Shothole (Coryneum Blight)
Stigmina carpophila
35 host plants
Last updated
You'll spot small brown lesions with shot-like holes on Japanese apricot (Prunus mume) leaves, especially on older foliage. This fungal blight shows up in spring through early summer during cool, wet weather. The disease matters because it can defoliate trees and stunt new growth. Prune out infected buds and twigs, rake fallen leaves, and avoid overhead watering. Sulfur or chlorothalonil applied at petal fall helps manage severe infections in cool temperate regions.
Remove blighted tissue promptly, cutting well below visible symptoms. Improve air circulation by thinning dense growth. Avoid overhead watering, especially during bloom and new growth periods when tissues are most susceptible. For recurring problems, preventive fungicide applications timed to protect new growth can reduce infection, but cultural controls should be your first approach.
Quick Reference
Management
Chlorothalonil, IMMUNOX, or sulfur products can also be applied in spring when petals fall. | Do not apply copper fungicides in spring. | Chlorothalonil or sulfur products can also be applied in spring when petals fall.
Cultural Controls
- Plant varieties such as 'Lovell' and 'Muir', which are reported to be blight-tolerant.
- Prune and destroy dead buds and cankered twigs if present.
- Rake and destroy infected leaves.
- Avoid overhead watering.
Several peach cultivars are not suitable for western Washington due to shothole disease pressure in the maritime climate.