Poplar: Leaf and shoot blight
Photo by: R.S. Byther
Biology
Leaf and shoot blight is a fungal disease which affects poplars, aspens, and willows. The fungus infects succulent leaves and twigs. Mature plant tissues are resistant.
Initial symptoms include the development of rapidly expanding dark brown or black spots on the leaves and shoots. Affected leaves and shoots are killed quickly, with the tissues turning dry and brittle.
Killed shoots often tip over in a blackened “shepherd’s crook”.
The fungi infecting poplars and aspens overwinter in infected shoots, but probably not in leaves. The disease can be spread by splashing water from the previous year’s infected shoots to new growth.
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 trees and prune to reduce humidity in the planting.
- Provide proper culture. Healthy, established trees are less severely affected by disease.
- Prune out and destroy infected plant parts when noticed (if practical).
- Rake and destroy infected leaves as a precautionary measure.
- Avoid overhead irrigation.
Chemical Management
IMPORTANT: Always read and follow label directions when working with pesticides.
For more information on using pesticides visit :
- Make applications during early shoot growth in spring.
- Homeowners should not make foliar applications to trees over 10 ft tall.
- Consult a commercial pesticide applicator for treatment of trees and shrubs over 10 ft. tall.
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.
Additional Images
Photo by: G.A. Chastanger
Photo by: R.S. Byther
WSU Extension programs and employment are available to all without discrimination.
Evidence of noncompliance may be reported through your local Extension office.