Compiled by Brian Hudelson and Hulubanche Kassa

The following diseases/disorders were identified at the Plant Disease Diagnostics Clinic from July 25, 2026 through July 31, 2026.

 

 

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Broad-Leafed Woody Ornamentals

Plant:  Boxwood
Disease/Disorder:  Fusarium Canker
Pathogen:  Fusarium sp.
County:  Waukesha

Plant:  Boxwood
Disease/Disorder:  Volutella Canker
Pathogen:  Volutella sp.
County:  Waukesha

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

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

Plant:  Oak (Red)
Disease/Disorder:  Chlorosis
Pathogen:  None
County:  Waukesha

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

Plant:  Oak (White)
Disease/Disorder:  Anthracnose
Pathogen:  Discula sp.
County:  Walworth

Plant:  Oak (White)
Disease/Disorder:  Tubakia Leaf spot
Pathogen:  Tubakia dryina
County:  Walworth

Plant:  Oak (Unspecified)
Disease/Disorder:  Oak Wilt
Pathogen:  Bretziella fagacearum
Counties:  Oneida, Waukesha

Plant:  Spirea
Disease/Disorder:  Phomopsis Canker
Pathogen:  Phomopsis sp.
County:  Kenosha

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Field Crops

Plant:  Corn
Disease/Disorder:  Southern Rust
Pathogen:  Puccinia polysora
Counties:  Chippewa, Jackson, Trempealeau

Plant:  Soybean
Disease/Disorder:  Charcoal Rot
Pathogen:  Macrophomina phaseolina
County:  Fond du Lac

Plant:  Soybean
Disease/Disorder:  Fusarium Root Rot
Pathogen:  Fusarium sp.
County:  Fond du Lac

Plant:  Soybean
Disease/Disorder:  Phytophthora Root and Stem Rot
Pathogen:  Phytophthora sp.
Counties:  Calumet, Fond du Lac

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Forage Crops

No New Diseases

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Fruit Crops

Plant:  Cranberry
Disease/Disorder:  Upright Dieback
Pathogen:  Phomopsis vaccinii
County:  Price

Plant:  Strawberry
Disease/Disorder:  Root/Crown Rot
Pathogen:  Fusarium sp.
County:  Washington

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Herbaceous Ornamentals

Plant:  Daisy (Shasta)
Disease/Disorder:  Crown Gall
Pathogen:  Agrobacterium tumefaciens
County:  Ottawa (MI)

Plant:  Daisy (Shasta)
Disease/Disorder:  Leafy Gall
Pathogen:  Rhodococcus facians
County:  Ottawa (MI)

Plant:  Lisianthus
Disease/Disorder:  Alternaria spot/blight
Pathogen:  Alternaria sp.
County:  Dane

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Houseplants

No New Diseases

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Needled Woody Ornamentals

Plant:  Arborvitae
Disease/Disorder:  Root Rot
Pathogens:  Phytophthora sp., Pythium sp.
County:  Dane

Plant:  Pine (White)
Disease/Disorder:  White Pine Blister Rust
Pathogen:  Cronartium ribicola
County:  Washington

Plant:  Spruce (Norway)
Disease/Disorder:  Cytospora Canker
Pathogen:  Cytospora sp.
County:  Dane

Plant:  Yew
Disease/Disorder:  Phomopsis Canker
Pathogen:  Phomopsis sp.
County:  Milwaukee

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Vegetable Crops

Plant:  Onion
Disease/Disorder:  Heat Stress (Suspected)
Pathogen:  None
County:  Dodge

Plant:  Onion
Disease/Disorder:  Root Rot
Pathogen:  Pythium sp.
County:  Green Lake

Plant:  Potato
Disease/Disorder:  Early Blight
Pathogen:  Alternaria solani
County:  Dane

Plant:  Potato
Disease/Disorder:  Walnut Toxicity (Suspected)
Pathogen:  Suspected
County:  Dane

Plant:  Pumpkin
Disease/Disorder:  Charcoal Rot
Pathogen:  Macrophomina phaseolina
County:  Portage

Plant:  Pumpkin
Disease/Disorder:  Fusarium Crown and Root Rot
Pathogen:  Fusarium sp.
County:  Portage

Plant:  Pumpkin
Disease/Disorder:  Phytophthora Crown and Root Rot
Pathogen:  Phytophthora sp.
County:  Portage

Plant:  Tomato
Disease/Disorder:  Early Blight
Pathogen:  Alternaria solani
County:  Dane

Plant:  Tomato
Disease/Disorder:  Walnut Toxicity (Suspected)
Pathogen:  Suspected
County:  Dane

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Specialty Crops

No New Diseases

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Miscellaneous

No New Entries

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Compiled by Brian Hudelson and Hulubanche Kassa

The following diseases/disorders were identified at the Plant Disease Diagnostics Clinic from July 18, 2026 through July 24, 2026.

 

 

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Broad-Leafed Woody Ornamentals

Plant:  Aspen
Disease/Disorder:  Transplant Shock (Suspected)
Pathogen:  None
County:  Dane

Plant:  Bladdernut
Disease/Disorder:  Ramularia Leaf Spot
Pathogen:  Ramularia sp.
County:  Dane

Plant:  Lilac (Shrub)
Disease/Disorder:  Septoria Leaf Spot
Pathogen:  Septoria sp.
Counties:  Dane, La Crosse

Plant:  Maple (Sugar)
Disease/Disorder:  Massaria Canker
Pathogen:  Massaria sp.
County:  Dane

Plant:  Maple (Sugar)
Disease/Disorder:  Steganosporium Canker
Pathogen:  Steganosporium sp.
County:  Waukesha

Plant:  Maple (Sugar)
Disease/Disorder:  Verticillium Wilt
Pathogen:  Verticillium sp.
County:  Dane

Plant:  Maple (Unspecified)
Disease/Disorder:  Heat Stress/Sunburn
Pathogen:  None
County:  Manitowoc

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

Plant:  Oak (Red)
Disease/Disorder:  Chlorosis
Pathogen:  None
County:  Waukesha

Plant:  Oak (Red)
Disease/Disorder:  Herbicide Damage
Pathogen:  None
County:  Dane

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

Plant:  Oak (Unspecified)
Disease/Disorder:  Chlorosis
Pathogen:  None
County:  Kewaunee

Plant:  Oak (Unspecified)
Disease/Disorder:  Oak Wilt
Pathogen:  Bretziella fagacearum
Counties:  Dane, Marathon

Plant:  Pear (Ornamental)
Disease/Disorder:  Pear Scab
Pathogen:  Venturia pirina
County:  Lincoln

Plant:  Redbud
Disease/Disorder:  Heat Stress/Sunburn
Pathogen:  None
County:  Dane

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Field Crops

Plant:  Soybean
Disease/Disorder:  Phytophthora Root and Stem Rot
Pathogen:  Phytophthora sp.
County:  Outagamie

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Forage Crops

No New Diseases

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Fruit Crops

Plant:  Apple
Disease/Disorder:  Apple Scab
Pathogen:  Venturia inaequalis
County:  La Crosse

Plant:  Apple
Disease/Disorder:  Bitter Rot
Pathogen:  Colletotrichum sp.
County:  La Crosse

Plant:  Apple
Disease/Disorder:  Cedar-Apple Rust
Pathogen:  Gymnosporangium juniperi-virginianae
County:  La Crosse

Plant:  Apple
Disease/Disorder:  Frogeye Leaf Spot
Pathogen:  Botryosphaeria obtusa
County:  La Crosse

Plant:  Pear
Disease/Disorder:  Pear Scab
Pathogen:  Venturia pirina
County:  La Crosse

Plant:  Strawberry
Disease/Disorder:  Anthracnose Fruit Rot
Pathogen:  Colletotrichum sp.
County:  Clark

Plant:  Strawberry
Disease/Disorder:  Common Leaf Spot
Pathogen:  Mycosphaerella fragariae
County:  Marathon

Plant:  Strawberry
Disease/Disorder:  Root Rot
Pathogens:  Phytophthora sp., Pythium sp., Rhizoctonia sp., Fusarium sp.
Counties:  Clark, Marathon

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Herbaceous Ornamentals

Plant:  Aralia
Disease/Disorder:  Crown Gall
Pathogen:  Agrobacterium tumefaciens
County:  Ottawa (MI)

Plant:  Hosta
Disease/Disorder:  Tobacco Rattle
Pathogen:  Tobacco rattle virus
County:  Pepin

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Houseplants

No New Diseases

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Needled Woody Ornamentals

Plant:  Juniper (Chinese)
Disease/Disorder:  Cytospora Canker
Pathogen:  Cytospora sp.
County:  Dane

Plant:  Pine (Bosnian)
Disease/Disorder:  Diplodia Shoot Blight and Canker
Pathogen:  Diplodia sp.
County:  Kenosha

Plant:  Pine (White)
Disease/Disorder:  Cytospora Canker
Pathogen:  Cytospora sp.
County:  Dane

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Vegetable Crops

Plant:  Bean (Snap)
Disease/Disorder:  Root Rot
Pathogen:  Pythium sp.
County:  Waushara

Plant:  Onion
Disease/Disorder:  Stemphylium Leaf Blight
Pathogen:  Stemphyllium sp.
County:  Columbia

Plant:  Tomato
Disease/Disorder:  Bacterial Canker
Pathogen:  Clavibacter michiganensis subsp. michiganensis
Counties:  Milwaukee, Rock

Plant:  Tomato
Disease/Disorder:  Early Blight
Pathogen:  Alternaria solani
County:  Waukesha

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Specialty Crops

No New Diseases

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Miscellaneous

No New Entries

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Compiled by Brian Hudelson and Hulubanche Kassa

The following diseases/disorders were identified at the Plant Disease Diagnostics Clinic from July 11, 2026 through July 17, 2026.

 

 

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Broad-Leafed Woody Ornamentals

Plant:  Azalea
Disease/Disorder:  Pestalotiopsis Leaf Spot
Pathogen:  Pestalotiopsis sp.
County:  Dane

Plant:  Elm (Unspecified)
Disease/Disorder:  Dutch Elm Disease
Pathogen:  Ophiostoma sp.
County:  Racine

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

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

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

Plant:  Oak (Unspecified)
Disease/Disorder:  Phomopsis Gall
Pathogen:  Phomopsis sp.
County:  Sawyer

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

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Field Crops

Plant:  Corn
Disease/Disorder:  Northern Corn Leaf Blight
Pathogen:  Exserohilum turcicum
County:  Dane

Plant:  Soybean
Disease/Disorder:  Phytophthora Root and Stem Rot
Pathogen:  Phytophthora sp.
County:  Waushara

Plant:  Soybean
Disease/Disorder:  Rhizoctonia Root Rot
Pathogen:  Rhizoctonia sp.
County:  Waushara

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Forage Crops

Plant:  Italian Ryegrass
Disease/Disorder:  Alternaria Leaf Spot
Pathogen:  Alternaria sp.
County:  Dane

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Fruit Crops

Plant:  Grape
Disease/Disorder:  Phomopsis Cane and Leaf Spot/Phomopsis Canker
Pathogen:  Phomopsis sp.
County:  Jefferson

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Herbaceous Ornamentals

No New Diseases

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Houseplants

No New Diseases

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Needled Woody Ornamentals

Plant:  Arborvitae
Disease/Disorder:  Phyllosticta Needle Blight
Pathogen:  Phyllosticta sp.
County:  Milwaukee

Plant:  Pine (Limber)
Disease/Disorder:  White Pine Blister Rust
Pathogen:  Cronartium ribicola
County:  Dane

Plant:  Pine (White)
Disease/Disorder:  Schweinitzii Root and Butt Rot
Pathogen:  Phaeolus schweinitzii
County:  Dane

Plant:  Spruce (Blue)
Disease/Disorder:  Rhizosphaera Needle Cast
Pathogen:  Rhizosphaera kalkhoffii
County:  Walworth

Plant:  Spruce (Unspecified)
Disease/Disorder:  Lirula Needle Blight
Pathogen:  Lirula sp.
County:  Eau Claire

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Vegetable Crops

Plant:  Cabbage (Napa)
Disease/Disorder:  Black Rot
Pathogen:  Xanthomonas campestris pv. campestris
County:  Waushara

Plant:  Cucumber
Disease/Disorder:  Anthracnose
Pathogen:  Colletotrichum orbiculare
County:  Winnebago (IL)

Plant:  Onion
Disease/Disorder:  Leaf Spot
Pathogen:  Colletotrichum gloeosporioides
County:  Waushara

Plant:  Tomato
Disease/Disorder:  Septoria Leaf Spot (Suspected)
Pathogen:  Septoria lycopersici
County:  Brown

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Specialty Crops

No New Diseases

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Miscellaneous

No New Entries

(Back To Menu)

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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.

 

 

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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

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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

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Forage Crops

No New Diseases

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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

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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

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Houseplants

No New Diseases

(Back To Menu)

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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

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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

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Specialty Crops

No New Diseases

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Miscellaneous

No New Entries

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