Powdery Mildew of Cucurbits

Sphaerotheca fuligena

Oidium spp.

Description:

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.

Biology:

Favoured by warm dry conditions.
Spores spread by wind.

Life Cycle:

Origin and History:

Distribution:

Significance:

Management and Control:

Use resistant varieties.
Apply fungicides from the first sign of disease.

Related and Similar Species:

References:

Acknowledgments:

Collated by HerbiGuide. Phone 08 98444064 or www.HerbiGuide.com.au for more information.