Compiled by Brian Hudelson and Hulubanche Kassa
The following diseases/disorders were identified at the Plant Disease Diagnostics Clinic from June 13, 2026 through June 19, 2026.
Broad-Leafed Woody Ornamentals
Plant: Beech (European)
Disease/Disorder: Botryosphaeria Canker
Pathogen: Botryosphaeria sp.
County: Waukesha
Plant: Beech (European)
Disease/Disorder: Phytophthora Canker
Pathogen: Phytophthora sp.
County: Waukesha
Plant: Forsythia
Disease/Disorder: Cold Injury
Pathogen: None
County: Crawford
Plant: Ginkgo
Disease/Disorder: Herbicide Damage
Pathogen: None
County: Calumet
Plant: Lilac (Japanese Tree)
Disease/Disorder: Anthracnose
Pathogen: Colletotrichum gloeosporioides
County: Milwaukee
Plant: Lilac (Japanese Tree)
Disease/Disorder: Verticillium Wilt
Pathogen: Verticillium sp.
County: Waukesha
Plant: Lilac (Shrub)
Disease/Disorder: Bacterial Blight
Pathogen: Pseudomonas syringae pv. syringae
County: Crawford
Plant: Lilac (Shrub)
Disease/Disorder: Cold Injury
Pathogen: None
County: Crawford
Plant: Maple (Norwegian Sunset)
Disease/Disorder: Verticillium Wilt
Pathogen: Verticillium sp.
County: Sheboygan
Plant: Maple (Red)
Disease/Disorder: Anthracnose
Pathogen: Discula sp.
County: Dane
Plant: Maple (Silver)
Disease/Disorder: Alternaria Leaf Spot
Pathogen: Alternaria sp.
County: Milwaukee
Plant: Maple (Silver)
Disease/Disorder: Anthracnose
Pathogen: Discula sp.
County: Milwaukee
Plant: Oak (Regal Prince)
Disease/Disorder: Herbicide Damage (Suspected)
Pathogen: None
County: Dane
Plant: Willow (Pussy)
Disease/Disorder: Anthracnose
Pathogen: Colletotrichum sp.
County: Crawford
Plant: Willow (Pussy)
Disease/Disorder: Monochaetia Leaf Spot
Pathogen: Monochaetia sp.
County: Crawford
Field Crops
No New Diseases
Forage Crops
No New Diseases
Fruit Crops
Plant: Apple
Disease/Disorder: Fire Blight
Pathogen: Erwinia amylovora
County: Waupaca
Plant: Raspberry
Disease/Disorder: Cane Blight
Pathogen: Leptosphaeria (Paraconiothyrium) coniothyrium
County: Dane
Herbaceous Ornamentals
Plant: Geranium (Wild)
Disease/Disorder: Bacterial Blight
Pathogen: Xanthomonas sp.
County: Green
Houseplants
No New Diseases
Needled Woody Ornamentals
Plant: Arborvitae
Disease/Disorder: Phomopsis Canker
Pathogen: Phomopsis sp.
County: Dodge
Plant: Arborvitae
Disease/Disorder: Phyllosticta Needle Blight
Pathogen: Phyllosticta sp.
County: Dodge
Plant: Spruce (Norway)
Disease/Disorder: Fertility Issues (Suspected)
Pathogen: None
County: Ozaukee
Plant: Spruce (Norway)
Disease/Disorder: Phomopsis Canker
Pathogen: Phomopsis sp.
County: Ozaukee
Plant: Spruce (Unspecified)
Disease/Disorder: Rhizosphaera Needle Cast
Pathogen: Rhizosphaera kalkhoffii
County: Dane
Plant: Spruce (Unspecified)
Disease/Disorder: Rhizosphaera Needle Cast (Suspected)
Pathogen: Rhizosphaera kalkhoffii
County: Dane
Plant: Spruce (Unspecified)
Disease/Disorder: Winter Burn (Suspected)
Pathogen: None
County: Dane
Vegetable Crops
Plant: Tomato
Disease/Disorder: Tomato Spotted Wilt
Pathogen: Tomato spotted wilt virus
County: Wood
Specialty Crops
No New Diseases
Miscellaneous
No New Entries