Nectria dieback
Description
Micro-habitat(s)
Whole tree
Distribution
Canada
Damage, symptoms and biology
Nectria cinnabarina acts mostly as a saprophyte, living on dead plant tissue, and as such is not generally considered a serious forest disease organism. However, it is also weakly pathogenic, colonizing stems and branches weakened by mechanical injury, physiological stress, or other disease. Damage by this fungus is often observed on recently transplanted ornamental shrubs and trees.
Infection occurs early in the spring in small wounds on branches and twigs. The fungus produces orange-pink fruiting bodies. The spores developing in the fruiting bodies cause new infections during the summer.
A second type of fruiting body appears later in the season. Its spores are dispersed early in spring, which allows the cycle to start again.
Other information
Two other related Nectria species cause notable cankers on hardwoods, but occur much less frequently in British Columbia: N. galligena Bres. in Strauss causes perennial "target" cankers on many hardwoods and fruit trees (European canker) (Fig. c), and N. ditissima Tul. causes large perennial stem cankers on red alder (Fig. d). Isolates of N. ditissima are being considered as biological control agents for red alder.
Canadian Forest Service Publications
Information on host(s)
Main host(s)
Alders, American chestnut, apples, basswood, bigleaf maple, black locust, cherries / plums, dogwoods, elders, elms, European larch, hazels, honey-locust, horsechestnuts, mountain-ash, plum, serviceberries, slippery elm, vine maple, western hemlock, white elm, willow