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Extension > Garden > Diagnose a problem > What's wrong with my plant? > Fruit > Raspberry > Dark spots or streaks on canes

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Raspberry > Canes > Dark spots or streaks on canes

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  • Image: Spur Blight 1
  • Image: Spur Blight 2
  • Image: Spur Blight 3

Spur Blight
Didymella applanata

  • Brownish purple lesions enlarge into streaks and cover much of the cane
  • Brown wedge-shaped area on leaves
  • Chestnut brown to purple oval lesions on young green canes where the leaves attach
  • Leaf and flower buds shrivel and die, and young fruit may fail to develop
  • As diseased canes mature, the outer layer dries out and becomes silvery. Cracked, tiny black dots can be seen on the silvery epidermis
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  • Image: Cane Blight

Cane Blight
Leptospaeria coniothyrium

  • Dark streaks on cane, always around a wound
  • Shoots wilt and die as fruit develops
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  • Image: Verticillium Wilt

Verticillium Wilt
Verticillium albo-atrum

  • Canes turn blue or have blue streaks
  • Leaves turn yellow and fall off from the bottom of the plant up
  • Reddish brown streaks may be seen in the center of infected canes if bark is peeled away
  • Black raspberries die in 1-3 years
  • Red raspberries may survive many years but with reduced vigor
  • More information on Verticillium Wilt...
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  • Image: Botrytis 1
  • Image: Botrytis 2
  • Image: Botrytis 3

Gray Mold
Botrytis cinerea

  • Light brown oval lesions form on canes where the leaves attach, and faded brown concentric circles are often visible within the lesion
  • Flowers are brown to black and dry out
  • Gray powdery spores cover part or all of the infected fruit under moist conditions
  • Infected fruit may remain attached as shriveled, dried, black “mummies”
  • Disease favored by wet conditions and temperatures between 41-86° F
  • More information on Gray Mold...
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  • Image: Anthracnose 1
  • Image: Anthracnose 2
  • Image: Anthracnose 3

Elsinoe veneta

  • Small purple spots on young green canes (up to ¼ inch), and centers turn gray with age
  • In late fall infected stems develop the characteristic hard and crusty “gray bark”
  • Small spots (1/16 inch) on leaves, white to gray center with purple borders
  • More information on Anthracnose...

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