Spring dead spot (SDS) is most prevalent in highly maintained bermudagrass lawns. Most other turfgrass diseases attack the foliage, but SDS does its damage below-ground. Therefore, SDS must be managed differently.
Infection occurs in late summer through fall while the grass is still growing, but symptoms go unnoticed until the next spring when the turf begins to break dormancy. As the turf goes dormant, the pathogen continues to attack the roots, causing root decay and increasing susceptibility to cold injury. The result is dead circular patches 6 inches to 3 feet in diameter that appear in the spring.
Preventive applications of trifloxystrobin or sterol fungicides, such as fenarimol, myclobutanil, or propiconazole, applied in early fall and again in the spring may help, but these treatments can become very expensive and require a professional to apply. To best manage SDS, the goal is to maintain a strong, healthy below-ground turf structure. The first step is to alleviate adverse soil conditions. Reducing soil compaction with core aerification, improving poor drainage issues, and dethatching to keep thatch accumulations below 1 inch will help.
Soil chemical properties and nutrition are also important. Maintaining soil pH between 5.5 and 6.0 tends to help suppress SDS severity. Keeping potassium levels high, especially from a fall application, helps to reduce SDS and increase turf winter hardiness whereas late-season, high-nitrogen applications may enhance the disease.
Throughout the growing season, maintaining an optimum mowing height and avoiding other plant stresses (drought, traffic, pests, etc.) will also develop a stronger, healthier turf.
For more information on this turf disease please follow this link to University of Arkansas Turf Website.