Powdery mildew is a common fungal disease of angiosperms and is so called because the mycelium of the fungus growing on the leaves, stems and flowers appears as a grayish white powdery coating. Powdery mildew is a disease separate and distinct from downy mildew. Although the signs of both diseases appear similar to the naked eye, powdery mildews are caused by fungi in the order Erysiphales while downy mildews are caused by fungi in the order Peronosporales.
Members of the order Erysiphales are considered obligate parasites of plants because they require a living host to survive. All attempts to grow them on artificial media have failed.
This page was prepared by Karen Monroe
It was last updated on 30 May 2000
Minor link updates on 31 Jan 2008 by M.J. Munster