Pythium blight, also called cottony blight or grease spot, is a fungal disease of turf-grasses. All turf-grasses are susceptible to attack and the disease is most aggressive during hot, humid conditions. Poorly drained soil is also a common condition of disease growth.
Pythium blight is identifiable by small spots or patches of blighted grass that suddenly appear during warm, damp periods. As the disease progresses, the grass leaves shrivel and the patches fade from green to light brown. With close examination early in the morning, cottony fungal growth can often be seen on the foliage.
To prevent the development of Pythium Blight on turfgrass ensure that good water management practices are followed to avoid over watering or moisture pooling. Increase aeration of the lawn and remove old thatch. Avoid over fertilizing the grass with excessive nitrogen.
If the symptoms of Pythium Blight appear, spray the affected areas with Agri-Fos Systemic Fungicide. Repeat the spraying every 14 to 21 days as necessary to prevent further spread. Repeat the following year when conditions are favorable to reemergence or when symptoms first appear.