefinder-based spray application technology.

scholarly journals ELEVATED MICROSPRINKLER BENEFITS CITRUS TREES IN A SEVERE ADVECTIVE FREEZE

HortScience ◽  
1990 ◽  
Vol 25 (9) ◽  
pp. 1137a-1137
Author(s):  
Larry R. Parsons ◽  
T. Adair Wheaton
Keyword(s):  
Application Rate ◽  
Water Application ◽  
Spray Application ◽  
Application Rates ◽  
Old Trees ◽  
Freeze Protection ◽  
Overhead Sprinkler ◽  
Citrus Trees

Undertree microsprinkler irrigation has protected 1 or 2 year old trees to a height of 1 meter during severe advective freezes. During the severe December 1989 freeze, microsprinklers elevated to 0.9 meter protected 5 year old citrus trees to a height of 2 meters. Limb breakage due to ice loading was negligible. Protection was achieved with water application rates less than half that required by some overhead sprinkler models. Survival is attributed to 1) continuous spray from the microsprinkler rather than periodic spray from a rotating overhead sprinkler, and 2) effective localized application rate on branches intercepting spray is more than average overall spray application rate. Elevated microsprinklers provide freeze protection to a greater height and allow for more rapid post-freeze recovery.

scholarly journals Development and Prototype Testing of an Agricultural Nozzle Clog Detection Device

2021 ◽  
Vol 64 (1) ◽  
pp. 49-61
Author(s):  
Chin Nee Vong ◽  
Peter Ako Larbi
Keyword(s):  
Droplet Size ◽  
Detection System ◽  
New Technology ◽  
Quality Characteristics ◽  
List Type ◽  
Spray Application ◽  
Nozzle Clogging ◽  
Spray Pattern ◽  
Extended Range ◽  
Low Drift

HighlightsPrototypes of an agricultural nozzle clog detection system (for 18 nozzles) have been successfully developed.Spray quality characteristics (droplet size, pattern, and coverage) were not significantly affected when testing the device with extended-range nozzles (TeeJet XR8004).Most of the spray quality characteristics were significantly affected when testing the device with ultra low-drift nozzles (John Deere PSULDQ2004).Abstract. Agricultural nozzles are the main components that perform the spraying of agrochemicals, and their proper functionality is a key element for uniform spray application on crops. Because nozzles have small orifices, they can become clogged when there is debris from the agrochemical in the tank. Nozzle clogging during spray application results in poor pest and weed management and increased cost for re-spraying the affected crop row. Measures used to prevent nozzles from clogging include using screens or strainers to filter out debris before it reaches the nozzle tip, as well as performing regular checks on the nozzles. However, nozzle clogging still occurs during spraying despite the precautions taken. Thus, a device that can detect nozzle clogging during spraying is necessary to enable a quicker response that will ensure uniform application across each row of the crop. A novel, patented device for detecting clogged nozzles that is externally attachable to each nozzle on a sprayer boom was developed in the Precision Application Technology Lab at Arkansas State University. The main objective of this article is to present a general description of this prototype nozzle clog detection device and the nozzle clog detection system. Spray droplet size and pattern tests under controlled conditions and spray coverage tests under field conditions were conducted with and without the device to determine if there were significant differences in droplet size, spray pattern, or spray coverage between using and not using the device. The tests demonstrated that this new technology has potential for detecting clogged nozzles without significantly influencing spray quality for extended-range nozzles but not for ultra low-drift nozzles. To increase the reliability of the performance of this new technology, further improvements in the design need to be considered. Keywords: Clogged nozzle, Detection, Droplet size, Prototype device, Spray coverage, Spray pattern.

scholarly journals Aerial Application Methods for Control of Weed Species in Fallow Farmlands in Texas

Agronomy ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1764
Author(s):  
Daniel E. Martin ◽  
Mohamed A. Latheef ◽  
Juan D. Lopez ◽  
Sara E. Duke
Keyword(s):  
Remote Sensing ◽  
Field Research ◽  
Application Rate ◽  
Spray Nozzle ◽  
Early Winter ◽  
Spray Application ◽  
Weed Species ◽  
Aerial Application ◽  
Application Methods ◽  
Over Time

Prolific growth of weeds, especially when followed by abundant rainfall, is common in Texas farmlands during early winter and progresses into spring when farmers begin chiseling and disking operations for spring-seeded cropping. This research sought to develop aerial application technologies designed to control unwanted vegetation in croplands left fallow until spring. The aerial nozzles used in the study were conventional hydraulic (CP), rotary atomizer, and electrostatically (ES) charged nozzles. Glyphosate at 0.4145 kg ae·ha−1 was applied on weeds using a fixed-wing aircraft equipped with various aerial nozzles used as treatments. The spray application rate for the conventional and rotary atomizer nozzles was 28.1 L·ha−1, while that for the ES charged nozzle was 9.4 L·ha−1. Aerial and ground-based remote sensing and visual estimates quantified weed vigor and canopy health. Both the CP and rotary atomizer nozzles were efficacious in suppressing weeds. ES charged on nozzles at one-third of the spray application rate of the CP and the rotary atomizer nozzles were equally effective in reducing weed vigor. More aerially applied replicated field research trials conducted over time and space are needed to unravel the differences between aerial spray nozzle technologies for controlling weed populations in Texas farmlands.

Effect of protective shields on drift and deposition characteristics of field sprayers

1993 ◽  
Vol 73 (4) ◽  
pp. 1261-1273 ◽  
Author(s):  
Thomas M. Wolf ◽  
Raj Grover ◽  
Keith Wallace ◽  
Stan R. Shewchuk ◽  
John Maybank
Keyword(s):  
Wind Speed ◽  
Droplet Size ◽  
Field Trials ◽  
Application Rate ◽  
Target Area ◽  
High Wind ◽  
Ground Speed ◽  
Wind Speeds ◽  
Spray Solution ◽  
Deposition Uniformity

Field trials were conducted to determine the effectiveness of shields in reducing off-target droplet drift from ground-rig sprayers. Sprayer booms ranging in width from 10 to 13.5 m and equipped with commercially available shields were operated along a 150-m swath in a field of approximately 20-cm-tall spring wheat in wind speeds ranging from 10 to 35 km h−1. Airborne drift was measured using aspirated air samplers. The use of an 80 flat fan tip (8001) at a pressure of 275 kPa and a ground speed of 8 km h−1 resulted in 7.5% of the 50 L ha−1 spray solution drifting off the target area. The use of protective cones with 8001 tips without lowering the boom reduced airborne drift by 33% at a 20 km h−1 wind speed, while a 65–85% drift reduction was accomplished with the combination of solid or perforated shielding and lowering the sprayer boom. Increasing the application rate to 100 L ha−1 by using 8002 tips reduced drift of the unshielded sprayer by 65%. Decreasing application rate to 15 L ha−1 by using 800017 tips increased drift by 29% despite the use of a shield. Off-target drift increased with increasing wind speeds for all sprayers, but the increase was less for shielded sprayers and coarser sprays. The decreased droplet size of spray from 110 tips increased drift when the boom height was the same as for 80 tips. High wind speeds, lower carrier volumes and finer sprays, 110 tips, and solid shields tended to decrease on-swath deposit uniformity, whereas a perforated shield or cones did not affect deposit uniformity. Key words: 2,4-D amine, droplet drift, aspirated air samplers, flat fan tips, deposition uniformity, droplet size

Droplet size and efficacy of an adulticide-larvicide ultralow-volume formulation on Aedes aegypti using different solvents and spray application methods

2011 ◽  
Vol 68 (1) ◽  
pp. 137-141 ◽  
Author(s):  
Laura Harburguer ◽  
Emilia Seccacini ◽  
Susana Licastro ◽  
Eduardo Zerba ◽  
Héctor Masuh
Keyword(s):  
Aedes Aegypti ◽  
Droplet Size ◽  
Spray Application ◽  
Application Methods
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