What the Patch Is That!

— Written By

The unusual weather in the Carolinas this fall and winter have led to substantial patch development on ultradwarf bermudagrass (UDB) putting greens. The most common diagnosis has been take-all root rot, however we have also diagnosed several cases of spring dead spot, cream leaf blight, and root-knot nematode. You may ask yourself why does this matter? It matters because the stand symptoms are all very similar and are impossible to separate in the field. A laboratory diagnosis is essential when you observe white patches this time of year. You’ll notice the stand symptoms are very similar for the following four diseases (see photos).

Take-All Root Rot

As mentioned in our last post, take-all root rot climbed to the top spot as the most commonly diagnosed disease of UDB greens in 2016. When we look closer at the data, these diagnoses were made primarily in the fall and winter months with a few showing up in the spring. While we understand very little about the epidemiology behind this disease, the current thought is that infection occurs during the summer months and symptoms aren’t noticed until the turf becomes stressed due to a shorter photoperiod and cooler soil temperatures in the fall of the year. With the recent warmer and wetter than normal weather, it’s no surprise this disease keeps showing up, even during the dead of winter…