Rhizoctonia solani

Host:

Annual Bluegrass, Creeping Bentgrass, Colonial Bentgrass, Velvet Bentgrass, Kentucky Bluegrass, Fine Fescue, Tall Fescue, Perennial Ryegrass

Environmental Requirements:

80-95 F, high moisture, high N

Stand Symptoms:

circular blighted areas, with "smoke ring" at margin (Usually)

Plant Symptoms:

water soaked blight on leaves, drying to dark brown

Fungal Signs:

whitish, cottony mycelium on affected turf when moisture is present. Hyphae have right-angled branching and are constricted at the branch point. There is also a septum near the branch point.

Environmental Modification:

avoid N fertilization during hot humid weather

Plant Resistance:

Tall Fescue and Colonial Bentgrass most susceptible