July! Dry Conditions, Traffic Hurts, 1st Japanese Beetles, Yellow Nutsedge and a Research Update
A new word has entered our 2022 growing season. Drought. We could see it coming. It’s turned into an overly dry growing season. How did that happen? No rain. Or better said, traces of rain. That’s been our past two weeks. In the landscape you begin to see what’s tough and what’s not tough. Tough is called xeriscape. Xeriscape is defined as “A style of landscape design requiring little or no irrigation.” We are now noticing those perennials more and more. Day lilies or Hemerocallis are standing tall right now. Tall in their bright blooms. Tall in their adaptability to warm conditions. Tall in their ability to withstand drought.
On golf courses and other highly maintained landscape areas it is now all about irrigation. It’s interesting to note that the last infrastructure that was really tested in 2022 was drainage (record wet conditions prevailed in spring). Now we begin to see just how well irrigation systems were designed and installed. And then there’s the characteristics of the water itself. On golf greens, many are not aware of how meticulous water management is. It turns out superintendents and staff water some areas by hand only. In one hand you will see a hose and in the other hand you will see a moisture meter. Sand-based greens are watered via data collection = the exact amount required.
Calendar says July 4th! Happy 4th from the Turfgrass Program — the half way mark in a golf season. As always we are thankful for our biggest supporter(s). Here’s to the CDGA green committee and CDGA board members. But there’s more. In appreciation of the gracious men and women who teach us as much as we (try) to teach them. Here’s to golf course superintendents and staff.
Weather Recap (June) by Shehbaz Singh, MS
Air Temperature. June 2022 was warmer than the normal. June’s air temperature varied from 52 to 100 °F versus the normal temperature range of 56 to 84 °F. In June 2022 Metropolitan Chicago experienced high temperatures of 90 °F or great on 9 days out of 30 days.
Precipitation. June 2022 for Chicago was dry with total precipitation accumulation of about 2.5 inches. The normal total precipitation for June is about 4 inches. In comparison, June 2021 saw total accumulated precipitation of about 7 inches.
Weather Forecast. Dry conditions are likely to continue. The chances of rainfall and thunderstorm are higher during first three days of week. Mostly sunny to partly cloudy conditions are to prevail by week’s end.
Conditions are now becoming increasingly dry in the Midwestern U.S. The U.S. Drought Monitor now includes portions of Illinois. Localized dry spot of sand-based golf greens will continue to be a top issue in summer 2022.
MIDWEST. “Some heavier rains fell across parts of the Midwest this week, especially in eastern Iowa and northern Minnesota. For areas that missed out, similar to the Southeast region, rapid drying is occurring in the short-term, leading to widespread introduction of abnormal dryness and short-term moderate drought. This week, short-term moderate drought was introduced or expanded across much of central Kentucky, the Illinois-Indiana border, and southeast Missouri. Parts of Kentucky are seeing corn leaves curl as a result of the recent hot and dry weather.”
For more information see the U.S. Drought Monitor website. Click here
The greatest potential of injury we see during periods of hot and dry weather has nothing to do with fungal disease et al. Instead it is abiotic factors that are most problematic. Wilting turfgrass is unable to tolerate traffic. Usually worst effects are when traffic occurs during midday at peak heat or when repeated traffic events occur over the same area. If you are out there enjoying the outdoors just remember to scatter traffic. Do not drive over areas that are beginning to go dormant. We began to see a lot of traffic injury this week.
Sources of Injury Could Be:
- Golf Carts — threat number 1. Scatter traffic and use paths as much as possible. Must abide by all rules with regard to golf cart traffic to protect turfgrass during dry summer conditions.
- Maintenance Equipment — mowers especially. Clean-up laps on the edges increasingly begin to create damage/marks. Adjust mowing practices accordingly to reduce risk. Mowing is not needed in dormant or semi-dormant areas.
- Foot traffic— on greens. Be more aware of how to properly walk on greens especially in areas near hole locations.
Japanese Beetles — Popillia japonica
The first identification of Japanese beetles wasn’t by the scouting efforts of the CDGA Turfgrass Program. Rather it was by the communication of a “scouting” golf course superintendent Tim White at Prestwick Country Club. I replied to his text with, “Wow. I’ve not seen in Chicago yet. I’ll be on the lookout. Thank you!!!” The very next day we found Japanese beetles crawling around on our OO7 creeping bentgrass green on the Bob Berry Sunshine Course. This week’s gold star for pest scouting goes to Tim. Thank you Tim!
Importance. Japanese beetles were first discovered in the United States in southern New Jersey in 1916. Adult beetles emerge during June and July. In summer, adults feed on the leaves of trees, shrubs and turfgrass species. Initially damage to landscape plants received a lot of press. For example, little leaf linden trees, Tilia cordata, were a favorite menu item. Today, there seems to be less of an issue with adult feeding. Possibly because multiple natural enemies are known to exist for Japanese beetles. Likely it took some time to fully develop. They range from bacteria, fungi, nematodes and other insects.
Root-feeding grubs are the primary concern. By mid-August, adults lay eggs in the soil by burrowing. Within 10–15 days, first instar larvae or white grubs hatch. White grubs feed on roots of turfgrass. Grub infested turf looks off-color and tan. Such symptoms are easily confused with drought stress.
Control. Many cultural, biological and insecticidal options exist.
- Bacteria known to cause milky disease such as Bacillus popilliae
- Entomopathogenic nematodes such as Steinernema glaseri
- Reduce high soil moisture conditions to help hinder grub development
- Reduce thatch to ensure insecticides reach annual white grubs efficiently
- Principle control of annual white grubs relies on long-lasting, systemic insecticidal control generally timed May through August
Yellow Nutsedge — Cyperus esculentus
Signs of a wet spring are out there. In this case we were able to identify a large area of yellow nutsedge, Cyperus esculentus, on Bob Berry Sunshine Course this week. It happened after the newly renovated native fineleaf fescue area was mown. A low lying swale area had established instead to this sometimes troublesome weed. Chicago golf course superintendents are reporting more of this weed in 2022. Identification requires investigation of a triangular stem. Sedges have edges!
- Yellow-green, shiny leaves with a distinct midrib.
- Triangular stems
- Favors full-sun areas with moist soils
Research Update — Summer Divots on the KBG and Creeping Bentgrass Divot Studies
The divot research continues. Located on two tee boxes at the Bob Berry Golf Course in Lemont, IL. One is a Piranah creeping bentgrass tee and the other is a HGT Kentucky bluegrass tee. A summer set of divots were made a week ago on June 22 and then filled the following day. It follows a spring set of divots made on April 19. We are continuing to collect data on the spring divots (still healing). This study is evaluating the success (or failure) of various divot mixes. It uses a randomized complete block design with 4 replications. Divot events occur in each of three seasons: spring, summer and fall. Why? For example, some divot mix treatments may work in spring, but not work during a hot, dry summer. The study is sponsored by the CDGA Green Committee and is in collaboration with the USGA Green Section’s Zach Nicoludis. Divot data is collected weekly and consists of visual quality, visual cover, normalized difference vegetation index (NDVI), soil moisture and soil temperature.
- Spring divots (Apr) & testing divot mix treatments; Began Apr 19, 2022
- Summer divots (Jun) & testing divot mix treatments; Began Jun 23, 2022
- Fall divots (Sep) & testing of divot mix treatments