Blueberry canker diseases | Berry Diagnostic Tool

Canker Diseases

Canker diseases may also cause dieback of shoots, and are sometimes confused with winter injury. In many cases, winter injured wood is susceptible to canker infection.

Cankers cause a characteristic flagging of shoots during summer. The canker restricts movement of water and nutrients, causing the cane to wilt and die.

Blueberry planting with several orange-tinted dead branches. Branches have curved "flagging" shape.

Fusicoccum canker tends to infect the lower portion of canes. On young canes, the lesions look like a bull’s eye.

Young blueberry twig with orange fusicoccum canker. Canker is elongated oval form and has ringlike gradation in color intensity. Center is whitish-orange and outer edges are more rust-colored.

In older canes, the interior wood is brown.

Old blueberry cane with brown discoloration under peeling bark.

Phomopsis canker infects canes through winter-injured wood, usually the tips of canes.

Blueberry twig tip, brown and dead from phomosis infection. Lower down the cane the wood is again healthy and green.

The canker grows down the cane, gradually killing it. Small spore-producing structures (pycnidia) can be seen on the canker margins.

Woody blueberry cane with small black spots arranged in an elongated oval shape.

Cutting into the green wood below the dead portion will reveal brown interior pith if the canker is still active (images below).

Cut blueberry twig with brown discoloration in semi-circle area.

Closeup of infected blueberry twig. Half of the cane is white and greenish surrounding the bark. Half of the cane is dark brown and appears dry beneath the bark.

For more information on blueberry canker diseases see the following –

Use these resources if you need additional help with diagnosis and to find solutions to your problem.