Warm season turfgrasses have greened up after winter and dead circular patches in burmudagrass lawns, athletic fields, and golf courses may be quite visible. The symptoms of this disease and problem are quite evident. As healthy turf breaks dormancy and begins to grow, the diseased patches remains brown.
The demise and ultimate death of the turf in these spots actually began as early as last fall and continued through the winter months. There could be one or more pathogens (Leptosphaeria spp., Gaeumannomyces spp., Ophiosphaerella sp.) infecting and colonizing the roots and stolons of the bermudagrass. Even though the infection began last fall, the symptoms were not evident then because the turf still had regenerative capacity to keep it alive. Once temperatures cooled below turf growth, the disease got the better hand.
While filling in of these dead areas may be slow, usually the turf will recover by the end of the summer. A slightly lower cutting height to encourage lateral growth, keeping thatch to a minimum, aerification to stimulate root growth, and a well-balanced fertility and watering regime will speed recovery.
Weed competition must also be managed. To reduce the severity of spring dead spot this coming winter, maintain adequate potassium levels, keep thatch levels below three-quarters of an inch, and raise the mowing height towards the end of the growing season. Fall applications of selected fungicides (DMI’s, strobularin’s) have given some protection.
Published April 9, 2012
Dr. Wayne Wells is an Extension Professor and Turfgrass Specialist. His mailing address is Department of Plant and Soil Sciences, Mail Stop 9555, Mississippi State, MS 39762. email@example.com