Description:

Leaf spot symptoms tend to vary with each pathogen/host pair from very small (pinhead size), solid brown to purple color lesions or spots to expanded lesions with bleached centers that girdle the leaf blade. Severely infected leaves turn purple or reddish color, giving the turf an overall purple cast. Severely infected leaves will eventually wither and dry to a light tan color. Distinct patches or patterns to the disease are usually not obvious. "Meltingoccurs under severe infections as turf areas thin and die. Lesions on stolons are dark purple to black.

Control:

Avoid excess nitrogen during potential disease development periods. The nitrogen level must be balanced with potassium. In areas that are affected routinely by this disease, increase the potassium level prior to the time the disease normally occurs. Use slow-release potassium sources or apply quick-release potassium sources more frequently.

Please check the "Extension Agents' Handbook of Insects, Plant Disease and Weed Control".