Compiled by Brian Hudelson and Hulubanche Kassa
The following diseases/disorders were identified at the Plant Disease Diagnostics Clinic from September 26, 2026 through October 2, 2026.
Broad-Leafed Woody Ornamentals
Plant: Beech (Unspecified)
Disease/Disorder: Phytophthora Canker
Pathogen: Phytophthora sp.
County: Ozaukee
Plant: Boxwood
Disease/Disorder: Fusarium Canker
Pathogen: Fusarium sp.
County: Washington
Plant: Boxwood
Disease/Disorder: Volutella Canker
Pathogen: Volutella sp.
County: Washington
Plant: Hydrangea
Disease/Disorder: Anthracnose
Pathogen: Colletotrichum sp.
County: Sheboygan
Plant: Hydrangea
Disease/Disorder: Septoria Leaf Spot
Pathogen: Septoria sp.
County: Sheboygan
Plant: Hydrangea
Disease/Disorder: Xanthomonas Leaf Blight
Pathogen: Xanthomonas sp.
County: Sheboygan
Plant: Lilac
Disease/Disorder: Septoria Leaf Spot
Pathogen: Septoria sp.
County: Waukesha
Plant: Magnolia
Disease/Disorder: Verticillium Wilt
Pathogen: Verticillium sp.
County: Dane
Plant: Maple (Norway)
Disease/Disorder: Verticillium Wilt
Pathogen: Verticillium sp.
County: Dane
Plant: Maple (Variegated)
Disease/Disorder: Anthracnose
Pathogens: Colletotrichum sp., Discula sp.
County: Waukesha
Plant: Oak (Black)
Disease/Disorder: Oak Wilt
Pathogen: Bretziella fagacearum
County: Eau Claire
Plant: Oak (Red)
Disease/Disorder: Herbicide Damage
Pathogen: None
County: Walworth
Plant: Oak (Red)
Disease/Disorder: Tubakia Leaf Spot
Pathogen: Tubakia sp.
County: Walworth
Field Crops
Plant: Soybean
Disease/Disorder: Stem Canker
Pathogen: Diaporthe phaseolorum
County: Chippewa
Forage Crops
No New Diseases
Fruit Crops
Plant: Apple
Disease/Disorder: Nectria Twig Blight
Pathogen: Tubercularia sp./Nectria sp.
County: Sawyer
Plant: Apple
Disease/Disorder: Phomopsis Canker
Pathogen: Phomopsis sp.
County: Sawyer
Plant: Apple
Disease/Disorder: Glomerella Leaf Spot
Pathogen: Colletotrichum sp.
County: Racine
Plant: Apple (‘Golden Delicious’)
Disease/Disorder: Necrotic Leaf Blotch
Pathogen: None
County: Racine
Herbaceous Ornamentals
Plant: Chrysanthemum
Disease/Disorder: Root/Crown Rot
Pathogen: Rhizoctonia sp.
County: Columbia
Plant: Hosta
Disease/Disorder: Hosta Virus X
Pathogen: Hosta virus X
County: Door
Houseplants
No New Diseases
Needled Woody Ornamentals
Plant: Spruce (Blue)
Disease/Disorder: Rhizosphaera Needle Cast
Pathogen: Rhizosphaera kalkhoffii
County: DuPage (IL)
Plant: Spruce (Unspecified)
Disease/Disorder: Phomopsis Canker
Pathogen: Phomopsis sp.
County: Trempealeau
Plant: Spruce (Unspecified)
Disease/Disorder: Rhizosphaera Needle Cast
Pathogen: Rhizosphaera kalkhoffii
County: Trempealeau
Vegetable Crops
No New Diseases
Specialty Crops
No New Diseases
Miscellaneous
No New Entries