August Cools! Peak Disease, Fairy Ring, Native Flowers, and Take-All Patch Research

A week ago peak summer heat in the forecast meant a late summer call of “all hands on deck”. As expected peak cool season turfgrass stress and peak disease pressure were experienced. But a silver lining. A fantastic forecast for the remainder of August promised an extended period of cooler, drier air. That cool down would move the growing season needle past August 15. A key calendar marker for those of us that grow. In the latter half of August, fall-like conditions usually materialize and things just get easier — especially if your job is to manage sand-based putting greens. Other parts of the country were not so lucky. A category 1 hurricane named Debby crossed the Florida Panhandle and flooded the southeastern coast as a tropical storm.

Image 1. Sand bunkers are hazards? We continue to evaluate a sand bunker study which looks at modern bunker construction methods as well as newer angular sands. The ability to study this and more on Bob Berry Sunshine Course in Lemont is thanks to the generosity of Wadsworth Golf Construction. Settle, Aug 8, 2024

Overall, the Illinois landscape throughout summer 2024 has performed admirably. Frequent rain is one way to do it. Not overly hot is way to do it. And July experienced both. On rain, the Illinois State Climatologist summarized data since 1895 and found this: “The preliminary statewide total July precipitation was 7.01 inches, 2.95 inches above the 1991–2020 average and the third wettest on record.” So what’s next? August? The predictions are 50/50 for above normal temperatures and the possibility of another wetter than normal month continues to remain in the mix. Whatever August brings, course conditions have already improved given drier conditions are present. Current course conditions are exactly where we want them. Therefore, “Have a good round — may the fours be with you.”.

Weather

Figure 1. Illinois saw a final heat wave (90s for highs) during August’s first week. Thereafter it cooled. Bob Berry Sunshine Course, Lemont, IL

Figure 2. Daily July average temperature departures in Springfield. Courtesy of Illinois State Climatologist

Figure 3. Tornadoes confirmed by the Chicago National Weather Service from July 15 storms. The largest single-day outbreak of tornadoes ever recorded in the Chicago area. courtesy National Weather Service

Scouting for Disease — Fairy Ring (multiple basidiomycete fungi)

A final bout of aggressive fairy ring was observed in early August. Some of our worst fairy ring occurs when it’s hot. Simply said, we are dealing with a thermophilic or heat-loving fungus.

Cultural practices that keep thatch (fairy ring’s food source) within acceptable levels (less than 1 inch) are as important as chemical control measures. Additionally, wetting agents are an integral part of treatment because hydrophobicity (water repelled) of the associated root zone is an additional factor associated with fairy ring.

Image 1. Fairy ring can be difficult to control because its occurrence can be in mid- to late summer and then requires curative control which is not as effective as preventative timings in the spring. Settle, Aug 9, 2024

Image 2. Cultural practices that help limit thatch accumulation (core aerification or verticutting) are paramount when dealing with fairy ring. Creeping bentgrass is particularly vulnerable given its stoloniferous spread (stolons are slow to decompose) creates a thatch layer. All basidiomycete fungi associated with fairy ring use organic matter as a food source. Settle, Aug 9, 2024

Fungicides

See newest 2024 recommendations in PPA-1: Chemical Control of Turfgrass Diseases 2024 (uky.edu).

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Native Prairie Forbes and Grasses Demonstration Study

Our primary objective in 2024 was to establish native Illinois flowers and grasses in an out-of-play area on Bob Berry Sunshine Course in Lemont, IL. We enlisted the advice and direction of Dave Ward. Dave is the former golf course superintendent of Coyote Run Golf Course in Homewood, IL. See his April, 2020 article titled A New Use For Old Bunker Sand.

Update

The demonstration study was planted on Jun 6, 2024. Establishment has been successful as of Aug 9, 2024. See table and photos below.

Table 1. Plants (forbs and grasses) selected for a native plant demonstration study on Bob Berry Sunshine Course in Lemont, IL.

Data

Every 14 days we are collecting information on rate of establishment and other aspects that are of interest.

• Plant height
• Plant width
• Number of flowers
• Flower color
• Presence of pollinators

Image 1. Planting of the native out-of-play area used a straw matt and about 350 greenhouse grown plugs (Possibility Place Native Plant Nursery, Monee, IL) for establishment in an out-of-play area at Bob Berry Sunshine Course, Lemont, IL. Settle, Jun 6, 2024

Image 2. In the center, a white flower of Monarda punctata or spotted bee balm (also called dotted mint or dotted horsemint) is seen. Illinois native forbs and grasses saw good establishment on Bob Berry Sunshine Course in Lemont, IL. Settle, Aug 9, 2024

Image 3. Asclepias tuberosa or butterfly weed (also called butterfly milkweed, orange milkweed) has an orange flower. Illinois native forbs and grasses saw good establishment on Bob Berry Sunshine Course in Lemont, IL. Settle, Aug 9, 2024

Image 4. Coreopsis lanceolata or sand coreopsis (also called lanceleaf coreopsis, lanceleaf tickseed) has a yellow to orange flower. Illinois native forbs and grasses saw good establishment on Bob Berry Sunshine Course in Lemont, IL. Settle, Aug 9, 2024

Image 5. Asclepias incarnata or swamp milkweed (also called pink milkweed) has a pink to purple flower. Illinois native forbs and grasses saw good establishment on Bob Berry Sunshine Course in Lemont, IL. Settle, Aug 9, 2024

Support is gratefully acknowledged from The FairWays Foundation

“The FairWays Foundation directly funds local and global projects that advance the conservation of our natural resources. These projects help to preserve the environment we live and work in whilst encouraging education and stewardship not only within our own industry but also within wider communities.”

Curative control of take-all patch (Gaeumannomyces graminis) in a creeping bentgrass fairway by Shehbaz Singh, MS

A BASF study is being conducted to evaluate the efficacy of fungicides to control take-all patch disease curatively on a fairway in play at Prairie Bluff Public Golf Course in Lockport, IL. Take-all patch, Gaeumannomyces graminis, is an important root rot disease of creeping bentgrass. It has been problematic in Chicago during the 2024 growing season.

Symptoms look yellow to bronze in color and range in size from a few inches to several feet in diameter. Patches appear thin and wilted and will often have a depressed or stunted appearance. Additionally thinned patches of creeping bentgrass then become vulnerable to encroachment by broaleaf and grassy weeds (dandelion, crabgrass, Poa annua).

Image 1. A BASF fungicide study to control take-all patch at Prairie Bluff Public Golf Course in Lockport, IL. Settle, Aug 7, 2024

Material and Methods

The small plot study has 12 treatments in a randomized complete block design with 4 replications. Individual plot size is 4 ft by 6 ft. Two curative applications were made at 21 days apart (Jun 17 and Jul 8). Treatments were immediately watered in after application with about 0.5 inch of water using sprinkler heads. This study represents curative control of take-all patch disease in the summer. Another study with the same treatments will be conducted in a different location on the fairway and will evaluate curative control in the fall.

Table 1. Treatments for a BASF study conducted in a creeping bentgrass fairway to control take-all patch at Prairie Bluff Golf Course, Lockport, IL.

Objectives

• Evaluate curative control of take-all patch in creeping bentgrass.
• Determine if a wetting agent can improve curative control of take-all patch in creeping bentgrass.
• Evaluate turf quality
• Evaluate any phytotoxicity

Measurements

• Visual Quality (1–9 scale, with 6 = minimum acceptable and 9 = best)
• Normalized Difference Vegetation Index (NDVI) using GreenSeeker/Trimble HCS-100
• Take-all Patch(% per plot)
• Color/Phytotoxicity (1–9 scale)

Results — Take-all Patch

An average of 45% of take-all patch disease was observed across all plots during the start of the study on Jun 17, 2024. In untreated plots, take-all patch remained higher than 35% on all rating dates from 17 June to 7 Aug, 2024.

Fungicides Without Wetting Agent. All fungicide treatments showed a trend of reduced take-all patch , with a few performing better than others. For example, take-all patch was reduced from 37% to 16.25% by Maxtima 0.8 fl oz on Aug 7. Ascernity 1 fl oz reduced take-all patch from 50% to 26.25%. BASF Experimental 1x rate reduced take-all patch from 41.75 to 13.25%. BASF Experimental 1.5x rate reduced take-all patch from 40% to less than or equal to 10% (an acceptable threshold). BASF Experimental 3x rate reduced take-all patch 41% to 11.2%.

Image 1. Take-all patch fungicide research without wetting agent. Photos of untreated versus BASF Experimental 1x rate, Prairie Bluff Golf Course, Lockport, IL. Singh, Aug 7, 2024

Fungicides With Wetting Agent. Excaliber 6 fl oz alone was the only treatment in the study to reduce take-all patch disease below 10% on Aug 7. Maxtima 0.8 fl oz plus Excaliber reduced take-all patch from 41% to 13.7%. BASF Experimental 1x rate plus Excaliber reduced take-all patch from 36.2% to 11.2%. BASF Experimental 1.5x rate plus Excaliber reduced take-all patch from 41.7% to 17.5%. BASF Experimental 3x rate plus Excaliber reduced take-all patch from 41.2% to 25%. Ascernity 1 fl oz plus Excaliber reduced take-all patch from 45% to 23.7%.

Image 2. Take-all patch fungicide research with wetting agent. Photos of untreated versus BASF Experimental 1x rate, Prairie Bluff Golf Course, Lockport, IL. Singh, Aug 7, 2024

Figure 1. Take-All Patch of treatments without a wetting agent in a creeping bentgrass fairway. Two 21 day interval applications were made (Jun 17 and Jul 8). Prairie Bluff Public Golf Course, Lockport, IL

Figure 2. Take-All Patch of treatments with a wetting agent in a creeping bentgrass fairway. Two 21 day interval applications were made (Jun 17 and Jul 8). Prairie Bluff Public Golf Course, Lockport, IL

Results — Visual Quality

Visual turf quality for untreated plots were unacceptable (less than 6.0) from Jun 17 to Aug 1.

Without Wetting Agent. Visual quality for a majority of fungicide treatments remained lower than 6.0 throughout the evaluation period. BASF Experimental at 1x and 1.5x rate was acceptable (6.0) on Jul 8. BASF Experimental at 1.5x rate was acceptable (6.25) on Aug 7.

With Wetting Agent. Visual quality was mostly lower than the acceptable limit (6.0) for all treatments. However, Excaliber 6 fl oz alone and Excaliber plus BASF Experimental at 1x rate saw acceptable turf quality (6.0) on Aug 7.

Figure 3. Visual turfgrass quality of treatments without a wetting agent in a creeping bentgrass fairway. Two 21 day interval applications were made (Jun 17 and Jul 8). Prairie Bluff Public Golf Course, Lockport, IL

Figure 4. Visual turfgrass quality of treatments with a wetting agent in a creeping bentgrass fairway. Two 21 day interval applications were made (Jun 17 and Jul 8). Prairie Bluff Public Golf Course, Lockport, IL

Final Image

Swamp milkweed! A bald-faced hornet (Dolichovespula maculata) is an active pollinator on swamp milkweed at Bob Berry Sunshine Course in Lemont, IL. Settle, Aug 8, 2024

Swamp milkweed (Asclepias incarnata) “The large, bright, terminal blossoms of this tall, showy perennial are made up of small, rose-purple flowers. The juice of this wetland milkweed is less milky than that of other species. The genus was named in honor of Aesculapius, Greek god of medicine, undoubtedly because some species have long been used to treat a variety of ailments.” For more see Asclepias incarnata- Lady Bird Johnson Wildflower Center.