Compiled by Brian Hudelson and Hulubanche Kassa
The following diseases/disorders were identified at the Plant Disease Diagnostics Clinic from July 25, 2026 through July 31, 2026.
Broad-Leafed Woody Ornamentals
Plant: Boxwood
Disease/Disorder: Fusarium Canker
Pathogen: Fusarium sp.
County: Waukesha
Plant: Boxwood
Disease/Disorder: Volutella Canker
Pathogen: Volutella sp.
County: Waukesha
Plant: Magnolia
Disease/Disorder: Verticillium Wilt
Pathogen: Verticillium sp.
County: Dane
Plant: Oak (Bur)
Disease/Disorder: Oak Wilt
Pathogen: Bretziella fagacearum
County: Dane
Plant: Oak (Red)
Disease/Disorder: Chlorosis
Pathogen: None
County: Waukesha
Plant: Oak (Red)
Disease/Disorder: Oak Wilt
Pathogen: Bretziella fagacearum
County: Dane
Plant: Oak (White)
Disease/Disorder: Anthracnose
Pathogen: Discula sp.
County: Walworth
Plant: Oak (White)
Disease/Disorder: Tubakia Leaf spot
Pathogen: Tubakia dryina
County: Walworth
Plant: Oak (Unspecified)
Disease/Disorder: Oak Wilt
Pathogen: Bretziella fagacearum
Counties: Oneida, Waukesha
Plant: Spirea
Disease/Disorder: Phomopsis Canker
Pathogen: Phomopsis sp.
County: Kenosha
Field Crops
Plant: Corn
Disease/Disorder: Southern Rust
Pathogen: Puccinia polysora
Counties: Chippewa, Jackson, Trempealeau
Plant: Soybean
Disease/Disorder: Charcoal Rot
Pathogen: Macrophomina phaseolina
County: Fond du Lac
Plant: Soybean
Disease/Disorder: Fusarium Root Rot
Pathogen: Fusarium sp.
County: Fond du Lac
Plant: Soybean
Disease/Disorder: Phytophthora Root and Stem Rot
Pathogen: Phytophthora sp.
Counties: Calumet, Fond du Lac
Forage Crops
No New Diseases
Fruit Crops
Plant: Cranberry
Disease/Disorder: Upright Dieback
Pathogen: Phomopsis vaccinii
County: Price
Plant: Strawberry
Disease/Disorder: Root/Crown Rot
Pathogen: Fusarium sp.
County: Washington
Herbaceous Ornamentals
Plant: Daisy (Shasta)
Disease/Disorder: Crown Gall
Pathogen: Agrobacterium tumefaciens
County: Ottawa (MI)
Plant: Daisy (Shasta)
Disease/Disorder: Leafy Gall
Pathogen: Rhodococcus facians
County: Ottawa (MI)
Plant: Lisianthus
Disease/Disorder: Alternaria spot/blight
Pathogen: Alternaria sp.
County: Dane
Houseplants
No New Diseases
Needled Woody Ornamentals
Plant: Arborvitae
Disease/Disorder: Root Rot
Pathogens: Phytophthora sp., Pythium sp.
County: Dane
Plant: Pine (White)
Disease/Disorder: White Pine Blister Rust
Pathogen: Cronartium ribicola
County: Washington
Plant: Spruce (Norway)
Disease/Disorder: Cytospora Canker
Pathogen: Cytospora sp.
County: Dane
Plant: Yew
Disease/Disorder: Phomopsis Canker
Pathogen: Phomopsis sp.
County: Milwaukee
Vegetable Crops
Plant: Onion
Disease/Disorder: Heat Stress (Suspected)
Pathogen: None
County: Dodge
Plant: Onion
Disease/Disorder: Root Rot
Pathogen: Pythium sp.
County: Green Lake
Plant: Potato
Disease/Disorder: Early Blight
Pathogen: Alternaria solani
County: Dane
Plant: Potato
Disease/Disorder: Walnut Toxicity (Suspected)
Pathogen: Suspected
County: Dane
Plant: Pumpkin
Disease/Disorder: Charcoal Rot
Pathogen: Macrophomina phaseolina
County: Portage
Plant: Pumpkin
Disease/Disorder: Fusarium Crown and Root Rot
Pathogen: Fusarium sp.
County: Portage
Plant: Pumpkin
Disease/Disorder: Phytophthora Crown and Root Rot
Pathogen: Phytophthora sp.
County: Portage
Plant: Tomato
Disease/Disorder: Early Blight
Pathogen: Alternaria solani
County: Dane
Plant: Tomato
Disease/Disorder: Walnut Toxicity (Suspected)
Pathogen: Suspected
County: Dane
Specialty Crops
No New Diseases
Miscellaneous
No New Entries