symptoms are small, effuse patches (colonies) of cottony 
mycelia (masses of fungal threads of hyphae that make up 
the body of the fungus). These occur on the upper and lower 
surfaces of the leaves. As these patches sporulate and age, 
they become a dull tan color. Chlorotic (yellow) patches 
may later surround the mildew colonies. As the wheat and 
the mildew colonies mature, the sexual stage of the fungus 
or cleistothecia are produced. The mildew fungus survives 
the summer in the absence of wheat in infested wheat debris 
in the cleistothecia.