Canker-staion of Plane - Ceratocystis fimbriata f.sp.platani
Symptoms / species
Impact / measures
Single trees or groups of dying or dead planes; wilt of single branches, on the stem around the bases of the branches large bark necroses; later on wilt of larger parts of the crown, coppices; sapflow lacking; sunken lesion in the bark of the stem, lentil-shaped or broad stripe-shaped, initially vinaceous, later coffee-brown; a characteristic macroscopic feature is the development of longitudinal and periclinal cracks in the bark, which are most typical for Platanus occidentalis, less typical for P.orientalis). No or only slight callusing! Opening the bark at the border of the discolored lesions with a knife reveals leopard-like dots (brown to dark violet) in the outer wood tissues. Cross sections through infected branches show radial, spindle-shaped, blueish-black discolorations in the springwood.
Affected tree species
Canker stain of Plane is the most dangerous disease of Platanus, causing the death of even large trees within relative short time. It is a disease of the vessels caused by the fungus Ceratocystis fimbriata f.sp. platani. The disease had invaded Europe at the end of the second world war probably with plant stock from the USA. Subsequently it spread in Italy and other mediterranean countries (actual spread France, Italy, Spain, Switzerland, Greece, Armenia). "Hot spots" are in numerous cities of Italy and Southern France, in Switzerland (Ticino and Geneve). Trees are infected by root contacts, by contaminated plant stock as well as soil. Stem and branch infections commonly occur through pruning and planting tools (wound infection, never by insects or wind!). Spores or the mycelium enter the bark via wounds; extension growth may reach 1m per year; even the heart woood is invaded. On the surface of the dead wood both asexual and sexual spores are produced.
Curative measures QUARANTAINE-ORGANISM (EPPO A2:
therefore obligation to report observations to the Federal Plant Protection Service! Removal (burning) of all infected plants; chemical treatment without any effect. The most effective precaution is the careful disinfection of pruning tools; provenance of plant stock should be checked for freedom of the disease!