Date of this Version
This NebGuide describes the causes, predisposing conditions, and symptoms of summer patch and necrotic ring spot, and provides recommendations for their control.
Two of the most destructive turfgrass patch diseases are summer patch and necrotic ring spot, both of which are present in Nebraska. The symptoms of necrotic ring spot and summer patch are essentially identical, making it difficult to distinguish the two apart in an affected turf. If the symptoms begin in May, necrotic ring spot is probably the cause; if they begin in July and August, then summer patch is suspect. In Nebraska summer patch is probably the most common of the two diseases.