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

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.

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Effect of Nozzle Angleson Spray Losses Reduction

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.564.216 ◽

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.

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

Applied Sciences ◽

10.3390/app10217826 ◽

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.

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

Sustainability ◽

10.3390/su12125068 ◽

2020 ◽

Vol 12 (12) ◽

pp. 5068 ◽

Cited By ~ 1

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

Journal of Experimental Agriculture International ◽

10.9734/jeai/2019/v38i330304 ◽

2019 ◽

pp. 1-7 ◽

Cited By ~ 1

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.

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DROPLET SIZE SPECTRA, DRIFT POTENTIAL, AND GROUND DEPOSITION PATTERN OF HERBICIDE SPRAYS

Canadian Journal of Plant Science ◽

10.4141/cjps74-091 ◽

1974 ◽

Vol 54 (3) ◽

pp. 541-546 ◽

Cited By ~ 13

Author(s):

J. MAYBANK ◽

K. YOSHIDA ◽

R. GROVER

Keyword(s):

Droplet Size ◽

Field Experiments ◽

Control Technique ◽

Hydraulic Pressure ◽

Spray Drift ◽

Reduced Pressure ◽

Size Spectra ◽

Nozzle Height ◽

Drift Potential ◽

Ground Deposition

Droplet size spectra and quantity of spray drift were studied for two types of flat-fan nozzles. The large orifice flat-fan nozzles operated at reduced pressure produced less drift potential; however, the spectrum of droplets was coarse. The properties of the whirl jet cone nozzles suggest that these would also produce less drift-prone material. The spray fraction likely to drift was calculated to be approximately 3–8% of the total volume of spray with the flat-fan nozzles. This was confirmed in field experiments using labelled herbicides and a liquid scintillation counting technique. A realistic pattern of the distribution of ground deposition density over a swath (obtained by field experiments), and a factor of three in density fluctuation suggest that the generally accepted concept of uniformity of spray distribution in experimental plots should be modified. Recommendations of spray drift control technique were proposed regarding the hydraulic pressure, nozzle height and orientation, travelling speed/pressure, and the size of orifice.

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Drift measurements for conditions of hydrogen cyanamide spraying in kiwifruit

New Zealand Plant Protection ◽

10.30843/nzpp.2018.71.186 ◽

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.

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Droplet Size Impact on Efficacy of a Dicamba-plus-Glyphosate Mixture

Weed Technology ◽

10.1017/wet.2018.118 ◽

2019 ◽

Vol 33 (1) ◽

pp. 66-74 ◽

Cited By ~ 5

Author(s):

Thomas R. Butts ◽

Chase A. Samples ◽

Lucas X. Franca ◽

Darrin M. Dodds ◽

Daniel B. Reynolds ◽

...

Keyword(s):

Droplet Size ◽

Herbicide Resistance ◽

Weed Management ◽

Integrated Weed Management ◽

Weed Species ◽

Application Process ◽

Biological Efficacy ◽

Particle Drift ◽

Drift Potential ◽

Droplet Sizes

AbstractChemical weed control remains a widely used component of integrated weed management strategies because of its cost-effectiveness and rapid removal of crop pests. Additionally, dicamba-plus-glyphosate mixtures are a commonly recommended herbicide combination to combat herbicide resistance, specifically in recently commercially released dicamba-tolerant soybean and cotton. However, increased spray drift concerns and antagonistic interactions require that the application process be optimized to maximize biological efficacy while minimizing environmental contamination potential. Field research was conducted in 2016, 2017, and 2018 across three locations (Mississippi, Nebraska, and North Dakota) for a total of six site-years. The objectives were to characterize the efficacy of a range of droplet sizes [150 µm (Fine) to 900 µm (Ultra Coarse)] using a dicamba-plus-glyphosate mixture and to create novel weed management recommendations utilizing pulse-width modulation (PWM) sprayer technology. Results across pooled site-years indicated that a droplet size of 395 µm (Coarse) maximized weed mortality from a dicamba-plus-glyphosate mixture at 94 L ha–1. However, droplet size could be increased to 620 µm (Extremely Coarse) to maintain 90% of the maximum weed mortality while further mitigating particle drift potential. Although generalized droplet size recommendations could be created across site-years, optimum droplet sizes within each site-year varied considerably and may be dependent on weed species, geographic location, weather conditions, and herbicide resistance(s) present in the field. The precise, site-specific application of a dicamba-plus-glyphosate mixture using the results of this research will allow applicators to more effectively utilize PWM sprayers, reduce particle drift potential, maintain biological efficacy, and reduce the selection pressure for the evolution of herbicide-resistant weeds.

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Spray Characteristics of Rotary Micro Sprinkler Nozzles Used in Orchard Pesticide Delivery

Transactions of the ASABE ◽

10.13031/trans.13445 ◽

2020 ◽

Vol 63 (6) ◽

pp. 1845-1853

Author(s):

Huseyin Guler ◽

Zhihong Zhang ◽

Heping Zhu ◽

Matthew Grieshop ◽

Mark A. Ledebuhr

Keyword(s):

Droplet Size ◽

Delivery Systems ◽

Orifice Diameter ◽

List Type ◽

Spray Drift ◽

Operating Pressure ◽

Size Distributions ◽

Multiple Variable ◽

Droplet Sizes ◽

Droplet Size Distributions

HighlightsDroplet sizes were determined for rotary micro sprinkler nozzles used in solid set canopy delivery systems.An empirical multiple-variable model was developed to predict volume median diameters in spray patterns.Sprinkler nozzles produced medium to coarse droplets to minimize pesticide drift in orchards and trellised systems.Droplet size information can be used to select optimal nozzles for either irrigation or pesticide delivery systems.Abstract. Rotary micro sprinkler nozzles can be used for both irrigation and pesticide applications in orchard systems, but little to no information is available on their droplet size distributions. In this study, the droplet size distributions were investigated and described for rotary micro sprinkler nozzles with five different orifice diameters. A particle/droplet laser image analysis system was used to measure droplet spectra at two pressures (207 and 310 kPa) and two radial distances (0.25 and 0.85 m) from the sprinkler nozzle center. Nozzle orifice sizes, rotational speeds, and flow rates were also measured. Droplet sizes varied with the orifice size, operating pressure, and sampling location. Spiral-shaped spray patterns formed due to the spinning discharge port, within which droplet densities varied with location, orifice diameter, and operating pressure. The volume medium diameters (Dv0.5) for green-black, orange-blue, black-black, blue-black, and red-gray nozzles were respectively 317, 338, 379, 352, and 218 µm at 207 kPa and 283, 250, 283, 270, and 222 µm at 310 kPa. An empirical multiple-variable regression model was developed to predict Dv0.5 in the spray patterns discharged from the nozzles. Test results demonstrated that the rotary micro sprinkler nozzles produced medium to coarse droplets that could be used to minimize spray drift while maintaining efficacy in orchard pesticide applications. Keywords: Chemical application, Droplet size, Irrigation, Rotary nozzle, Spray drift reduction.

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Performance of two combine harvester header in soybean crops

Scientific Electronic Archives ◽

10.36560/1312020737 ◽

2020 ◽

Vol 13 (2) ◽

pp. 1

Author(s):

E. M. Samogim ◽

T. C. Oliveira ◽

Z. N. Figueiredo ◽

J. M. B. Vanini

Keyword(s):

Experimental Design ◽

Crop Yield ◽

Field Performance ◽

Travel Speed ◽

The Other ◽

Combine Data ◽

Mato Grosso ◽

Tukey Test ◽

Combine Harvester ◽

And Performance

The combine harvest for soybean crops market are currently available two types of combine with header or platform, one of conventional with revolving reel with metal or plastic teeth to cause the cut crop to fall into the auger header and the other called "draper" headers that use a fabric or rubber apron instead of a cross auger, there are few test about performance of this combine header for soybean in Mato Grosso State. The aim of this work was to evaluate the soybean harvesting quantitative losses and performance using two types combine header in four travel speed. The experiment was conducted during soybean crops season 2014/15, the farm Tamboril in the municipality of Pontes e Lacerda, State of Mato Grosso. The was used the experimental design of randomized blocks, evaluating four forward harvesting speeds (4 km h-1, 5 km h-1, 6 km h-1 and 7 km h-1), the natural crops losses were analyzed, loss caused by the combine harvester (combine header, internal mechanisms and total losses) and was also estimated the field performance of each combine. Data were submitted to analysis of variance by F test and compared of the average by Tukey test at 5% probability. The results show the draper header presents a smaller amount of total loss and in most crop yield when compared with the conventional cross auger.

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Effects of herbicides on growth and number of actinomycetes in soil and in vitro

Pesticidi i fitomedicina ◽

10.2298/pif1604121s ◽

2016 ◽

Vol 31 (3-4) ◽

pp. 121-128 ◽

Cited By ~ 3

Author(s):

Ljiljana Santric ◽

Ljiljana Radivojevic ◽

Jelena Gajic-Umiljendic ◽

Marija Saric-Krsmanovic ◽

Rada Djurovic-Pejcev

Keyword(s):

Growth And Development ◽

Application Rate ◽

Significant Inhibition ◽

The Other ◽

Transient Effects ◽

Herbicide Application ◽

Laboratory Conditions

This study was conducted under laboratory conditions to investigate the effects of herbicides (nicosulfuron, metribuzin and glyphosate) on the number of actinomycetes in soil and growth of several isolates of actinomycetes in vitro. The lowest tested concentrations equalled the recommended rates (1X), while the other three were five-fold (5X), ten-fold (10X) and fifty-fold (50X). Samples were collected for analysis 3, 7, 14, 30 and 45 days after herbicide application. Treatment with the two highest concentrations of herbicides (10X and 50X) caused a significant inhibition of the number of actinomycetes in soil and growth of the isolates in vitro. The obtained data indicated that the effect depended on the type of herbicide, application rate, duration of activity and actinomycetes isolate. The study suggests that herbicide applications in soil caused transient effects on the growth and development on actinomycetes community in soil.

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