September Cools! Significant Summer Weather, Cyanobacteria, Yellow Tuft, Tee Research

9 min readSep 8, 2023

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It felt like Labor Day Oven holiday weekend. And it was. And for many it was a good thing. A last minute time to enjoy a final summertime experience of swimming in the lake or pool. And if you were a golfer? Conditions were perfect (firm and fast as they say). Although if you were maintaining sand based greens, the 0.01 inch height of cut surface would have been looking a little dry (and wilty). And so irrigation was being applied (hand watering) to dry areas in display of a characteristic silver to purple appearance. The technical term? “Wilt watch”. The good news is that it (the extreme heat) wasn’t going to last. The technical term? “The forecast”. A favorable forecast was predicting cooler temperatures and the possibility of some much needed rain. In the end, areas actually saw much, much more rain than expected. The technical term for that? “Liquid gold”.

**Image 1.** Fall color? Tenacity selective herbicide study by Syngenta is being investigated to reverse contamination by creeping bentgrass in a HGT Kentucky bluegrass golf tee. The unwanted creeping bentgrass will turn white and eventually the bluegrass will flourish again. A randomized complete block design with 5 ft by 10 ft plots (3 treatments replicated 4 times), Bob Berry Sunshine Course, Lemont, IL. Settle Sep 6, 2023

Things will always look a little disheveled after a period of heat + drought — even if it’s a short 4 day episode. And that’s where we are. Nevertheless, summer 2023 looked much better than expected given what we saw outside the weather norms (cool, dry, wet, hot-humid, hot-dry). From lawns to landscapes, we survived (required work). Even the hostas are still looking good given minimal inputs. The technical term for that? “Resilient”. In the end we saw more success than failure. More often than not, our region stayed out of the news as far as extreme weather was concerned. One primary reason was that extended periods of heat (uninterrupted days with 90+ highs) did not materialize in Illinois. We will now see a transition into the cooler temperatures of fall. The technical term for that? “September”.

Weather

**Figure 1. Dramatic change.** High temperatures saw a string of four days that were at or near 90 degrees. The event was striking because it was bookended cool periods, Bob Berry Sunshine Course, Lemont, IL.

August Precipitation Totals

Rainfall amounts are always very different from area to area. That is a significant fact that affects those that manage turfgrass and the landscape. It is easily be seen if you take a look at a network of regional weather stations. Legend: Dark blue dots = 1.00 to 1.99 inches, Yellow dots = 2.00 to 3.99 inches, Orange dots = 4.00 to 9.99 inches.

For more see CoCoRaHS Mapping System.

**Figure 2.** Precipitation totals always vary significantly from city to city, suburb to suburb, golf course to golf course. Here is accumulated precipitation for the entire month of August, 2023. The local weather summary for August: “It was also relatively dry across most of the area with the monthly precipitation totals for both Chicago and Rockford ending up nearly 3” below normal.”

Significant Weather Events — Summer, 2023

If you thought maintaining a golf course was easy, think again. It is the unusual weather events that require quick adjustments. Those events often create additional work. And then it’s not about the grass. Instead it’s about the trees.

**Image 1.** A Honey locust tree (Gleditsia triacanthos) with twisted off limbs (very unusual damage for a tree with strong wood). This was caused by a July 12 tornado outbreak in the Chicago area. Twin Orchard Country Club, Long Grove, IL. Settle, Aug 31, 2023

Click links below to see more details (information courtesy NOAA)

July 2, 2023: Significant flash flooding in Chicago and nearby suburbs
July 12, 2023: Localized tornado outbreak with 13 tornadoes across northeast Illinois
July 14, 2023: Storms produce damaging winds across northern Illinois and an EF-0 tornado in DuPage County
July 28–29, 2023: Multiple rounds of storms, including several late night tornadoes and damaging winds
August 23–24, 2023: Late summer heat wave results in consecutive days with 115+° heat indices

Cyanobacteria (also known as Blue Green Algae)

Following a rain event this week we saw an outbreak of cyanobacteria on greens in Chicago. It was a surprise. Greens, as it turns out are susceptible, to cyanobacteria, anywhere thinning may occur — scalping often occurs on ridges.

Contacts

One of the most important fungicides groups that we rotate in our disease control are known as multi-site inhibitors or “contacts”. Two examples widely used include Daconil (chlorothalonil) and Fore (mancozeb). In addition to foliar fungal disease control, they are typically very good for algae control as well. These products last for about 14 days given they act on contact — after 14 days the product that has been applied is gone.

**Image 1. Scouting Helps Others:** Examples of Cyanobacteria (blue-green algae) on the surface of creeping bentgrass golf green. It occurs immediately after or during extended period of rainfall. Because it is usually an uncommon issue of greens sharing photos not only helps to diagnose this issue, but will help others learn how to identify it. Courtesy photos: Tony Frandria, Sep 6, 2023

Plant Density or Plant Health

A second strategy involves improving plant density or as some say plant health. There are many different ways that that can be done. But one way is by simply using phosphites in a preventative fungicide program. Phosphites provide the systemic control of Pythium root rot (creeping bentgrass at green height is susceptible). In general, phosphites have been a game changer by providing a backbone of Pythium prevention for greens. And with that comes greater turfgrass density and what that brings. Some good research has been conducted on this aspect with regard to additional benefits of phosphites = cyanobacteria reduction. “When applied at the appropriate rate, phosphites can be safely used to control cyanobacteria on putting greens.”

Yellow Tuft (Downey Mildew)

A shift in environmental conditions from hot and dry to cool and wet is not a subtle shift. It is a big shift. And with that brings a big shift in what we see as we are scouting for pests in the field.

This week, I identified signs of yellow tuft on a Penncross creeping bentgrass tee on Bob Berry Sunshine Course in Lemont. The tee suffers from poor drainage and would be part of the problem (native clay soils).

But I wasn’t the first to find yellow tuft. That report belongs to Tim Christians at Makray Memorial Golf Club in Barrington, IL. Because he had reported it earlier, I was able to keep an eye out for it. And just like that, I found it. Pest management, as it turns out, is often a collaborative effort.

**Image 1.** Signs of yellow tuft (chlorotic/yellow patches) on a Penncross creeping bentgrass tee, Bob Berry Sunshine Course, Lemont, IL. Settle, Sep 6, 2023

**Image 2.** A sign of yellow tuft. Close up of irregular growth (elevated growth/etiolation) associated with a Penncross creeping bentgrass tee, Bob Berry Sunshine Course, Lemont, IL. Settle, Sep 6, 2023

**Image 3.** Signs of yellow tuft. Close up of irregular growth (hyper-tillering) associated with a Penncross creeping bentgrass tee, Bob Berry Sunshine Course, Lemont, IL. Settle, Sep 6, 2023

**Image 4.** Signs of yellow tuft. Chlorotic, hyper-tillering of Penn G-2 creeping bentgrass on a golf green. Courtesy photos: Tim Christians, Aug 30, 2023

More On Yellow Tuft

Yellow Tuft Disease of Turfgrasses: A Review of Recent Studies Conducted in Rhode Island. 1980. Noel Jackson.

Is it Poa or Yellow Tuft? June 14, 2010. Marcus Jones, Iowa State Extension Outreach.

Are Your Greens Yellow? July 28, 2009. Lane Tredway, Syngenta.

Tee Research — September by Shehbaz Singh, MS

As a part of monthly evaluation of greens, fairways, and tees at Bob Berry Sunshine Course, all tees were evaluated last week.

Background

All tees at the Bob Berry Sunshine Course in Lemont were seeded with different turfgrass species/varieties during a 2020 renovation project by the Wadsworth Golf Construction Company. Before renovation, all tees were creeping bentgrass. The tees are currently in their third year of establishment and surfaces consist of five turfgrass species that include; creeping bentgrass, colonial bentgrass, Kentucky bluegrass, perennial ryegrass and tall fescue.

Data Collection

As before, data was collected in three parallel lines on the tee surface. Readings are averaged across each of the three lines. The following parameters were evaluated:

1. Turfgrass Quality (1–9, 6 acceptable and 9 best)

2. Normalized Difference Vegetation Index using GreenSeeker by Trimble

3. Weed Contamination (%)

4. Turfgrass Density (%)

5. Localized Dry Spot (%)

On each tee, four sampling points were selected in a systematic way (four corner points of 10-ft width square in center of tee) for evaluation of following measurements. A 0.5 inch diameter soil probe was used and the average unit of four samples was used.

6. Maximum Root Length (inches)

7. Thatch Depth (inches) Thatch depth was measured taking the average of four 0.5-inch diameter soil sample.

8. Shear Strength using Shear Strength Tester by Turf-Tech International Inc., Florida

9. Root Feeding Nematodes (number per 100 g soil) using lite sucrose extraction and centrifugation

HD Sport 2 Kentucky Bluegrass (Sand Capped Soil Root Zone)

Data: Quality 5.6, NDVI 0.71, Density +80%, Root Length 5.1 in, LDS 10%, and Thatch 1.1 in

Notes: Visual quality unacceptable. High bentgrass contamination and more than 10% localized dry spots. Reduction in quality was most due localized dry spots. Contamination 68.3% (mainly creeping bentgrass- a research trial is being conducted on this tee for selective removal of bentgrass using Tenacity herbicide).

HGT Kentucky Bluegrass (Sand Capped Soil Root Zone)

Data: Quality 5.6, NDVI 0.70, Density 96.6 %, Root Length 5.4 in, LDS 15%, Thatch 1.1 in

Notes: Visual quality unacceptable. Highest contamination of creeping bentgrass among all tees and prone to localized dry spots. Contamination 86.6 % (mainly creeping bentgrass-research trial is being conducted on this tee for selective removal of bentgrass using tenacity herbicide).

RTF Tall Fescue Tee C (Sand Capped Soil Root Zone)

Data: Quality 5.3, NDVI 0.67, Turf Density +90%, LDS 13.3%, Root Length 6.2 in, Thatch 1.1 in, Contamination 61.6% (mainly creeping bentgrass- a research trial is being conducted on this tee for selective removal of bentgrass using Tenacity herbicide)

RTF Tall Fescue Tee H: (Soil Root Zone)

Data: Quality 6.3, NDVI 0.71, Turf Density +95%, Root Length 6.2 in, Thatch 0.78 in, Contamination 16.6 % (mainly Poa annua)

Notes: Tall fescue tees have deeper roots and less localized dry spot. Tee H looked best among all tees during this time of year.

Penncross 2.0 Creeping Bentgrass Tee (Sand Capped Soil Root Zone)

Data: Quality 4.6, NDVI 0.57, Density 85%, LDS 45%, Root Length 6.25 in, Thatch 0.78 in

Notes: The most localized dry spot. Contamination is minimal. Root length reduced compared to August. Contamination 5% (Poa annua).

Musket Colonial Bentgrass Tee (Sand Capped Soil Root Zone)

Data: Quality 4.3, NDVI 0.55, Density 53%, LDS 8.3%, Root Length 4.4 in, Thatch 0.6 in

Notes: Unacceptable quality. The lowest turf density and thatch accumulation among all other tees due to its bunch type growth habit. Contamination 26.6% (creeping bentgrass).

Piranha Creeping Bentgrass (Sand Capped Soil Root Zone)

Data: Quality 6.3, NDVI 0.69, Density 85%, LDS 10%, Root Length 6.6 in, Thatch 1.2 in

Notes: Acceptable quality. Tee had more than 10% localized dry spot. Contamination 5% (Poa annua).

Flagstick Creeping Bentgrass: (Sand Capped Soil Root Zone)

Data: Quality 4.6, NDVI 0.63, Density 68.3%, LDS 15%, Root Length 5.25 in, Thatch 0.95

Notes: Unacceptable quality. Had high incidence of localized dry spot and poor density versus other bentgrass varieties. Contamination (6.6% Poa annua).