The multicoloured dwarfing disease of spruce has been observed and studied since 1950 on Norway spruce (Picea excelsa Link) in Eastern Slovakia, in the region of the Poprad and Dunajec rivers. The mass dying of trees was primarily attributed to honey fungus [Armillariella mellea (Vahl ex Fr.) P. Karst.]. The authors present consistent differences between the common infection of spruce by this fungus and the “multicoloured dwarfing disease of spruce.” Their hypothesis that this is a viral disease was confirmed electron-microscopically by detecting isometric particles in the needles of diseased spruces. Armillariella mellea probably acts as a vector in this process and contributes to the faster death of infected trees. The transmission of the multicoloured dwarfing disease of spruce was successfully achieved by grafting using bark shields.
Černý A., Ludvík J., Hervert V., Blattný C. Sr. (1977): Vielfarbige Verkümmerung der Fichte und Zusammenhang dieser Erkrankung mit dem massenhaften Auftreten des Hallimasches in der Ostslowakei. – Česká Mykologie 31(3): 126–131.
