2024 CDGA Turfgrass Program Summary Report
Temperatures. Growing season 2024 saw a warm summer. Highs of 90°F or more occurred on 19 days this summer with June experiencing an early heat wave. Official records at Chicago O’Hare Airport saw a new record on June 17 (97°F) and June 19-20 would break the century mark (102°F and 104°F, respectively). Similar peak heat was absent in July, a time of frequent rainfall and cloud cover. During summer, maximum air temperatures of 90°F or more occurred in relatively short durations of 6 days or less. Taken together, a reduced risk of physiological decline of cool season turfgrass occurred in 2024.
Spring Rains. Regular rainfall and wet soils were experienced during spring 2024. This provided lush, green golf course roughs and home lawns which would last until late summer. Little to no irrigation inputs were required. Unfortunately, saturated soils unable to dry is the prime ingredient for the development of fungal root rots.
Two Industry Turfgrass Research Field Days. In 2024, the Bob Berry Sunshine Course hosted two field days which would spotlight newer products of two companies. NuFarm has brought back to the market a new formulation of Velocity. Velocity PM is a selective herbicide able to remove annual bluegrass from creeping bentgrass in tees and fairways. Corteva launched a new broad-spectrum fungicide called Floxcor and it was tested for control of dollar spot and brown patch. Newer broadleaf herbicides by Corteva, GameOn and Defender, were able to control difficult-to-control weeds like white clover.
Diagnostic Services. A total of 69 diagnostic course visits occurred in 2024. This was a 40% increase over 2023 which saw 42 course visits. All are initiated by golf course superintendents.
Spring Root Rots Problematic. A root rot known as take-all patch of creeping bentgrass was prevalent this growing season due to saturated soils in the spring. Golf fairways with native clay soils and high traffic are most susceptible. Preventive fungicides do not always work well for this disease. Annual aerification procedures (hollow core or solid tine) are the best defense against soil compaction as well as root rots like take-all patch. Take-all patch was experienced in fairways by a majority of golf courses in the Chicago District. Such levels had not been experienced since 2012.
Summer Dollar Spot. Our most chronic foliar disease, dollar spot, was at epidemic levels during summer 2024. Unusually rapid dollar spot development occurred during an extended period of hot, humid weather in July and August. More fungicides are used to prevent this single disease. New dollar spot resistant varieties of creeping bentgrass are now changing this.
Fall Localized Dry Spot and Fairy Ring. September and October were especially dry months in 2024. Localized dry spot and associated hydrophobic soils were commonplace in sand-based greens. Similar effects can be caused by a group of soil/thatch inhabiting fungi known as fairy ring. Regular applications of soil wetting agents will remain a key cultural practice that golf course superintendents must use during droughts.
A New Disease. A new fungal disease called yellow ring was identified at three Chicago-area golf courses in 2024. Yellow ring is a type of fairy ring that negatively impacts annual bluegrass. It has previously been reported in the Mid-Atlantic region. The CDGA diagnosis was genetically confirmed with collaboration from the University of Connecticut, Rutgers University and Penn State.
Annual Bluegrass Weevil (ABW) Update. We continue to monitor and confirm the presence of this new insect pest in Illinois. So far, ABW has been identified at 10 golf courses in Chicago. All are located in the north suburbs and we saw an increase of 8 courses in 2024. Most frequently midday wilt stress and damage is associated with putting green collars. It is caused by root-feeding larvae/grubs. Newer classes of insecticides are labeled for ABW and are effective when applied as a preventive or a curative. An earlier spring timing is required because adults overwinter.
Lemont Research. In 2024, Shehbaz Singh completed his third year as Manager of Turfgrass Research. Companies with sponsored work continue to grow. The list now includes The Andersons, Aquatrols, BASF, Corteva, Envu, Harrell’s, NuFarm, PBI Gordon, Precision Laboratories, Rhizosolutions and Syngenta. Numerous studies occurred on Bob Berry Sunshine Course and a majority focused on weed and disease control.
New Permanent Studies. A total of seven permanent CDGA studies have been added. Each compliments an environmental aspect of interest. 1) A dollar spot resistant creeping bentgrass variety trial for fairways. 2) A bermudagrass and zoysiagrass variety trial for tees. 3) Illinois native forbs and grasses for out-of-play areas. 4) Two honeybee hives for pollination. 5) Fine fescues and low growing flowers to attract pollinators for roughs. 6) Selective herbicide Tenacity for removal of creeping bentgrass from Kentucky bluegrass for tees (a collaboration with Purdue University). 7) Annual CDGA Green Committee research project.
Off-Site Research. In 2024, off-site research was conducted at three new locations: Calumet County Club in Homewood, Prairie Bluff Golf Club in Lockport, and Prestwick Country Club in Frankfort. Two studies focused on disease control with fungicides and included fairy ring in greens and take-all patch in fairways. One study focused on newer nematicides for control of root-feeding nematodes in greens. In Glenview, we continue to conduct multiple studies to investigate disease (dollar spot and brown patch in tees, greens, fairways) and weed control (moss in greens and yellow nutsedge in tallgrass areas). In 2024, approximately ten studies were conducted at North Shore Country Club in collaboration with Dan Dinelli.
Silvery Thread Moss Research. Shehbaz presented a poster summarizing two years of moss research conducted at North Shore Country Club at the annual American Society of Horticulture Science Meeting in September, 2024. Silvery thread moss remains a problem in newer greens no matter the creeping bentgrass variety. We are testing safe alternatives to herbicides for moss control.
Frequent Sand Topdressing Research. This study was initiated by the CDGA green committee. It is being conducted on a USGA-spec root zone with a ‘Pure Distinction’ creeping bentgrass putting green surface in Lemont. Fine round sand versus a larger sub-angular sand are being investigated for topdressing use. Each is applied with or without 10% biochar (organic matter). Ten applications every 14 days occurred in 2024. Preliminary findings indicate sand topdressing can improve desired agronomic characteristics of putting greens. Over time, the addition of biochar may improve plant health. The study will be repeated in 2025.
Communications. A total of 27 weekly Turfgrass Scouting Reports were written in 2024. These reports provide information on weather, diagnostics and research. For example, a new fairy ring-like disease of putting greens was discovered at three courses. It matched a disease known as yellow ring of annual bluegrass which was reported on social media by the University of Connecticut.
CDGA Golfer Magazine Turf Column. CDGA Green Committee continues to write about turfgrass topics of interest. In 2024, the turf column in the CDGA Golfer saw five articles and we began a new educational video series. Each represents a golfer’s perspective. Many topics are relevant to concerns of playability as well as the environment.
Flowers & Pollinators. For the first time, Sunshine Course welcomed two beehives as well as a selection of native Illinois forbs full of flowers for pollinators. In 2024, we would like to acknowledge the expertise and support of Brian Thomson of Honey Lake Bee Company in North Barrington, IL and Dave Ward of Coyote Run Golf Course, Homewood, IL.
