On high value turf, such as golf course putting greens, tees, and possibly fairways, preventative fungicide applications may be justified. Red Thread, Laetisaria fuciformis and Pink Patch, Limonomyces roseipellis Symptoms and signs These two diseases present similar symptoms and appear as irregularly shaped patches of blighted grass. From a distance, affected areas have a reddish or pinkish cast. These diseases are usually restricted to the leaves, leaf sheaths, and stems, but in severe cases, may kill the entire plant. In the early stages of infection, symptoms appear as small blighted areas on leaves that enlarge rapidly to cover most of the leaf.
Affected leaves dry out and fade to a bleached straw color.
During moist weather, the leaves may become covered with the pink gelatinous growth of the causal fungi. Symptoms and signs of red thread disease on perennial ryegrass. In the case of pink patch, affected leaves are covered with the pink fluffy growth of the causal fungus. Symptoms and signs of pink patch disease on perennial ryegrass. Disease cycle The fungi overwinter as a dried gelatinous mycelium covering on infected dead leaves or in clipping debris from previously infected plants.