Using a sound cultural practice that will keep the grass growing vigorously will help control Fusarium Blight. This disease occurs in the late spring or early fall. It is characterized by circular patterns of dead grass blades in the turf. These range from 1-50 feet in diameter. Blades and sheather are pulled easily from stolons because of deterioration in the attachment area.
Stolons often remain green.
The entire spot eventually may become green during a long growing season. Disease development occurs most rapidly in temperatures between 75-85 degrees F when free moisture is present. F. This explains seasonal development. Some lawns are affected almost every year, while others are damaged only occasionally. Fungicide application should be made when brown patch is expected.