Anamorph produces on hyaline conidiophores catenate conidia of oblong to cylindrical shape, not including fibrosin bodies, 32–44 x 12–15 μm in size.

[citation needed] B. graminis is unique among the Erysiphales by having conidia with a primary germ tube and finger-shaped ("digitate") appressoria.

[clarification needed] These were shown to be subject to positive selection, due to their implication in the gene-for-gene relationship to defeat plant disease resistance.

[citation needed] This has allowed wheat powdery mildew to maintain genetic flexibility, variability and thus a great potential for pathogen variation.

[citation needed] Wheat powdery mildew is an obligate biotroph with a poorly understood evolutionary history.

tritici's genome is a mosaic of haplogroups with different divergence times, which explains its unique pathogen adaptability.

[citation needed] Powdery mildew of wheat is relatively easy to diagnose[8] due to the characteristic little white spots of cotton-like mycelia.

[10] As the disease progresses, the patches turn gray and small dark black or brown cleistothecia form in the mycelium mass.

[11] Wheat powdery mildew thrives in cool humid conditions and cloudy weather increases chances of disease.

Conidia can recognize the host plant and within one minute of initial contact, the direction of germ tube growth is determined.

[13] After initial infection, the fungus produces haustoria inside of the wheat cells and mycelium grows on the plant's outer surface.

Powdery mildew of wheat thrives in cool, humid climates and proliferates in cloudy weather conditions.

Dense, genetically similar plantings provide opportune conditions for growth of powdery mildew.

[11] Controlling the disease involves eliminating conducive conditions as much as possible by altering planting density and carefully timing applications and rates of nitrogen.

Crop rotation with non-host plants is another way to keep mildew infection to a minimum, however the aerial nature of conidia and ascospore dispersal makes it of limited use.

Another chemical treatment involves treating wheat with a silicon solution or calcium silicate slag.

Silicon helps the plant cells defend against fungal attack by degrading haustoria and by producing callose and papilla.

[17] Milk has long been popular with home gardeners and small-scale organic growers as a treatment for powdery mildew.

Milk is diluted with water (typically 1:10) and sprayed on susceptible plants at the first sign of infection, or as a preventative measure, with repeated weekly application often controlling or eliminating the disease.

Studies have shown milk's effectiveness as comparable to some conventional fungicides,[18] and better than benomyl and fenarimol at higher concentrations.

[19] Milk has proven effective in treating powdery mildew of summer squash,[19] pumpkins,[18] grapes,[20] and roses.

Powdery mildew can be found in all wheat growing areas of the United States but usually will be most severe in the east and southeast.

[11] Powdery mildew has become a more important disease in some areas because of increased application of nitrogen fertilizer, which favors the development of the fungus.

[14] Yield Losses up to 45 percent have been shown in Ohio on susceptible varieties when plants are infected early and weather favors disease.