Effects of soil fumigation and inoculation with pure culture of Hebeloma cylindrosporum on survival, growth and ectomycorrhizal development of Norway spruce and douglas fir seedlings

Abstract

AbstractIn a bare‐root nursery we have determined the incidence of soil fumigation and mycorrhizal inoculation on survival growth and ectomycorrhizal development of Norway spruce and Douglas fir seedlings. Three experimental designes were installed in 1978, 1981 and 1982.Soil fumigation eliminated or reduced Rbizoctonia solani, Pytbium sp. and probably Fusarium oxysporum propagules. Fumigation improved Norway spruce seedlings performance, particularly in the second year. Douglas fir seedlings seemed less sensitive to soil‐borne pathogens tha Norway spruce seedlings.Two years after inoculation, Hebeloma cylindrosporum increased Norway spruce growth by 40% and Douglas fir growth by 30 % in comparison with seedlings grown in fumigated soil and mycorrhizal with the naturally occurring fungus Thelephora terrestris.Both, fumigation and artificial inoculation increased Norway spruce seedling growth by 110 % and Douglas fir seedling growth by 50 %.