Across Varying Levels of Sprayer Technology and Operator Experience
Plus, What’s New with
WETTING AGENTS
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Ifany profession is prepared for the challenges and changes a new season can bring, it is turfgrass managers. From a wet beginning to the summer to anticipated heat waves in the later parts of the season, PTC members have adjusted their staffing, maintenance and management programs to reflect the current conditions.
Likewise, PTC and PSU are making adjustments for changes in leadership and staff. With our new board finally in place (see page 9), PTC is ready to partner with and support the new teaching and leadership staff at PSU. We look forward to introducing you to the new team when all turf positions are filled.
In this issue, you’ll find research from some familiar names at PSU (What’s New with Wetting Agents) and from Dr. Chase Straw (Assessing Application Error on Sports Fields across Varying Levels of Sprayer Technology and Operator Experience). Dr. Straw joined the PSU team in January as Assistant Professor of Turfgrass Soils and Director of the Center for Sports Surface Research.
Also in this issue, you’ll find information about the 2026 Pennsylvania Turf Conferences. Make sure to get those dates on your calendar! Continuing education, networking and certifications are an essential part of continuing to grow in knowledge and advance your career and the turfgrass community.
As always, your support and involvement in Pennsylvania Turfgrass Council are vital to the success of our industry – get involved and keep our organization growing and thriving!
Tom Bettle
PTC President
Tom Bettle Turf Research Center Manager 724-321-0321 • trbettle@psu.edu
Monoj Chhertri Professor of Turfgrass Science 814-863-3606 • mkc6518@psu.edu
Michael A. Fidanza, Ph.D. Professor of Plant & Soil Science 610-396-6330 • maf100@psu.edu
David R. Huff, Ph.D. Professor of Turfgrass Breeding and Genetics 814-863-9805 • drh15@psu.edu
Bradley Jakubowski Assistant Teaching Professor 814-865-7118 • brj8@psu.edu
John E. Kaminski, Ph.D. Professor of Turfgrass Science 814-865-3007 • kaminski@psu.edu
Timothy Lulis Teaching and Research Assistant 814-865-0697 • ttl101@psu.edu
Ben McGraw, Ph.D. Professor of Turfgrass Science 814-865-1138 • bam53@psu.edu
Dianne Petrunak Academic Adviser, Turfgrass Science and World Campus 814-863-0139 • dmp6@psu.edu
Max Schlossberg, Ph.D. Associate Professor of Turfgrass Nutrition / Soil Fertility 814-863-1015 • mjs38@psu.edu
Chase Straw Professor of Turfgrass Soils 502-229-9838 • cms9424@psu.edu
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2026 Northeastern PA Turf Conference
WILL TAKE PLACE ON Thursday, February 12, 2026 at Mohegan Pennsylvania Casino Resort in Wilkes-Barre, PA
2026 Eastern Pennsylvania Golf, Lawn, Landscape and Sports Turf Conference
IS TAKING PLACE
Thursday, January 29, 2026 at Shady Maple Conference Center in East Earl, PA
2026 Western Pennsylvania Golf, Lawn, Landscape and Sports Turf Conference
IS TAKING PLACE
Wednesday, February 25, 2026 at Hollywood Casino at The Meadows in Washington, PA
Penn State Berks Gets a New Mower 2025 PTC Board of Directors
By Dan Brey
Inrecent years since the pandemic, the turfgrass area at Penn State’s Berks Campus – known as “Valentine East” – has struggled to keep the turf maintained properly to support teaching, research, and outreach. Although Penn State’s Office of Physical Plant agreed to provide the mowing and maintenance of the site, it has been a significant challenge in terms of funding and also availability of dedicated staff. The Toro zero-turn mower there has been dependable and loyal for many years, but this spring it finally mowed its last blade of grass. A new rotary lawn-height mower was desperately needed, however, the current financial situation within the Pennsylvania State University made the goal of obtaining a new mower seem unlikely. Therefore, the Pennsylvania Turfgrass Council stepped in to help.
A new Toro zero-turn rotary mower was purchased this summer. Funding was provided through a partnership between Pennsylvania Turfgrass Council and Penn State Berks. The Pennsylvania Turfgrass Council’s Equipment Grant Program paid for half the cost of the new mower, with an agreed match for the other half from Penn State Berks (Dr. Todd Migliaccio, Associate Dean, Office of Academic Affairs). “This is a positive first step in helping us to rebuild Valentine East, and it sends a message to our turfgrass science students that you are an important part of our teaching mission here at Penn State Berks,” said Dr. Mike Fidanza, Professor of Plant and Soil Science, and Director of the Center for the Agricultural Sciences and a Sustainable Environment.
The next priority is to repair the irrigation system. Also, the creeping bentgrass areas need to be re-established, and autonomous mowers will most likely be utilized to maintain those areas. For now, the lawn-height areas will be maintained with the new mower.
Thank you to the Pennsylvania Turfgrass Council for your support of the turfgrass science program at Penn State Berks. •
Dan Brey is the Chief Mechanic in the Office of Physical Plant at Penn State’s Berks Campus, in Reading, PA.
The new Toro Z-Master 4000 HDX XL recently arrived at Penn State’s Berks Campus to maintain the turfgrass teaching and research areas. An initial “test run” proved it is just what the turf plots needed. Thank you to the Pennsylvania Turfgrass Council !
PRESIDENT Tom Bettle Penan State trb19@psu.edu 724-321-0321
204 Timberwood Trail Centre Hall, PA 16828
VICE PRESIDENT
Steve Craig Centre Hills Country Club grounds@centrehillscc.com 814-237-5414
153 Country Club Road State College, PA 16801
SECRETARY-TREASURER
Timothy Wilk Scotch Valley CC twilk728@gmail.com 814-931-5373 18 Clubhouse Dr Hollidaysburg, PA 16648
PAST PRESIDENT
Rick Catalogna Harrell’s rcatalogna@harrells.com 412-897-0480
101 Royalbrooke Drive Venetia, PA 15367
DIRECTORS
Pete Ramsey Range End Golf Club pete@rangeendgolfclub.com 717-577-5401
303 Golf Club Ave. Dillsburg, PA 17019
Thomas Goyne Pittsburgh Steelers goynet@steelers.nfl.com 412-292-4808 900 Art Rooney Ave Pittsburgh, PA 15212
Tanner Delvalle Fisher & Son Company tdelvalle@fisherandson.com 484-843-0600 1803 W End Ave Pottsville, PA 17901
John Chassard Lehigh Country Club jchassard34@gmail.com 484-357-8974
2319 S Cedar Crest Blvd Allentown, PA 18103
Dan Douglas Reading Fightin Phils dougdirt@comcast.net 610-301-5906 709 Beyer Ave Reading, PA 19605
Matthew Wolf Penn State mkw144@psu.edu 315-404-9811 119 Physical Plant BLDG University Park, PA 16802
Mike DeLeonibus 3 Lakes Golf Course mvd1219@comcast.net 412-303-7955 6700 Saltsburg Road Pittsburgh, PA 15235
Chris Markel Grove City CC cmarkel537@gmail.com 412-527-9994 73 Country Club Rd Grove City, PA 16127
STAFF
Kristen Althouse Pennsylvania Turfgrass Council Kalthouse113@gmail.com 814-237-0767 PO Box 99 Boalsburg, PA 16827
Assessing Application Error on Sports Fields Across Varying Levels of Sprayer Technology and Operator Experience
By
Department of Soil and Crop Sciences, Texas A&M University, College Station, Texas, USA
Weston Floyd, CSFM, Megan Muesse, Hailey Tucker, Opeyemi Alabi, Jacob Winger, and Chase Straw, Ph.D.
Figure 2. An inexperienced operator making an application using the GNSS sprayer at Southwood Park
Figure 1. The experienced operator making an application using the GNSS sprayer at Veterans Park
The
demand for precise input application and operational efficiency in turfgrass has driven the development of Global Navigation Satellite System (GNSS)-equipped sprayers, which offer several advantages over conventional systems. Features like individual nozzle control and automated operation within preset boundaries reduce the need for manual boom control, while enhancements such as sub-centimeter precision correction and autosteer further minimize human error.
Despite these benefits, GNSS sprayers have seen limited adoption in the broader turfgrass industry, with increased interest primarily in the golf course sector. Early adopters report benefits such as reduced treated area, shorter application times, less reliance on operator expertise, and improved accuracy. However, testimonials remain scarce in sports field management, where skepticism about the technology’s value persists.
As the sports field industry increasingly embraces sustainable practices and faces rising labor costs, the demand for technological solutions is expected to grow. Overcoming hesitancy toward new technologies will require extensive demonstrations to promote adoption. Currently, there is limited unbiased data on the benefits of GNSS-equipped sprayers for sports field managers.
This research aims to fill that gap by quantifying application errors on sports fields using different sprayer technologies and operator experience levels. The hypothesis is that as technology advances, discrepancies in misses, overlaps, and overspray will decrease, reducing the total sprayed area and minimizing differences between experienced and inexperienced operators.
Study design, equipment, and application process
Research was conducted from winter 2022 to summer 2023 in College Station, TX, at Veterans Park and Athletic Complex and Southwood Athletic Park. Identical studies were performed on softball/baseball and soccer fields at both locations. Using a crossover design, six treatments—manual, GNSS, and GNSS + autosteer sprayer technologies, each operated by both experienced and inexperienced operators—were applied to three fields of each type at both locations. Each field received all six treatments to evaluate technology performance across operator skill levels.
At Veterans Park, a Toro Workman 200 Spray System (18 ft. boom) with Ninja GPS Spray Control, a Smart7 GNSS receiver, and Polaris autosteer was used (Figure 1). At Southwood Park, a John Deere ProGator with an Above Par Tech sprayer (20 ft. boom), a GPS 7500 GNSS receiver, and SteadySteer autosteer was employed (Figure 2). Both sprayers featured correctional services, individual nozzle control, automatic rate control, on-screen guidance, and adjustable spray parameters.
One experienced operator with nearly 20 years of sports field spraying experience, including three years with GNSS and autosteer, was assigned to each location. Four inexperienced college students, new to both spraying and the technology, were assigned to specific locations and field types, ensuring their inexperience remained consistent. Each student received a 30-minute training session on sprayer controls before their first application.
Field boundaries were georeferenced once using the sprayers’ GNSS receivers to establish consistent target areas for all fields, aiding in GNSS and GNSS + autosteer treatments. The average target areas were 74,899 ft² for Veterans Park’s softball fields and 37,631 ft² for Southwood Park’s baseball fields, with soccer fields averaging 88,244 ft² and 33,644 ft² at Veterans and Southwood, respectively. Water was used for treatments at 65 gallons per acre, and designated level areas were marked for filling and draining the sprayers. Sprayers were filled to 150 gallons for Veterans Park and 80 gallons for Southwood, based on field size.
At Veterans Park, the dual-nozzle sprayer used FastCap 422FC11004 and 422FC11006 nozzles, while Southwood Park used a single-nozzle sprayer with COMBO-JET SR110-08 nozzles. The accuracy of the water volume in the tank was confirmed by measuring in five-gallon increments and validating the flow meters against the computer outputs before the initial treatments.
Treatment applications occurred from December 2022 to May 2023 at Veterans Park and from June to July 2023 at Southwood Park, depending on field availability and weather. To prevent tire tracks from being used as a guide, sufficient time was allowed between applications for the tracks to disappear. Sprayers operated at 2.5 mph, controlled by a speed regulator.
For manual treatments, monitors were covered, and foam markers guided operators, who manually controlled the booms. GNSS treatments used foam markers and on-screen maps, while GNSS + autosteer treatments added autosteer. Both GNSS treatments featured individual nozzle control, with a 100% overlap setting. After each treatment, remaining water was drained via valve and hand pump. Spray data were stored in the sprayers’ computers and later exported for analysis.
Data processing and analysis
The study measured target area misses, overlaps, and overspray. Data downloaded from the sprayer computers included field boundaries, sprayer paths, and coverage. The percentage of target area missed and overlapped was calculated by comparing the spray coverage to the field boundaries, excluding non-target areas. Missed areas were identified where no spray was applied and overlaps where sections were sprayed more than once. These percentages were then calculated as a proportion of the total target area. Overspray was calculated by subtracting the amount of water left in the tank after spraying from the initial volume. The percentage of overspray was determined by dividing the actual volume applied by the intended volume for the target area, then multiplying by 100. Any values over 100% indicated overspray.
The percent total volume saved between treatments was determined by subtracting the lower percentage from the higher one, dividing the absolute value of this difference by the higher percentage, and then multiplying by 100 to convert it into a percentage. For example, if treatment A used 105% of the intended volume (i.e., 5% overspray) and treatment B used 110% of the intended volume (i.e., 10% overspray), then the total volume savings by using treatment A is 4.6%, calculated as ((|105110|)/110)*100 = 4.6%.
Only the 422FC11004 nozzles were used at Veterans Park in manual mode because individual nozzle control could not be turned off when dual nozzles were active, resulting in a lower spray volume since the sprayer isn’t designed for single-nozzle operation. Therefore, the percent target area overspray was analyzed separately by location, as the manual total volume applied data from Veterans Park was unreliable. However, this issue did not affect the percent of the target area missed and overlapped, as spatial spray data were recorded for all treatments.
Misses, overlaps, and overspray on softball / baseball fields
The results for percent target area missed were similar across locations, so data were combined for treatments and locations. Inexperienced operators using manual sprayers had the highest percentage of missed areas (3.7%), while experienced operators showed no major differences across sprayer technologies. There was also no difference in missed areas between GNSS and GNSS + autosteer, regardless of operator experience. Southwood Park had more missed areas (2.4%) compared to Veterans Park (1.4%).
For percent target area overlapped, results differed by location, so data are presented separately for each. At Veterans Park, the manual sprayer used by inexperienced operators caused the highest overlap (8.3%). In other cases, both experienced and inexperienced operators performed similarly across sprayer technologies. As technology advanced, overlap decreased, with GNSS + autosteer reducing overlap to less than 2% (Figure 3).
At Veterans Park, overspray was similar between operators within each technology level, but advanced technology reduced overspray. GNSS + autosteer led to 2.1% overspray compared to 6.3% with GNSS, saving 4% of the total water volume. For inexperienced operators, autosteer reduced overspray by 3.3%.
At Southwood Park, there were no significant differences in overspray between operators within each technology level, but experienced operators generally
had higher overspray. While there wasn’t a clear advantage between manual and GNSS or GNSS and GNSS + autosteer, switching from manual to GNSS + autosteer significantly reduced overspray. For experienced operators, overspray dropped from 11.5% with manual to 6.5%, and for inexperienced operators, it dropped from 9.7% to 5.7%, resulting in a 3.7% reduction in total water used.
Misses, overlaps, and overspray on soccer fields
The results for percent target area missed on soccer fields were consistent across locations, so data were combined for treatment
EXPERIENCED OPERATOR
analysis. The manual inexperienced operator had the highest percentage of missed target area (2.8%), which was higher than all other treatments. There were no differences in missed areas among experienced operators across any level of sprayer technology. Additionally, there was no difference in missed areas between GNSS and GNSS + autosteer, regardless of operator experience.
Similarly, the results for percent target area overlapped were consistent across locations, so data were pooled for analysis. The manual inexperienced operator had the highest overlap (6.4%), significantly more than the manual experienced operator (4.3%). The manual experienced operator’s overlap was similar to that of the GNSS inexperienced operator (3.6%), and both operator
INEXPERIENCED OPERATOR
Figure 3. Maps of target area overlapped on softball fields at Veterans Park across manual, GNSS, and GNSS + autosteer sprayer technologies (rows) and operator experience (columns).
GNSS
Manual
Veterans Park
GNSS + Autosteer
Target Overlap
types showed similar results within the GNSS and GNSS + autosteer technologies. Overlap decreased as sprayer technology advanced, with both operator types achieving less than 1% overlap using GNSS + autosteer (Figure 4).
The results for percent target area oversprayed differed slightly between locations, so data are presented separately. At Veterans Park, operator experience did not affect overspray with the GNSS sprayer, with both experienced and inexperienced operators having similar overspray rates (6.2% and 6.5%, respectively). However, the addition of autosteer reduced overspray to 2.3% for experienced
operators and 3.8% for inexperienced operators, resulting in total water savings of 3.7% and 2.5%, respectively.
At Southwood Park, overspray results were similar between operators within each sprayer technology level, though the inexperienced operator consistently had slightly higher overspray. For experienced operators, overspray decreased from 11.1% with manual to 8.3% with GNSS, but there was no further reduction with GNSS + autosteer (6.2%). For inexperienced operators, overspray dropped from 12.1% with manual to 10.2% with GNSS and further to 7.0% with GNSS + autosteer.
Overall, both operator types saw a reduction in overspray as sprayer technology advanced. Moving from manual to GNSS technology reduced overspray by 2.8% for experienced operators and 1.9% for inexperienced operators. Upgrading from GNSS to GNSS + autosteer reduced overspray by 2.1% for experienced operators and 3.2% for inexperienced operators. Switching from manual to GNSS + autosteer technology resulted in total water savings of 4.4% for experienced operators and 4.6% for inexperienced operators.
Recommendation for sports field managers
EXPERIENCED
INEXPERIENCED
Inexperienced operators using manual spray mode had the highest rates of misses and overlaps, except for overlaps on Southwood Park’s baseball fields. GNSS and autosteer technologies significantly reduced these errors across all locations and field types (Figure 5). Standard deviations of misses and overlaps decreased with advanced technologies, especially when comparing inexperienced manual mode to GNSS + autosteer, indicating more consistent applications. Additionally, advanced technology reduced overspray and the total volume applied. Investing in GNSS-equipped sprayers with autosteer minimizes reliance on experienced operators, reduces errors, and enhances consistency. This study used factory settings, so further improvements might be possible by adjusting overlap parameters
Acknowledgements
The authors wish to extend their gratitude to the Texas Turfgrass, Research, Education, and Extension Endowment for providing funding for this study. They also want to express their thanks to GLK Turf Solutions and Traqnology for providing the Above Par Tech sprayer and real-time kinematic correction service, respectively, for use in the study. Additionally, appreciation goes to Stephan Richardson, the Parks Operations Manager of the City of College Station, Curtis Richmond, the Southwood Park Supervisor, Keith Fails, the Veterans Park Supervisor, and Ken Rost and Cam Schafer from Frost, Inc. for their support of this project.
Figure 4. Maps of target area overlapped on soccer fields at Southwood Park across manual, GNSS, and GNSS + autosteer sprayer technologies (rows) and operator experience (columns).
MANUAL
GNSS + AUTOSTEER
Figure 5. An inexperienced applicator making a pass using manual mode (left) and GNSS + autosteer (right) on soccer fields at Veterans Park.
What’s New with Wetting Agents
By Michael Fidanza, Ph.D., Stan Kostka, Ph.D., and Tom Malehorn
Example of a wetting agent field evaluation study on a creeping bentgrass (Agrostis stolonifera ‘L-93’) practice putting green at Mountain Branch Golf Club (Joppatowne, MD). Wetting agent treatments were applied from April through October, 2023. ‘Other’ was applied at 1.5 fl oz/1000 ft2 every 14 days starting in April; Excalibur® was first applied at 4 fl oz/1000 ft2 in April, followed-by 3 fl oz/1000 ft2 every 28 days. From soil evaluations in August, water infiltration into the rootzone profile is indicated by the blue dye. Source: iGin Research.
Soil surfactants are commonly called “wetting agents” in the turfgrass industry, and there are many, many wetting agent products in today’s turf market. In 2012, the USGA Green Section article
— Understanding the different wetting agent chemistries — advanced our understanding of these products in a logical manner. Another good article on wetting agents also appeared in the USGA Green Section — Factors to consider when developing a wetting agent program. Both of those articles and more can be found at: https://tinyurl.com/4f2v8m8r. Recently, wetting agent categories were proposed in a further attempt help the end user understand their chemical properties: https://tinyurl.com/ywyexm4x
Overall, in golf course and sports turf management, wetting agents are employed to improve infiltration, mitigate water repellency (i.e., hydrophobic conditions), and enhance hydration in soils and rootzones. Wetting agents also are useful for enhancing certain soil directed pesticides, improving flushing of excess salts, indirectly helping turf survive the winter, and improving spring green-up and recovery.
Retainers versus Penetrants?
The marketing of some wetting agent products can lead one to believe there is precise knowledge of clearly definable modes-of-action, that specific desired outcomes under diverse environmental conditions can prescribe how and when they should be applied, that soil responses can be turned on and off simply by changing what product is applied, or that product “X” can dramatically influence a specific turfgrass surface condition or expectation.
These sorts of questions have only been researched on a handful of products. Researchers at the University of Arkansas, University of Wisconsin, Michigan State University, and the University of Wageningen (Netherlands) have demonstrated that certain wetting agents can increase soil water content under droughty conditions, and lower soil water content during periods of excessive rainfall. Keepin-mind, most of these results come from turf growing on sand or sandy loam rootzones. Does this mean those wetting agents tested are physically “holding onto” (retaining) water in the rootzone, or “pushing” (penetrating) water through the rootzone? Our soil physics colleagues would question that statement. The terms retainer and penetrant are not listed in the soil science terminology, but these terms are used to market wetting agents.
Data remain lacking on the nature and differentiation of products sold as “wetters”, “water retainers”, and “penetrants”. There are many claims based on reports-fromthe-field or on misperceptions or misinterpretations of visual observations. When considering a wetting agent ask for thorough, documented, replicated field research (either from university or industry researchers). A recent article in the USGA Green Section provides further insight into this topic:
O’Brien, D., Fidanza, M., Kostka, S., and Richardson, M. 2023. Penetrants vs. Retainers: Understanding Wetting Agent Clamins and the Science Behind them. USGA Green Section Record. https://www.usga.org/ content/usga/home-page/coursecare/green-section-record/61/ issue-10/penetrants-vs--retainers-understanding-wetting-agent-claimsand.html
Over the past two decades, wetting agents have moved from products applied to correct localized dry spots to broader applications in water management, however, marketing claims often outpace the science. Research continues to build upon our understanding of what wetting agents can and cannot do. Understanding the mode-of-action, effects on soil physical phenomena, and effects on soil biology and rhizosphere dynamics are the future. A foundation is being built to support science-based uses of these unique soil amendment compounds.
Conclusion
• Soil surfactants or “wetting agents” lead the way for sustainable water use and water conservation practices on U.S. golf courses.
• Recent research has quantified beneficial effects of using wetting agents, with more work in progress.
• The marketing terms “retainer” and “penetrant” are not soil science terms.
• Ask to see research-based information when considering a wetting agent product.
• Research efforts are underway in the U.S. and Europe that will increase our understanding of how wetting agents affect turf rootzone physical, chemical, and biological properties.
Dr. Mike Fidanza (maf100@psu.edu) is a Professor of Plant and Soil Science at the Berks Campus, Pennsylvania State University, Reading, PA; Dr. Stan Kostka (stan. kostka@gmail.com) is a Visiting Scholar at Penn State Berks Campus; Tom Malehorn (intlturf@gmail.com) is a Penn State turf alum and principal scientist with iGin Research, in Westminster, MD.
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