HPIPM:Potato Powdery Mildew

Taxonomy

Domain	Eukarya
Kingdom	Fungi
Phylum	Ascomycota
Subphylum	Pezizomycotina
Class	Leotiomycetes
Subclass	Leotiomycetidae
Order	Helotiales
Family	Erysiphaceae
Genus	Golovinomyces

Scientific Name

Golovinomyces cichoracearum

Scientific Name Synonyms

Erysiphe cichoracearum

Common Name

powdery mildew

Author: Howard F. Schwartz and David H. Gent

Identification and Life Cycle

Powdery mildew is caused by the fungus Erysiphe cichoracearum. The disease rarely occurs in the High Plains, and is only reported to cause economic damage to potato in Washington State under furrow irrigation.

Plant Response and Damage

Powdery mildew symptoms appear on leaves as white, powdery, circular to irregularly shaped patches. Mildew lesions are apparent on both sides of leaves as dusty, grayish brown deposits. Light brown flecks on stems and petioles often form, and large areas may become water-soaked with blackened spots. Lower leaves become yellow and then die, or may quickly blacken and then fall off. Internodes can become twisted and brittle. Plants can be killed.

Biological Control

No biological control practices have been developed for powdery mildew.

Cultural Control

Powdery mildew is rarely a problem on potato grown under center pivot irrigation.

Chemical Control

Due to constantly changing labels, laws and regulations, the sponsors of this web site assume no liability for the suggested use of any chemicals noted in the management section. Contact your local pest management personnel for current information on labeled pesticides that can be used for the intended plant disease, insect pest or weed.