Extension > Garden > Diagnose a problem > What's wrong with my plant? > Deciduous Trees > Ribes > Spots or blotches on leaves
Ribes > Leaves > Spots or blotches on leaves
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White Pine Blister Rust
Cronartium ribicola
- Light yellow angular leaf spots on upper leaf surface
- Hair like orange spore producing structures on lower leaf surfaces
- Powdery orange spores may be present
- In highly susceptible varieties infected leaves may drop
- More information on White Pine Blister Rust
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Cluster Cup Rust
Puccinia caricina
- Yellow spots on leaves and developing fruit in spring
- Clusters of tiny orange cups form under leaf spots and on infected fruit or petioles
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Mycosphaerella leaf spot
Mycosphaerella ribis (Septoria ribis)
- Small, irregular brown spots with gray centers on leaves
- Leaves turn yellow, brown and then drop prematurely
- Symptoms often occur on bottom of plant first
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Powdery mildew
Phyllactina guttata
- White, powdery spots or blotches on leaves
- Leaves and stems may be completely covered with white, powdery fungal growth
- Leaves may yellow and drop prematurely
- Young leaves and shoots may be curled and twisted
- Entire shrub may appear gray or discolored
- More information on powdery mildew
