Spring Dead Spot (Disease complex (fungi) - Leptosphaeria korrae, Gaeumannomyces graminis var. graminis, Ophiosphaerella herpotricha): When turf begins regrowth in early spring, well-defined circular dead spots become evident. Individual spots may range in size from a few inches to several feet in diameter and are usually depressed. Margins of affected areas are usually even, but may become irregular when individual spots grow together to form large areas. Leaves of affected turfgrass are a bleached straw color, while stolons and roots are black and rotted. Spring Dead Spot is a crown, root and stolon rot of dormant grass. Turf recovers very slowly during the summer from stolons creeping in from the border of affected areas. Disease develops again the following year in the same areas and spots enlarge each year.
Management: Fungicide applications must begin in late summer or early fall when the fungus is thought to be most active. Judicious use of nitrogen fertilizer helps to reduce disease severity. Ammonium-based nitrogen fertilizer combined with potassium reduce spring dead spot over time.