It is a seasonal disease problem that becomes noticeable during hot and steamy weather. The fungus kills turf plants by causing severe blighting and defoliation of the leaves. It has not been shown to infect the roots of turfgrasses. Gray leaf spot tends to be more problematic on intensively managed turfgrasses that are fertilized with high nitrogen applications during the summer months. Over-fertilization, soil compaction, and improper irrigation practices contribute to disease activity. Extended leaf wetness periods from overhead and/or late evening irrigations increase disease susceptibility. Leaf spots start as small, dark brown lesions that enlarge into an oval or elongated area on the leaves or sheaths. Lesions later appear as a tan, “diamondshaped” spot with a narrow purple or brown margin. During moist weather conditions, the spots become covered with a gray, velvety layer of spores and mycelium.
- Ornamentals