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Seed Crop, Crucifers (Brassica and Raphanus spp.)-Sclerotinia Stem Rot By C. M. Ocamb Cause Sclerotinia sclerotiorum is a cosmopolitan fungus that occurs across the globe, infecting a very large number of plant species including radish and Brassica crops. ...

Seed Crop, Crucifers (Brassica and Raphanus spp.)-White Leaf Spot and Gray Stem By C. M. Ocamb Cause The fungus, Neopseudocercosporella capsellae (formerly Pseudocercosporella capsellae, sexual stage: Mycosphaerella capsellae), has been observed in variou ...

Seed Treatment See: Vegetable Seed Treatment Barley, Oat, Rye, Triticale, and Wheat Seed Treatments Fungicide Effectiveness as Seed Treatments for Cereal Diseases ...

Senecio cineraria-Wilt Cause The OSU Plant Clinic has found Fusarium sp. on dusty miller Jacobaea maritima, formerly Senecio cineraria). It survives in the soil as thick-walled, dormant chlamydospores, which germinate in response to exudates from nearby p ...

Serviceberry (Amelanchier spp.)-Rust See: Pear (Pyrus spp.)- Pacific Coast Pear Rust Cedar, Incense- Broom Rust Cause Seven Gymnosporangium spp, fungi. The spore stages produced on serviceberry or others in the rose family do not reinfect these hosts. The ...

Shasta Daisy (Leucanthemum x superbum)-Leaf Spot (Leaf Blotch) Cause Septoria leucanthemi, a fungus that overwinters on plant refuse and on living plants. Spores can be spread by splashing water from rain or irrigation. Once on the leaf, spores germinate ...

Shasta Daisy (Leucanthemum x superbum)-Shoot Proliferation and Leafy Gall See: Greenhouse Plants, Ornamental- Shoot Proliferation and Leafy Gall ...

Skimmia-Crown and Root Rot Cause The OSU Plant Clinic has found several soilborne organisms associated with skimmia root problems including Phytophthora sp., Pythium sp., and Fusarium sp. in addition to Armillaria root rot. These pathogens are typically f ...

Skimmia-Leaf Spots Cause The OSU Plant Clinic has found Ascochyta sp. and Pleospora sp. in association with leaf spots of skimmia. Leaves may become wet for extended periods of time in the shade, which is favorable for leaf spotting organisms. These plant ...

Smoke Tree (Cotinus coggygria)-Powdery Mildew See: Maple (Acer spp.)- Powdery Mildew ...