Editing Spruce (section)

==== ''Rhizosphaera kalkhoffi'' needle cast ====
''Rhizosphaera'' infects white spruce, [[blue spruce]] (''Picea pungens''), and Norway spruces throughout Ontario, causing severe defoliation and sometimes killing small, stressed trees. White spruce is intermediately susceptible. Dead needles show rows of black fruiting bodies. Infection usually begins on lower branches. On white spruce, infected needles are usually retained on the tree into the following summer. The fungicide Chlorthalonil is registered for controlling this needle cast (Davis 1997).<ref name="davis">Davis, C. (24 September 1997) "Tree talk". ''The Sault Star''. Marie, Ontario. p. B2.</ref>