Larch cancer
The larch cancer is caused by the fungus willkommii Lachnellula caused frequent disease of European larch .
The larch crayfish infestation manifests itself as resin flow and deformations on twigs, branches and trunk. Cancer-like growths can be seen in the cross-section of an infected tree. Although it is not cancer in the medical sense, it is called tree cancer . Practically only the European larch is affected ; the Japanese larch is considered resistant. These perennial crabs can become enormous and lead to the complete devaluation of the trunks. Local deformations or open wounds on branches or trunks are noticeable. Younger branches can die off. On older trunks there are even wound craters that are no longer overgrown. Only stem crabs are economically significant, which arise when a branch infection occurs very close to the stem and the fungus migrates into the stem bark. The dying side branch in the center of the trunk wound remains recognizable for a long time.
The infection associated with ascospores primarily in the fall instead of; preferred sites of infection are needle scars and short shoots . As with other crustaceans, the host tries in vain to invade the area of the cortex affected by the cancer and to seal it off with peridermia . However, especially during the dormant period of vegetation, the cancer often succeeds in overcoming the peridermia and destroying attempts to invade it.
literature
- Heinz Butin : Diseases of the forest and park trees. Diagnosis, biology, control. 2 spore boards . 3rd, revised and expanded edition. Thieme, Stuttgart and New York 1996, ISBN 3-13-639003-2