DECEMBER / JANUARY 2026
The Official Publication of the Tennessee Turfgrass Association, the Tennessee Valley Sports Field Management Association and the Tennessee Golf Course Superintendents Association
HIGHLIGHTS FROM THE 60th Annual TTA Conference & Trade Show PLUS An Updated Roundup on Glyphosate
We’ve just made it through Christmas, my favorite time of year. It’s a season filled with good food, good fellowship, and good fun. The New Year brings many resolutions, but more importantly, the 60th Annual Tennessee Turfgrass Conference. This year, like always, it was a terrific event that brought like-minded people together to discuss the status of our industry. The Board of Directors worked diligently to put all the pieces together to form one of the best turf conferences in the country. Thank you all for your attendance and support of this event.
This marks the end of my term as President of this great association. Many people before me laid the groundwork that this group is firmly built upon. I joined the Board in 2015 and have thoroughly enjoyed my time working with a great group of people. There are people like Doug Ward and Bill Marbet, two titans in their respective industries. Melissa Martin and her dedication and willingness to pick up the phone whenever I call. The knowledge on this board is tremendous. The help from the University of Tennessee cannot be matched anywhere else in the country. Dr. Becky Bowling and her team are a tremendous asset to this association. Thank you to all of you who continue to put time and effort into the association.
Ryan Blair will be taking the reins, and I know he will do a fantastic job. Thank you for allowing me to be a part of Tennessee Turfgrass and I look forward to the future of this industry and its fantastic members.
Ryan Storey
TTA President
The Tennessee Turfgrass Association 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, Tennessee Turfgrass Magazine, or its editors. Likewise, the appearance of advertisers, or Turfgrass Association members, does not constitute an endorsement of the products or services featured in this, past or subsequent issues of this quarterly publication. Copyright © 2026 by the Tennessee Turfgrass Association. Tennessee Turfgrass is published bi-monthly. Subscriptions are complimentary to members of the Tennessee Turfgrass Association. Third-class postage is paid at Jefferson City, MO. Printed in the U.S.A. Reprints and Submissions: Tennessee Turfgrass allows reprinting of material. Permission requests should be directed to the Tennessee Turfgrass Association. 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.
Tennessee Turfgrass is the official publication of The Tennessee Turfgrass Association
400 Franklin Road Franklin, Tennessee 37069 (615) 928-7001
info@ttaonline.org www.ttaonline.org
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Leading Edge Communications, LLC 206 Bridge Street Franklin, Tennessee 37064 (615) 790-3718
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EDITOR
Dr. James Brosnan
TTA OFFICERS
President Ryan Storey Line to Line LLC
Vice President
Ryan Blair, CGCS Holston Hills Country Club
Secretary / Treasurer Bart Cash Crossroads Sod Farm
Past President Chris Sykes PGA Golf Club
Executive Director Melissa Martin Tennessee Turfgrass Association
TTA BOARD OF DIRECTORS
Kevin
TTA ADVISORY MEMBERS OF THE BOARD
Dr. Jim Brosnan
Joe Hill
Dr. Brandon Horvath
Lynn Ray
Jeff Rumph
Dr. Tom Samples
Dr.
Dr. Wes Totten
HIGHLIGHTS FROM THE AND
OnJanuary 5th through 7th, turfgrass professionals from across the state and beyond gathered at the Murfreesboro Embassy Suites for the 60th Annual Tennessee Turfgrass Association Conference and Trade Show. It’s easy to let annual conferences become a mindless routine, but the TTA staff, board and conference committee made this year’s conference anything but routine.
From education to CEUs to business meetings to corn hole to awards to a busy trade show, the three-day conference was packed with opportunities to grow in knowledge and make valuable connections in preparation for another busy season of turfgrass management.
TTA would like to thank the speakers who shared their time and expertise to make this year’s conference exceptional:
Dr. Paul Giordano
Dr. Jim Brosnan
Dr. Brandon Horvath
Dr. Becky Bowling
Dr. Darrell Hensley
Chava McKeel
Zoe Haub Hinton
Dillon McCallum
Dr. Midhula Gireesh
Taylor Reeder
Michael McCormick
Pat Rose, CGCS
Dr. Lee Miller
Jim West, PGA, ARWC
John Ballard, CGCS
Chris Ball, CSFM
Lou Warner
Dr. Kyley Dickson
Bland Cooper
Darren Seybold
Bryan Ogle
Logan Smith
Creig Kimbro
Dr. John Sorochan
Rhys Fielder
Taylor Williams
Tony Altum
Michael Brownlee
CONGRATULATIONS TO OUR AWARD RECIPIENTS!
PRIVATE COURSE OF THE YEAR
Richland Country Club Nashville, TN
HIGH SCHOOL FIELD OF THE YEAR
Watertown High School Baseball Field
Watertown, TN
HIGH SCHOOL FIELD OF THE YEAR
PUBLIC COURSE OF THE YEAR
COLLEGIATE FIELD OF THE YEAR
Watertown High School Baseball Field
Gatlinburg Golf Course
Watertown, TN
Pigeon Forge, TN
Fesmire Baseball Field, Union University Jackson ,TN
MUNICIPAL SPORTS FIELD OF THE YEAR
Columbia American Little League Columbia, TN
CONGRATULATIONS TO OUR AWARD RECIPIENTS!
TNGCSA SUPERINTENDENT OF THE YEAR
Nick Bisanz
TPC Southwind
TNGCSA EQUIPMENT MANAGER OF THE YEAR
Andy Gasparini
Belle Meade Country Club
TNGCSA ASSISTANT SUPERINTENDENT OF THE YEAR
Grayson Guthrie
The Governor’s Club
THANK YOU TO OUTGOING PRESIDENT Ryan Storey for your dedication to TTA !
linkedin.com/company/theturfzone
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Getting national updates from Chava McKeel of GCSAA about Governmental Affairs, addressing advocacy efforts shaping the future of the golf industry.
State of the Turf: Emerging Trends in Golf and Beyond was an engaging open discussion led by moderator Will Houchin alongside Drs. Becky Bowling, Jim Brosnan, and Brandon Horvath.
Using scientific reasoning to separate fact from fiction in turfgrass management
Tiftuf Bermuda | Tifway Bermuda | Bluegrass Blends Stadium Zoysia | Zeon Zoysia | Rebel Supreme Fescue Many Varieties Maintained At .500
MONDAY (AM)—SATURDAY TO ACCOMMODATE YOUR JOB NEEDS
• Backed By Two Decades of Rigorous Testing
• Requires 38% Less Water
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BWI Companies, Inc. 23 www.bwicompanies.com
Carolina Green Corp. 25 www.cgcfields.com
Coosa Valley Turf Farms 19 www.coosavalleyturffarms.com
Corbin Turf & Ornamental Supply 21 www.corbinturf.com
Crossroads Sod Farm 23 www.csfsod.com
DryJect 29
Greene County Fertilizer Co. 33 www.greenecountyfert.com
Jackson Sand 31 www.jacksonsand.com
McCurdy Sod Farms, LLC 31 www.mccurdysodfarms.com
North Georgia Turf Company, Inc. 17 www.ngturf.com
Progressive Turf Equipment Inc. 13 www.progressiveturfequip.com
Regal Chemical Company Back Cover www.regalchem.com
Site One 3 www.siteone.com
Smith Seed Services 19 www.smithseed.com
Smith Turf & Irrigation 5 www.smithturf.com
Sod Solutions 35 www.SodSolutionsPro.com
Super-Sod 7 www.supersod.com
Sur-Line Turf, Inc. 37 www.surlineturf.com
The Aquatrols Company 13 www.aquatrols.com
The Turf Zone 15, 25 www.theturfzone.com
The Turfgrass Group 11 www.theturfgrassgroup.com
Tri-Turf Sod Farms Inside Back Cover www.triturfsod.com
Trimax Mowing Systems 27 www.trimaxmowers.com
Turf Mountain Sod, Inc. 37 www.turfmountain.com
Winstead Turf Inside Front Cover, 25 www.winsteadturffarms.com
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This calendar highlights Extension-led professional development opportunities for turfgrass managers and green industry professionals across Tennessee in 2026. Events include a mix of in-person programs and virtual learning opportunities designed to support continuing education, workforce development, and applied management decision-making.
FEBRUARY 25, 2026
Winter Lawn & Landscape Service Operators Continuing Education
Location:
Lane Agri-Park (Rutherford County Extension Office), 315 John R. Rice Blvd., Auditorium, Murfreesboro, TN
Points offered?: Yes
Contact:
Rutherford County Extension Office – (615) 898-7710)
Mr. Justin Stefanski – jski@utk.edu
CONTINUED
APRIL 2026
Spring Horticulture Workshop
Location: Shelby County (Memphis area), TN
Points offered?: Yes
Contact:
Shelby County Extension Office – (901) 752-1207
Mr. Joseph Seago – jseago@utk.edu
•Chemicals
•Fertilizers
•Nutritionals
•Seed
•Irrigation & Watering Products
•Landscaping Materials
•Erosion Control Products
•STIHL Battery-Powered Equipment
•Safety Gear
•Golf Accessories
•Athletic Field Products
APRIL 7, 2026
Turf Tuesdays: Turfgrass Management at Belle Meade Country Club
Location: Virtual
Points offered?: Yes
More Information:
https://www.tnturfgrassweeds.org/turftuesday
Contact: Dr. Jim Brosnan – jbrosnan@utk.edu
MAY 15, 2026
Grounds Management Short Course (Day 2)
Location: Knoxville, TN
Points offered?: Yes
More Information: https://knox.tennessee.edu/grounds-management
Contact: Mr. Lee Rumble – drumble@utk.edu Knox Co. Extension – (865) 215-2340
JUNE 2, 2026
Turf Tuesdays: Sports Turf Management Across Tennessee
Location: Virtual
Points offered?: Yes
More Information: https://www.tnturfgrassweeds.org/turftuesday
Contact: Dr. Jim Brosnan – jbrosnan@utk.edu
MAY 5, 2026
Turf Tuesdays: A Historic Career in Turfgrass Management
Location: Virtual
Points offered?: Yes
More Information:
https://www.tnturfgrassweeds.org/turftuesday
Contact: Dr. Jim Brosnan – jbrosnan@utk.edu
JUNE 11, 2026
Green Industry Field Day
Location: Knoxville, TN
Points offered?: Yes
More Information: https://plantsciences.tennessee.edu/green-industry-field-day/
Contact: Dr. Amy Fulcher – afulcher@mail.tennessee.edu or Tennessee Nursery and Landscape Association – (931) 473-3951
JULY 7, 2026
Turf Tuesdays: Landscape Ornamental Management Update
Location: Virtual
Points offered?: Yes
More Information: https://www.tnturfgrassweeds.org/turftuesday
Contact: Dr. Jim Brosnan – jbrosnan@utk.edu
JULY 15, 2026
Beat the Heat on the Plateau
Location: Plateau AgResearch and Education Center, 320 Experiment Station Rd., Crossville, TN 38571
Points offered?: Yes
More Information: https://uthort.tennessee.edu/uthort-pros https://plantsciences.tennessee.edu/turfgrass/
Contact: Dr. Becky Grubbs Bowling – rgrubbs5@utk.edu or Mr. Gregg Upchurch – gupchurch@utk.edu
JULY 30, 2026
Beat the Heat in the Scenic City
Location: Chattanooga, TN (venue forthcoming)
Points offered?: Yes
More Information: https://uthort.tennessee.edu/uthort-pros https://plantsciences.tennessee.edu/turfgrass/
Contact: Dr. Becky Grubbs Bowling – rgrubbs5@utk.edu or Haley Treadway – haleytreadway@utk.edu
the
AUGUST 13, 2026
Location: Rutherford County, TN
Points offered?: Yes
More Information: https://uthort.tennessee.edu/uthort-pros https://plantsciences.tennessee.edu/turfgrass/
Contact: Dr. Becky Grubbs Bowling – rgrubbs5@utk.edu
Mr. Justin Stefanski – jski@utk.edu
JULY 23, 2026
Location: Agricenter International, 7777 Walnut Grove Rd., Memphis, TN 38120
Points offered?: Yes
More Information: https://uthort.tennessee.edu/uthort-pros https://plantsciences.tennessee.edu/turfgrass/
Contact: Dr. Becky Grubbs Bowling – rgrubbs5@utk.edu or Mr. Joseph Seago – jseago@utk.edu
AUGUST 4, 2026
Turf Tuesdays: Firefly – A New Golf Course Property in Tennessee
Location: Virtual
Points offered?: Yes
More Information: https://www.tnturfgrassweeds.org/turftuesday
Contact: Dr. Jim Brosnan – jbrosnan@utk.edu
AUGUST 21, 2026
the
Location: Knox County, TN
Points offered?: Yes
More Information: https://uthort.tennessee.edu/uthort-pros https://plantsciences.tennessee.edu/turfgrass/
Contact: Dr. Becky Grubbs Bowling – rgrubbs5@utk.edu
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SEPTEMBER 1, 2026
Turf Tuesdays: Turfgrass Management at Lookout Mountain Club
Location: Virtual
Points offered?: Yes
More Information: https://www.tnturfgrassweeds.org/turftuesday
Contact: Dr. Jim Brosnan – jbrosnan@utk.edu
OCTOBER 13 – 14, 2026
BEACON 26
(Bridging Education, Careers, and Opportunities in Turfgrass)
Location: Knoxville, TN
Points offered?: No
More Information: https://plantsciences.tennessee.edu/turfgrass-2/events https://uthort.tennessee.edu/uthort-pros/
Contact: Dr. Becky Grubbs Bowling – rgrubbs5@utk.edu
NOVEMBER 4 – 5, 2026
Location: Agricenter International, 7777 Walnut Grove Rd., Memphis, TN 38120
Points offered?: Yes
Contact: Mr. Joseph Seago – jseago@utk.edu
Shelby County Extension Office – (901) 752-1207
OCTOBER 6, 2026
Turf Tuesdays: A Historic Career in Turfgrass Extension
Location: Virtual
Points offered?: Yes
More Information: https://www.tnturfgrassweeds.org/turftuesday
Contact: Dr. Jim Brosnan – jbrosnan@utk.edu
OCTOBER 22, 2026
West TN Lawn & Landscape Review
Location: Jackson, TN
Points offered?: Yes
Contact: Celeste Luckey Scott – cscott52@utk.edu
EARLY 2027 EVENTS TO WATCH FOR:
Middle Tennessee Landscape and Grounds Short Course (January)
Chattanooga (CHA) Landscape Short Course (January)
Knox County Grounds Maintenance Short Course – Day 1 (January)
Updated January 14, 2026
José Javier Vargas Almodóvar Research Associate II Turf & Ornamental Weed Science
The University of Tennessee 2431 Joe Johnson Drive 252 Ellington Plant Sci. Bldg. Knoxville, TN 37996 (865) 974-7379 jvargas@utk.edu tnturfgrassweeds.org @UTweedwhisperer
Jim Brosnan, Ph.D. Professor, The University of Tennessee Director – UT Weed Diagnostics Center 112 Plant Biotechnology Bldg. 2505 EJ Chapman Drive. Knoxville, TN 37996 Office: (865) 974-8603 tnturfgrassweeds.org weeddiagnostics.org mobileweedmanual.com @UTturfweeds
Greg Breeden Extension Specialist, The University of Tennessee 2431 Center Drive 252 Ellington Plant Sci. Bldg. Knoxville, TN 37996-4561 (865) 974-7208 gbreeden@utk.edu tnturfgrassweeds.org @gbreeden1
Kyley Dickson, Ph.D. Associate Director, Center for Athletic Field Safety Turfgrass Management & Physiology (865) 974-6730 kdickso1@utk.edu @DicksonTurf
Midhula Gireesh, Ph.D. Assistant Professor and Extension Specialist Department of Entomology and Plant Pathology
The University of Tennessee UT Soil, Plant and Pest Center 5201 Marchant Drive Nashville, TN 37211 mgireesh@utk.edu (615) 835-4571
Becky Bowling, Ph.D. Assistant Professor and Turfgrass Extension Specialist The University of Tennessee 112 Plant Biotechnology Bldg. 2505 E.J. Chapman Dr. Knoxville, TN 37919 (865) 974-2595 Rgrubbs5@utk.edu @TNTurfWoman
John Stier, Ph.D. Associate Dean
The University of Tennessee 2621 Morgan Circle 126 Morgan Hall Knoxville, TN 37996-4561 (865) 974-7493
jstier1@utk.edu turf.utk.edu @Drjohnstier
Brandon Horvath, Ph.D. Associate Professor, Turfgrass Science
The University of Tennessee 252 Ellington Plant Sci. Bldg. 2431 Joe Johnson Drive Knoxville, TN 37996 (865) 974-2975 bhorvath@utk.edu turf.utk.edu @UTturfpath
John Sorochan, Ph.D. Professor, Turfgrass Science The University of Tennessee 2431 Joe Johnson Drive 363 Ellington Plant Sci. Bldg. Knoxville, TN 37996-4561 (865) 974-7324 sorochan@utk.edu turf.utk.edu @sorochan
Nar B. Ranabhat, Ph.D. Assistant Professor and Extension Plant Pathologist Department of Entomology and Plant Pathology
University of Tennessee UT Soil, Plant and Pest Center 5201 Marchant Drive, Nashville, TN, 37211 (615) 835-4572 nranabhat@utk.edu @UTplantPathoDoc
History, Use, Issues, and Alternatives
By Jeffrey Derr, Ph.D. and Adam Nichols Virginia Tech, Hampton Roads Agricultural Research and Extension Center
Glyphosate continues to be in the news, primarily because of the court cases concerning glyphosate and human health. There are still thousands of lawsuits related to glyphosate and human health (https://www.lawsuit-informationcenter.com/roundup-lawsuit.html). In this article we discuss some background information on this herbicide as well as alternatives to this chemical.
The glyphosate molecule is similar to the amino acid glycine. The chemical name is N-(phosphonomethyl)glycine, a relatively small molecule compared to newer herbicides. It is the active ingredient in products such as Bayer’s Roundup PROMAX, as well as in generic products sold under a variety of trade names. Since the chemical is off patent (patent expired around 2000), other companies besides Bayer can sell this herbicide under their own trade name. Some examples of other trade names for products that contain glyphosate include Glyphosate, Gly Star, Glypho, and Prosecutor, among others, for terrestrial use. There also are formulations that can be used in aquatic sites, such as Accord, AquaMaster, and Rodeo.
Bayer does not market glyphosate to homeowners, only to commercial applicators. However, glyphosate is still available to homeowners, with one example being Hi-Yield Super Concentrate Killzall Weed & Grass Killer, which is sold in quart containers. Homeowners also can purchase the commercial formulations, such as Razor Pro, Prosecutor, Roundup ProMax, and Roundup QuikPro as there are no restrictions on homeowners purchasing those products. A disadvantage to homeowners is that the commercial products are sold in quantities often too large for homeowner needs, such as 2.5 gallon jugs which can treat 5 acres.
To add some confusion, there are products being sold that do not contain glyphosate but use the Roundup name and are primarily targeted towards homeowners. For example, there is Roundup for Lawns, which contains MCPA, quinclorac, dicamba, and sulfentrazone. These four herbicides are selective
in lawns for general weed control compared to the nonselective herbicide glyphosate. There is Roundup Weed and Grass Killer Concentrate, which contains triclopyr, fluazifop, and diquat and is an alternative to glyphosate for weed control in driveways, along fences, and certain other areas. Roundup Dual Action contains triclopyr, fluazifop, and diquat, along with imazapic to extend the residual control.
The initial formation of this herbicide was an isopropylamine salt of glyphosate, which is still widely used, although other salt formulations are available now, such as the potassium salt and the dimethylamine salt. This becomes important when comparing products. We need to look at the amount of glyphosate acid in products, not the amount of active ingredient, since the different salt formulations differ in their molecular weight. For example, Roundup PROMAX contains 5.5 pounds per gallon of the potassium salt of glyphosate (ai) or 4.5 lbs/gallon glyphosate acid (ae). Prosecutor Pro contains 4.0 lbs/gallon of the isopropylamine salt of glyphosate (ai) or 3.0 lbs/gallon glyphosate acid (ae). So Roundup PROMAX contains 50% more glyphosate acid than Prosecutor Pro per gallon and applications rates in terms of fluid ounces of product per acre are lower that for Prosecutor Pro.
Besides glyphosate, there are other chemicals in commercial formulations, usually water and a surfactant. As an example of a formulation, Roundup PROMAX contains the potassium salt of glyphosate at 48.7% by weight, surfactant(s) at 8.8%, and water plus minor ingredients at approximately 42%.
Surfactants can aid in the absorption of herbicides by weeds. One example would be POEA (polyoxyethylene tallow amine). Concerns have been raised about the toxicity of this surfactant to aquatic organisms such as tadpoles, salamanders, and frogs. Aquatic formulations of glyphosate either do not contain a surfactant or contain a surfactant that has not shown to be an issue. That is why certain formulations of glyphosate are not labeled for aquatic use – not due to the toxicity of glyphosate but due to toxicity concerns about the surfactant to amphibians and other aquatic organisms. For glyphosate products that do not contain a surfactant, one generally needs to add an approved one for optimum weed control.
Glyphosate was found to control weeds by a Monsanto scientist in 1970. The herbicide was patented in 1971 and was introduced commercially as Roundup in 1974. Glyphosate use has increased over time, especially when Roundup-Ready crops were introduced, starting with Roundup Ready soybeans in 1996. These soybean lines, and later corn, cotton, and other crop cultivars, were developed to be resistant to glyphosate through biotechnology. For these genetically-modified crops, glyphosate could be applied overtop for selective weed control. Bayer purchased Monsanto in 2018 and continues to market glyphosate to commercial applicators.
Decreased down time, increased revenue.
The surface is very “puttable.”
The dots are sand that is level with the turf.
DryJect® is a high-pressure, water based injection system that blasts holes through the root zone and fractures the soil profile. Plus, it automatically fills holes as it aerates.
DryJect® makes a big difference in playability … right away!
Glyphosate inhibits the enzyme enolpyruvyl shikimate-3-phosphate (EPSP) synthase, needed for synthesis of the aromatic amino acids tryptophan, tyrosine, and phenylalanine in plants. Animals, including people, do not make these amino acids as they need to get these chemicals in their diet. Plants though must make these amino acids, which are the building blocks of proteins. So glyphosate inhibits a process that occurs in plants but not in animals. Result – a chemical that controls plants with low acute toxicity to animals.
Glyphosate is a nonselective postemergence herbicide, meaning that it controls essentially all weeds. The recent development of certain weed species developing resistance, such as glyphosateresistant horseweed, has pushed researchers and growers to find alternative means to control these weed species. However, most weed species are still susceptible to glyphosate.
Glyphosate is systemic, so it moves into and controls underground portions of weeds (roots, rhizomes, tubers, etc.), making it the preferred product for perennial weed control in many situations. This chemical binds to soil particles and has essentially no soil activity, so crops can be planted a week after application.
Glyphosate is used for preplant weed control/site preparation, lawn renovation, spot treatment of weeds in landscape beds, as a directed spray application in fruit and nursery production, and for noncrop weed management, such as guard rails, railroad lines, and parking lots, among other uses. It controls grasses, sedges, and broadleaf weeds, making it a broad-spectrum herbicide.
One measure of acute toxicity is the LD50, the dose required to kill 50% of the test animal, usually rats. The higher the LD50, the lower the toxicity. The acute oral LD50 for glyphosate is greater than 5,000 mg/kg (Bayer 2023). For comparison, the acute oral LD50 (rat) for aspirin ranges from 200 to 1,500 mg/kg according to the National Center for Biotechnology Information (2025) and ThermoFischer (2025), making aspirin significantly more acutely toxic than glyphosate.
Another point to keep in mind is that risk associated with a given pesticide is based on the toxicity of the chemical along with the exposure level.
It has been suggested that glyphosate causes non-Hodgkin lymphoma (NHL), a type of cancer, and other diseases, although the link between glyphosate and cancer is inconclusive (see the review articles Boretti 2024, Gonzalez-Moscoso 2023). In a 2020 publication, Boretti states that the link between non-Hodgkin lymphoma and Roundup is shown to be extremely weak.
The International Agency for Research on Cancer (IARC), part of the World Health organization, lists glyphosate as a probable human carcinogen in Group 2A, along with burning of wood, eating red meat, high-temperature frying, night work shifts, being a hairdresser or barber, exposure to inorganic lead compounds, spraying insecticides, and manufacture of art glass, among others (IARC 2025).
In February 2020, the Environmental Protection Agency (EPA) published the interim decision registration review decision (ID) for glyphosate (EPA 2025). As part of that decision, EPA found that when glyphosate is used in accordance with its current label, glyphosate is unlikely to be a human carcinogen. EPA scientists had performed an independent evaluation of available data for glyphosate and found no risks of concern to human health from current uses of glyphosate, no indication that children are more sensitive to glyphosate, no evidence that glyphosate causes cancer in humans, and no indication that glyphosate is an endocrine disruptor. On March 20, 2020, the glyphosate ID was challenged in the U.S. Court of Appeals for the Ninth Circuit. On June 17, 2022, the U.S. Court of Appeals for the Ninth Circuit vacated the human health portion of the glyphosate ID and the EPA determined that withdrawal of the glyphosate ID was appropriate. The EPA is currently updating its evaluation of the carcinogenic potential of glyphosate to better explain its findings and to include the current relevant scientific information.
Another issue that has been mentioned is that glyphosate may affect bacteria in the gut microbiome. Certain bacteria can be adversely affected by exposure to glyphosate. One concern is an impact on the gut bacteria in honeybees, potentially increasing susceptibility to pathogens (Mottaa et al. 2018, Castelli 2021.)
We do not have a ready alternative to glyphosate that provides the same level of weed control and use, especially for perennial weeds. There are other chemicals that have little to no soil residual and that affect both grasses and broadleaf weeds when applied postemergence and thus can address some of the uses for glyphosate.
There are contact nonselective chemicals available for control of annual weeds and suppression of perennial weeds that do not have soil residual. This group includes pelargonic acid (Scythe) and diquat (Reward, Diquat), which are targeted towards commercial applicators. These chemicals work very quickly, with injury to weeds often within hours when applied under warm, sunny conditions. Keep in mind that contact herbicides have no effect on underground plant parts, so perennial weeds will regrow from underground tubers, rhizomes, or bulbs, requiring additional applications. Also, large plants of annuals can be harder to control as thorough coverage of weed foliage is required. Ideally, annual weeds are treated when they are less than four inches tall. In addition, annual grassy weeds can be harder to control than annual broadleaf weeds as their growing points are less exposed compared to broadleaf plants.
Ortho Ground Clear is a combination of pelargonic acid, the contact herbicide mentioned above, along with imazapyr, a preemergence and postemergence herbicide. Imazapyr poses a risk to desired trees and shrubs due to the potential for root uptake and systemic injury, thus significantly limiting where it can be applied in homeowner situations.
Another contact herbicide that we have evaluated is Spruce, a product targeted towards homeowners. This product, from Proctor and Gamble, contains geraniol (an alcohol in geranium, rose oil, citronella oil), cornmint oil (from wild mint Mentha arvensis), and sodium lauryl sulfate (surfactant found in coconut and palm kernel oil). It is not EPA registered, but is exempt under the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA). Also, Spruce is not approved for organic use. Spruce did not perform well in our trial, although we did have some difficult-to-control weed species in that study.
Roundup Weed and Grass Killer Concentrate, mentioned earlier, contains two systemic herbicides, triclopyr for broadleaf weeds, and fluazifop for grassy weeds, along with the contact herbicide diquat. We have not seen the same level of perennial weed control as we have seen with glyphosate products. Also, this mixture will
have a degree of residual activity, potentially poses a concern if seeding a treated area soon after application.
In my opinion, the best alternative to glyphosate is glufosinate, another nonselective postemergence herbicide that is inactivated upon contact with soil. It works faster on weeds than glyphosate, but it is not as systemic as glyphosate. So glyphosate generally provides greater control of perennial weeds, especially perennial grasses, compared to glufosinate. Glufosinate will generally provide better control of perennial weeds than contact herbicides. Commercial formulations of this active ingredient include Cheetah Pro and Finale, among others. One homeowner formulation of this herbicide is BioAdvanced Weed and Grass Killer Super Concentrate which is sold in a ready-to-use container as well as a one quart concentrate, so the quantity sizes are appropriate for homeowners.
In the study we conducted at the station in 2025, the contact herbicides Scythe and Spruce caused rapid injury to the weed species in the trial. But by 12 days after treatment, the weeds recovered from that injury. Glufosinate (Cheetah Pro) and glyphosate (Roundup Quik Pro), both with systemic action, showed significant weed control at 12 days (Figure 1). We showed those plots at our Turfgrass Field Day in June of this year.
These are chemicals that are OMRIapproved (Organic Materials Review Institute) for weed control. All of the products we have tested are contact herbicides and thus much less effective than the systemic herbicide glyphosate for perennial weed control. One such chemical is 20% acetic acid, sold under such names as Weed Pharm but this formulation carries a danger label. There are long-chain fatty acid products such as ammonium nonanoate (AXXE) and Suppress (capric/caprylic acid). Scythe is similar to these fatty acid products but Scythe is not approved for organic use. There are products based on plant oils, such as citrus oil (d-limonene) sold as Avenger. There are other plant oil-containing products sold, using clove oil, cinnamon oil, or others but some of these products are not approved for organic use. These plant oils have also acted as contact nonselective herbicides.
Keep in mind that you must use products labeled for weed control. Mixing vinegar, table salt, and dishwashing liquid and applying it as an herbicide is not a legal treatment.
Read the literature cited in this article and determine for yourself the benefits and risks to use of glyphosate and the other chemicals mentioned. Be careful about articles you read on the internet, in newspapers, and in other media. Sometimes claims are made about chemicals that are not supported by scientific research. Ask to see data from published, peer-reviewed articles in scientific journals.
If you plan to continue using glyphosate, as we continue to do here at the research station, follow information listed on the label. For example, the Personal Protective Equipment (PPE) for Roundup PROMAX is a long sleeve shirt, long pants, shoes, and socks ( https://www.cdms.telusagcg. com/ldat/ld0RI000.pdf) Read and follow all label directions. Make sure the product you use has a label for the site to be treated.
Bayer. 2023. Roundup Promax Safety Data Sheet. https://www.cdms.telusagcg.com/ldat/mp0RI003.pdf.
Boretti, A. 2024. Comprehensive risk-benefit assessment of chemicals: A case study on glyphosate. Oxico.l Rep. 2024 Nov 7;13:101803. doi: 10.1016/j. toxrep.2024.101803.
Boretti, A. 2020. Glyphosate and non-Hodgkin Lymphoma. Asian Journal of Organic & Medicinal Chemistry 5(4), pp. 340–347. doi: 10.14233/ajomc.2020. AJOMC-P301.
Castelli, L,. S. Balbuena, B. Branchiccela, P. Zunino, and J. Liberti. 2021. Impact of Chronic Exposure to Sublethal Doses of Glyphosate on Honey Bee Immunity, Gut Microbiota and Infection by Pathogens. Microorganisms . DOI:10.3390/microorganisms9040845.
EPA (Environmental Protection Agency). 2025. Glyphosate. https://www.epa.gov/ingredients-usedpesticide-products/glyphosate. Accessed October 3, 2025.
LIED BIOLOGICAL Gonzalez-Moscoso, M., D. MezaFigueroa , N, V. Martínez-Villegas, and M. R. Pedroza-Montero . 2023 GLYPHOSATE IMPACT on human health and the environment: Sustainable alternatives to replace it in Mexico. Chemosphere (Nov 2023). DOI:10.1016/j.chemosphere.2023.139810.
International Agency for Research on Cancer. IARC Monographson the Identification of carcinogenic hazard to humans. https://monographs.iarc.who.int/ list-of-classifications. Accessed October 3, 2025.
Mottaa, E.V., K. Raymanna, and N.A. Morana,1. 2018. Glyphosate perturbs the gut microbiota of honey bees. Proc. Nat. Acad. Sci. 115( 41):10305–10310.
National Center for Biotechnology Information (2025). PubChem Compound Summary for CID 2244, Aspirin. https://pubchem.ncbi.nlm.nih.gov/compound/ Aspirin#section=Acute-Effects. Accessed October 3, 2025.
ThermoFischer. 2009. Safety data sheet for acetylsalicylic acid. https://www.fishersci.com/store/ msds?partNumber=AC158180500&productDescription= ACETYLSALICYLIC+ACID+50GR&vendorId=VN0003211 9&countryCode=US&language=en. Accessed October 10, 2025.
Jeffrey Derr and Adam Nichols are located at Virginia Tech’s Hampton Roads Agricultural Research and Extension Center in Virginia Beach.
GRASS SO GREEN THAT WE NEEDED AN EXTRA “E”
Turf starts with Greene County Fert.
Landon Erbrick, Paul Bartley, Mark Hoffman and Tanzeel Rehman – Auburn University
J. Bryan Unruh – University of Florida
Asthe landscape industry faces mounting labor challenges, tightening environmental regulations, and growing pressure to improve efficiency, the emergence of mowing technologies are generating widespread attention. But do these machines actually deliver on their promises of cost savings, labor efficiency, and sustainability?
A multi-disciplinary team of researchers from Auburn University, the University of Florida, and the University of Georgia has launched a multi-year research initiative to answer that very question. Supported by industry partners and the United States Department of Agriculture (USDA), this effort is part of a larger grant-funded project titled “Landscape Equipment Sustainability Strategies: Do More with LESS.” The project involves a comprehensive evaluation of large-platform autonomous mowers to assess their real-world performance, cost-effectiveness, and operational safety across a variety of landscape conditions.
Look for Latitude 36 at the following stadiums: Florida State SMU
The adoption of automation in turf care is no longer a theoretical discussion. Manufacturers have introduced commercial autonomous platforms, and early adopters are already deploying them on sports fields, university campuses, and business parks, yet independent research remains scarce on the topic.
Most prior studies have focused on small-platform robotic mowers primarily used in residential settings (Figure 1). Traditionally, these machines relied on perimeter wires and random navigation patterns, limiting their efficiency and scalability. However, recent technological advancements—such as real-time kinematic (RTK) positioning and EPOS (Exact Positioning Operating System) navigation—have dramatically improved the precision, reliability, and adaptability of small autonomous mowers. This rapid evolution in positioning and sensing technologies has expanded the potential for autonomy in turf management far beyond the homeowner market.
Building on these advancements, largeplatform autonomous mowers, that is, commercial-scale machines capable of operating both manually and autonomously, have now entered the market. These systems aim to address many of the industry’s most pressing challenges, including labor shortages, rising operational costs, and increasing sustainability demands. Our research seeks to evaluate these emerging technologies through a rigorous, data-driven approach to help landscape contractors, municipalities, and turf managers make informed decisions about integrating autonomy into large-scale operations.
This project is evaluating large-platform commercial mowers across four equipment categories:
• Manual gas-powered
• Manual battery-powered
• Autonomous gas-powered
• Autonomous battery-powered
We’re conducting real-world field trials using standardized test plots with varying levels of landscape complexity, from open square acres to obstacle-rich environments designed to mimic trees, bed edges, and other site constraints. Our goal is to understand how different combinations of power source (gas vs. battery) and operator mode (manual vs. autonomous) influence performance, cost, safety, and usability in professional landscaping scenarios.
Across hundreds of acres of mowing in diverse conditions, we’re tracking:
• Labor Efficiency –Time per acre, supervision requirements, and total operator hours
• Energy or Fuel Consumption –Gallons or kilowatthours per acre
• Mowing Productivity –Speed (acres/hour) under manual vs. autonomous operation
• Cost of Ownership –Lifetime return on investment (ROI) including equipment price, maintenance, energy, and labor
• Operational Safety & Setup Time –Issues related to autonomous deployment, landscape variability, and required oversight
• Adaptability to Landscape Types –How autonomy performs in simple vs. complex site conditions
Together, these data will help landscape contractors, fleet managers, and municipal buyers evaluate whether, how, and when to adopt autonomous and batterypowered equipment based on real numbers, not hype or pressure.
We’re also conducting obstacle detection trials using mannequins and field hazards at multiple approach angles to understand how these machines interpret and react to real-world variables (Figure 2).
Our team is especially interested in hybrid operation strategies, where a single operator supervises an autonomous unit while mowing with another, significantly boosting productivity without a full leap into autonomy.
This research comes at a critical time. As noise restrictions, emissions regulations (e.g., California AB 1346), and labor shortages reshape the industry, many contractors are asking: What’s the smart next investment?
By delivering field-tested, brand-agnostic insights, our goal is to help professionals:
• Make evidence-based equipment choices
• Optimize labor deployment strategies
• Understand technology limitations and serviceability
• Prepare for future regulations and automation trends
