powdery mildew

noun

1

: an ascomycetous fungus (family Erysiphaceae) producing abundant powdery conidia on the host

2

: a plant disease caused by a powdery mildew

Examples of powdery mildew in a Sentence

Recent Examples on the Web

For example, the Prairifire crab apple (Malus ‘Prairifire’), a 20-foot-tall tree with red flowers, and the Adirondack crab apple (Malus ‘Adirondack’), a narrow, upright cultivar with white blooms, both have excellent resistance to apple scab, fire blight, rust and powdery mildew. —Beth Botts, Chicago Tribune, 1 Feb. 2026

Additionally, Makrut limes are susceptible to diseases like citrus canker, powdery mildew, and root rot. —Sj McShane, Martha Stewart, 16 Jan. 2026

Fungicides labeled for powdery mildew include products containing the active ingredients chlorothalonil, myclobutanil, and propiconazole. —Kim Toscano, Southern Living, 31 Dec. 2025

The first is powdery mildew, prevalent throughout the growing season, recognized by a fuzzy white layer on leaf surfaces, puckering the foliage. —Joshua Siskin, Oc Register, 27 Dec. 2025

Word History

First Known Use

1889, in the meaning defined at sense 1

Rhymes for powdery mildew

• accrue
• ado
• ainu
• aircrew
• airscrew
• anew
• askew
• baboo
• babu
• bamboo
• beaucoup
• bijou

Kids Definition

powdery mildew

noun

: a fungus that is a parasite and produces a large number of powdery spores on the host

also : a plant disease caused by such a fungus