Download or read book The Effect of Adjuvants at High Spray Pressures for Aerial Applications written by W. Clint Hoffmann and published by . This book was released on 2016 with total page 16 pages. Available in PDF, EPUB and Kindle. Book excerpt: Controlling droplet size is a critical part of making any successful agrochemical spray application. This is particularly true for higher-speed aerial applications where secondary atomization from air shear becomes the most dominant factor driving spray droplet size. Previous research has shown that higher spray pressures can result in larger droplet-sized sprays by increasing the exit velocity of the spray liquid from the nozzles, which in turn decreases the differential velocity between the spray liquid and surrounding airstream, reducing secondary breakup. This work explores the effects of higher-than-normal spray pressures on two typical aerial application nozzles in the presence of a formulated herbicide spray solution, with and without additional adjuvants. Generally, the spray solution effects followed trends seen in previous studies, with crop oil-containing adjuvants resulting in the largest droplet-sized sprays and the silicones and polymers the smallest. Increasing spray pressure increased droplet size across all combinations of nozzle, airspeed, and spray solution, without exception. The most promising results from this work showed that for typical high-end application airspeeds, increasing spray pressure from the lowest to highest pressures tested generally resulted in spray classifications increasing at least one size coarser. The results from this work demonstrate that larger, faster-flying agricultural aircraft can adopt current methods, with potentially minor equipment adjustments, to generate medium and larger spray qualities and to allow for more efficient applications while meeting agrochemical product label requirements.
Download or read book Effects of Adjuvants and Dynamic Surface Tension on Spray Properties Under Simulated Aerial Conditions written by WR. Dexter and published by . This book was released on 1998 with total page 12 pages. Available in PDF, EPUB and Kindle. Book excerpt: The literature on the effects of active ingredients, adjuvants and surface active agents on the droplet size of agricultural sprays is reviewed. The effects of various agricultural adjuvants on the droplet size distributions of a herbicide sprayed in a wind tunnel simulating an aerial application were determined using a Malvern laser diffraction instrument. All adjuvants caused a decrease in droplet size, which varied with adjuvant type and concentration. Measurements of equilibrium surface tension, dynamic surface tension at 20 ms, density, and viscosity were recorded. Droplet size did not correlate linearly with equilibrium surface tension: only at the lowest surface tensions was any significant decrease in droplet size observed. Droplet size correlated better with dynamic surface tension for each adjuvant over most of the surface tension range, but with different slopes for each adjuvant. At high concentrations of surfactant, bubbles of air were observed within captured droplets and the size distribution became bimodal.
Download or read book Effects of Formulated Glyphosate and Adjuvant Tank Mixes on Atomization from Aerial Application Flat Fan Nozzles written by W. Clint Hoffmann and published by . This book was released on 2013 with total page 16 pages. Available in PDF, EPUB and Kindle. Book excerpt: This study was designed to determine if the present USDA-ARS spray-nozzle models, which were based on spray solutions of water plus non-ionic surfactant, could be used to estimate spray droplet-size data for different spray formulations through use of experimentally determined correction factors. Twelve spray-solution treatments were evaluated, ten of which contained a formulated glyphosate product and nine of these contained an additional tank-mix adjuvant. Droplet-size testing was conducted across multiple operational points (nozzle-orifice size, nozzle orientation, spray pressure, and airspeed), in a high-speed wind tunnel, which corresponds to the response surface experimental model used to develop the present spray-nozzle models. The hypothesis that the different treatment solutions would respond linearly across a range of operational parameters and that a correction factor from relative to water plus non-ionic surfactant solution was proven false. When compared to water or the water plus non-ionic surfactant, the changes in atomization across the operation spectrum of the nozzle were not consistent and varied by formulation. Attempts to apply regression fits for a correction factor based on solution physical properties were not successful. With the formulated glyphosate tank mix used, none of the adjuvants tested, except the polymer, showed significant changes in droplet size under the high air shear regime. Whereas there is likely a need to develop formulated product-specific atomization models, the further addition of adjuvants do not significantly change the atomization characteristics, and, as such, should not require a unique spray-nozzle model.
Download or read book Aerial Spray Adjuvants for Herbicidal Drift Control written by H. Gratkowski and published by . This book was released on 1973 with total page 24 pages. Available in PDF, EPUB and Kindle. Book excerpt: Increased public concern about pesticides requires that foresters reduce drift and insure precise application of herbicides to the areas requiring treatment. Drift control is necessary near waterways and other ecologically sensitive areas. This publication discusses available drift control adjuvants for herbicidal sprays. These include invert emulsions, thickening agents, particulating agents, and foam sprays. Commercially available adjuvants are described and their use, advantages, and disadvantages are discussed. Thickening agents and foam sprays show special promise for drift reduction in aerial application of herbicides on forest lands.
Download or read book Effects of Spray Adjuvants on Spray Droplet Size from a Rotary Atomizer written by Chenghai Yang and published by . This book was released on 2016 with total page 9 pages. Available in PDF, EPUB and Kindle. Book excerpt: Rotary atomizers are used in a number of aerial applications, such as forest pest spraying and mosquito control sprays. These types of atomizers have a rotating cage at speeds of 2,000 to 10,000 revolutions per minute (rpm) through which a spray is emitted and atomized. Many applicators routinely add spray adjuvants to change the droplet size, reduce drift potential, or to reduce evaporative effects of a particular spray solution; therefore, six commonly used classes of spray adjuvants were evaluated to determine their effects on droplet size. If an applicator's only concern was minimizing spray drift, the applicator could choose a polymer or high surfactant oil concentrate for helicopter speeds and a polymer for fixed-wing applications. For applicators working under hot, dry conditions where evaporation is a concern, choosing an oil-based adjuvant to help get better coverage by creating smaller droplets that do not evaporate would be recommended. Understanding the role the different adjuvant types play in the final droplet size of the spray is key to successfully setting up and making applications with rotary atomizers.
Download or read book The Impact of Spray Adjuvants on Solution Physical Properties and Spray Droplet Size written by Bradley K. Fritz and published by . This book was released on 2018 with total page 11 pages. Available in PDF, EPUB and Kindle. Book excerpt: Over the past several years, numerous anecdotes from aerial applicators have surfaced concerning observations of increased numbers of fine droplets seen in the applied spray clouds, often associated with tank mixtures that contain crop-oil concentrates (COCs) and foliar fertilizers (FFs). Efforts were made herein to correlate surface tension and viscosity to spray droplet size under a variety of aerial application conditions, but these efforts were unsuccessful. In addition, spray mixtures were examined to compare relative evaporation rates. Researchers are encouraged to actively pursue this line of work. The addition of several adjuvants and FFs were found to significantly affect spray droplet size, so applicators should pay careful attention to spray tank composition when making aerial spray applications.
Download or read book Spray Adjuvant Effects on Droplet Size Spectra Measured by Three Laser Based Systems in a High Speed Wind Tunnel written by J. B. Ross and published by . This book was released on 2008 with total page 12 pages. Available in PDF, EPUB and Kindle. Book excerpt: Spray droplet size has long been recognized as the most important variable that aerial applicators can influence to mitigate spray drift from the application site. There are several different technologies that are used by researchers to measure droplet size from spray nozzles. The objective of these studies was to determine the influence of eight spray adjuvants on the droplet size spectrum produced by two nozzles in a high-speed wind tunnel when characterized using three different droplet size measurement systems. The adjuvant, nozzles, and airspeeds used in these studies are commonly used by aerial applicators. Three droplet sizing systems (Malvern laser diffraction, PMS optical array probe, and LaVision laser imaging) were simultaneously operated to measure the spray droplet size spectra for each adjuvant, airspeed, and nozzle combination. Two spray nozzles (a D6-46 nozzle and a D2 straight stream nozzle) were evaluated in a high-speed wind tunnel at airspeeds of 45 and 58 m/sec. There were significant differences in the droplet size spectra produced by the eight spray adjuvants tested. There were also significant differences between the droplet size values reported by the three measurement systems (Malvern, LaVision, and PMS) evaluated; however, there was considerable agreement trendwise. In general, the Malvern reported smaller spray droplet size spectra values than the LaVision, while the PMS system generally reported the largest spray droplet size spectra values. These tests are the first reported studies where all three droplet sizing systems were operated simultaneously.
Download or read book Forest and Range Aerial Pesticide Application Technology written by Aerial Application Technology Workgroup and published by . This book was released on 1979 with total page 122 pages. Available in PDF, EPUB and Kindle. Book excerpt: Identifies and discusses 10 general problem areas related to forest and rangeland aerial spray application.
Download or read book Guidelines on Good Practice for Aerial Application of Pesticides written by and published by Food & Agriculture Org.. This book was released on 2001 with total page 52 pages. Available in PDF, EPUB and Kindle. Book excerpt: These guidelines have been prepared to offer practical help and guidance to all those involved in using pesticides for food and fibre production as well as in Public Health programmes. The guidelines in this document cover the application of pesticides using aircraft, including the activities on the ground in support of the aerial application .
Download or read book Pesticide Application Methods written by Graham Matthews and published by John Wiley & Sons. This book was released on 2014-03-31 with total page 556 pages. Available in PDF, EPUB and Kindle. Book excerpt: PESTICIDE APPLICATION METHODS Pesticide Application Methods is the standard work for all those involved in crop protection. This fully revised and expanded edition provides up-to-date information on the different types of application techniques and how they should be used to ensure efficient and effective pest control. The third edition of this excellent book was published more than 10 years ago, since when a number of important developments have taken place. Examples include changes to legislation both in the EU and USA concerning water quality. This has an impact on how spray is applied and, more particularly, how the sprayer is designed to minimise quantities that remain in the equipment when spraying is completed, and in addition inform how and when the sprayer is cleaned. Concern about spray drift has also continued and has led to more research on how to reduce the amount of spray that moves downwind from a treated area. Important new information on this topic is included within the new edition. Professor Graham Matthews has been joined by two new co-authors to increase the breadth and depth of coverage in this updated edition of Pesticide Application Methods. This important new edition is a commercially significant reference tool and will be of great use and interest to all those working in crop protection, including agricultural entomologists and plant pathologists, pesticide scientists, advisors and consultants, large-scale growers, agricultural and horticultural scientists, agrochemical industry personnel including those involved in equipment supply and product formulation. Libraries in government and commercial research establishments, universities and agricultural colleges where agricultural and biological sciences are studied and taught should have multiple copies of this definitive book on their shelves.
Download or read book Drift Control Adjuvant Benchmarking in Agricultural Spray Applications written by Kevin Penfield and published by . This book was released on 2014 with total page 12 pages. Available in PDF, EPUB and Kindle. Book excerpt: Drifting of fine droplets during the application of pesticides is an issue of increasing commercial and regulatory importance. Spray drift damages susceptible crops, wastes resources, and results in inconsistent weed control. Several strategies are currently used to mitigate this problem. These include enhanced nozzle technology, improved application techniques, and inclusion of drift control additives in the final tank mix. Elimination of small diameter droplets ("driftable fines") is a key goal. Measurements were made of droplet size distributions of sprayed pesticide formulations containing commercial products representative of the leading drift control technologies, including guar, polyacrylamides, lecithin, and oil/surfactant mixtures. Effects of spray nozzle and pressure were also evaluated. Nozzle technology plays a large role in determining the spray droplet size spectrum. However, there is a strong interplay between nozzle design and formulation variables. We found that drift control agents have greater impact on spray from flat fan nozzles. Also, the ranking of adjuvants depends on the nozzle technology in use: for glyphosate/ammonium sulfate solutions, polymers were more effective in reducing fines from a flat fan nozzle, while surfactant-based products were marginally superior when an air induction nozzle was used. The regulatory community is currently focused on mitigating the generation of small droplets. However, the generation of oversized droplets also effects spray efficacy. The impact of drift control agents on the breadth of the droplet size spectrum is an aspect of drift control which is often overlooked. We found that emulsion-based products tighten the droplet size distribution, while the polymer-based products shift the mean droplet diameter up, broadening the distribution in the process: while the latter effect may earn better ratings from regulatory agencies concerned exclusively with spray drift mitigation, it may be less helpful in enhancing application efficacy.
Download or read book Aerial Application of Agricultural Chemicals written by and published by . This book was released on 1976 with total page 36 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Aerial Application Equipment for Herbicidal Drift Reduction written by R. E. Stewart and published by . This book was released on 1976 with total page 28 pages. Available in PDF, EPUB and Kindle. Book excerpt: This publication provides silviculturists and managers of utility rights-of-way with a description and evaluation of available helicopter spray application equipment. Modified conventional equipment will reduce drift of sprays in normal carriers and apply various high-viscosity sprays. Specialized spray systems have found limited use in forestry; they are more commonly used on utility rights-of-way. Most of the available spray systems or spray adjuvants reduce but do not completely eliminate drift. Maximum drift reduction with present equipment and adjuvants is obtained with the Microfoil Boom.
Download or read book Apply Pesticides Correctly written by United States Pesticide Programs Office and published by . This book was released on 1976 with total page 16 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Effect of Adjuvants Pesticide Formulation and Spray Nozzle Tips on Spray Droplet Size written by Kelli L. Nelms and published by . This book was released on 2009 with total page 11 pages. Available in PDF, EPUB and Kindle. Book excerpt: Many factors, including adjuvants, pesticide formulations, and nozzle tips, affect spray droplet size. It is important to understand these factors as spray droplet size affects both drift and efficacy of pesticides, which is a main concern with pesticide application. A laser particle analyzer was used to determine the spray droplet size and distributions of a range of formulations sprayed through several types of nozzle tips. Nozzles included were extended range flat fan sizes 11003 and 11005 (Spraying Systems XR), air induction flat fan sizes 11005 and 11004 (AI), air induction extended range flat fan size 11005 (AIXR), preorifice flat fan size 11005 (TT), and a second preorifice flat fan size 2.5 (TF). Several deposition/retention adjuvants were studied, including Array, Interlock, In-Place, and Thrust. Another study looked at diflufenzopyr + dicamba (Status, BASF) in combination with several adjuvants. Also, three fungicides were evaluated at differing spray volumes. Results indicated that the droplet size of some nozzle tips is more affected than others by changes in the contents of the spray solution.
Download or read book Adjuvants and Agrochemicals written by Paul N. P. Chow and published by CRC Press. This book was released on 2018-01-18 with total page 236 pages. Available in PDF, EPUB and Kindle. Book excerpt: Studies of Adjuvants involve many scientific fields from basic research of the chemistry, through investigations into physiological effects and environmental impact, to mixture formulation and field use. These important areas are illustrated in these two volumes, which are contributions from the First International Symposium on Adjuvants for Agrochemicals, held in Brandon, Manitoba on August 5 to 7, 1986. A total of 200 participants from 19 countries met to discuss their common interest in adjuvant science, technology, and application. It is the editors hope that these volumes will stimulate interest in and promote a better understanding of the chemical, physiological, and agronomic aspects of adjuvants as they relate agrochemicals. In addition, the revisedAdjuvants for Agrochemicals: A Selected Bibliography of World Literature in the English Language will be a valuable resource for agricultural researchers and other users. We hope that adjuvant research will lead to even safer, more efficient, and more economical use of chemicals in agriculture and forestry.
Download or read book Wind Tunnel and Field Evaluation of Drift from Aerial Spray Applications with Multiple Spray Formulations written by Robert E. Wolf and published by . This book was released on 2013 with total page 18 pages. Available in PDF, EPUB and Kindle. Book excerpt: The impact of tank mix adjuvants and a formulated fungicide on spray atomization and in-field movement under aerial application conditions was examined. High speed wind tunnel testing was conducted to determine droplet size resulting from treatments selected for evaluation in the field. These treatments included a "blank" (water plus a non-ionic surfactant) as well as five additional solutions with a formulated fungicide, four of which have an additional adjuvant. The wind tunnel testing measured droplet size using the flat fan nozzles and operational parameters (spray pressure, nozzle orientation, and airspeed) selected for field trials. These treatments were then evaluated in the field for both in-swath and downwind deposition, with a mass balance on the measured results used to compare each of the formulated product treatments to a reference treatment. Wind tunnel results showed the formulated product tank mixes resulted in significantly different droplet sizes than the water and non-ionic surfactant "blank" reference sprays. Additional adjuvants resulted in minimal changes in droplet size as compared to the formulated product mixture. However the polymer tested broadened the droplet size distribution. Drift modeling of the wind tunnel droplet size results demonstrated little difference between the formulated product and spray adjuvant spray mixtures. However, all treatment solutions significantly reduced modeled drift as compared to the reference treatment. While the field study results did highlight significant differences between treatments solutions, it also showed a great degree in data variability as a result of meteorological and sampling issues. These results have led the authors to conclude that field testing of potential drift reduction technologies under aerial application conditions will be cost prohibitive and likely would give highly variable results. Wind tunnel evaluations at certified laboratories offer a much quicker and inexpensive method for evaluating large numbers of nozzle and spray formulation treatments.
