WSU Extension

Hortsense

Raspberry
 
Disease
Anthracnose 
Boron deficiency 
Fruit rot and cane Botrytis 
Phytophthora root rot 
Powdery mildew 
Spur blight 
Yellow rust 
Insect
Aphids 
Brown marmorated stink bug 
Cutworms and armyworms 
Dryberry mite 
Leafrollers 
Loopers 
Raspberry beetle (raspberry fruitworm) 
Raspberry crown borer 
Root weevils 
Rose stem girdler 
Spider mites 
Spotted wing Drosophila (SWD) 



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Caption: Raspberry spur blight
Photo by: R.S. Byther
  
Raspberry : Spur blight
(revision date: 2/26/2016)


Biology
In early April, pin-point size black fruiting bodies (perithecia) can be found in the gray affected areas of cane tissue. The fruiting bodies release ascospores, which infect leaves on both fruiting canes and primocanes. Brown necrotic spots with yellow margins form on fruiting-cane leaves when rainy weather lasts through late spring. Infected leaves become chlorotic and drop prematurely in severe cases. However, primocane leaves develop brown "V-shaped" lesions (with a yellow margin between the dead and living portion of leaves). The fungus then grows through the leaf stalk (petiole) and invades stem tissues around buds, turning them brown or purple. Buds on infected canes are more susceptible to winter injury, and fruiting laterals may be stunted. Infected areas become gray in winter. Spur blight is also found on Loganberry and Youngberry. The "Willamette" cultivar of red raspberry, while susceptible, suffers little damage and is considered "tolerant".
Management Options

Non-Chemical Management
  • Remove and destroy old fruiting canes after harvest.
  • Keep plant rows narrow.
  • Practice good weed control.
  • Control early primocane growth.
  • Plant resistant or tolerant cultivars.
Select non-chemical management options as your first choice!

Chemical Management

Spray at bloom or when shoots are 8 to 10 inches long. Repeat applications according to label instructions.

Listed below are examples of pesticides that are legal in Washington. Always read and follow all label directions.
  • Captan 50% WP Fruit & Ornamental
    Active ingredient: captan  |  EPA reg no: 4-459
  • This list may not include all products registered for this use.
Images

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Caption: Raspberry spur blight
Photo by: R.S. Byther
Caption: Raspberry spur blight
Photo by: R.S. Byther
Caption: Raspberry spur blight
Photo by: R.S. Byther
Caption: Raspberry spur blight spore tendrils
Photo by: L.J. du Toit