Scouting Report: May 7th
Cloudy skies and below average temperatures were prevalent this week. This wasn’t the start of May we envisioned after sprinting out of the gates in March.
Daytime air temperatures in the lower 50’s were not conducive for turfgrass growth and vigor. Plummeting soil temperatures may not have been helping out our beneficial microbes. Steady cloud cover hasn’t been favorable for light dependent reactions. Excessive rain and saturated soil conditions wasn’t helping either.
Soil temperatures across the state have plummeted since the latter half of April. The optimal soil temperature for root growth of most cool-season turfgrasses is between 50–65 degrees F. Fortunately, many of us in the state are still above the 50 degree threshold for active root growth. Unfortunately, turfgrass roots also need adequate oxygen in the soil to take advantage of these temperatures. Oxygen in the soil may have been limiting this past week.
Last weekend, the warm water of the gulf opened up as a low pressure system barreled through the heartland.
This system brought flooding conditions to many regions of the state. More than 8 inches of rain fell in southern Illinois. Over the past two weeks, more than 10 inches of rain was observed across the Midwest.
Oxygen levels can become deficient under saturated soils. Oxygen tends to fill the macro pore space in the soil profile and water tends to occupy the micro pore space. Under heavy rainfall and saturated soil conditions, water occupies both spaces. This is one of the reasons why many golf courses spike or needle tine putting green surfaces.
I have seen other pieces of equipment that can perform similar duties such as the Air2G2 systems and the PlanetAir units. The important aspect is to keep plants as healthy as possible before the advent of summer stress.
An interesting note, not a single county in the entire Midwest is under any drought criteria. So at least nobody’s well should run dry anytime soon.
Unfavorable environmental conditions were observed for much of this week. Unfortunately, this environment may have been conducive for opportunistic pests that taken advantage of a weakened plant. The big culprit this week were diseases. However, this report will begin with weeds and insects.
The cooler weather this week wasn’t cold enough to knock back crabgrass. Crabgrass is slowly coming along in full-sun areas. Those in the northern portion of the state may still be able to apply a preventative spray as the majority of crabgrass may not germinate until soil temperatures exceed 70 degrees F.
Further south, we are beginning to think about follow up timing to ensure that goosegrass populations stay in check. I haven’t heard about goosegrass germination in any region of the state yet.
Cooler temperatures did seem to reduce insect activity and emergence. Some have observed an increasing number of BTA adults near putting green surfaces.
Pathogens can be opportunistic when environmental conditions favor disease development more than turf growth and vigor. This is when weakly pathogenic organisms can finally get the upper hand on host material.
Rhizoctonia cerealis may have been one of the those weakly pathogenic organisms that was able to inflict some minor damage this week in Chicagoland. This organism incites the disease yellow patch (syn. cool-temperature brown patch).
This disease primarily affects the foliage of slowly growing turf in the spring and fall months. The pathogen is active when air temperatures are between 50–65 degrees F. Persistent cloud cover and frequent rainfall exacerbate symptoms of this disease.
This past week was actually the 2nd outbreak of yellow patch in the Chicago area. The first outbreak occurred in the first week of April. Environmental conditions during each yellow patch episode were similar.
Yellow patch activity was most noticeable on recently renovated creeping bentgrass putting greens. This includes (but not limited to) the cultivars 007 and pure distinction. Yellow patch activity was less pronounced on older creeping bentgrass greens or in mixed stands of creeping bentgrass and annual bluegrass.
It is unclear how damaging yellow patch can be on newly renovated putting greens. My observations this week indicate that only the older leaves of creeping bentgrass were affected. In each case I observed healthy root architecture and undamaged crowns.
I suspect that the onset of more favorable environmental conditions will be the best treatment against this disease. Sunny skies and more seasonable temperatures should be enough to swing the pendulum more towards the bentgrass and away from this opportunistic pathogen.
If a fungicide application is warranted, consider watering in those products. For some of you, now is the time to start formulating an action plan against other soilborne diseases.
Those with a prior history of take-all patch should be monitoring soil temperatures and upcoming weather patterns. According to most publications, the take-all patch organism (Gaeumannomyces graminis f. sp. avenae) is active when soil temperatures are 55–65 degrees F under moist conditions. Areas in central Illinois have already been in that range for quite some time.
Areas around Chicago (west suburbs) have also hit those benchmark temperatures. The 5-day moving average soil temperatures in the St. Charles area exceeded the 55 degree threshold on April 16th and remained above 55 degrees until April 28th.
Since April 29th, soil temperatures have dropped below 55 degrees in the Chicago area. However, the advent of more seasonable temperatures will likely put many of you all within the range for preventive take-all applications.
A sample collected on April 28th did show some suspicious hyphae growing along a root of a creeping bentgrass plant. What was concerning is that the root was pearly white and was most likely a newer root produced this spring. The hyphae growing along this particular root suggests that some colonization of Gga may have been occurring this spring. Although, at this time, above ground symptoms were not very distinguishable.
Other diseases were observed this week as well. Pink snow mold was active from Chicago northward.
Pink snow mold activity was predominately limited to creeping bentgrass/annual bluegrass fairways. Damage wasn’t very severe and wall-to-wall applications are probably not warranted.
Mysterious rings were also observed on annual bluegrass collars. This diagnosis is still pending, but appears to be caused by a basidiomycete fungus upon initial review.
Moving forward, dollar spot may be gearing up in the state. Numerous reports out east have already documented wide spread dollar spot activity. A few reports have already trickled in areas just south of Chicago.
I also foresee many spray applications for fairy ring prevention in the Chicago area in the near future. It has been difficult to make a wall-to-wall fairway sprays for fairy ring prevention due to wet soils and wind.
Check plot of the week
Annual bluegrass seedheads on putting green height turf are in full force. This putting green was not sprayed with any seedhead suppression applications. The area in this photo with no seedheads are of a perennial biotype of annual bluegrass that was sodded three years ago. It’s interesting to see the visual differences in seedhead emergence between the biotypes.
Volunteer opportunities in the area
Mr. Sam MacKenzie and crew are hosting the 2017 KPMG Women’s PGA Championship at Olympia Fields on June 27-July 2nd.
They are actively recruiting volunteers to assist in course maintenance during the championship week.
Volunteers may also be needed for the NCAA Golf Championship at Rich Harvest Farms (May 18th through May 23rd). For inquiries contact golf course superintendent Jeff VerCautren.
The 2017 BMW Championship will be held at Conway Farms from September 11th through the 17th. For volunteer inquiries contact assistant golf course superintendent Anthony Mieske (firstname.lastname@example.org).