Currant, Gooseberry: Powdery mildew
Photo by: R.S. Byther
Biology
Powdery mildew is a fungal disease. Characteristic white patches of powdery fungal growth develop on shoots, fruit, and either or both sides of the leaves. infected tissues are often stunted and distorted, and infected leaves may drop prematurely. On the berries, the fungal patches turn rusty brown as they age. Infected berries are typically smaller than normal, with rough, cracked surfaces.
The fungus probably overwinters on twigs and infected plant debris and possibly also in buds. Disease development is favored by cool, rainy weather in the spring and early summer.
Management Options
See "Using Integrated Pest Management (IPM) in the Landscape" for successful problem management techniques.
Non-chemical Management
Select non-chemical management options as your first choice!
- Space plantings and prune to provide good air circulation and reduce humidity.
- Provide proper culture.
- Clean up plant debris. Prune out and destroy/discard (do not compost) diseased plant materials.
Chemical Management
IMPORTANT: Always read and follow label directions when working with pesticides.
For more information on using pesticides visit :
- Make a sulfur product application at pre-bloom (just before blossoms are ready to open), a second application at full bloom, and a third application 2 weeks later.
- NOTE: Lilly Miller Sulfur Dust is registered for use on GOOSEBERRY ONLY.
Approved Pesticides
If you choose to use a pesticide, some examples of products that are legal in Washington are listed below. Some products are labeled for just INDOOR or just OUTDOOR use, or may allow both uses. Be sure to choose a product appropriate for your situation. Always read and follow all label directions.
WSU Extension programs and employment are available to all without discrimination.
Evidence of noncompliance may be reported through your local Extension office.