European canker—Nectria galligena
European canker can infect both apple and pear trees. In California, this is a minor pest. Reddish brown
lesions develop around infected leaf scars on young
shoots or spurs. Concentric ridges develop around the sunken areas of dead tissue. The bark over the
diseased area cracks and the edges may take on a papery appearance.
Life cycle
Solutions
European canker is managed primarily by pruning and by using protectant fungicides. Prune and
destroy diseased wood early in summer. In apples, some varieties
are more susceptible than others. If trees are
infected with European canker, apply a freshly prepared Bordeaux
mixture or a fixed copper material at
label rates during early leaf fall, before rains begin. Where the disease is serious, make a second application
when 0.75 of the leaves have fallen. Timing of sprays is critical. Treatments are particularly necessary
when warm fall weather causes a prolonged leaf fall.
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Canker
encircling terminal part of twig
Canker
around leaf scar
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