Take-all and Summer Patch

Dr. Tredway's post indicated that the temperatures in the Southeast are toasty. Well we were that way last week. The Midwest experienced some extremely warm temperatures, Tuesday was in the 90's, Wednesday was in the upper 80's and Thursday was back in the 90's. Plus nighttime temperatures were hot with high humidity. These conditions reminded me of my days working in Dr. Tredway's program in balmy North Carolina. Last week we had a flush of samples come in to the Turfgrass Diagnostic Clinic at UW-Madison and by the end of the week I was sick at looking at brown patch!

I mentioned last week that the weather in the Midwest never ceases to amaze me, well last week was smoking hot and the high yesterday and today did not get above 65 F. It was actually chilly in July! Last week we saw the development of Pythium blight, brown patch, take-all patch and dollar spot exploded. We even saw some anthracnose on Poa annua at a local Madison golf course. I apologize if I sound a little excited because last year we didn't see squat! Dollar spot would not even show its face in our plots at the OJ Noer.

Back to the issues, take-all patch will likely be diagnosed a lot throughout the Midwest. Many golf course superintendents made applications targeting take-all patch at the appropriate time, but the soil temperatures remained conducive for infection well into June this year. Consequently, we are seeing a lot of "mild" infections. Mild is not a good term, but we do not have another way of describing what we are seeing. The stand symptoms are not very severe nor is the discoloration in the vascular cylinder, but the symptoms are definitely characteristic of take-all patch.

Unfortunately once take-all patch symptoms develop, fungicide applications do not suppress the symptoms. The best approach is to carefully watch the affected areas and hand water them when necessary. A light fertilizer application will also help alleviate the symptoms. Take-all patch is a disease of roots and typically appears in the same place every year, so you likely know the areas that take-all patch occurs. If you do not want to lose grass, then hand watering and lightly fertilizing those areas proactively may help.

This is the time to consider preventative applications for summer patch in Poa annua and Kentucky bluegrass stands. Although the weather turned mild this week, temperatures will probably rebound making conditions favorable for summer patch development. We did see anthracnose develop at a local Madison golf course. This particular course has severely limited nitrogen on putting greens and of course our research area has not received any fungicide applications. Anthracnose has probably not developed on most courses in the Midwest, so preventative applications may still be effective. Dr. Tredway and Dr. Bruce Clarke have found that applications of a tank mixture of Signature and Daconil to be most effective against anthracnose in creeping bentgrass and Poa annua stands. I'm looking forward to what the weather will bring next week, until then enjoy the summer cool-down.