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

"Then the rainiest June since the 1950s helped the spread of downy and powdery mildew" he told The Telegraph.

From The Daily Beast

The powdery mildew, unlike most other fungus troubles of the grape, is most prevalent in hot dry weather.

From Project Gutenberg