Small black over-wintering structures called perithecia are often found in powdery mildew affected areas. Control may also be achieved with the use of fungicides applied as soon as symptoms are visible. Among the compounds registered for use in Connecticut are potassium bicarbonate, ultra fine oil, sulfur, triadimefon, or thiophanate-methyl fungicides. Consult the label for dosage rates, safety precautions, and directions for use. Smut , Entyloma spp.
Smuts are diseases caused by fungi.
While most smut diseases attack the reproductive parts of plants such as flowers, replacing them with a sooty black mass of fungal spores, smut diseases of perennials often result in light spots on leaves and are called white smuts. This disease is not typically serious, and usually can be controlled removal of infected plant debris. Stem rot, Sclerotium rolfsii. Infected plants and soil should be removed, and fresh clean soil used as a replacement. The pathogen is a prokaryotic organism without cell walls.