Development and training of a national spray application work group

Final Report for EW13-022

Project Type: Professional Development Program
Funds awarded in 2013: $57,862.00
Projected End Date: 12/31/2016
Region: Western
State: California
Principal Investigator:
Gwen-Alyn Hoheisel
Washington State University
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Project Information


Nationally, there is a significant programmatic gap in spray application technology education in perennial crops that limits adoption of new, safer, more efficient pesticide application technologies and practices.  We proposed to create a national network of trained extension personnel to deliver to growers and consultants, research-based information on newer technologies and reinforce the fundamentals of safe, effective pesticide delivery. 

This project had two main activities: 1) train educators working as Extension faculty and crop consultants, and 2) disseminate information to producers so that they improve their spray applications.  Over the course of the entire project, we conducted two train-the-trainer courses at Cornell University and developed educational material. Educational material developed by participants for use in producer training is currently shared via Google Drive.  Each of the training classes were expected to conduct eight educational events in their local area.  We have far surpassed this goal, as detailed in our ‘Accomplishments’ and ‘Impacts’. 

At the project’s end, a significant, national programmatic gap will be bridged and agricultural spray application education improved, benefiting agricultural producers, pesticide handlers and farm workers, the environment and local communities. 

Project Objectives:

The goal of this project was to set U.S. deciduous tree and vine growers solidly on a path towards more effective, more efficient, and safer spray application programs.  Successful completion of our extension project will improve grower profitability by lowering production costs and improving pest management while reducing pesticide loss from the farm.  To reach our goals we will:

  1. Establish a national spray application work group (SAWG) and connect members to ensure the SAWG is sustained after the grant ends.
  2. Increase grower and custom-sprayer operator awareness of practices and technologies that improve spray application efficiency, efficacy, and reduce off-farm pesticide movement due to drift and runoff.
  3. Increase adoption of best practices and technologies that improve spray application efficiency and reduce drift and runoff.

In years one and two, we conducted a train-the-trainer courses to develop a Spray Application Working Group (SAWG).  Each train-the-trainer workshop trained eight educators working as Extension faculty, teachers, or crop consultants.  Each cohort of trainees was to offer at least one workshop or training opportunity to growers highlighting the best management practices of spray application technology.  Through trainings, we expected to directly engage 800 growers annually.  Over the course of years 1-3, a minimum of 4 extension publications, presentations, or trade journal articles were to be created to aid in grower education.  Collaboration and co-authorship among extension faculty was expected so that lasting relationships are built.  Through shared training and development of materials, a larger network of trained professionals was created.  The train-the-trainer workshops success was measured by a 75% improvement in educators’ knowledge and ability to conduct additional educational events. 


The majority of U.S. fruit and nut production relies on the basic axial fan airblast sprayer design that has not been significantly modified since it was patented in 1949 and in general is an inefficient, unsustainable sprayer for modern horticultural systems (Fox et al. 2008).  Other sprayers and technologies exist that promise to be more sustainable (more efficient, target specific, and reduce drift) but adoption of these newer technologies has been slow.  Our objective is to provide a foundation for education in spray application technology by creating a national network of trained extension personnel who will share research-based information about the effectiveness of newer technologies with growers. 

Changes in spray application technology create both a need and an opportunity for research and extension to improve targeted deposition and reduce drift (Kaine and Bewsell, 2008).  Few growers benefit from the existing body of knowledge and new technologies, because of two limitations.  First, there is a lack of comparative data on the relative costs and benefits of new technologies in specific regional and horticultural settings.  Second, budget cuts have virtually eliminated extension specialists in perennial crop spray application technology, leaving extension generalist (county horticulturists) to deliver extension education in this field.  These personnel lack the training necessary to help growers and thus growers lack access to information.  Our project will address the later limitation by creating a network of trained professionals who can easily share the information with producers.

Many extension educators and pest management researchers, who work in specialty crops, including some on this project, are attempting to develop educational programs on application technology but have been hampered by limited to no training in agricultural engineering.  There have been some efforts funded by SARE to educate agricultural industries or evaluate sprayers (Palmer and Breth, 1993; Grande, 2008; Jentsch, 2010); however, none have focused on building educational networks for perennial crops.  Sustainability workbooks have been developed with varying degrees of information on BMP of application technology (California Sustainable Winegrowing Alliance, 2006; VineWise, 2006; Vine Balance, 2009).  Our train-the-trainer programs will empower educators to bolster these widely used programs and/or develop new programs as well as build capacity and communication platforms to share information on application technology research and education.


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  • Steve Castagnoli
  • Andrew Landers
  • Franz Niederholzer

Education & Outreach Initiatives



We established a national spray application work group (SAWG) through face-to-face trainings and sustained it through monthly phone calls and shared documents.  In years 1 and 2, 15 participants participated in a 4-day train-the-trainer workshop at Cornell University.  The training was conducted by Dr. Andrew Landers who used the book Effective Fruit Spraying series ( as a general template for the workshop.  The train-the-trainer program provided participants with an understanding of both theoretical and practical components of spray application technology.  Aimed at county extension educators and farm consultants with little or no knowledge of the engineering aspects of application technology, the course showed participants how sprayers can be adjusted to minimize drift and increase canopy coverage. The course included sprayer components, calibration, canopy deposition, and worker safety.  Specific topics in sprayer components such as pump maintenance and selection, pressure regulation, nozzle selection, droplet formation and deposition, and technologies for drift reduction were discussed.  Calibration topics included nozzle replacement, aligning spray patterns to match the canopy, and measuring canopy volume.  Canopy deposition focused on the effects of forward speed, air speed/volume and application rate upon the amount of material on the target (i.e. fruit or leaf).  Worker safety addressed proper methods for filling and cleaning the sprayer that minimize operator contamination, time, and environmental pollution.  Included with all of engineering lessons were also lessons on effective methods of teaching farmers and operators similar information about application technology.  Participants were expected to conduct at least one grower-focused workshop in their local regions within a year. 

Figure of one tool used to demonstrate air movement to growers.  Showed to participants at the Cornell training.  

Originally, the third year was designated to evaluate our progress via surveys and interviews with course participants.  However, the majority of that was done in years 1-2.  Instead, we took advantage of our growing collaboration, desire for more knowledge, and funds from other related grants to conduct an international train-the-trainer workshop.  We met at Washington State University-Irrigated Ag Research and Extension Center in Prosser.  Attendees included approximately half of the SAWG members, 10 other regional trainers and consultants, as well as manufacturers from Spain and Belgium.  The training was conducted by Dr. Emilio Gil from the University of Catalunya, Spain who is an expert working with the European Union to implement application technology engineering and education.  

Since year 2, SAWG members have conducted monthly teleconferences.  We have shared presentations, current education techniques, and lessons.  We have also started to read and discuss monthly a sentential journal paper on a specific topic.  All documents shared and meeting minutes are stored on a shared google drive account. 

Outreach and Publications

The outreach and workshops offered were described in detail in the ‘accomplishment’ section.  Over the course of two years, several publications were produced for growers.  A blog post ( was written with hyperlinks to YouTube videos for discussing the effects of ground speed on spray coverage.  The post was picked up by the Western Farm Press, which generated more traffic (557 views) to the YouTube videos.  A video series on 6 topics was produced by a SAWG member at Pennsylvania State University and Dr. Jason Deveau at OMAFRA in Canada.  SAWG members also published and consulted on the following articles in trade journal magazines: 

  • From Recommendation to Application: How PCAs Can Help Minimize Drift, Ensure Coverage, California Association of Pest Control Advisers magazine
  • Practical Steps To Improving Sprayer Performance; American/Western Fruit Grower Magazine
  • Vineyard Airblast Sprayer Calibration for Improved Deposition; Lodi Wine Growers Association online newsletter
  • Make Every Drop Count; Good Fruit Grower
  • 6 Steps to Calibrating an airblast, Fruit Matters: a WSU newsletter
Outcomes and impacts:

There have been two foci of this program.  First was to educate and inspire an engaged group of professionals to devote some of their work time to application technology and collaboration among group members.  The second focus was to develop and deliver educational opportunities for producers.  Therefore we have presented impacts that demonstrate both the team building and learning of educators as well as research and education for producers. 

After each Cornell course (years 1 and 2), the participants were surveyed to determine their knowledge gained and change in activities. Prior to the training, only three participants had a majority of their programming centered on application technology.  The others were not regularly giving presentations or workshops on methods to improve sprayer performance.  By providing training, we doubled the number of workshops and presentations available to producers.  More importantly, the quality of the education has improved due to a better understanding on ways to improve coverage and how to teach that to producers.  Participants identified these specific lessons learned: 1) differences and new developments in sprayer designs, 2) the function of sprayer components, 3) improved spraying techniques and the role of air as it leads to better deposition and less drift, 4) methods to increase the timeliness of applications resulting in better disease and insect control, 5) technologies to reduce off-target drift.  Specific methods to enhance their educational programs included: 1) techniques for demonstrating drift potential, 2) use of fluorescent tracers at night to show coverage, 3) use of a vertical “Patternator” to show spray patterns, and 4) faster sprayer calibration techniques.  The information gleaned from each class differed slightly from the first and second cohort, so the monthly phone calls have increased knowledge sharing across both classes. 

The gained knowledge and expertise has allowed SAWG members to continue collaboration where there was minimal before, branch out into new research, and lead education and regulatory efforts. Through our regular calls we have developed opportunities to meet and present together at field days and grower meetings.  Members of the SAWG group have jointly submitted three other proposals for education and research in application technology in California, Oregon, and Washington.  Three SAWG members were successful in securing $250,000 in grant funds to expand application technology education in Washington State. These funds are not only expanding classes but also contributed to our continued education through an additional in-depth train-the-trainer course in year 3.  Two of the SAWG members are assisting state and local legislatures understand the intricacies of spraying and causes of off-target drift to better guide regulations. 

As discussed in the accomplishments, the expectations given to the trainers has been surpassed.  Educators in Washington State have created a one-day hands-on curriculum on calibrating and optimizing airblast sprayers.  This course is included now in the regular training offered by the state department of agriculture and by doing so we have had long-term impacts of changing policy and resources in just two years of this grant. 

Project Outcomes

Project outcomes:

There have been two foci of this program.  First was to educate and inspire an engaged group of professionals to devote some of their work time to application technology and collaboration among group members.  The second focus was to develop and deliver educational opportunities for producers.  Therefore we have presented accomplishments that demonstrate both the team building and learning of educators as well as research and education for producers. 

The initial training sessions were conducted in November 2013 (year 1) and September 2014 (year 2) with 8 people participated in each of the 4-day “Train-the-Trainer Course on Application Technology”.  The participants work across the nation and Canada (Washington, Oregon, California, Pennsylvania, New Hampshire, British Columbia) and include Extension faculty, community college professors, and crop consultants. The participants have established a Google Drive account to share presentations, papers, and pictures. Our monthly phone calls have led to the submission multiple grants and improved our presentations through shared resources.  Three SAWG members from the Washington State Department of Agriculture received funds from Washington Specialty Crop Block Grant (K1782).  That grant and funds from this grant were used to conduct a third more in-depth train-the-trainer course. We as a group recognized that we wanted more education and invited a world renowned agricultural engineer from Spain who has led the EU effort application technology reform and education.

We expected at least 32 (16 per year) educational events to be conducted by the group after training sessions in the first two years.  The participants were inspired and surpassed our minimum expectations.  Over the next two years, a total of 39 workshops were conducted with 1577 producers attending which represented more than 9,000 acres of fruit and vegetable farms.  Educators also calibrated 86 individual sprayers that would be used on over 7366 acres of farmland.  Trainees also gave 42 shorter (i.e. 20-30 minute) presentations at various fruit and vegetable meetings reaching approximately 2923 producers. 

The Washington State educators have also developed a 1-day sprayer calibration/optimization course that is now funded through the state department of agriculture with additional funding from grower groups and chemical companies. Approximately 232 farm managers and operators were trained over two years in eight workshops. The course is offered in Spanish and English and focuses at least half the time to hands-on learning activities in the field.

Figure showing a training class for managers and operators.  


Potential Contributions

The contributions of this project’s SAWG members may strengthen the focus and programs on integrated pest management and agricultural engineering in each of their regional and land grant universities’.  Already, University of California has invested in the a new position for application technology research and education.  SAWG members working with other regions are now looking to expand their training and collaboration to states not originating in this grant.  Some funds through the Specialty Crop Research Initiative have been awarded to provide such training.  The increased communication among people passionate about sprayer technology has encourage the development of more audience-specific tools, improved educational materials, and more other online articles and resources.

Future Recommendations

The SAWG group would like to continue future projects in research and education.  It is generally considered that problems of technology adoption and machine operation to reduce off-target drift will need a multi-faceted solution.  There needs to be evaluation of current technologies so that educators have research based information to share with producers.  There needs to be education on current technologies so that gains can be attained in the short term.  Lastly, new technologies must be developed and evaluated.  A priority should be placed on technologies that minimize human input and error and allow more automation and sensing of optimal coverage as matched to the canopy architecture, sprayer configuration, and environmental conditions. Members of the SAWG group will pursue grants and projects in all of these areas and are committed to sharing the work with the group. 

Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the view of the U.S. Department of Agriculture or SARE.