Canker-like swellings on twigs, branches and stems, mostly elongated, of various size and later opening longitudinally; bordered by callus; infested crown parts with shrubby and dense branching (witches brooms), in the cankers orange colored, disc-shaped fruiting-bodies (apothecia) about 1 mm in size.
Affected tree species
On moist sites with high air humidity (depressions), epidemics favoured by light deficiency, stand density and high precipitation. Furthermore there is a relation to certain provenances of larches. The disease causes a slow dieback of twigs and branches and more rarely of the stem.
Curative measures Curative Measures are not possible;
remove carefully infective plant material
thinning of dense stands
afforestation only with well adapted provenances