Cloudy & Wet! Take All Patch, Yellow Tuft, Dollar Spot Peaks and Moss Research

6 min readSep 29, 2023

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What a week! The first long stretch of cool, wet weather in the fall can be difficult to stomach. And it was. A good friend of mine (Randy Kane) said, “Fall is like spring, only it’s goes backwards…”. It was as cloudy as it gets. During this week I was looking up information on low light levels and what impact that can have on plants (golf greens in this particular case). The good news, weather-wise, was that warmer than usual temperatures had actually held in late September. Also, sunny conditions were to return — the forecast. Nevertheless, it is officially fall and the landscape is changing. For example, we are currently experiencing the first batch of larger leaves on the ground — native white oaks (Quercus). Increasingly we are noticing a popular street tree in yellow glow — thornless honeylocust (Gleditsia).

**Image 1.** Cloudy, cool and wet conditions combined to create conditions of high disease pressure for roots. Beneath this dew covered OO7 creeping bentgrass green a yellowish, patchy look is caused, in part, by a root rot, Bob Berry Sunshine Course, Lemont, IL. Settle, Sep 27, 2023

And what do fall conditions look like if you are a tillering turfgrass plant? More than a few golf courses saw their prize possessions (greens) look a little off-color. The extended period of cloudy conditions experienced caused some subtle, chlorotic symptoms (observations of yellow, patchy thinning of greens). It turned out, the cool, wet environmental conditions matched those needed by certain root rot fungi (Gaeumannomyces et al.). Glad that’s over (for now). And now it’s time to wind down our weekly communications. Number 31 will be the final Scouting Report for 2023. To be sure, if anything unusual occurs during the winter months you’ll see a “Special Edition”. Growing season 2023 was consistently, inconsistent and memorable!?! Always a group effort. Always a collaboration of expertise. Always in the name of plant science. Always a lot of work. See you in 2024!

Weather

**Figure 2.** Long range seasonal temperature forecast for the United States as of Sep 21, 2023. Courtesy NOAA

**Figure 3.** Long range seasonal precipitation forecast for the United States as of Sep 21, 2023. Courtesy NOAA

Fall Turfgrass Education — PLEASE SIGN UP NOW

Click Here To Sign Up for Complimentary Seminar

Round Table Discussion on Sand Bunker Technology at CDGA’s Midwest Golf House and a Field Trip to Cog Hill Golf & Country Club in Lemont.

Superintendent Panel: Reed Anderson and Don Cross
Industry Expert: Doug Myslinski
See Chicago’s Newest Bunkers: Cog Hill’s Dubsdred Course

**Image 1.** Bunker design and maintenance is not to be underestimated. North Shore CC, Glenview, IL. Settle, Sep 25, 2023

Root Rots, various fungi involved

Take-All Patch of Bentgrass, Gaeumannomyces avenae

It’s always about the weather (in part). It is called the disease triangle (plant pathology 101). In this case it went like this.

Three Components Needed for Plant Disease (Take-All Patch Example)

Host = Bentgrass (Agrostis)
Pathogen = Soilborn Fungus, (Gaeumannomyces avenae)
Environmental Conditions = Cool, Wet (late spring, then in fall)

Solutions for Take-All Patch

Use Preventive Fungicides — time in autumn or early spring
Correct Soil pH — should be maintained below 6.5 (5.5–6.5 preferred)
Manganese Deficiency — known to exacerbate take-all patch
Restricted Roots —use aerification methods annually to improve rooting
“Baby the Turf” — light, frequent applications of fertilizer to compensate for damaged roots (similarly, irrigation must be adjusted)

**Image 1.** Sampling for take-all patch in a newer OO7 creeping bentgrass practice putting green, North Shore Country Club, Glenview, IL. Settle, Sep 28, 2023

**Image 2.** Actual patch symptoms (yellowing and thinning) are subtle and hard to see. North Shore Country Club, Glenview, IL. Settle, Sep 28, 2023. Settle, Sep 28, 2023

**Image 3.** Even with active root rot, the actual roots can appear normal with good biomass and overall root length (2–4 inches in this case). Settle, Sep 28, 2023

**Image 4.** Dark runner hyphae associated with take-all patch of OO7 creeping bentgrass on roots. Settle, Sep 28, 2023

**Image 5. H**yphopodia associated with take-all patch of OO7 creeping bentgrass on roots. Settle, Sep 28, 2023

Yellow Tuft (Downy Mildew)

Continued development of yellow, hyper-tillering creeping bentgrass has occurred the entire month of September. In many cases we believe it is due to a fungus called downy mildew. And certain fungicides are the solution.

However, creeping bentgrass under stress (abiotic) can also show strange growth. The current outbreaks probably represent a combination of the two. More research is needed.

**Image 1.** Signs of yellow tuft in a OO7 creeping bentgrass fairway which previously suffered from summer stress due to drought/localized dry spot. It suggests abiotic stress factors play a role in this diseases’ development. In September, it was prevalent throughout the Chicago District. Bob Berry Sunshine Course, Lemont, IL. Settle, Sep 27, 2023

**Image 2.** Closeup of yellow tuft in a OO7 creeping bentgrass fairway. Bob Berry Sunshine Course, Lemont, IL. Settle, Sep 27, 2023

**Image 3.** Hyper tillering plants are a sign of yellow tuft in a OO7 creeping bentgrass fairway. Bob Berry Sunshine Course, Lemont, IL. Settle, Sep 27, 2023

Dollar Spot (Clarireedia jacksonii)

Continued development of dollar spot has also occurred the entire month of September. A new fungal name (previously known as Sclerotinia homoeocarpa) of an old problem. It represents our most chronic disease of cool season turfgrasses. Its occurrence can begin in May and then will continue until October. A span of approximately 5–6 months. In cool, humid regions environmental conditions do not interrupt its development in summer.

Dollar spot isn’t limited to “fine turfgrass” of golf courses. We also can see it develop in higher cut roughs and lawns with fewer inputs. It peaks each September if wet conditions exist.

**Image 1.** General discoloration can be caused by a number of factors. In this case it turns out dollar spot is causing much of the blotchy look seen. Bob Berry Sunshine Course, Lemont, IL. Settle, Sep 27, 2023

**Image 2.** Close up of bleached white leaf blades primarily caused by a foliar fungal disease. This Kentucky bluegrass rough is highly susceptible to dollar spot. Bob Berry Sunshine Coure, Lemont, IL. Settle, Sep 29, 2023

Silvery Thread Moss Research by Shehbaz Singh, MS

Silvery thread moss (Bryum argenteum) control on a creeping bentgrass green is being conducted as a part of our sponsored turfgrass research. All granular treatment products were supplied by the study sponsor The Andersons.

Location — Nursery green at North Shore Country Club, Glenview, IL.
Objective — To investigate novel approaches to moss control on greens.
Hypothesis — Newer granular products are useful to control moss.
Treatment Description — Four granular products (The Andersons) and one liquid product (FMC).

**Table 1.** Treatments used for a study to control silvery thread moss in a creeping bentgrass nursery green. North Shore Country Club, Glenview, IL

Study Details

Design. Six treatments arranged in a randomized complete block design with 4 replications. Individual plot size: 3 ft x 3 ft.

Application. All treatments were applied every 14 days starting beginning July 10, 2023. All granular products were carefully broadcasted by hand to ensure uniformity. The liquid product Quicksilver was applied using CO2-powered backpack sprayer operated at 40 psi using a three nozzle boom (XR TEEJET 8004VS). Treatments were applied in water equivalent to 2 gal per 1000 sq ft.