Natural Occurrence of Seiridium cardinale on Thuja in Germany

Seiridium cardinale (Wagener) Sutton & Gibson (syn. Coryneum cardinale Wagener) is the most dangerous parasitic fungus of cypress and other Gupressaceae, already appearing in epidemic proportions, especially in the mediterranean area. Recently (in 1989, 1990 and 1991) this pathogen has been detected in the northern part of Germany (Hamburg and Schleswig-Holstein) naturally infecting Thuja. The geographical distribution and the progressive spread of S. cardinale is reviewed. Diagnostic features of the fungus, modes of host penetration, principal symptoms of the disease, ways of dispersal and control methods are described. Possible causal factors for the recently observed occurrence of 5. cardinale in the north of Germany are discussed.