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

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.

Biomechanical Comparison of Fibrin Sealants for Mesh Fixation

2018 ◽  
Vol 84 (5) ◽  
pp. 633-636
Author(s):  
Charles P. Shahan ◽  
Nathaniel F. Stoikes ◽  
Esra Roan ◽  
Patrick Reese ◽  
David L. Webb ◽  
...  
Keyword(s):  
Mesh Fixation ◽  
Early Recurrence ◽  
Fixation Strength ◽  
Spray Application ◽  
Lap Shear ◽  
Application Techniques ◽  
Tissue Interface ◽  
Application Methods ◽  
Biomechanical Comparison ◽  
Early Fixation

Adhesive use for fixation in hernia repair allows for complete and immediate mesh surface area adherence. Little is known about the fixation strengths of the products and application methods available. The purpose of this study was to compare the immediate and early strength of fixation of Tisseel™ and Evicel™ using hand and spray application techniques. Sixteen Mongrel swine underwent implantation of large-pore, mid-weight polypropylene mesh fixated with either Tisseel™ or Evicel™, applied by hand or with a spray apparatus. Time points studied were zero and four days. All samples underwent lap shear testing to quantify the strength of the mesh–tissue interface as an indicator of mesh fixation strength. Thirty Day 4 and 16 Day 0 samples were tested. Manually applied Tisseel™ mean fixation strength was 2.05 N/cm at Day 0 and 6.02 N/cm at Day 4. Sprayed Tisseel™ had mean fixation strength of 1.22 N/cm at Day 0 and 7.21 N/cm at Day 4. Manually applied Evicel™ showed mean fixation strength of 0.92 N/cm at Day 0 and 6.73 N/cm at Day 4. Mean fixation strength of sprayed Evicel™ was 0.72 N/cm at Day 0 and 6.70 N/cm at Day 4. Analysis of variance showed no difference between groups at Day 0 or Day 4. Immediate strength of mesh fixation could have significant implications for early recurrence and mesh contraction. This study demonstrates that no difference exists in immediate or early fixation strength between these two brands of sealants or their method of 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 Reduced Herbicide Antagonism of Grass Weed Control through Spray Application Technique

Agronomy ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 1131 ◽  
Author(s):  
Luke H. Merritt ◽  
Jason Connor Ferguson ◽  
Ashli E. Brown-Johnson ◽  
Daniel B. Reynolds ◽  
Te-Ming Tseng ◽  
...  
Keyword(s):  
Weed Control ◽  
Environmental Sustainability ◽  
Field Studies ◽  
Italian Ryegrass ◽  
Spray Application ◽  
The Third ◽  
Application Method ◽  
Application Methods ◽  
Over The Top ◽  
Grass Weed

Dicamba and 2,4-D tolerance traits were introduced to soybean and cotton, allowing for over the top applications of these herbicides. Avoiding antagonism of glyphosate and clethodim by dicamba or 2,4-D is necessary to achieve optimum weed control. Three field studies were conducted in fallow fields with broadleaf signalgrass (Urochloa platyphylla) and Italian ryegrass (Lolium perenne ssp. multiflorum) pressure. A tractor-mounted dual boom sprayer was modified to spray one of three application methods: (1) two herbicides tanked-mixed (TMX); (2) two herbicides in separate tanks mixed in the boom line (MIL); and (3) two herbicides in separate tanks applied through separate booms simultaneously (SPB). One study compared the three application methods with sethoxydim applied with bentazon, the second compared clethodim applied with dicamba or 2,4-D, and the third compared glyphosate applied with dicamba or 2,4-D. In most cases over all three trials, there was a 7–15% increase in efficacy when using the SPB application method. Antagonism of all the herbicide combinations above was observed when applied using the TMX and MIL methods. In some cases, antagonism was avoided when using the SPB method. The separate boom application method increased efficacy, which allowed herbicides to be used more effectively, resulting in improved economic and environmental sustainability of herbicide applications.

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 Biocontrol of Listeria monocytogenes on Fresh-Cut Produce by Treatment with Lytic Bacteriophages and a Bacteriocin

2003 ◽  
Vol 69 (8) ◽  
pp. 4519-4526 ◽  
Author(s):  
Britta Leverentz ◽  
William S. Conway ◽  
Mary J. Camp ◽  
Wojciech J. Janisiewicz ◽  
Tamuna Abuladze ◽  
...  
Keyword(s):  
Listeria Monocytogenes ◽  
Pathogenic Bacteria ◽  
Fruits And Vegetables ◽  
Retail Market ◽  
Spray Application ◽  
The Past ◽  
Apple Slices ◽  
Fresh Cut ◽  
Application Methods ◽  
Honeydew Melon

ABSTRACT The fresh-cut produce industry has been the fastest-growing portion of the food retail market during the past 10 years, providing consumers with convenient and nutritious food. However, fresh-cut fruits and vegetables raise food safety concerns, because exposed tissue may be colonized more easily by pathogenic bacteria than intact produce. This is due to the higher availability of nutrients on cut surfaces and the greater potential for contamination because of the increased amount of handling. We found that applied Listeria monocytogenes populations survived and increased only slightly on fresh-cut Red Delicious apples stored at 10°C but increased significantly on fresh-cut honeydew melons stored at 10°C over 7 days. In addition, we examined the effect of lytic, L. monocytogenes-specific phages via two phage application methods, spraying and pipetting, on L. monocytogenes populations in artificially contaminated fresh-cut melons and apples. The phage mixture reduced L. monocytogenes populations by 2.0 to 4.6 log units over the control on honeydew melons. On apples, the reduction was below 0.4 log units. In combination with nisin (a bacteriocin), the phage mixture reduced L. monocytogenes populations by up to 5.7 log units on honeydew melon slices and by up to 2.3 log units on apple slices compared to the control. Nisin alone reduced L. monocytogenes populations by up to 3.2 log units on honeydew melon slices and by up to 2.0 log units on apple slices compared to the control. The phage titer was stable on melon slices, but declined rapidly on apple slices. The spray application of the phage and phage plus nisin reduced the bacterial numbers at least as much as the pipette application. The effectiveness of the phage treatment also depended on the initial concentration of L. monocytogenes.

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 The entomological impact of passive metofluthrin emanators against indoor Aedes aegypti: A randomized field trial

2021 ◽  
Vol 15 (1) ◽  
pp. e0009036
Author(s):  
Gregor J. Devine ◽  
Gonzalo M. Vazquez-Prokopec ◽  
Wilbert Bibiano-Marín ◽  
Norma Pavia-Ruz ◽  
Azael Che-Mendoza ◽  
...  
Keyword(s):  
Aedes Aegypti ◽  
Randomized Control Trial ◽  
Sampling Period ◽  
Target Population ◽  
Randomized Control ◽  
Application Methods ◽  
Pre Treatment ◽  
Rate Ratios ◽  
Blood Meals ◽  
Made In

Background In the absence of vaccines or drugs, insecticides are the mainstay of Aedes-borne disease control. Their utility is challenged by the slow deployment of resources, poor community compliance and inadequate household coverage. Novel application methods are required. Methodology and principal findings A 10% w/w metofluthrin “emanator” that passively disseminates insecticide from an impregnated net was evaluated in a randomized trial of 200 houses in Mexico. The devices were introduced at a rate of 1 per room and replaced at 3-week intervals. During each of 7 consecutive deployment cycles, indoor resting mosquitoes were sampled using aspirator collections. Assessments of mosquito landing behaviours were made in a subset of houses. Pre-treatment, there were no differences in Aedes aegypti indices between houses recruited to the control and treatment arms. Immediately after metofluthrin deployment, the entomological indices between the trial arms diverged. Averaged across the trial, there were significant reductions in Abundance Rate Ratios for total Ae. aegypti, female abundance and females that contained blood meals (2.5, 2.4 and 2.3-times fewer mosquitoes respectively; P<0.001). Average efficacy was 60.2% for total adults, 58.3% for females, and 57.2% for blood-fed females. The emanators also reduced mosquito landings by 90% from 12.5 to 1.2 per 10-minute sampling period (P<0.05). Homozygous forms of the pyrethroid resistant kdr alleles V410L, V1016L and F1534C were common in the target mosquito population; found in 39%, 24% and 95% of mosquitoes collected during the trial. Conclusions/Significance This is the first randomized control trial to evaluate the entomological impact of any volatile pyrethroid on urban Ae. aegypti. It demonstrates that volatile pyrethroids can have a sustained impact on Ae. aegypti population densities and human-vector contact indoors. These effects occur despite the presence of pyrethroid-resistant alleles in the target population. Formulations like these may have considerable utility for public health vector control responses.

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.

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