Diseases of Black Spruce in Ontario

Over 70 diseases have been found and recorded on black spruce (Picea mariana [Mill.] B.S.P.) in Ontario (Davis and Myren 1990). They range from vigorous pathogens capable of causing death or serious injury to trees, through weak pathogens able to infect only those trees already predisposed by other damaging agents, to saprophytes that derive their nourishment from dead plant material. Wood decay fungi belong to this last category.

The diseases of black spruce include root rots, stem decays, cankers, rusts, and needle blights. Minor damage to spruce wood products is caused by stains and molds.