Effect of Air-assisted Spray Application Rate on Spray Droplet Deposition Distribution on Fruit Tree Canopies

2016 ◽  
Vol 32 (6) ◽  
pp. 739-749 ◽  
Keyword(s):  
Application Rate ◽  
Fruit Tree ◽  
Spray Application ◽  
Droplet Deposition ◽  
Spray Droplet ◽  
Tree Canopies

scholarly journals Influence of Spray Volume on Spray Deposition and Coverage within Nursery Trees

2008 ◽  
Vol 26 (1) ◽  
pp. 51-57 ◽  
Author(s):  
H. Zhu ◽  
R.H. Zondag ◽  
R.C. Derksen ◽  
M. Reding ◽  
C.R. Krause
Keyword(s):  
Spray Deposition ◽  
Foliar Spray ◽  
Tree Height ◽  
Application Rate ◽  
Spray Application ◽  
Application Rates ◽  
Tree Canopies ◽  
Nursery Trees ◽  
Spray Volume ◽  
Volume Method

Abstract Information on better utilizing airblast sprayers to achieve high pesticide spray application efficiency in nursery tree production is needed. Foliar spray deposition and coverage at different heights inside crabapple tree canopies were investigated for a conventional airblast sprayer operating at four different application rates ranging from 230 to 900 liters/ha [24 to 94 gallons per acre (GPA)]. Deposition on the ground at various distances from the sprayer was also measured at the 700 liters/ha (73 GPA) application rate. Foliar deposition and coverage on targets below 2.6 m (8.5 ft) inside tree canopies increased as the application rate increased, but the increase in the coverage was much lower than the deposition. For trees taller than 2.6 m (8.5 ft), the sprayer could not deliver uniform spray deposition and coverage across the tree height. The portion of trees below 2.1 m (6.9 ft) was well covered by the spray deposits with 230 liters/ha (24 GPA) application rate while higher application rates resulted in over spray application. Less than 30% of total spray volume was deposited on target trees while over 34% of the total spray volume was lost on the ground. The tree-row volume method should include foliage density and tree-row gaps to avoid excessive estimation of spray application rates for nursery tree crops.

SPRAY DROPLET DISTRIBUTION AND HERBICIDE UPTAKE IN SEQUENTIAL APPLICATIONS OF DICLOFOP-METHYL AND MCPA FOR WEED CONTROL IN BARLEY

1979 ◽  
Vol 59 (1) ◽  
pp. 93-98 ◽  
Author(s):  
F. A. QURESHI ◽  
W. H. VANDEN BORN
Keyword(s):  
Acetic Acid ◽  
Leaf Surface ◽  
Avena Fatua ◽  
Wild Oat ◽  
Spray Application ◽  
Spray Droplet ◽  
Wild Oats ◽  
Droplet Distribution ◽  
Spray Droplets ◽  
Spray Volume

Uptake of 14C-diclofop-methyl {methyl 2-[4-(2,4-dichlorophenoxy)phenoxy propanoate]} by leaves of wild oats (Avena fatua L.) was reduced significantly in the presence of MCPA {[(4-chloro-o-tolyl)oxy]acetic acid]}, especially the dimethylamine formulation. If the herbicides were applied separately, the degree of interference with uptake depended on the extent of overlap of droplets of the two spray preparations on the leaf surface. Spray volume and direction of spray application were important factors in minimizing the mixing of spray droplets on the leaves if the two herbicides were applied separately with a tandem arrangement of two sprayers. Such a sequential application of MCPA ester and diclofop-methyl in a field experiment provided significantly greater wild oat control than could be obtained with a tank mix of the same two herbicides, but the results were not consistent enough to recommend the procedure for practical use.

scholarly journals Spray Deposition on Weeds (Palmer Amaranth and Morningglory) from a Remotely Piloted Aerial Application System and Backpack Sprayer

Drones ◽  
2020 ◽  
Vol 4 (3) ◽  
pp. 59
Author(s):  
Daniel Martin ◽  
Vijay Singh ◽  
Mohamed A. Latheef ◽  
Muthukumar Bagavathiannan
Keyword(s):  
Spray Deposition ◽  
Tap Water ◽  
Application Rate ◽  
Palmer Amaranth ◽  
Test Results ◽  
Herbicide Application ◽  
Aerial Application ◽  
Spray Droplet ◽  
Application System ◽  
Leaf Surfaces

This study was designed to determine whether a remotely piloted aerial application system (RPAAS) could be used in lieu of a backpack sprayer for post-emergence herbicide application. Consequent to this objective, a spray mixture of tap water and fluorescent dye was applied on Palmer amaranth and ivyleaf morningglory using an RPAAS at 18.7 and 37.4 L·ha−1 and a CO2-pressurized backpack sprayer at a 140 L·ha−1 spray application rate. Spray efficiency (the proportion of applied spray collected on an artificial sampler) for the RPAAS treatments was comparable to that for the backpack sprayer. Fluorescent spray droplet density was significantly higher on the adaxial surface for the backpack sprayer treatment than that for the RPAAS platforms. The percent of spray droplets on the abaxial surface for the RPAAS aircraft at 37.4 L·ha−1 was 4-fold greater than that for the backpack sprayer at 140 L·ha−1. The increased spray deposition on the abaxial leaf surfaces was likely caused by rotor downwash and wind turbulence generated by the RPAAS which caused leaf fluttering. This improved spray deposition may help increase the efficacy of contact herbicides. Test results indicated that RPAASs may be used for herbicide application in lieu of conventional backpack sprayers.

Spray Droplet Deposition on a Three-Dimensional Object

1978 ◽  
Vol 21 (5) ◽  
pp. 0806-0812 ◽  
Author(s):  
G. L. Barker ◽  
J. F. Thompson ◽  
Jr. ◽  
E. D. Threadgill
Keyword(s):  
Three Dimensional ◽  
Droplet Deposition ◽  
Spray Droplet ◽  
Dimensional Object

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 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 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.

Architectural Characteristics and Heliotropism May Improve Spray Droplet Deposition in the Middle and Low Canopy Layers in Soybean

Crop Science ◽  
2018 ◽  
Vol 58 (5) ◽  
pp. 2029-2041 ◽  
Author(s):  
Mariele Müller ◽  
Miroslava Rakocevic ◽  
Andréia Caverzan ◽  
Walter Boller ◽  
Geraldo Chavarria
Keyword(s):  
Droplet Deposition ◽  
Spray Droplet ◽  
Architectural Characteristics
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