Phylum, Order

Ascomyte, Erysiphaceae

Powdery Mildew

B1 Powdery Mildew on Rosa

Scientific Name

Eryspiple, Microsplocera, Pyllactinea, Podosphaera, Sphaeotheca, Ursicinula, Oidinum

Common Name

Powdery Mildew


100 species found worldwide.

Physical Description

Obligate plant parasite, White mycelium covers plant, like wool.

Life Cycle

Produces Conidia spores and Ascospores from fruting grey bodies, this is carried by insect or wind to neighbouring plants, and mycelium may grow through soil or wound into the plant.

Method Of Attack

Mycelium feeds on sap internally.

Damage Caused

Plants discolour, yellow, distort and debilitate plant into decline and death. Serious in warm, dry conditions.

Control Methods

Fungicide applied in summer at 2 week intervals during dry season. Systemic fungicides best: Triforine, benomyl, thiophanate-methyl. Space plants, lower temperature, water plants. Maintain hygiene.

Stage Vulnerable


Plants Affected

Maples, Anenomes, Anthirhinium, Aster, Begonia, Calendula, Carnation, Carrot, Chrysanthemum, Clematis, Cyclamen, Honeysuckle, Hydrenga, Laburnum, Marigold, Lupin, Myosotis, Poppies, Phlox, Valerian.

Information Collated by James M. Burton as part of H.N.D. Course at Pencoed Agricultural College.
Chemical Information Correct as of 06:06:97. Always read and follow the instructions when using fungicides.