Compiled by Brian Hudelson and Hulubanche Kassa
The following diseases/disorders were identified at the Plant Disease Diagnostics Clinic from July 4, 2026 through July 10, 2026.
Broad-Leafed Woody Ornamentals
Plant: Beech (Tri-Color)
Disease/Disorder: Phomopsis Canker
Pathogen: Phomopsis sp.
County: Dane
Plant: Birch (Paper)
Disease/Disorder: Septoria Leaf Spot
Pathogen: Septoria sp.
County: Eau Claire
Plant: Birch (‘Whitespire’)
Disease/Disorder: Lichens
Pathogen: None
County: Dane
Plant: Birch (‘Whitespire’)
Disease/Disorder: Sooty Mold
Pathogen: Miscellaneous sooty mold fungi
County: Dane
Plant: Boxwood
Disease/Disorder: Volutella Canker
Pathogen: Volutella sp.
County: Milwaukee
Plant: Catalpa
Disease/Disorder: Verticillium Wilt
Pathogen: Verticillium sp.
County: Dane
Plant: Dogwood
Disease/Disorder: Powdery Mildew
Pathogen: Oidium sp.
County: Sauk
Plant: Hydrangea
Disease/Disorder: Fertility Issues (Suspected)
Pathogen: None
County: Sauk
Plant: Kentucky Coffeetree
Disease/Disorder: Herbicide Damage
Pathogen: None
County: Dane
Plant: Lilac (Shrub)
Disease/Disorder: Anthracnose
Pathogen: Gloeosporium sp.
County: Sauk
Plant: Lilac (Shrub)
Disease/Disorder: Phytoplasma Disease
Pathogen: Unspecified phytoplasma
County: Sauk
Plant: Lilac (Shrub)
Disease/Disorder: Septoria Leaf Spot
Pathogen: Septoria sp.
County: Sauk
Plant: Lilac (Shrub)
Disease/Disorder: Sphaeropsis Canker
Pathogen: Sphaeropsis sp.
County: Dane
Plant: Maple (Norway)
Disease/Disorder: Cytospora Canker
Pathogen: Cytospora sp.
County: Dane
Plant: Maple (Unspecified)
Disease/Disorder: Verticillium Wilt
Pathogen: Verticillium sp.
County: Dane
Plant: Oak (Red)
Disease/Disorder: Oak Wilt
Pathogen: Bretziella fagacearum
County: Dane
Plant: Oak (White)
Disease/Disorder: Anthracnose
Pathogen: Discula sp.
County: Dane
Plant: Oak (White)
Disease/Disorder: Chlorosis
Pathogen: None
County: Dane
Plant: Oak (White)
Disease/Disorder: Herbicide Damage
Pathogen: None
County: Dane
Plant: Rose
Disease/Disorder: Black Spot
Pathogen: Marssonina rosae
County: Walworth
Plant: Rose
Disease/Disorder: Herbicide Damage
Pathogen: None
County: Walworth
Plant: Walnut (Black)
Disease/Disorder: Anthracnose
Pathogen: Gloeosporium sp.
County: Dane
Plant: Walnut (Black)
Disease/Disorder: Herbicide Damage
Pathogen: None
County: Dane
Field Crops
Plant: Soybean
Disease/Disorder: Seedling Blight
Pathogens: Phytophthora sp., Rhizoctonia sp.
County: Grant
Plant: Wheat
Disease/Disorder: Alternaria Leaf Spot
Pathogen: Alternaria sp.
County: Dane
Plant: Wheat
Disease/Disorder: Bacterial Streak
Pathogen: Xanthomonas sp.
County: Dane
Plant: Wheat
Disease/Disorder: Root Rot
Pathogens: Fusarium sp., Pythium sp., Bipolaria sorokiniana
County: Dane
Forage Crops
No New Diseases
Fruit Crops
Plant: Apple
Disease/Disorder: Sphaeropsis Canker
Pathogen: Sphaeropsis sp.
County: Rock
Plant: Pear
Disease/Disorder: Root/Crown Rot
Pathogen: Phytophthora sp.
County: Sawyer
Plant: Raspberry (Black)
Disease/Disorder: Anthracnose
Pathogen: Sphaceloma necator
County: Green Lake
Plant: Strawberry
Disease/Disorder: Chemical Burn (Suspected)
Pathogen: None
County: Ashland
Plant: Strawberry
Disease/Disorder: Root Rot
Pathogens: Phytophthora sp., Pythium sp., Rhizoctonia sp., Fusarium sp.
County: Wood
Herbaceous Ornamentals
Plant: Baptisia
Disease/Disorder: Crown Gall
Pathogen: Agrobacterium tumefaciens
County: Ottawa (MI)
Plant: Begonia
Disease/Disorder: Gray Mold/Botrytis Blight
Pathogen: Botrytis cinerea
County: Manitowoc
Plant: Clematis
Disease/Disorder: Virus Disease
Pathogen: Unspecified plant virus
County: Sauk
Plant: Hosta
Disease/Disorder: Crown Gall
Pathogen: Agrobacterium tumefaciens
County: Ottawa (MI)
Plant: Hosta
Disease/Disorder: Leafy Gall
Pathogen: Rhodococcus facians
County: Ottawa (MI)
Plant: Peony
Disease/Disorder: Anthracnose
Pathogen: Colletotrichum sp.
County: Milwaukee
Plant: Peony
Disease/Disorder: Leaf Blotch
Pathogen: Graphiopsis chlorocephala
County: Manitowoc
Plant: Phlox
Disease/Disorder: Herbicide Damage
Pathogen: None
County: Walworth
Plant: Miscellaneous Herbaceous Ornamentals
Disease/Disorder: Root Rot
Pathogens: Phytophthora sp., Pythium sp., Fusarium sp., Thielaviopsis sp.
County: Manitowoc
Houseplants
No New Diseases
Needled Woody Ornamentals
Plant: Arborvitae
Disease/Disorder: Phyllosticta Needle Blight
Pathogen: Phyllosticta sp.
Counties: Dane, Sawyer, Waukesha
Plant: Juniper
Disease/Disorder: Cytospora Canker
Pathogen: Cytospora sp.
County: Sawyer
Plant: Juniper
Disease/Disorder: Diplodia Shoot Blight and Canker
Pathogen: Diplodia sp.
County: Washington
Plant: Juniper
Disease/Disorder: Phomopsis Tip Blight
Pathogen: Phomopsis juniperovora
Counties: Kenosha, Sawyer, Walworth, Waukesha
Plant: Juniper
Disease/Disorder: Root/Crown Rot
Pathogen: Phytophthora sp.
County: Kenosha
Plant: Spruce (Blue)
Disease/Disorder: Spruce Needle Drop
Pathogen: Setomelanomma holmii
County: Dane
Plant: Spruce (Unspecified)
Disease/Disorder: Winter Burn
Pathogen: None
County: Douglas
Vegetable Crops
Plant: Brussels Sprouts
Disease/Disorder: Black Rot
Pathogen: Xanthomonas campestris pv. campestris
County: Crawford
Plant: Cucumber
Disease/Disorder: Anthracnose
Pathogen: Colletotrichum orbiculare
County: Dane
Specialty Crops
No New Diseases
Miscellaneous
No New Entries