Effects of Spray Volume and Droplet Size on Herbicide Efficacy PDF Download

Author: William Harris Morris
Publisher:
ISBN:
Category : Herbicides
Languages : en
Pages : 44

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Author: Barbara Houston
Publisher:
ISBN:
Category :
Languages : en
Pages : 0

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Book Description
Herbicide performance is directly related to the amount of active ingredient that has been deposited on the plant. Hence, spray solution characteristics and application parameters are crucial in determining the efficacy of an herbicide application. To maximize the effectiveness of chemical control, methods to deliver full chemical dose must be utilized: allowing the active ingredient to be readily absorbed once added to the carrier and mitigating off-target movement and low herbicide doses. Water is the most frequently used carrier in herbicide applications. Chemical parameters, such as water hardness and pH, can have a critical role in herbicide performance. It is generally believed that weak acid herbicides, such as glyphosate and 2,4-D, have higher dissociation in higher carrier pH, which leads to decreased uptake into plants. Moreover, increased concentration of hard water cations may have antagonistic effect on weak acid herbicide applications. To overcome the negative effect of water quality on weak acid applications, addition of water conditioning adjuvants is recommended. Carrier volume and droplet size are crucial parameters in application technology that can also impact herbicide performance. Nozzles and their spray characteristics have gone under significant development in past decades to enhance spray potential under a wide range of conditions. Introduction of air inclusion nozzles provided the ability to create larger droplets at the same pressure and flow rate as conventional nozzles, resulting in less drift. Controlling off target movement essentiality decreases the potential for herbicide resistance selection on weeds, as well as injury on sensitive crops. Hence, the objectives of this research were to investigate water quality, carrier volume and droplet size effects on herbicide efficacy and drift potential.

Author: Jake McNeal
Publisher:
ISBN:
Category :
Languages : en
Pages : 106

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The application of pesticides in agriculture production systems is a complex process and involves a series of factors that dynamically interact to impact overall pesticide application efficacy. Spray droplet formation, target impaction and deposition, plant uptake, and subsequent biological response are all functions of pesticide active ingredient, nozzle selection, application pressure, and carrier volume. Smaller spray droplets with a lower kinetic energy result in greater spray droplet retention on the leaf surface relative to larger droplets. Consequently, larger spray droplets with higher kinetic energy are poorly retained on the leaf surface and yield minimal coverage of leaf surface tissue. While smaller droplets maximize target coverage and spray droplet retention, larger spray droplets minimize off-target movement and agrichemical transport. Consequently, application factors that maximize pesticide efficacy and minimize off-target movement are often incongruous elements. Therefore, the objective of this research was to evaluate the impact of carrier volume and spray droplet size on the efficacy of various pesticide applications in Mississippi. These data indicate that 1) for thrips and tarnished plant bug control, acephate and sulfoxaflor are superior dicamba application partners relative to dimethoate and thiamethoxam, respectively, insecticide efficacy did not vary due to spray droplet size when applied without dicamba, and maximum efficacy was achieved with a carrier volume of 187 L ha-1; 2) dicamba + acephate and dicamba + thiamethoxam or sulfoxaflor are efficacious options to control Palmer amaranth relative to dicamba applied alone, and maximum Palmer amaranth control was achieved with a carrier volume of 187 L ha-1; 3) cotton defoliation efficacy is positively and negatively correlated with carrier volume and spray droplet size, respectively, and maximum efficacy was achieved with cotton defoliation programs consisting of two-applications, each with a carrier volume of 187 L ha-1 and 200 μm droplets; 4) soybean harvest aid efficacy is primarily a function of the harvest aid applied and that the impact of carrier volume and spray droplet size varies across harvest aids. However, when paraquat is applied, a carrier volume between 47 and 187 L ha-1 should be utilized with droplets of 200-500 μm to maximize harvest aid efficacy.

Author: Brian Richardson
Publisher:
ISBN:
Category : Herbicides
Languages : en
Pages : 302

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To improve the efficiency of herbicide applications, each stage of the spray application process must be considered. Two of these stages, the process of spray deposition within plant canopies and the influence of the form of the spray deposit on efficacy were investigated. The effect of droplet size, spray volume, and droplet trajectory on the vertical distribution of spray deposits was measured within canopies of bracken fern (Pteridium aquilinum L. Kuhn) and greenleaf manzanita (Arctostaphylos patula Greene). Spray containing a fluorescent tracer was applied using spinning disc and flat fan nozzles, and deposition was measured on horizontal strings placed at various levels in the canopy. Spray deposition profiles were not significantly affected by droplet size. With bracken, 50 1/ha application volumes gave greater deposition than at 100 1/ha. Spray deposition was increased, particularly with the vertically oriented manzanita foliage, when droplets entered the canopy with a significant horizontal component to their trajectory. The foliage structure of bracken and manzanita canopies was measured using a point quadrat vegetation sampling technique. A model to predict spray deposition profiles was then developed, and observed deposition profiles were compared to predicted profiles. With bracken, the modelled profile was close to, but underestimated, the measured deposit attenuation. With manzanita, the predicted deposit profile overestimated deposit attenuation, suggesting that the vertically moving droplets were reflected from the foliage inclined at 72° from the horizontal. The effects of droplet size, spray volume, and herbicide rate on phytotoxicity were also investigated. Glyphosate and fluroxypyr were applied to bracken fern and greenleaf manzanita, respectively, using spinning discs. Increasing glyphosate concentration or the area of foliage wetted were equally effective in enhancing efficacy on bracken fern. A smaller droplet size and higher spray volume increased the efficacy of fluroxypyr on manzanita. For both species and chemical combinations, the addition of a surfactant, L-77, showed the greatest potential for increasing the efficiency of spray applications. In general, using small droplets with a horizontal velocity component, and a suitable surfactant will increase spray efficiency. High herbicide concentrations may be beneficial if localized scorch does not occur.

Author: Justin Harrison Carroll
Publisher:
ISBN:
Category : Herbicides
Languages : en
Pages : 108

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An Apache AS1220 self-propelled boom sprayer with a 27.4 m (90 ft) boom was equipped with different sizes (02, 04 and 06) and types (TeeJet AI, XR, AIXR and TTI) of nozzles to achieve medium, very coarse and ultra coarse droplet sizes traveling 11 km/h (7 mph), 19 km/h (12 mph), and 29 km/h (18 mph). These combinations of speed and droplet size were evaluated for percent coverage of the spray and percent control of targeted weeds 3, 7, and 15 days after treatment (DAT). Four replications were conducted for each speed and droplet size combination except for at 19 km/h (12 mph) where only three replications were used (35 plots). Significant (p

Author: Andre de Oliveira Rodrigues
Publisher:
ISBN:
Category :
Languages : en
Pages : 93

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Book Description
One of the largest challenges in agriculture is weed management. Improper or sub-optimal application techniques can cause decreased weed control and increased environmental contamination. Effective weed management is highly correlated with the product and the application method. Herbicide performance are affected by environmental conditions; they influence the physiology and growth of a plant and as well the herbicide performance. Among all environmental factors, rain shortly after herbicide application is one of the most harmful issues to the performance of the herbicide. Droplet size is a key factor in pesticide applications in regards to both drift and efficacy. Droplet size can be altered by several application parameters, such as the nozzle type, pressure, orifice size and spray solution. Droplet size is a key component in pesticide application with respect to overall application efficacy and off-target movement. As tank mix ingredients can significantly influence the resulting droplet size, agitation systems are critical to ensuring proper mixing of all components and overall performance. Sitting time, a period where the tank is held in a non-agitated state, potentially affects droplet size as well. The objectives of this research were: 1) understand the influence of nozzle spacing, boom height, nozzle type, on weed control, also expand the scientific knowledge on aforementioned parameters. 2) Evaluate the effect of rainfall after herbicide application on weed control, following certain intervals in order to understand the wash off effect. 3) Analyze the impact of nozzle type, application speed and pressure on weed control, in order to contribute to a more reliable recommendation of such parameters. This research highlights the impact of parameters regulated by the sprayer on weed control and allow a better understanding of how non-chemical parameters affect the efficacy on weed management, as well as a greater understanding on absorption and evaporation of herbicide plus losses of application efficacy. The results will clarify some of the most concerning question on one of the most complex process in agriculture.

Author: Thomas R. Butts
Publisher:
ISBN: 9780438262904
Category : Spraying and dusting in agriculture
Languages : en
Pages : 0

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Book Description
The objectives of this research were to: (1) identify the influence of application parameters on droplet size, droplet exit velocity, nozzle tip pressure, and spray pattern uniformity from a PWM sprayer, (2) create best use PWM recommendations to optimize pesticide applications from these sprayers, (3) investigate the effect of spray droplet size and carrier volume on the efficacy of multiple herbicide solutions, (4) establish novel weed management recommendations based on an optimum droplet size, and (5) determine the plausibility of using PWM sprayers in site-specific weed management strategies.

Author: Pedro Henrique Urach Ferreira
Publisher:
ISBN:
Category :
Languages : en
Pages : 92

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Book Description
Field studies conducted in Missouri and Mississippi, in 2017 and 2018, respectively, indicated no droplet size effect on PRE herbicide efficacy, regardless of the herbicide, weed, soil, crop residue and weather conditions during spraying. Nozzle type enhanced herbicide efficacy for one location and herbicide. The TTI60 dual fan nozzle increased pendimethalin weed control, up to 91%, in a high organic matter (OM) soil with large clods and substantial weed pressure. Pendimethalin efficacy was reduced under high OM soils (> 2%) while metribuzin efficacy was reduced under low OM (

Author: Elizabeth J. Jones
Publisher:
ISBN:
Category : Herbicides
Languages : en
Pages : 20

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Author: Fiaz Ahmad
Publisher: BoD – Books on Demand
ISBN: 1838819215
Category : Technology & Engineering
Languages : en
Pages : 538

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Book Description
Food security is one of the primary themes of the United Nations’ Sustainable Development Goals. In this regard, agricultural engineering is considered the backbone of agriculture, and agricultural mechanization is considered a helpful way to enhance crop yield and farmers’ profitability. Technology in Agriculture presents research in the field of agricultural engineering technologies and applications in agricultural equipment engineering, biosystem engineering, energy systems engineering, and computers in agriculture. It provides an overview of recent advancements in agricultural engineering and examines key aspects of emerging technologies and their applications. In addition, the book explores modern methodologies such as artificial intelligence and machine learning for agricultural mechanization.