Powdery Mildew of Cucurbits

Sphaerotheca fuligena

Oidium spp.


A fungal disease that first shows as white spots in the underside of older leaves. These may expand to cover both side of the leaf with a white powdery coating. Vine growth stops and leaves may yellow and die. Fruit size is reduced and may be more prone to sunburn.

Species Affected:

Apple Cucumbers, Cucumber, Grammas, Marrow, Pumpkin, Rockmelon, Squash, Watermelon.

Green Gem Cucumbers are resistant.

Dixie Jumbo, Gulf Coast, Early Dawn, Planter's Jumbo and Saticoy Rockmelons are tolerant.


Favoured by warm dry conditions.

Spores spread by wind.

Life Cycle:

Origin and History:



Management and Control:

Use resistant varieties.

Apply fungicides from the first sign of disease.

Related and Similar Species:



Collated by HerbiGuide. Phone 08 98444064 for more information.