Bundled Up in July

A few posts ago I wrote about Pythium blight and brown patch. That was in late June when our highs were consistently in the 90's. We have since moved into a considerable cool down in the Midwest. Highs lately have ranged from the upper 60's to lower 80's with very low relative humidity. Matter of fact last night the low temperature for parts of Northern Wisconsin was 36 F! That's damn cold for the middle of July. The first picture is from Derek Settle of the CDGA and it was taken on July 1 at 1:00pm.

Since the weather has cooled down significantly, so has disease activity. Dollar spot development has significantly slowed in our research plots at the OJ Noer and we have not heard of any major outbreaks anywhere in the Midwest. In previous post I mentioned a dollar spot forecasting model or spray advisory that Damon Smith and I are developing. Well to date the model has only suggested two dollar spot applications, yet most superintendents in our area have applied at least two and some have applied as many as four! Again the model is in its infancy, but is showing real promise.

Brown patch and Pythium blight activity have come to a screeching halt and areas that were damaged seem to be recovering quite well. Currently we have diagnosed take-all patch 5 times from samples submitted from Iowa, Minnesota and Wisconsin. I suspect if the temperature warms up we will see a lot more take-all patch samples. This year was difficult for take-all patch fungicide applications. The Midwest experienced a significant warming in mid-April that drove soil temperatures up into the mid-50's. Yet we did not get above 65 F in many regions until mid to late June. Resdiuals from early fungicide applications may not have lasted until mid to late June, leaving a window of opportunity for the take-all patch fungus to infect. Consequently we are expecting to see a lot more take-all patch come through the lab here at UW.



If take-all patch symptoms do develop on your course, the best thing to do is mark the area somehow and "nurse" it through the summer. Light applications of fertilizer and hand watering should limp those areas through the summer months. Who knows the weather may remain relatively cool for the remainder of the summer.