Compiled by Brian Hudelson and Dante Tauscheck

The following diseases/disorders were identified at the Plant Disease Diagnostics Clinic from August 23, 2025 through August 29, 2025.

 

 

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Broad-Leafed Woody Ornamentals

Plant:  Buckeye (Bottlebrush)
Disease/Disorder:  Guignardia Leaf Blotch
Pathogen:  Guignardia aesculi
County:  Columbia

Plant:  Catalpa
Disease/Disorder:  Verticillium Wilt
Pathogen:  Verticillium sp.
County:  Sheboygan

Plant:  Cherry (Black)
Disease/Disorder:  Root Rot
Pathogen:  Phytophthora sp., Rhizoctonia sp.
County:  Dane

Plant:  Crabapple
Disease/Disorder:  Chlorosis
Pathogen:  None
County:  Green

Plant:  Elm (American)
Disease/Disorder:  Blackspot
Pathogen:  Asteroma ulmeum
County:  Waukesha

Plant:  Lilac
Disease/Disorder:  Cold Injury (Suspected)
Pathogen:  None
County:  Dane

Plant:  Magnolia
Disease/Disorder:  Verticillium Wilt
Pathogen:  Verticillium sp.
County:  Dane

Plant:  Maple
Disease/Disorder:  Girdling Roots (Suspected)
Pathogen:  None
County:  La Crosse

Plant:  Maple
Disease/Disorder:  Overly Deep Planting
Pathogen:  None
County:  La Crosse

Plant:  Oak (Bur)
Disease/Disorder:  Anthracnose
Pathogen:  Discula sp.
County:  Dane

Plant:  Oak (Bur)
Disease/Disorder:  Tubakia Leaf Spot
Pathogen:  Tubakia dryina
County:  Dane

Plant:  Oak (Pin)
Disease/Disorder:  Anthracnose
Pathogen:  Discula sp.
County:  Dane

Plant:  Oak (Pin)
Disease/Disorder: Chlorosis
Pathogen:  None
County:  Dane

Plant:  Oak (Pin)
Disease/Disorder:  Tubakia Leaf Spot
Pathogen:  Tubakia dryina
County:  Dane

Plant:  Oak (Red)
Disease/Disorder:  Oak Wilt
Pathogen:  Bretziella fagacearum
County:  Cook (IL)

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:  Tubakia Leaf Spot
Pathogen:  Tubakia dryina
County:  Dane

Plant:  Oak (Unspecified)
Disease/Disorder:  Oak Wilt
Pathogen:  Bretziella fagacearum
County:  Dane

Plant:  Pear (Callery/Ornamental)
Disease/Disorder:  Fire Blight
Pathogen:  Erwinia amylovora
Counties:  Dane, Waukesha

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Field Crops

Plant:  Corn (Field)
Disease/Disorder:  Southern Corn Rust
Pathogen:  Puccinia polysora
County:  Lafayette

Plant:  Corn (Field)
Disease/Disorder:  Tar Spot
Pathogen:  Phyllachora maydis
County:  Lafayette

Plant:  Soybean
Disease/Disorder:  Soybean Cyst Nematode
Pathogen:  Heterodera glycines
County:  Sheboygan

Plant:  Soybean
Disease/Disorder:  Sudden Death Syndrome
Pathogen:  Fusarium virguliforme
Counties:  Lafayette, Sheboygan

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Forage Crops

No New Diseases

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Fruit Crops

Plant:  Apple (‘Honeycrisp’)
Disease/Disorder:  Honeycrisp Leaf Mottle
Pathogen:  None
County:  Wood

Plant:  Apple (Miscellaneous Varieties)
Disease/Disorder:  Fertility Issues (Suspected)
Pathogen:  None
County:  Wood

Plant:  Apple (Miscellaneous Varieties)
Disease/Disorder:  Frogeye Leaf Spot (Suspected)
Pathogen:  Botryosphaeria obtusa
County:  Wood

Plant:  Apple (Miscellaneous Varieties)
Disease/Disorder:  Sooty Blotch
Pathogen:  Miscellaneous sooty blotch fungi
County:  Wood

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Herbaceous Ornamentals

Plant:  Hosta
Disease/Disorder:  Anthracnose
Pathogen:  Colletotrichum sp.
County:  Columbia

Plant:  Hosta
Disease/Disorder:  Foliar Nematode
Pathogen:  Aphelenchoides sp.
County:  Columbia

Plant:  Hosta
Disease/Disorder:  Southern Blight
Pathogen:  Athelia rolsii
County:  Dane

Plant:  Iris (German Bearded)
Disease/Disorder:  Bacterial Soft Rot
Pathogen:  Pectobacterium sp.
County:  Burnett

Plant:  Wild Petunia
Disease/Disorder:  Rust
Pathogen:  Puccinia lateripes
County:  Marathon

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Houseplants

No New Diseases

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Needled Woody Ornamentals

Plant:  Fir (Fraser)
Disease/Disorder:  Rhizosphaera Needle Cast
Pathogen:  Rhizosphaera sp.
County:  Adams

Plant:  Spruce (Black Hills)
Disease/Disorder:  Rhizosphaera Needle Cast
Pathogen:  Rhizosphaera kalkhoffii
County:  Portage

Plant:  Spruce (Black Hills)
Disease/Disorder:  Transplant Shock
Pathogen:  None
County:  Portage

Plant:  Spruce (Unspecified)
Disease/Disorder:  Spruce Needle Drop
Pathogen:  Setomelanomma holmii
County:  Fond du Lac

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Vegetable Crops

Plant:  Potato 
Disease/Disorder:  Gray Mold
Pathogen:  Botrytis sp.
County:  Waushara

Plant:  Potato 
Disease/Disorder:  White Mold
Pathogen:  Sclerotinia sclerotiorum
County:  Waushara

Plant:  Pumpkin
Disease/Disorder:  Bacterial Wilt
Pathogen:  Erwinia tracheiphila
County:  Kenosha

Plant:  Pumpkin
Disease/Disorder:  Fusarium Crown Rot
Pathogen:  Fusarium sp.
County:  Kenosha

Plant:  Pumpkin
Disease/Disorder:  Powdery Mildew
Pathogen:  Oidium sp.
County:  Dane

Plant:  Tomato
Disease/Disorder:  Septoria Leaf Spot
Pathogen:  Septoria lycopersici
County:  Vernon

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Specialty Crops

No New Diseases

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Miscellaneous

No New Entries

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