Extension > Garden > Diagnose a problem > What's wrong with my plant? > Deciduous Trees > Prunus > Discolored areas of branches or twigs
Prunus > Trunk/Branches > Discolored areas of branches or twigs
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Bacterial spot and canker
Pseudomonas syringae pv. syringae
- Sunken dark colored elliptical cankers form on branches
- Sticky gums (gummosis) or sour-smelling liquid are excreted from infected branches
- Blossoms turn brown, especially after frost damage
- Angular, brown to black leaf spots that eventually drop out leaving holes and giving a ragged appearance on leaves
- More information on Bacterial spot and canker
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Branch cankers
Valsa leucostoma, Leucostoma spp.
- Cankers are brown to black sunken areas on branch that may have cracked bark and discolored reddish brown sapwood
- Random dead branches seen throughout canopy
- Raised black pimple like fungal structures form on cankers and dead branches, exude orange tendrils of spores in wet weather
- Sticky gum exudes from branch cankers
- Leaves on random branches wilt, turn yellow then brown
- Infected branches don't leaf out in spring
- Common on trees stressed by drought, winter injury, wounds, insect feeding or other factors
- More information on canker
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Scurfy scale
Chionaspis furfura
- Infested twigs and branches show dieback in canopy
- Adults are white and covered by a white cocoon-like armor, which gives the appearance of white bumps along the stem or branches
- Crawlers or juvenile scales are light purple
- Cocoon-like armor can be seen year round but crawlers can be seen in June
- More information on scale insects
