Comparison of Spray Droplet Size and Coverage for Nozzles Used for Agronomic Weed Control

2009 ◽  
Author(s):  
Robert E Wolf ◽  
Cory Friedli ◽  
Brian Lauer
Keyword(s):  
Weed Control ◽  
Droplet Size ◽  
Spray Droplet

Effect of Formulation and Nozzle Type on Droplet Size with Isopropylamine and Trimesium Salts of Glyphosate

1997 ◽  
Vol 11 (4) ◽  
pp. 639-643 ◽  
Author(s):  
Thomas C. Mueller ◽  
Alvin R. Womac
Keyword(s):  
Nonionic Surfactant ◽  
Weed Control ◽  
Droplet Size ◽  
Management Tool ◽  
Spray Droplet ◽  
Droplet Distribution ◽  
Extended Range ◽  
Glyphosate Formulation ◽  
Nozzle Type ◽  
Flat Fan Nozzle

When spray mixtures were examined using a laser spray droplet analyzer, the new isopropylamine glyphosate formulation produced more small droplets than a previous isopropylamine salt of glyphosate formulation or glyphosate–trimesium plus nonionic surfactant. The use of a pre-orifice flat-fan nozzle and an impact type flat-fan nozzle reduced the amount of small droplets produced compared to an existing extended range flat-fan nozzle, while maintaining a spray droplet distribution that could still provide good weed control. The new nozzle technologies could provide a useful management tool to manage potential drift situations.

Fading Activities of Herbicidal Droplets Amended with Emulsifiable Spray Adjuvants on Cucurbitaceous Leaves

2018 ◽  
Vol 61 (6) ◽  
pp. 1881-1888
Author(s):  
Jeng-Liang Lin ◽  
Heping Zhu
Keyword(s):  
Weed Control ◽  
Droplet Size ◽  
Spray Deposition ◽  
Herbicide Application ◽  
Spray Droplet ◽  
Coverage Area ◽  
Maximum Coverage ◽  
Fading Time ◽  
Selection Of ◽  
Spray Adjuvants

Abstract. Understanding reactions of surfactant-amended droplets on difficult-to-wet weed surfaces could help develop application strategies to increase herbicide efficacy. Behaviors of herbicidal droplets containing different emulsifiable anti-evaporation spray adjuvants were investigated by characterizing 250 and 450 µm herbicidal droplet dispersion and fading time on cucurbitaceous leaves placed inside a 20°C chamber at 30% and 60% relative humidity (RH). Droplet maximum coverage area increased with droplet size but not with RH, while droplet fading time increased with both droplet size and RH. Despite 450 µm droplets having greater maximum coverage area than 250 µm droplets, the larger droplets had higher fading rates and lower ratios of maximum coverage area to droplet volume. Droplet maximum coverage area and fading time on leaves were affected by adding spray adjuvants to the herbicide-only solution. The Uptake surfactant was more effective than the other two surfactants (AntiEvap+BS1000 and Enhance) in increasing droplet maximum coverage area and fading time. Compared to the herbicide-only solution, addition of Uptake surfactant to the herbicide solution could increase maximum coverage area by 68% and 52% for 250 and 450 µm droplets, respectively, but addition of AntiEvap+BS1000 or Enhance surfactants did not show significant increase. Similarly, addition of Uptake surfactant to the herbicide-only solution increased droplet fading times by 11.1% and 13.2% at 30% and 60% RH, respectively, for 250 µm droplets and by 34.7% and 2.8% at 30% and 60% RH, respectively, for 450 µm droplets. In contrast, addition of AntiEvap+BS1000 surfactant reduced fading time, and addition of Enhance surfactant did not significantly affect fading time. Therefore, appropriate selection of spray adjuvants for herbicide applications could significantly influence droplet deposit behaviors on cucurbitaceous leaves, leading to improved effectiveness of weed control. Keywords: Herbicide application, Spray deposition, Spray droplet, Surfactant, Weed control.

Evaluation of optimal droplet size for control of Palmer amaranth (Amaranthus palmeri) with acifluorfen

2020 ◽  
Vol 34 (4) ◽  
pp. 511-519
Author(s):  
Lucas X. Franca ◽  
Darrin M. Dodds ◽  
Thomas R. Butts ◽  
Greg R. Kruger ◽  
Daniel B. Reynolds ◽  
...  
Keyword(s):  
Weed Control ◽  
Droplet Size ◽  
Prediction Models ◽  
Additive Model ◽  
Plant Morphology ◽  
Palmer Amaranth ◽  
Future Research ◽  
Geographical Differences ◽  
Spray Droplet ◽  
Drift Field

AbstractAcifluorfen is a nonsystemic PPO-inhibiting herbicide commonly used for POST Palmer amaranth control in soybean, peanut, and rice across the southern United States. Concerns have been raised regarding herbicide selection pressure and particle drift, increasing the need for application practices that optimize herbicide efficacy while mitigating spray drift. Field research was conducted in 2016, 2017, and 2018 in Mississippi and Nebraska to evaluate the influence of a range of spray droplet sizes [150 μm (Fine) to 900 μm (Ultra Coarse)], using acifluorfen to create a novel Palmer amaranth management recommendation using pulse width modulation (PWM) technology. A pooled site-year generalized additive model (GAM) analysis suggested that 150-μm (Fine) droplets should be used to obtain the greatest Palmer amaranth control and dry biomass reduction. Nevertheless, GAM models indicated that only 7.2% of the variability observed in Palmer amaranth control was due to differences in spray droplet size. Therefore, location-specific GAM analyses were performed to account for geographical differences to increase the accuracy of prediction models. GAM models suggested that 250-μm (Medium) droplets optimize acifluorfen efficacy on Palmer amaranth in Dundee, MS, and 310-μm (Medium) droplets could sustain 90% of maximum weed control. Specific models for Beaver City, NE, indicated that 150-μm (Fine) droplets provide maximum Palmer amaranth control, and 340-μm (Medium) droplets could maintain 90% of greatest weed control. For Robinsonville, MS, optimal Palmer amaranth control could be obtained with 370-μm (Coarse) droplets, and 90% maximum control could be sustained with 680 μm (Ultra Coarse) droplets. Differences in optimal droplet size across location could be a result of convoluted interactions between droplet size, weather conditions, population density, plant morphology, and soil fertility levels. Future research should adopt a holistic approach to identify and investigate the influence of environmental and application parameters to optimize droplet size recommendations.

Spray Droplet Size Distributions Delivered by Air Blast Orchard Sprayers

1977 ◽  
Vol 20 (2) ◽  
pp. 0232-0237 ◽  
Author(s):  
D. L. Reichard ◽  
H. J. Retzer ◽  
L. A. Liljedahl ◽  
F. R. Hall
Keyword(s):  
Droplet Size ◽  
Size Distributions ◽  
Spray Droplet ◽  
Air Blast ◽  
Droplet Size Distributions

Droplet size impact on lactofen and acifluorfen efficacy for Palmer amaranth (Amaranthus palmeri) control

2019 ◽  
Vol 34 (3) ◽  
pp. 416-423
Author(s):  
Lucas X. Franca ◽  
Darrin M. Dodds ◽  
Thomas R. Butts ◽  
Greg R. Kruger ◽  
Daniel B. Reynolds ◽  
...  
Keyword(s):  
Droplet Size ◽  
Pulse Width Modulation ◽  
Effective Means ◽  
Cost Effective ◽  
Palmer Amaranth ◽  
Target Movement ◽  
Spray Droplet ◽  
Spray Droplets ◽  
Droplet Sizes ◽  
Biomass Reduction

AbstractHerbicide applications performed with pulse width modulation (PWM) sprayers to deliver specific spray droplet sizes could maintain product efficacy, minimize potential off-target movement, and increase flexibility in field operations. Given the continuous expansion of herbicide-resistant Palmer amaranth populations across the southern and midwestern United States, efficacious and cost-effective means of application are needed to maximize Palmer amaranth control. Experiments were conducted in two locations in Mississippi (2016, 2017, and 2018) and one location in Nebraska (2016 and 2017) for a total of 7 site-years. The objective of this study was to evaluate the influence of a range of spray droplet sizes [150 (Fine) to 900 μm (Ultra Coarse)] on lactofen and acifluorfen efficacy for Palmer amaranth control. The results of this research indicated that spray droplet size did not influence lactofen efficacy on Palmer amaranth. Palmer amaranth control and percent dry-biomass reduction remained consistent with lactofen applied within the aforementioned droplet size range. Therefore, larger spray droplets should be used as part of a drift mitigation approach. In contrast, acifluorfen application with 300-μm (Medium) spray droplets provided the greatest Palmer amaranth control. Although percent biomass reduction was numerically greater with 300-μm (Medium) droplets, results did not differ with respect to spray droplet size, possibly as a result of initial plant injury, causing weight loss, followed by regrowth. Overall, 900-μm (Ultra Coarse) droplets could be used effectively without compromising lactofen efficacy on Palmer amaranth, and 300-μm (Medium) droplets should be used to achieve maximum Palmer amaranth control with acifluorfen.

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