Effect of fertilization on growth and ectomycorrhizal development of container-grown and bare-root nursery conifer seedlings

The effect of three levels of fertilizer on thegrowth of three species of containerized-grownconifer seedlings (Pinus contorta, Picea glauca, and Picea mariana) and twospecies of bare-root conifer seedlings (Pinus sylvestris and Larix sibirica),and on the colonization of these seedlings bysix species of ectomycorrhizal fungi (Hebeloma longicaudum, Laccaria bicolor,Paxillus involutus, Pisolithustinctorius, Rhizopogon vinicolor andSuillus tomentosus), was studied. Thegrowth of the seedlings in both container-grownand bare-root nurseries increased as the levelsof fertilizer increased. For better seedlinggrowth and environmental quality it may be possible to reduce the level of fertilizers in commercial nurseries upto 33% by using selected mycorrhizal fungi.Ectomycorrhizal colonization in all seedlingswas not affected by fertilizer levels. Hebeloma longicaudum, L. bicolor, P.involutus, and P. tinctorius formedwell-developed ectomycorrhizae, whereasectomycorrhizal development by R.vinicolor and S. tomentosus was poor.Native mycorrhizal fungi colonizednon-inoculated control seedlings; however,their colonization was always lower than withinoculated fungi.