Summer Heat! 90 Degree Days, Take All Patch, July 12 Field Day, and White Clover Control
It was a hot one? Yes. This week was all about early heat and it wasn’t even summer yet. That’s next week. This isn’t the first time we’ve seen early heat. The nearest year that this June reminded us of in Chicago was 2012. For example, up to now (June 16) Chicago’s Midway Airport has recorded 10 days of 90 degree highs in 2022. The same story occurred in the years 1988 and 2012. I remember 2012 and it was both HOT and DRY. In a week, automatic irrigation systems saw their first big use (since last summer) and sand-based golf greens saw careful monitoring for midday wilt stress. By the end of an especially active week of weather we (the upper Midwest) cooled down again. A break!
Fewer trees and shrubs are currently flowering. Lush, dense, healthy, green tree canopies are now what you notice the most and that might be the reason. Nevertheless, Japanese tree lilacs, Syringa reticulata, are still presenting their long lasting, greenish-white flowers. Also, amassive Catalpa tree, C. speciosa, in full bloom caught my eye with its distinctive white, upright terminal panicles. And the small serviceberry trees, Amelanchier x lamarckii, were showing their red berries right on time— Juneberry its other nick name.
Weather Recap (June’s 2nd full week) by Shehbaz Singh, MS
Air Temperature. Chicago experienced quite warm weather. Across the suburbs, the air temperature ranged from 59 to 98°F. Most days, low temperatures were higher than 65°F. On Tuesday (June 14th), the highest temperature (98°F) was recorded so far this year. In 2021, the highest temperature recorded for June was 93°F.
Precipitation. So far, the accumulated rainfall for June is 2.4 inches and represents normal rainfall accumulation. On Monday, June 13th, 0.8 inch of precipitation was experienced and this represented the largest rain event.
Weather forecast. Weather next week is to be mostly sunny (start) to partly cloudy (end). Air temperature will range from 69 to 96° F on most days. High humidity and windy conditions are expected on Monday and Tuesday next week. Chances of rain are higher at week’s end.
Counting 90 Degree Highs/Days
A break in the weather. From a growers perspective (insert golf course superintendent and staff here) this is what needs to happen. Midway airport broke high temperature records on three consecutive days from June 14-16. The new records for high temperature on those dates are 100, 100 and 97°F respectively. Cool-season turfgrass (C-3) cannot tolerate heat for extended periods. It’s all about plant physiology. All of what we see in the landscape (turfgrass included) is adapted for this region = a cool, humid environment. Photosynthesis just can’t keep up (green plants adapted for cool conditions) if it stays hot. The take home message? Respiration (energy burning) can and will exceed photosynthesis (energy production) when conditions are hot. In the meantime, we’ve been doing to now is grow/maintain healthy plants. This allows the build up of carbohydrates prior to summer’s heat. In 2022, Mother Nature has introduced summer heat early. Just keep the breaks coming too.
Take All Patch (Gaumannomyces graminis var. avenae) of Creeping Bentgrass
The first diagnosis of take all patch occurred in a creeping bentgrass green. It often goes unnoticed in the spring. Actually, it is a common fungal root rot disease of creeping bentgrass. Symptoms usually do not appear until first wilt stress and that means June for us in the upper Midwest. If 2022 becomes a year predominated by drought, expect to see more and more of take all patch.
It is a perennial disease and golf courses that have a history of take all patch will see it in the same locations (fairways or greens) each year. It is most problematic in areas where compaction from traffic and equipment also occurs. This is because root growth and recovery will be limited or will not happen. Though we are seeing take all patch now, summer is a time when take all patch is naturally suppressed by warmer soil temperatures.
Conditions. Caused by a root-infecting fungus that is most active during cooler spring soil temperatures (55–65 degrees).
Symptoms. Initial symptoms appears as a small depressed, circular, and thinned patch. Patches can enlarge up to 2 feet in diameter. Shoot density of t creeping bentgrass inside the patch is reduced.
Soil pH. A soil pH greater than 6.5 is associated with chronic and severe take all patch.
Cultural Practice Considerations
- Maintain the soil pH between 5.5 to 6.5
- Monitor and avoid nutrient deficiencies (P and K)
- Improve soil water drainage through coring
- Prevent midday wilt stress in summer, otherwise severe thinning results
July 12 Field Day at the Bob Berry Sunshine Course sponsored by PBI-Gordon
This will be our first field day since the re-dedication of the Bob Berry Sunshine Course on June 11, 2021. During 2020, the golf course underwent major renovations with the generous work and support of many. One company, Wadsworth Golf Construction Company, did a majority of the earth moving etc. required for the overhaul of Sunshine Course. Wadsworth also promotes the game of golf through the Wadsworth Golf Charities Foundation. “Improving society through the moral, ethical and cultural codes of golf.” The foundation is directed by Mr. Doug Myslinski. For more information on each click on the links above.
White Clover Control
White clover (Trifolium repens) is a difficult weed to control. On Bob Berry Sunshine Course, white clover is one of our most chronic perennial weeds.
Identification. It is a perennial broadleaf weed that has trifoliate leaves with or without a wedge-shaped mark. Each trifoliate leaf has a short petiole. Flowers are white and turn pink as they age
For more on white clover control, below is a summary by Shehbaz Singh. It provides data an ongoing research study in a Kentucky bluegrass rough at the Bob Berry Sunshine Course in Lemont.
Location. Bob Berry Sunshine Course, Lemont, Illinois
Objective. Demonstrate post-emergent white clover control.
Treatment. Treatments (7) were made twice to a Kentucky bluegrass rough with heavy white clover weed pressure on May 12 and on June 7, 2022. Applications were made using a CO-2 powered backpack sprayer with flat fan nozzles. Plots used are 4 ft x 6 ft with 3 replicates.
Sponsor. PBI-Gordon, Shawnee, KS
Final Photo
