Compiled by Brian Hudelson and Hulubanche Kassa
The following diseases/disorders were identified at the Plant Disease Diagnostics Clinic from October 17, 2026 through October 23, 2026.
Broad-Leafed Woody Ornamentals
Plant: Bittersweet (American)
Disease/Disorder: Root Rot
Pathogens: Pythium sp., Thielaviopsis sp., Fusarium sp.
County: Rock
Plant: Maple (Sugar)
Disease/Disorder: Steganosporium Canker
Pathogen: Steganosporium sp.
County: Waukesha
Plant: Oak (Bur)
Disease/Disorder: Bur Oak Blight
Pathogen: Tubakia iowensis
County: Kenosha
Plant: Oak (Unspecified)
Disease/Disorder: Herbicide Damage
Pathogen: None
County: Rock
Field Crops
No New Diseases
Forage Crops
No New Diseases
Fruit Crops
Plant: Apple
Disease/Disorder: Bitter Rot
Pathogen: Colletotrichum sp.
County: Jefferson
Plant: Apple
Disease/Disorder: Phomopsis Canker
Pathogen: Phomopsis sp.
County: Milwaukee
Herbaceous Ornamentals
Plant: Butterfly Weed
Disease/Disorder: Root Rot
Pathogens: Rhizoctonia sp., Fusarium sp.
County: Rock
Houseplants
No New Diseases
Needled Woody Ornamentals
Plant: Spruce (Blue)
Disease/Disorder: Rhizosphaera Needle Cast
Pathogen: Rhizosphaera kalkhoffii
County: Door
Vegetable Crops
Plant: Potato
Disease/Disorder: Bacterial Soft Rot
Pathogen: Pectobacterium atrosepticum, Pectobacterium carotovorum subsp. carotovorum
County: Waushara
Plant: Potato
Disease/Disorder: Black Dot
Pathogen: Colletotrichum coccodes
County: Adams
Plant: Potato
Disease/Disorder: Black Scurf
Pathogen: Rhizoctonia sp.
County: Adams
Plant: Potato
Disease/Disorder: Leak
Pathogen: Pythium sp.
County: Adams, Waushara
Specialty Crops
No New Diseases
Miscellaneous
No New Entries