Cytospora canker infects a branch then eventually kills it. The lower branches are attacked first then progressively higher branches. The needles turn brown to reddish brown and eventually drop off. White resin patches are seen on infected branches. Prune off infected branches. Water spruces during dry weather.
Spruce may be attacked by needle casts. One, caused by Lophodermium piceae, causes needles to turn yellow or brown and drop off. Another, caused by Rhizosphaera kalkhoffi, affects the lowest needles first then moves up the tree. Infected needles are a mottled yellow. Sprays of chlorothalonil control needle cast caused by Lophodermium.
Several rust diseases attack spruce but these are rarely seen. Infected needles turn yellow and drop off.
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|Cytospora canker on spruce - 44K||Cytospora canker on spruce - 71K|
|Cytospora canker on colorado spruce, resin patches - 20K||Cytospora canker on colorado spruce, resin patches - 20K|