Turfgrass Scouting Report: May 6

A cold start to Spring has been followed by above normal temperatures for much of the region. Much of April has been a complete wash for managing warm season grasses in the south and cool-season grasses to the north. It wasn’t uncommon to hear reports of blowing off snow just to be able to punch holes. Glancing at the Spring Leaf Index, it appears much of the northern two-thirds of the state was about 15–20 days behind schedule by April 30.

The first week of May led off with near record warmth in the northern portions of the state. The warmth can serve as a fresh reminder how quickly things can catch up. Most courses (away from the lake) have definitely turned the corner towards greener pastures. One limited factor was precipitation earlier in the week. Dry conditions led many to charge up the irrigation system and begin hand watering in a few hot spots.

Soil temperatures at the 4-inch depth in St. Charles, IL. Courtesy of the Illinois State Water Survey.

The rise in air temperatures have led to the first big spike in soil temperatures. Soil temperatures at the 4-inch depth have sprinted past 50 degrees and top out at about 60 in the past week. As a result, nature has responded by unleashing the stench of the bradford pear bloom.

I am sure many folks have seen and smelled the blooming bradford pear.

It has been a busy few days at the CDGA. The rise in soil temps has made us dust off the sprayers and begin our take-all patch trials in Chicagoland.

It is important to irrigate following applications for the disease take-all patch.

Take-all patch applications tend to begin in the spring has soil temps climb above 50 degrees. A friendly reminder that the infection court is located in the roots and applications should be immediately watered in.

The University of Wisconsin showcased snow mold research in Wausau, WI, earlier this week.

Next, we headed up to Wausau, WI, to check out a snow mold field day. At this particular research site, snow mold pressure was moderate. Dr. Koch not only presented on research results at this location, but also touched on his research findings in more northern locations.

A main take-home message from this year, is that more active ingredients are needed as disease pressure increases. Some formulated products now contain 3 to 4 active ingredients. That is important as some more northerly locations experienced close to 180 days of continuous snow cover.

Areas of zoysiagrass slow to green up? That reason may be due to large patch disease.

We finished off the week in Effingham, IL, and made the first spring application for large patch. The causal agent of large patch is a very close relative to the pathogen that incites brown patch disease. We we happy to see that our inoculation made last September was finally producing visual symptoms in the non-treated control plots.

This week there were only a few pest reports. However, as I type this, I can imagine that all the rain in the past few days in northern IL will likely stir things up a bit.

Insects

For the first time this spring I have finally seen flying insects out and about. I could even hear the bees as I walk past the blooming rhododendron bushes at the golf house. Below the ground, I have also I started to notice a few ant mounds developing on putting greens. Before the rain, it was pretty dry and these critters made quick work of the dry sand.

Air and soil temperatures weren’t the only things heating up this week. Courtesy D. Dinelli

After the heavy rains, the moist soils coupled with warm nighttime temperatures created a cozy atmosphere for a couple of nightcrawlers.

Weeds

A flush of poa seedheads were observed in select roughs this week.

I’m seeing a flush of annual bluegrass seedheads in rough areas and I’m starting to a see a few in nontreated fairway surfaces. Most courses who have followed up a late-fall application with spring applications are in great shape.

Forsythia blooms are a phenological indicator of crabgrass germination.

Forsythia is in bloom across many locations. This is a great phenological indicator that often correlates with the emergence of crabgrass. It is likely we will start to see rapid crabgrass germination in hot spot areas after the recent rains. Further south, goosegrass germination has been observed in Tennessee and will likely creep up into southern Illinois in the next week or so.

Diseases

Despite the late-week rain, diseases have been kept at bay for the most part. This is likely due to the sweeping wind that has accompanied the spring storms. Below the surface, the casual agents of fairy ring and take-all patch are now likely active. These two diseases are best managed before the onset of visible symptoms.

The causal agent of take-patch is likely active right now in Chicagoland. Photo from 2017.

Strobilurin fungicides and a few of the older DMI fungicides can work pretty well against these diseases. The advantage of including a DMI in the tank-mixture is the added bonus of providing a little dollar spot suppression to start off the season. Another chemistry that can work well for take-all patch is thiophanate-methyl. Despite the rampant dollar spot resistance to this chemistry, it still has a lot of utility in other aspects of turf disease management.

Twitter: CDGATurfgrassProgram

Email: jbenelli@CDGA.org