- First appears as sunken distinct patches 1 to 2½ – in. in diameter (about the size of a silver dollar). Often the patches coalesces to form a large diseased area. Irregular lesions occur on the blades of the grass, shaped like a “hour glass,” usually light tan in color with a reddish-brown border. Stems may also be affected. Cobweb-like mycelium is often noticeable in morning before dew dries.
Conditions Favoring Infestation and Typically Yearly Occurrence
Favored by high humidity, prolonged moisture (e.g., dews) on the foliage, excessive thatch and low fertility. Temperatures range 60 to 85 F, from late winter until early summer and then early summer until frost.