Dry Heat! Drought, LDS, Lance Nematodes, CDGA Field Day and Wetting Agent Research
It’s been a week of warmth. I think we can say it went a bit beyond what is normal for early September. Abnormal. And so goes one more chapter in this difficult growing season we now know as 2025. Chapter 3 goes something like this: Buckle Up for a Hot, Dry Fall. The current dry conditions are certainly not helping recovery of cool season turfgrasses. Hot and dry conditions do not fulfill the growth requirements of fragile turfgrass seedlings. Drought is now impacting a growing list of Midwestern states which now includes Missouri, Kentucky, Illinois, Indiana, Ohio and Michigan. Besides increasing the risk of fire outdoors, drought is also known to ruin fall foliage due to premature leaf drop; a survival mechanism to reduce water loss and conserve moisture.
Drought in September is poorly timed. It turns out golf course superintendents and staff as well as lawn care experts are also conducting an important cultural practice known as fall aerification. Did I mention that some are laying sod this fall? You better stick around and not go on vacation! The recommendation is to keep the soil moist, but not overly. And so, in the first two weeks of successful sod establishment you will need to water judiciously 2 to 4 times a day (assumes no rainfall). It’s required. Dry conditions are also causing consternation among Chicago District superintendents because a majority have “opened up” playing surfaces (greens, tees, fairways) via a hollow core or solid tine. Just like sod, aerification will requires additional water to avoid drought stress and to allow regrowth/filling in. In other news farmers are watching conditions carefully. As of September 11, the drought monitor for the state of Illinois has begun to ratchet up. For example, Severe Drought (D2) is now being reported in both central and southern Illinois. In contrast northern Cook County (Chicago) looks better though it too has begun reporting a small area as abnormally dry (D0). Scouting for midday wilt stress and mitigating plant damage via timely irrigation — and cultural practices to conserve water — is now at the top of the priority list for all growers. We can learn a few things from folks out west like Utah State University. Come on rain!
Weather
Scouting for Abiotic (localized dry spot) or is it Biotic (lance nematodes) — look-a-likes
This week at a field day conducted at the Bob Berry Sunshine Course we were able to display an investigation of what appeared to be localized dry spot. The result of soil samples taken showed that lance nematode, Hoplolaimus galeatus, populations were associated with symptoms resulting from midday wilt stress turf loss of 007 creeping bentgrass caused by root loss.
Samples were collected from block number 4 in each small plot (4 ft by 6 ft) of a fungicide study that used six treatments. Ectoparasitic nematodes extraction was by a modified light sucrose which used centrifugation. A block (number 4) of six treatments were chosen to share in this report because strongest symptoms existed in this area (see image 1).
Why Now? Symptoms of Nematode Damage in Creeping Bentgrass Putting Greens
- Lance nematode population densities are known to peak in midsummer.
- Creeping bentgrass suffers natural root decline due to supraoptimal soil temperatures in midsummer. And is more pronounced in especailly hot summers (2025 here).
- Other stressors of plant health are usually also involved — too much foot traffic on a green or a perimeter clean up lap by mowers (see below).
Lance Nematode Control Coming in 2026
- Control of lance nematodes continues to remain lacking. Part of why might be because this nematode feeds on roots both outside (ectoparasite) and inside (migratory endoparasite). Populations inside roots may have a level of protection from applications of nematicides.
- Current nematicides either do not control lance nematodes effectively or require multiple applications to get the job done.
- Syngenta will soon be launching a new nematicide named Trefinti labeled for turfgrass. It is a SDHI class of chemistry. Will offer suppression of lance and other important nematodes such as sting and root knot.
References
Fidanza, M., 2022. Verdure: Lance nematodes play hide-and-seek Golf Course Management.
Settle, D.M., J.D. Fry, T.C. Todd and N.A. Tisserat. 2006. Populations dynamics of the lance nematode (Hoplolaimus galeatus) in creeping bentgrass. Plant Disease 90(1):44–50 (https://doi.org/10.1094/PD-90-0044).
CDGA Turfgrass Program Field Day for CAGCS — Chicagoland Association Golf Course Superintendents
Poa Control via Velocity PM — May 13, 2024 1st application
Selective control of Poa annua has a few options. One which has been well-studied has recently seen increased interest. This is because a new formulation with a different level of its active ingredient (Bispyribac sodium) became available again. To differentiate itself as a new product Velocity was renamed Velocity PM. The PM stands for Poa Management.
Visual Ratings of Residual Poa Control by Velocity PM — May 6, 2025
- 3% Poa annua by Velocity PM Low Rate (5 applications at 0.75 fl oz/A)
- 13.7% Poa annua by Velocity PM Mid Rate (3 applications at 1.5 fl oz/A)
- 30% Poa annua by Velocity PM High Rate (1 application at 4.5 fl oz/A)
- 60% Poa annua (untreated)
Plant health research via Envu fungicides in rotation
Fungicides in one study contain technology known as Signature (a proprietary green pigment) by Bayer (now known as Envu). Site selection for field research is most important. We chose a ‘007’ creeping bentgrass green that sees high disease pressure (shade) as well as heat stress (lack of air movement) due to its location near large cottonwood trees (the state tree of Kansas!).
The CDGA Green Committee had a sand topdressing study idea
‘Pure Distinction’ creeping bentgrass at green height continues to remain weakly rooted in a sand topdressing study at Bob Berry Sunshine Course in Lemont, IL. We learned that hard fact at a field day demonstration. Following a difficult summer, creeping bentgrass remains root-less?
Dollar spot no more?
Well not exactly, but after two years the results across 20 creeping bentgrass varieties at fairway height showed that newer varieties, such as ‘Piper’ and ‘Oakley’ and their combination ‘Centennial’, are highly resistant to dollar spot disease. To date, this low input study has required only 1 curative fungicide application (Oct 9, 2024) to address dollar spot.
White Clover is a weed?
Well certainly not if you are a honey bee = it’s flower nectar is a food source! But there are certain instances when this broadleaf weed can dominate turfgrass systems. Kentucky bluegrass is especially vulnerable. A study in 2025 found a May (May 13, 2025) timing was slow (5 weeks) to provide complete control versus a June (June 13, 2025) timing (3 weeks). Also use of a Non-ionic surfactant adjuvant was found to be helpful.
Honey Bee, Apis mellifera
The addition of honey bees (Apis mellifera) has provided a higher level of environmental stewardship on Bob Berry Sunshine Course in Lemont. For example approximately 0.5 acre of out-of-play natural areas were added. A new short grass and forbes prairie study with all selections from Illinois brought native plant species and insects to the course. Finally, broadleaf herbicide inputs were reduced to allow good levels of white clover to remain in all Kentucky bluegrass roughs.
Can you speak Italian?
Of the five European subspecies we have chosen the ones that come from Italy. Specifically it is known as Apis mellifera ligustica. You see the Italian honey bee is most used for commercial beekeeping worldwide. Why?Docile queens and hardworking workers. They look good too. Golden-orange in color.
Wadsworth Golf Construction Company
Sunshine Course was updated in 2020! This was due to an extensive renovation project to update the original 2002 design by Joe Jemsek Jr. Construction from tee to green now includes things like a new suite of bunkers which represents combinations of products which are currently in use. Wadsworth Golf Construction Company provided all renovation tweeks and all efforts were coordinated by Doug Myslinski.
Wetting Agent Research sponsored by RhizoSolutions
The introduction and weather sections of this scouting report should have you worried about drought. It turns out one of the best ways to help mitigate drought stress is offered by surfactants or wetting agents that are applied and then immediately watered in to the soil. This addresses soil health and helps to mitigate things like hydrophobic areas that can then develop into above ground symptoms known as localized dry spot or LDS.
- Certain wetting agent products may reduce dollar spot and has been reported previously with DewCure.
- Post-infection (curatively applied) research has shown that fairy ring and root rot disorders like take-all patch of bentgrass can benefit by a wetting agent application.
- Wetting agents may also be helpful to mitigate LDS caused by short roots due to nematode feeding.
- The response can be as good or better than a fungicide or nematicide application.
Materials and Methods
The study is being conducted on a ‘007’ creeping bentgrass fairway at the Bob Berry Sunshine Course in Lemont, IL. The site is a native clay-loam soil. The study designs is a randomized complete block with 11 treatments and 4 replications. Individual plot size is 4 ft x 6 ft. The first application was made on May 8, 2025 and applications are being made every 28 days. The wetting agents by RhizoSolutions LLC are experimental and proprietary.
Objective
Evaluate experimental wetting agents for improved plant health during conditions of drought.
Data Collected
- Visual Quality (1–9 scale, with 6 = minimum acceptable and 9 = best)
- Normalized Difference Vegetation Index (NDVI) by using GreenSeeker/Trimble HCS-100
- Drought Stress (% per plot)
- Volumetric Water Content (% per plot) by using Spectrum Technologies TDR 350 Moisture Meter
- Visual Green Color (1–9 scale, with 6 = minimum acceptable and 9 = best)
Education & Communication by CDGA’s Green Committee by CDGATV
We all know that honey comes from bees. However do you know how those bees produce it and the role that golf courses can play?
More and more golf courses are implementing honey bee colonies, including the Bob Berry Sunshine Course at Midwest Golf House. In the CDGATV videos linked here, Sheldon L Solow from the CDGA Green Committee and Brian Thomson from Honey Lake Bee Company discuss the process to start a colony, why this practice is important for the environment and much more.
Final Photo
“Nodding wild onion is native in open woods and slopes from Canada to Mexico, including northeast Illinois. Mounds of flat, grass-like leaves support stalks of nodding, bell-shaped, pinkish-white flower clusters in June through August. Great plant for front of the border, rock garden, and naturalized areas. Hardiness zones include Zone 4, Zone 5 (Northern Illinois), Zone 6 (City of Chicago), Zone 7, Zone 8.” For more see Morton Arboretum
