Abstract: | Young spruce trees Picea abies (L.) Karst.] artificially inoculated with Rhizosphaera kalkhoffii B. and Lophodermium piceae (F.) v. H. were exposed to fumigations with O3 and SO2 and drought. These treatments showed no influence on the infection-rates of the fungi. R. kalkhoffii proved to be a saprophyte living for a long period as an epiphyte on the needle surfaces. |