powdery mildew

noun

1. any of various parasitic fungi of the ascomycete order Erysiphales, which produce a powderlike film of mycelium on the surface of host plants.
2. Plant Pathology. a disease caused by powdery mildew, characterized by yellowing and death of the foliage and a white mealy growth of fungus on the surface of above-ground parts.

powdery mildew

noun

1. a plant disease characterized by a superficial white powdery growth on stems and leaves, caused by parasitic ascomycetous fungi of the family Erysiphaceae: affects the rose, aster, apple, vine, oak, etc
2. any of the fungi causing this disease

powdery mildew

/ pou′də-rē /

1. Any of various important plant diseases caused by fungi, especially those of the family Erysiphaceae, which produce powdery conidia on the surface of the hosts leaves and stems.

Word History and Origins

Origin of powdery mildew¹

An Americanism dating back to 1885–90

Example Sentences

While diseases such as early blight and powdery mildew are already well-known by gardeners, they are appearing more frequently, especially for those in northern climates who are experiencing warmer weather than in prior years.

From Salon

It favors shade and mild temperatures, so if your grapes are not getting full sun, that could increase the likelihood of powdery mildew.

From Seattle Times

That eliminates waste, and goes a long way toward preventing diseases like powdery mildew.

From Seattle Times

It’s often written in notation, so “PM” will refer to powdery mildew, and “CMV” will refer to cucumber mosaic virus.

From Seattle Times

Maples are prone to many diseases, such as anthracnose, verticillium wilt, and powdery mildew, but I am still confused, so I call Brian Crooks, a forester with the Western Pennsylvania Conservancy.

From New York Times