Spring 2021 • Vol. 10/No. 2
Revisiting Dr. Houston Couch’s Advice on Maximizing Fungicide Efficacy Through Proper Application Techniques Plus, Dissecting Infield Playability
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Vol. 10 / No. 2 • Spring 2021
Publisher: Leading Edge Communications, LLC 206 Bridge Street, Suite 200 Franklin, TN 37064 Phone: (615) 790-3718 Fax: (615) 794-4524 info@leadingedgecommunications.com Pennsylvania Turfgrass Editor Max Schlossberg, Ph.D. Penn State University • mjs38@psu.edu
10
Pennsylvania Turfgrass Associate Editor Heather Welch Penn State University • hgw1@psu.edu President Tom Fisher Wildwood Golf Club – Allison Park, PA (412) 518-8384 Vice President Rick Catalogna Harrell’s Inc Territory Manager (412) 897-0480 Secretary-Treasurer Shawn Kister Longwood Gardens, Inc. – Kennett Square, PA (484) 883-9275 Past President Pete Ramsey Range End Golf Club – Dillsburg, PA (717) 577-5401
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18
Features
Departments
10 Cover Story
6 President’s Update
Revisiting Dr. Houston Couch’s Advice on Maximizing Fungicide Efficacy Through Proper Application Techniques
14 Feature Article
Dissecting Infield Playability
6 Penn State Turf Team 7 Advertiser Index 8 Penn State News Find this issue, Podcasts, Events and More: THETURFZONE.COM
18 Between the Lines
KAFMO’s Brad Jakubowski Honored with 2020 STMA Founder’s Award
4 Pennsylvania Turfgrass • Spring 2021
Cover Photo by Maxim Schlossberg
Director of Operations Tom Bettle Penn State University Assistant Director of Operations Nicole Kline Pennsylvania Turfgrass Association Directors Steve Craig Centre Hills Country Club Tanner Delvalle Penn State Extension Elliott Dowling USGA Andy Moran University of Pittsburgh Tim Wilk Scotch Valley Country Club Matt Wolf Penn State University
Spring 2021 • Pennsylvania Turfgrass
5
President’s Update
CHANGE IS THE ONLY CONSTANT
One
year ago, our best laid plans for the coming season were perfectly clear. Well thought out agronomic programs required a little discretionary tweaking, our crews were polished and rested, and years of experience had us prepared for any weather or agronomic challenges that surely lay ahead. Following a period of great uncertainty, Spring of 2020 blossomed into a renaissance of public utilization of our golf courses and parks with great zeal and veracity. Many of our properties were inundated with near record numbers of patrons as the public’s yearning for normalcy was found in the green spaces we so expertly tend to. Conversely, an unfortunate pall of silence fell over shuttered sports facilities, as entire seasons were repeatedly postponed, or even worse, cancelled. For all of us, this was hopefully a seamless exhibition of our best laid agronomic plans, polished staffing, and years of experience. Regardless of your circumstance, the mantra “Growing Grass is the Easy Part” rang loud and true early and often. While great homage should be paid to our healthcare and public service workers, a sincere debt of gratitude is owed to those of you who confidently went about your business to provide and maintain these wonderful green spaces. Our recreational areas provided an outlet for exercise and safe socialization when so few destinations existed; truly an oasis in a desert of options. Whether or not we personally acknowledge it, our Yeoman’s work will echo far beyond the 2020 season. Untold stories of peaceful refuge sought by somebody struggling, a family enjoying time together on your grounds, or a child taking up a sport are woven into the fabric of the past year. As we embark upon the 2021 season, we once again take what we learned yesterday and apply it to today; but just like every season, change is the only constant. Many of us took our lumps in 2020, whether it be running a Member/Guest on a skeleton crew, dragging a hose for what seemed like an eternity, or simply prevailing through the normal rigors of a season magnified by the turbulent world around us. Challenges like those make us better Turf Managers and hopefully better people. May the lessons learned and the wisdom obtained in the past 12 months benefit us all in the 2021 season and beyond.
Tom Fisher
Penn State Turf Team
Jeffrey A. Borger Senior Instructor in Turfgrass Weed Management 814-865-3005 • jborger@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 Genetics 814-863-9805 • drh15@psu.edu
Brad Jakubowski Instructor of Plant Science 814-865-7118 • brj8@psu.edu
John E. Kaminski, Ph.D. Professor of Turfgrass Science 814-865-3007 • jek156@psu.edu
Peter J. Landschoot, Ph.D. Professor of Turfgrass Science 814-863-1017 • pjl1@psu.edu
Ben McGraw, Ph.D. Associate Professor of Turfgrass Entomology 814-865-1138 • bam53@psu.edu
Andrew S. McNitt, Ph.D. Professor of Soil Science 814-863-1368 • asm4@psu.edu
2021 PTC President Max Schlossberg, Ph.D. Associate Professor of Turfgrass Nutrition / Soil Fertility 814-863-1015 • mjs38@psu.edu The Pennsylvania Turfgrass Council (PTC) serves its members in the industry through education, promotion and representation. The statements and opinions expressed herein are those of the individual authors and do not necessarily represent the views of the association, its staff, or its board of directors, Pennsylvania Turfgrass, or its editors. Likewise, the appearance of advertisers, or PTC members, does not constitute an endorsement of the products or services featured in this, past or subsequent issues of this publication. Copyright © 2021 by the Pennsylvania Turfgrass Council. Pennsylvania Turfgrass is published quarterly. Subscriptions are complimentary to PTC members. Presorted standard postage is paid at Jefferson City, MO. Printed in the U.S.A. Reprints and Submissions: Pennsylvania Turfgrass allows reprinting of material published here. Permission requests should be directed to the PTC. We are not responsible for unsolicited freelance manuscripts and photographs. Contact the managing editor for contribution information. Advertising: For display and classified advertising rates and insertions, please contact Leading Edge Communications, LLC, 206 Bridge Street, Suite 200, Franklin, TN 37064, (615) 790-3718, Fax (615) 794-4524.
6 Pennsylvania Turfgrass • Spring 2021
Al J. Turgeon, Ph.D. Professor Emeritus of Turfgrass Management aturgeon@psu.edu
Wakar Uddin, Ph.D. Professor of Plant Pathology 814-863-4498 • wxu2@psu.edu
POWER UP YOUR SOIL.
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Spring 2021 • Pennsylvania Turfgrass
7
Penn State News • In Memoriam
Pennsylvania Turfgrass Council honors two distinguished researchers and educators. Drs. Watschke and Waddington will be remembered for their dedication to our industry.
Thomas L. Watschke Thomas L. Watschke, PhD, 76, of State College, passed away peacefully November 18, 2020 at the Mount Nittany Medical Center. He is survived by his wife, Christa, daughters Katelyn and Madison, his son Jon, and three grandchildren. Tom was a member of the Grace Lutheran Church in State College. Born April 12, 1944 in Charles City, Iowa, Dr. Watschke received his BS from Iowa State University and his MS and PhD in Agronomy from Virginia Polytechnic Institute and State University. Upon graduation in 1970, Tom moved to Penn State University to join the Crop and Soil Sciences Dept. Throughout his career at Penn State, Tom coordinated the undergraduate turfgrass science program and advised all students in that major. He also designed and taught several online courses through PSU’s World Campus. His primary research focused on the use of plant growth regulators and herbicides for use in turfgrass systems. His most influential studies revealed the positive influence of turfgrass on mitigating the movement of fertilizers and pesticides into waterways. Other research areas included turfgrass physiology, turfgrass establishment methodology, and the evaluation of bio-stimulants. His environmental research supported the golf course turfgrass industry in several court cases. He retired from PSU in 2005 as Professor Emeritus, but continued consulting at many golf courses around the world where he enjoyed collaborating with former students and witnessing their success. Outside of his professional passions, Tom enjoyed spending time with family and friends, fishing, golf, watching all sports and traveling to warm climates. Anyone who interacted with Tom, both personally and professionally knew him to be a kind and caring individual. His magnetic personality lit up countless rooms.
Donald Van Pelt Waddington Donald Van Pelt Waddington, PhD, 89, of Boalsburg, died peacefully January 1, 2021. He was preceded in death by his wife of 55 years, Caroline Wicker Waddington. He is survived by six children, 12 grandchildren, and 10 great grandchildren. He was a member of State College Presbyterian Church since 1965. Born Dec. 31, 1931 in Norristown, PA, Dr. Waddington earned his BS from Penn State in 1953. After serving the US Army in the Korean War, Dr. Waddington earned his MS from Rutgers and PhD from the University of Massachusetts in 1960 and 1964, respectively. He began teaching at Penn State in 1965 and retired in 1991 as Emeritus Professor of Soil Science. Meanwhile, his research focused on soil amendment, nutrient availability and uptake, soil test calibration, nitrogen source evaluation, and surface characteristics of athletic fields. He and the late Dr. “Jack” Harper, Penn State Extension Specialist, collaborated on groundbreaking studies related to safety and playability of field surfaces. His research facilitated development of athletic field safety and performance standards currently employed by the National Football League. Dr. Waddington received the Pennsylvania Turfgrass Council’s Distinguished Service Award, and the Sports Turf Managers Association’s Dr. William H. Daniel Award. Dr. Waddington taught more than 1,100 students in the two-year turf management, four-year undergraduate, and graduate programs. The Keystone Athletic Field Managers Organization established an annual scholarship to honor his contributions along with those of Dr. Jack Harper, called the Waddington/ Harper Scholarship. 8 Pennsylvania Turfgrass • Spring 2021
Research Updates
Differences in dollar spot resistance among DMI fungicides By John Kaminski and Maureen Kahiu Building on previous research investigating the scope of dollar spot resistance to various fungicides in Pennsylvania, research is now under way to determine if differences in resistance exist among fungicides within the demethylation inhibiting (DMI) chemical class. Eight DMI fungicides are currently available, but most resistance studies have relied on propiconazole to represent resistance across the entire chemical class. With variability being observed in the length of dollar spot control among the commercially available products, our research aims to elucidate potential differences in resistance across all DMI fungicides. Field trials were initiated in 2020 at two locations. Commercially available DMI fungicides were applied at various rates and timings and disease monitored. Although data is currently being analyzed, three additional field studies are planned for 2021. Trials will be conducted at golf courses previously identified as having low, moderate, and high levels of resistance to propiconazole. In addition to field studies, isolates of Clarireedia spp. are currently being screened in vitro for resistance across all DMI fungicides. In addition to resistance assays, studies are also being conducted to characterize differences in turfgrass safety among DMI fungicides.
Research Update from the McGraw Lab Field research was somewhat diminished in 2020 given that the start of the pandemic coincided with early spring-active insect projects. Travel was limited in March and April, though most of our chemical efficacy trials, as well as summer and fall pest projects, continued as normal. European crane flies (ECF) and chinch bugs dominated the turfgrass insect pest discussion in 2020. These are two pest complexes that are not normally a concern unless environmental conditions allow for their populations to increase substantially or makes their feeding more noticeable. The drought that lingered into fall led to many reports of chinch damage to fine fescue surrounds on golf courses. Damage is often confused with drought stress. Our laboratory is looking to infest our chinch bug fine fescue farm on campus. If you (or anyone you know or love) has chinch bug issues, then please let us know! We would be happy to take them off your hands. ECF populations exploded after two years of above normal rainfall. Two species are present in Pennsylvania though “The European Crane Fly” (Tipula paludosa) has greater potential to damage turf. This insect has begun to appear outside of northwestern Pennsylvania. Early detection is essential to slowing the spread. If you observed crane fly adults emerging from the turf in fall and have larval damage in spring, please let us know! Moisture has an influence on population outbreaks. We are keeping our fingers crossed that the drought during the egg laying period reduced populations.
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ALUMNI UPDATES Spencer Hennen (@byHennen), BS ’12, is the golf course superintendent at Westmoreland CC in Export, PA. T-Jay Creamer (@TJayC17), BS ’21, is the golf course superintendent at Olympic View GC, Victoria, BC, Canada. Brian Chasensky, BS ’11, is the golf course superintendent at Northmoor CC in Highland Park, IL. Spring 2021 • Pennsylvania Turfgrass
9
Cover Story
Revisiting Dr. Houston Couch’s Advice on
Maximizing Fungicide Efficacy Through Proper Application Techniques By Michael Fidanza, Ph.D., Professor of Plant and Soil Science Pennsylvania State University, Berks Campus, Reading, PA and John Kaminski, Ph.D., Professor of Turfgrass Science Pennsylvania State University, University Park, PA
The
late Dr. Houston Couch (1924 — 2004), published a series of three articles in 1984 and 1985 on methods, techniques, and other factors to improve fungicide applications to turf. He was a turfgrass pathologist at Pennsylvania State University early in his career, and at Virginia Tech for the remainder of his career. In 2002, he received the prestigious GCSAA Col. John Morley Distinguished Service Award, and was recognized in 2003 with the USGA Green Section Award. Since those ‘Dr. Couch articles’,
there have been many advances in spray application equipment and technology over the past several years in both the agricultural and green industry sectors, as well as research on making adjustments to spray nozzles to improve or ensure product delivery and performance. Let’s revisit water-carrier spray volume and spray tips or nozzles. Water-Carrier Volume. In golf course turf management, a commonly accepted rule-of-thumb is to calibrate your sprayer to deliver 1 (one) gallon of water-carrier per 1000 square feet
Henry “Butch” Wetzel, retired golf course superintendent from St. David’s GC (Wayne, PA), going through a sprayer calibration exercise with different spray nozzle types. Also be sure to check the sprayer’s hoses, water filter, screens, and check the nozzles for proper function and alignment.
10 Pennsylvania Turfgrass • Spring 2021
for fairways, tees. and roughs, and 2 (two) gallons water/1000 sq ft for greens. That 1 gallon amount also is common for sports turf, lawns, and sod farms. Incidentally, 1 gal/1000 sq ft equals 43.56 gal water per acre, and 2 gal/1000 sq ft equals 87.12 gal water per acre. Some turf managers use an even 50 gal water per acre (which is 1.15 gal/1000 sq ft) or 100 gal water per acre (which is 2.3 gal/1000 sq ft). Of course, more water-carrier volume translates to longer time required to operate the sprayer and repeatedly fill the spray tank to make product applications. In turf management, we don’t have the option of flying an airplane over a site and making aerial spray applications at a low volume of 5 gal water/acre as is the case with field crops. Proper and effective spray applications take time, and of course employee safety is a top priority. The proper water-carrier volume is important to ensure accurate delivery and distribution of the product to ensure optimum product performance and efficacy, and to legally follow product label instructions. It also means driving your sprayer as slow as 3 to 4 mph across the turf, or walking a ‘spray hawk’ across greens, so it does take time. Calibrate your sprayer or spray system for the proper ground speed and pump pressure to deliver the amount of water-carrier volume you desire and train your employees to check the calibration periodically throughout the “spray season”. Nozzles. The nozzle or spray tip represents the last piece of equipment to come into contact with the spray solution before it reaches the turf. Don’t let the least expensive part of your sprayer be responsible for a very expensive mistake. The nozzle forms the spray solution into spray droplets and a spray pattern. After all the careful calculations of product rates and timings and formulations, and careful calibration and maintenance of your sprayer, it all comes down to water droplets. Regularly check all nozzles on the spray boom for wear or damage, and periodically measure water output from each nozzle to ensure the same amount is dispensed or at least within 5% variance among all the nozzles along the spray boom. And what about nozzle spacing? Whether you prefer a 10" boom height or 20" boom height (i.e., distance from the turf surface to the bottom of the nozzles on the spray boom), make sure the space between the nozzles is equal to the boom height in a “1-to-1” ratio. For example, for a 20" boom height, the nozzles should be spaced 20" apart. There are many nozzle-types available, but they are all responsible for forming the spray droplets and spray pattern. For turf applications, the flat-fan spray pattern is preferred, not a hollow cone pattern. The flat-fan spray pattern delivers a uniform distribution of droplets evenly across the turf surface. The hollow cone spray pattern is good for certain pesticide applications in production agriculture and orchards but will not produce a uniform or evenly distributed amount of spray droplets on a flat turf surface. Among the many flat-fan nozzles, the TeeJet brand XR (“extended range”) nozzle is commonly used in turf applications and produces the classic flat-fan spray pattern. Keep in mind there are many other nozzle types and brands available. The TurfJet nozzle is also considered a standard flat-fan nozzle, but the droplets produced are very large, resembling raindrops. These larger water droplets are good for reducing drift, but compromise on getting uniform and complete coverage. The air induction (AI) nozzle also produces a flat-fan pattern and is constructed to draw air inside to mix with the spray liquid
Spray droplets are important for safe and effective delivery of plant protection and plant health products to the turf.
Many spray nozzle makes, models, and types are available today for the turf industry.
Spring 2021 • Pennsylvania Turfgrass 11
Cover Story • continued
resulting in a larger droplet filled with an air bubble but very few fine droplets prone to drift. The AI nozzle will not eliminate spray drift 100%, but it will dramatically and effectively reduce drift compared to the other nozzle types. There are many flatfan nozzle choices, and other nozzle types and brands available. Whichever nozzle you choose, a good rule-of-thumb is to be sure the nozzle produces spray droplets of medium or coarse or very coarse size, which is best for fungicide applications to turf. Be sure to review the nozzle manufacturer’s information (i.e., tables and charts, or mobile ‘apps’) so you are sure to select the best nozzle for your intended use, the appropriate sprayer operating pressure and sprayer travel speed, and any other recommendations necessary to ensure success. Spray nozzle turrets have become common on spray booms and provide the option of having two to three to five different nozzle types at the ready. If you want to try a different nozzle or a new and improved nozzle, apply water through it onto water sensitive paper and visually check for uniform and complete coverage (water sensitive spray cards available at gemplers.com).
Operate the sprayer and groundspeed and operating pressure as recommended by the manufacturer or as you have it calibrated and see if the nozzle you chose provides the coverage you need. Also, frequently inspect the nozzles for clogging or other malfunctions, and don’t forget to verify that the product(s) in the spray tank solution have dissolved and is(are) in proper suspension. And of course, keep accurate records to ensure legal compliance as well as having the “recipe” (i.e., best water-carrier volume and nozzle-type) for maximizing your spray applications.
Example of the influence of spray droplet size on penetrant fungicide performance. Headway 1.3EC (a.i. = azoxystrobin and propiconazole; acropetal penetrant mode of activity) applied on a 14-day interval. Fine, medium, and coarse spray droplets produced from a flat-fan nozzle, extremely coarse spray droplets produced using a hollow-cone nozzle. All nozzles were calibrated to deliver the same product rate in the four different spray droplet sizes. Objective was preventive dollar spot control on a creeping bentgrass fairway test site with four replications in the Mid-Atlantic USA region. Rating date example shown from mid-July. Best dollar spot control achieved when fungicide delivered through a nozzle that produced medium or coarse droplets. Fine droplets are subject to drift off-target, and extremely coarse droplets results in poor fungicide coverage which translates to poor disease control. Note, one inch = 25,400 microns, or one micron = 0.00004 inch; sewing thread is approximately 150 microns diameter. Source: Plant Disease Management Reports 3:T064 (2009).
Example of the influence of spray droplet size on contact fungicide performance. Daconil Ultrex 82.5WDG (a.i. = chlorothalonil; contact mode of activity) applied on a 14-day interval. Fine, medium, and coarse spray droplets produced from a flat-fan nozzle, extremely coarse spray droplets produced using a hollow-cone nozzle. All nozzles were calibrated to deliver the same product rate in four different spray droplet sizes. Objective was preventive dollar spot control on a creeping bentgrass fairway test site with four replications in the Mid-Atlantic USA region. Rating date example shown from mid-July. Best dollar spot control achieved when fungicide delivered through a nozzle that produced medium or coarse droplets. Fine droplets are subject to drift off-target, and extremely coarse droplets results in poor fungicide coverage which translates to poor disease control. Note, one inch = 25,400 microns, or one micron = 0.00004 inch; sewing thread is approximately 150 microns diameter. Source: Plant Disease Management Reports 3:T064 (2009).
12 Pennsylvania Turfgrass • Spring 2021
References Couch, H.B., J.M. Garber, and D. Jones. 1984. Turfgrass fungicides, part I: Application method and effectiveness. Golf Course Management 52(7):40, 42-43, 46, 48, 50-52. Couch, H.B. 1984. Turfgrass fungicides, part II: Dilution rates, nozzle size, nozzle pressure and disease control. Golf Course Management 52(8):73-76, 78, 80.
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Spring 2021 • Pennsylvania Turfgrass 13
Feature Story
Dissecting Infield Playability By Evan C. Mascitti and Andrew McNitt, PhD
A
baseball often touches two different surfaces during the same play. This sets baseball apart from other ball
sports. Most ground balls take their first bounce on the turf and are fielded on the infield skin (Figure 1). The concentration of play in this small area means that infield playability consumes much of the grounds crew’s focus. Experienced managers know instinctively when the ball is reacting the way they want, and they can produce a consistent surface despite changing weather conditions. Playability can be an ambiguous term because it is easy to observe but hard to describe.
Figure 1: Most action occurs on the infield skin.
This article unpacks infield playability by combining practical observations with bite-size pieces of physics. We will cover the following ideas: 1. Consistency is king 2. Components of speed 3. Corkboard = plasticity + stiffness
Consistency is king Above all else, infielders want a consistent, predictable surface. This means no surprises about how the ball will react from one hop to the next, and that the field will play identically throughout a game and over the season. Elite athletes can field almost any ball, fast or slow — so long as the bounces are the same, each and every time. Infielders prefer ground balls to “hug” the surface: a shallow path makes the ball easier to track and collect. The grass and dirt areas should have similar speed and the transition between them should be seamless. Predictability is crucial for players to be able to do their jobs. If the final hop is deflected by just a few degrees, the ball can easily carom off the heel of a player’s glove or scoot beyond his reach.
Components of speed Players and coaches sometimes ask us to “speed up” or “slow down” the infield, usually by adjusting the cutting height of the turf. Ball response is more nuanced than fast vs. slow, and canopy height plays only a minor role. However, it has been said that perception is reality, so a perceived change may satisfy such a request – even if we fib about having lowered the reels by 1/8" or so. Ball response is divisible into three important elements: pace, bounce, and spin.
Pace Pace is the relative velocity of a ball after impact. Infield pace is mostly determined by hardness and friction. It is measured as a simple ratio, the Coefficient of Restitution (COR):
There is limited research on infield pace, but data suggest that soil properties affect COR more than cutting height or thatch. Dr. Jim Brosnan measured COR on real infields and on research plots (Brosnan and McNitt, 2008a; b; 2011). Infield COR ranged from 0.4 to 0.6, meaning a ball retained 40 to 60 % of its initial velocity after the first bounce. COR was generally higher on skinned surfaces than synthetic turf, which had a similar (but slightly higher) COR than natural grass. In the work by Dr. Brosnan, pace was closely related to surface hardness. Hardness is easy to measure with the familiar Clegg hammer or the F-355 device (for synthetic infields). Brosnan and McNitt (2008a) found that most infield skins had Clegg values well over 100 Gmax – much higher than values 14 Pennsylvania Turfgrass • Spring 2021
The turfgrass industry has proven its resilience over and over, and when 2020 brought so many unexpected changes and challenges, you showed up to support each other and the organizations that bring turfgrass managers together. At Leading Edge Communications, we are proud to partner with the associations and companies that keep the industry and professionals growing.
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Feature Story • continued
recommended for turf areas (Figure 2). However, it is worth noting that some fields in this study were substantially drier than typical game moisture. In a baseball context, hardness may be more useful for managing playability than safety, as baseball players are never tackled and rarely become injured by falling on the surface.
Ball-to-surface friction is determined by soil texture, presence of conditioner, and the all-important water content (Goodall et al., 2005). A thick conditioner layer reduces surface friction because the granules rotate like ball bearings as the ball shears against them. The ball will skid rather than checking up. Friction also affects the ball’s release angle, which in turn alters the bounce height (Figure 3).
Bounce
Figure 2: Surface hardness on baseball infields generally exceeds values recommended for American football.
Figure 3: If the ball can skid through impact, initial spin will influence the release angle. Adapted from Daish, 1972.
The term bounce defines the vertical rebound of a ball after impact. Some research on cricket pitches suggests that the ball “speed” experienced by a real athlete is more related to bounce than pace. Adams et al. (2005) found that umpires’ perception of speed was more closely linked to the ball’s rebound height than its velocity. A higher bounce means the ball carries farther between bounces, leading to the perception of a faster surface. Any debate about whether a perceived faster surface really has a greater pace or a greater bounce is purely scholastic, because the players’ experience is what ultimately matters. Bounce is related to hardness, and a harder surface will appear faster, even if only due to its higher bounce.
Spin The influence of ball spin can be large or small, depending on the ball-to-surface friction coefficient μ (Daish, 1972). If μ is large, the ball “rolls” during impact and its new spin rate is determined by the original incoming velocity. If μ is small, the ball retains some spin as it skids through impact and its release angle is steeper (Figure 3, bottom panel). The latter is the usual case on closely-mown turfgrass. You can observe this phenomenon during batting practice. It’s hard to hit accurate fungoes with full effort, so experienced coaches prefer a flatter but more controlled trajectory with some backspin. The steeper release angle helps compensate for lost velocity by increasing the ball’s carry after its first bounce. It’s unusual for a ground ball to be hit with backspin during a game. Most ground balls have forward spin and release at an angle beneath their incoming trajectory (Figure 3, top panel).
Corkboard = plasticity + stiffness
Figure 4: (A) This “corkboard” infield will not affect ball path because of its plastic yet stiff consistency. (B) Large, ragged cleat marks may cause erratic bounces, leading to errors or injuries.
16 Pennsylvania Turfgrass • Spring 2021
We associate the word plastic with man-made products like disposable water bottles – but the word is actually derived from plastikos, an ancient Greek term for clay. Plastikos roughly translates to “fit for shaping.” Plasticity is perhaps the most useful property of clay: it helps potters to mold clay into useful objects before firing, and it allows a groundskeeper to scarify, shave, and pack soil with proper moisture. New grounds interns are quickly taught the sacred importance of moisture management. Plasticity is important for two reasons. First, it means the soil will be smoothly remolded around players’ cleats, rather than “chunking out” or shattering into chips. This delivers the coveted corkboard surface and minimizes the number of imperfections which could cause bad bounces, as shown in Figure 4. The second reason is that if a ball does hit one of the cleat marks, the soil will readily deform again – allowing the ball to continue its initial path. Plasticity provides the “give” which makes well-watered soil so nice to play on.
Plasticity alone is not enough. Most finegrained soils are plastic at high water contents, but many lose their shear strength when so much moisture is added. Such a soil can never provide stable footing if watered to a plastic condition — the players will sink and slide, leading to injuries. Other materials retain more stiffness when wetted above the plastic limit. Stiffness is a measure of the force needed to deform the soil. An ideal infield soil retains a plastic and stiff consistency, even under hot sun or during a rain game. Designing these types of mixes is a current research topic at Penn State. We recently created a laboratory method to measure the cleat-in/cleat-out effect. We are using the method to test infield mixes containing various clay minerals, since these respond differently as the soil wets or dries. Thanks are extended to the PA Turfgrass Council, KAFMO, and the SAFE Foundation for supporting the project. On a synthetic turf infield “skin,” surface deformation happens differently. The fibers (rather than soil water) reduce the rotating and sliding of infill particles. The sand: rubber ratio and particle size distribution of the infill may also affect performance.
Summary Ball response can be managed intuitively, but it helps to consider the underlying physics. Consistency is most important. What infielders experience as speed is a combined effect of pace, bounce, and spin. Conditioners reduce the effects of ball spin by lowering surface friction. The soil must be both stiff and plastic to achieve the coveted corkboard. Future research could define new playability measures and how to achieve them.
References Adams, W.A., S.W. Baker, D.M. James, and R.J. Young. 2005. Measuring and Modelling the Bounce and Pace of County Championship Cricket Pitches. International Turfgrass Society Research Journal 10(1021-1026): 1021–1026. Brosnan, J.T., and A.S. McNitt. 2008a. Surface Conditions of Highly Maintained Baseball Fields in the Northeastern United States : Part 1 , Non-Turfed Basepaths. Applied Turfgrass Science (April). doi: 10.1094/ATS-2008-0520-01-RS.
Brosnan, J.T., and A.S. McNitt. 2008b. Surface Conditions of Highly Maintained Baseball Fields in the Northeastern United States: Part 2, Synthetic versus Natural Turfgrass. Applied Turfgrass Science (April): 8. doi: 10.1094/ATS-2008-0520-02-RS. Brosnan, J.T., A.S. McNitt, and T.J. Serensits. 2011. Effects of surface conditions on baseball playing surface pace. Journal of Testing and Evaluation 39(3). doi: 10.1520/ JTE103215.
Daish, C.B. 1972. The Physics of Ball Games. The English Universities Press, London. Goodall, S.A., K. Guillard, W.M. Dest, and K.R. Demars. 2005. Ball response and traction of skinned infields amended with calcined clay at varying soil moisture contents. International Turfgrass Society Research Journal 10: 1085–1093.
Spring 2021 • Pennsylvania Turfgrass 17
Between the Lines
KAFMO’s Brad Jakubowski Honored with
2020 STMA FOUNDER’S AWARD
W
hen Penn State Plant Science instructor and KAFMO Board member Brad Jakubowski learned that he was slated to receive a 2020 STMA Founder’s Award, he says he was “utterly speechless and humbled. I felt so honored being considered for an award for an association I’ve grown to love.” Brad joins three other KAFMO members as recipients of the Daniel Founder’s Award for educators (Jeff Fowler in 2005, Dr. Andrew McNitt in 2000, and Dr. Donald Waddington in 1999); he is the tenth KAFMO member to receive an STMA Founder’s Award. STMA’s highest honors, the Founders’ Awards, recognize those members who have made significant contributions to STMA and to the profession. Founder Dr. William Daniel set the pattern for educator/researcher involvement in STMA. The partnership between educators and researchers and the sports turf managers who incorporate these advances on the field is key to the progress of the industry. The Daniel Award recognizes an individual who has made significant contributions to the industry through research, teaching, or extension.
Deep Roots
Brad Jakubowski is an instructor of golf course irrigation and drainage, landscape irrigation and water management, and turfgrass management in the Penn State Turfgrass Science program. He also manages PSU Turf Science’s digital presence. As a Ph.D. candidate, he is studying impact attenuation on natural and synthetic athletic turfgrass fields. Jakubowski has been involved with the green industry for nearly 30 years, working in the areas of residential/commercial irrigation, golf course, and sport field. He previously directed the two-year Sports Turf Management Program for the University of Nebraska and helped to develop their new Turfgrass and Landscape Management Degree Program. Brad Jakubowski’s roots in Turf Management go deep. “I started in turfgrass as an eighth grader, taking care of an estate and working at a par 3 golf course,” he reminisces. “I built my first bunker with a skid steer loader back in 1987, and that bunker is still there.” His background in sports turf deepened while directing the University of Nebraska’s two-year sports turf management program. He had asked Tony Koski from Colorado State University where to take his students for a turf conference and heard about the STMA. “Tony said if you go there, you’ll never leave, and he was right. I didn’t.” He is a 15-year member of STMA, co-founder of the STMA Intercollegiate Student Challenge and recently served on the STMA board of directors. “There
Keystone Athletic Field Managers Organization 1451 Peter’s Mountain Road Dauphin, PA 17018-9504 www.KAFMO.org • Email: KAFMO@aol.com 18 Pennsylvania Turfgrass • Spring 2021
were and are so many mentors!” he says. Dr. Tom Samples gave him his first opportunity to speak at the Tennessee Turf Conference and is still one of his biggest supporters. He is also grateful to Mike Andresen, Lynda Wightman, Dave Minner, Tony Koski, Gwen Stahnke, Leah Brilman, and Andy McNitt. “Without them, my path in sports turf would have been extremely limited.”
Career High Points
When Jakubowski looks back on his career, this award is one of several high points. Another, he recalls, was the day they called him about his nomination to the STMA Board of Directors. “It was August, and I was working with a group of baseball players in rebuilding their pitcher’s mound. It definitely made pounding new clay a lot easier on a hot afternoon!” Another peak was helping to develop the STMA Student Challenge. He still remembers meeting with Chad Follis and Jeff Salmond in San Antonio years ago to discuss how to propose it. The first challenge in Phoenix had 13 teams competing. Since then, they commonly have over 30. “My biggest challenges have been working diligently to find or develop quality programming and education for the STMA membership. It’s a difficult association to outgive,” he says. “No matter how hard you try, they always have a way of giving back in abundance!” In addition to his other responsibilities, Jakuboski manages Penn State’s online Turf programs. Covid-19 challenged everyone, but he was fortunate to already have been working on a new online turfgrass irrigation course. This gave him an existing online infrastructure to use as a supplement for in-person classes and made the transition to a full-time online course much more seamless. With the online structure in place, he could develop curriculum that was as practical as possible for his students. For example, he sent home packets made up of irrigation sprinklers, nozzles, and a valve, to be disassembled and reassembled in real time, giving the students some hands-on experience with their normal classwork. Teaching in a mixed mode, with some students present in class while other students were online, forced him to experiment with using both methods simultaneously. He says it was very rewarding. “I love teaching and it was an unexpected dream that I was fortunate enough to fall into. As they say, you’ll honestly never go to work a day in your life if you do what you love!”
Details and Dreams
When asked what challenges he sees for young people entering turf management now, he noted first that the field is becoming more competitive. “Make the most of every learning opportunity, whether in the classroom, on the field, or working around the home.” He advises aspiring turf managers to take advantage of internship opportunities. “There are so many good turfgrass managers willing to help you learn as much as possible, it would be crazy not to! Do multiple internships -- the more you learn, the more marketable you become.” He also cautions that “the small things make a difference. Incorrectly apply Teflon tape, for example, and you may have a leak that breaks free at the bottom of the ninth with the bases loaded.” At the end of a season, many turfgrass managers will discuss their options and an intern draft takes place, he says. Employers notice the little things, like who is not afraid to pound clay, do plumbing, rake grass, and fill water coolers. Finally, he counsels, “Don’t be afraid to dream!” One of his favorite memories is of student Seth Burchill. “He dreamt of working with the Chargers and lo and behold, now he’s painting for the Chargers. That stuff really works!”
Contact: Linda Kulp, Executive Secretary Phone: 717-497-4154 kulp1451@gmail.com
Contact: Dan Douglas, President Phone: 610-375-8469 x 212 KAFMO@aol.com
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