All posts by hudelson

Wisconsin Disease Almanac – May 30, 2025

May 31, 2025 hudelson

Compiled by Brian Hudelson and Dante Tauscheck

The following diseases/disorders were identified at the Plant Disease Diagnostics Clinic from May 24, 2025 through May 30, 2025.

Page Table of Contents

Click the links below to jump to the document section.

Broad-Leafed Woody Ornamentals
Field Crops
Forage Crops
Fruit Crops
Herbaceous Ornamentals
Houseplants
Needled Woody Ornamentals
Vegetable Crops
Specialty Crops
Miscellaneous

Broad-Leafed Woody Ornamentals

Plant: Aspen
Disease/Disorder: Venturia Leaf and Shoot Blight
Pathogen: Venturia moreletii
County: La Crosse

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

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

Plant: Oak (Unspecified)
Disease/Disorder: Armillaria Root Disease (Suspected)
Pathogen: Armillaria sp.
County: Dane

Plant: Pear (Callery)
Disease/Disorder: Cold Injury (Suspected)
Pathogen: None
County: Waukesha

Plant: Rhododendron
Disease/Disorder: Root Rot
Pathogen: Pythium sp.
County: Washington

Plant: Rhododendron
Disease/Disorder: Seimatosporium Leaf Spot
Pathogen: Seimatosporium sp.
County: Washington

(Back To Menu)

Field Crops

No New Diseases

(Back To Menu)

Forage Crops

No New Diseases

(Back To Menu)

Fruit Crops

Plant: Gooseberry
Disease/Disorder: Gooseberry Rust
Pathogen: Puccinia caracina var. pringsheimiana
County: Dane

Plant: Peach
Disease/Disorder: Peach Leaf Curl
Pathogen: Taphrina deformans
County: Dane

(Back To Menu)

Herbaceous Ornamentals

Plant: Pachysandra
Disease/Disorder: Volutella Blight
Pathogen: Volutella pachysandricola
Counties: Milwaukee, Waukesha

Plant: Pansy
Disease/Disorder: Root Rot
Pathogens: Phytophthora sp., Rhizoctonia sp.
County: Kenosha

Plant: Peony
Disease/Disorder: Cold Injury
Pathogen: None
County: Vernon

(Back To Menu)

Houseplants

No New Diseases

(Back To Menu)

Needled Woody Ornamentals

Plant: Arborvitae
Disease/Disorder: Transplant Shock (Suspected)
Pathogen: None
County: Waukesha

Plant: Arborvitae
Disease/Disorder: Urine Damage (Suspected)
Pathogen: None
County: Waukesha

Plant: Fir (Unspecified)
Disease/Disorder: Phyllosticta Needle Blight
Pathogen: Phyllosticta sp.
County: Waukesha

Plant: Spruce (Unspecified)
Disease/Disorder: Rhizosphaera Needle Cast
Pathogen: Rhizosphaera kalkhoffii
County: Clark

Plant: Spruce (Unspecified)
Disease/Disorder: Rhizosphaera Needle Cast (Suspected)
Pathogen: Rhizosphaera kalkhoffii
County: Saratoga (NY)

(Back To Menu)

Vegetable Crops

No New Diseases

(Back To Menu)

Specialty Crops

No New Diseases

(Back To Menu)

Miscellaneous

Mushroom ID: Glistening Inky Cap (Coprinellus micaceus)
County: Dane

(Back To Menu)

WI Disease Almanac

Wisconsin Disease Almanac – May 23, 2025

May 24, 2025 hudelson

Compiled by Brian Hudelson and Dante Tauscheck

The following diseases/disorders were identified at the Plant Disease Diagnostics Clinic from May 17, 2025 through May 23, 2025.

Page Table of Contents

Click the links below to jump to the document section.

Broad-Leafed Woody Ornamentals
Field Crops
Forage Crops
Fruit Crops
Herbaceous Ornamentals
Houseplants
Needled Woody Ornamentals
Vegetable Crops
Specialty Crops
Miscellaneous

Broad-Leafed Woody Ornamentals

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

Plant: Crabapple
Disease/Disorder: Lichens
Pathogen: None
County: Florence

Plant: Crabapple
Disease/Disorder: Phomopsis Canker
Pathogen: Phomopsis sp.
County: Dane

Plant: Crabapple
Disease/Disorder: Sapsucker Damage
Pathogen: None
County: Florence

Plant: Crabapple
Disease/Disorder: Sphaeropsis Canker
Pathogen: Sphaeropsis sp.
County: Dane

Plant: Lilac
Disease/Disorder: Ascochyta Leaf Blight
Pathogen: Ascochyta sp.
County: Walworth

(Back To Menu)

Field Crops

No New Diseases

(Back To Menu)

Forage Crops

No New Diseases

(Back To Menu)

Fruit Crops

Plant: Apple
Disease/Disorder: Sooty Mold
Pathogen: Miscellaneous sooty mold fungi
County: Iowa

Plant: Plum
Disease/Disorder: Black Knot
Pathogen: Apiosporina morbosa
County: Jefferson

(Back To Menu)

Herbaceous Ornamentals

Plant: Pachysandra
Disease/Disorder: Volutella Blight
Pathogen: Volutella pachysandricola
Counties: Columbia, Waukesha

(Back To Menu)

Houseplants

No New Diseases

(Back To Menu)

Needled Woody Ornamentals

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

Plant: Fir (White)
Disease/Disorder: Phomopsis Canker
Pathogen: Phomopsis sp.
County: Dane

Plant: Juniper
Disease/Disorder: Phomopsis Tip Blight
Pathogen: Phomopsis juniperovora
County: Milwaukee

Plant: Juniper
Disease/Disorder: Winter Burn (Suspected)
Pathogen: None
County: Waukesha

Plant: Spruce (Norway)
Disease/Disorder: Winter Burn (Suspected)
Pathogen: None
Counties: Milwaukee, Washington

Plant: Spruce (Unspecified)
Disease/Disorder: Rhizosphaera Needle Cast
Pathogen: Rhizosphaera kalkhoffii
County: Dane

(Back To Menu)

Vegetable Crops

Plant: Cabbage
Disease/Disorder: Damping-Off
Pathogen: Pythium sp.
County: Waushara

Plant: Cantaloupe
Disease/Disorder: Damping-Off
Pathogen: Pythium sp.
County: Monroe

Plant: Pea
Disease/Disorder: Root Rot
Pathogen: Pythium sp.
County: Waushara

(Back To Menu)

Specialty Crops

No New Diseases

(Back To Menu)

Miscellaneous

No New Reports

(Back To Menu)

WI Disease Almanac

Wisconsin Disease Almanac – May 16, 2025

May 17, 2025 hudelson

Compiled by Brian Hudelson and Dante Tauscheck

The following diseases/disorders were identified at the Plant Disease Diagnostics Clinic from May 10, 2025 through May 16, 2025.

Page Table of Contents

Click the links below to jump to the document section.

Broad-Leafed Woody Ornamentals
Field Crops
Forage Crops
Fruit Crops
Herbaceous Ornamentals
Houseplants
Needled Woody Ornamentals
Vegetable Crops
Specialty Crops
Miscellaneous

Broad-Leafed Woody Ornamentals

Plant: Hickory
Disease/Disorder: Phomopsis Gall
Pathogen: Phomopsis sp.
County: Door

Plant: Oak (Unspecified)
Disease/Disorder: Armillaria Root Disease
Pathogen: Armillaria sp.
County: Walworth

Plant: Trees and shrubs (Miscellaneous)
Disease/Disorder: Herbicide Damage
Pathogen: None
County: Dane

(Back To Menu)

Field Crops

No New Diseases

(Back To Menu)

Forage Crops

No New Diseases

(Back To Menu)

Fruit Crops

Plant: Apple
Disease/Disorder: Phomopsis Canker
Pathogen: Phomopsis sp.
County: St. Croix

Plant: Apple
Disease/Disorder: Transplant Shock (Suspected)
Pathogen: None
County: St. Croix

Plant: Apple
Disease/Disorder: Winter Injury (Suspected)
Pathogen: None
County: St. Croix

Plant: Raspberry
Disease/Disorder: Root Rot
Pathogen: Phytophthora sp.
County: Milwaukee

(Back To Menu)

Herbaceous Ornamentals

Plant: Bergenia
Disease/Disorder: Transplant Shock (Suspected)
Pathogen: None
County: Waukesha

Plant: Bergenia
Disease/Disorder: Winter Injury (Suspected)
Pathogen: None
County: Waukesha

Plant: Herbaceous Ornamentals (Miscellaneous)
Disease/Disorder: Herbicide Damage
Pathogen: None
County: Dane

Plant: Monarda
Disease/Disorder: Gray Mold (Botrytis Blight)
Pathogen: Botrytis sp.
County: Green

Plant: Monarda
Disease/Disorder: Winter Injury (Suspected)
Pathogen: None
County: Green

Plant: Pachysandra
Disease/Disorder: Volutella Blight
Pathogen: Volutella pachysandricola
Counties: Milwaukee, Waukesha

Plant: Pachysandra
Disease/Disorder: Winter Injury (Suspected)
Pathogen: None
County: Milwaukee

(Back To Menu)

Houseplants

No New Diseases

(Back To Menu)

Needled Woody Ornamentals

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

Plant: Arborvitae
Disease/Disorder: Root Rot
Pathogen: Phytophthora sp.
County: Dane

Plant: Arborvitae
Disease/Disorder: Transplant Shock (Suspected)
Pathogen: None
County: Grant

Plant: Arborvitae
Disease/Disorder: Water Stress (Suspected)
Pathogen: None
County: Dane

Plant: Arborvitae
Disease/Disorder: Winter Burn (Suspected)
Pathogen: None
County: Grant

Plant: Juniper
Disease/Disorder: Winter Burn (Suspected)
Pathogen: None
Counties: Milwaukee, Sheboygan

Plant: Pine (Japanese White)
Disease/Disorder: Cyclaneusma Needle Blight
Pathogen: Cyclaneusma minus
County: Dane

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

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

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

Plant: Spruce (White)
Disease/Disorder: Fertility Issues (Suspected)
Pathogen: None
County: Dane

Plant: Spruce (White)
Disease/Disorder: Winter Burn (Suspected)
Pathogen: None
County: Dane

Plant: Trees and shrubs (Miscellaneous)
Disease/Disorder: Herbicide Damage
Pathogen: None
County: Dane

Plant: Yew
Disease/Disorder: Twig Blight
Pathogen: Sphaeropsis sp.
County: Dane

(Back To Menu)

Vegetable Crops

No New Diseases

(Back To Menu)

Specialty Crops

No New Diseases

(Back To Menu)

Miscellaneous

No New Reports

(Back To Menu)

WI Disease Almanac

Wisconsin Disease Almanac – May 9, 2025

May 10, 2025 hudelson

Compiled by Brian Hudelson and Dante Tauscheck

The following diseases/disorders were identified at the Plant Disease Diagnostics Clinic from May 3, 2025 through May 9, 2025.

Page Table of Contents

Click the links below to jump to the document section.

Broad-Leafed Woody Ornamentals
Field Crops
Forage Crops
Fruit Crops
Herbaceous Ornamentals
Houseplants
Needled Woody Ornamentals
Vegetable Crops
Specialty Crops
Miscellaneous

Broad-Leafed Woody Ornamentals

Plant: Crabapple
Disease/Disorder: Lichens
Pathogen: None
County: Dane

Plant: Oak (Unspecified)
Disease/Disorder: Armillaria Root Disease
Pathogen: Armillaria sp.
County: Waukesha

Plant: Oak (Unspecified)
Disease/Disorder: White Rot
Pathogen: Trichaptum biforme
County: Waukesha

(Back To Menu)

Field Crops

No New Diseases

(Back To Menu)

Forage Crops

No New Diseases

(Back To Menu)

Fruit Crops

Plant: Apple
Disease/Disorder: Frost Crack
Pathogen: None
County: Sauk

Plant: Apple
Disease/Disorder: Sap Rot
Pathogen: Schizophyllum commune
County: Sauk

Plant: Nectarine
Disease/Disorder: Peach Leaf Curl
Pathogen: Taphrina deformans
County: Nassau (NY)

(Back To Menu)

Herbaceous Ornamentals

Plant: Geranium
Disease/Disorder: Iron/Manganese Toxicity (Suspected)
Pathogen: None
County: Dane

Plant: Lobelia
Disease/Disorder: Heat Stress (Suspected)
Pathogen: None
County: Jefferson

Plant: Pachysandra
Disease/Disorder: Volutella Blight
Pathogen: Volutella pachysandricola
Counties: Milwaukee, Waukesha

Plant: Pachysandra
Disease/Disorder: Winter Injury (Suspected)
Pathogen: None
Counties: Milwaukee, Waukesha

Plant: Phlox (Garden)
Disease/Disorder: Phytoplasma Disease
Pathogen: Unspecified Phytoplasma
County: Green

Plant: Phlox (Garden)
Disease/Disorder: Root Rot
Pathogen: Pythium sp.
County: Green

(Back To Menu)

Houseplants

No New Diseases

(Back To Menu)

Needled Woody Ornamentals

Plant: Arborvitae
Disease/Disorder: Cytospora Canker
Pathogen: Cytospora sp.
County: Milwaukee

Plant: Arborvitae
Disease/Disorder: Root Rot
Pathogen: Phytophthora sp.
County: Waukesha

Plant: Hemlock (Eastern)
Disease/Disorder: Root Rot
Pathogen: Phytophthora sp.
County: Dane

Plant: Juniper
Disease/Disorder: Winter Burn (Suspected)
Pathogen: None
County: Milwaukee

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

Plant: Spruce (Norway)
Disease/Disorder: Rhizosphaera Needle Cast
Pathogen: Rhizosphaera kalkhoffii
County: Waukesha

Plant: Spruce (Unspecified)
Disease/Disorder: Spruce Needle Drop
Pathogen: Setomelanomma holmii
County: Waukesha

Plant: Spruce (Unspecified)
Disease/Disorder: Transplant Shock
Pathogen: None
County: Dane

Plant: Spruce (Unspecified)
Disease/Disorder: Water Stress
Pathogen: None
County: Waukesha

(Back To Menu)

Vegetable Crops

No New Diseases

(Back To Menu)

Specialty Crops

No New Diseases

(Back To Menu)

Miscellaneous

No New Reports

(Back To Menu)

WI Disease Almanac

Wisconsin Disease Almanac – May 2, 2025

May 3, 2025 hudelson

Compiled by Brian Hudelson and Dante Tauscheck

The following diseases/disorders were identified at the Plant Disease Diagnostics Clinic from April 26, 2025 through May 2, 2025.

Page Table of Contents

Click the links below to jump to the document section.

Broad-Leafed Woody Ornamentals
Field Crops
Forage Crops
Fruit Crops
Herbaceous Ornamentals
Houseplants
Needled Woody Ornamentals
Vegetable Crops
Specialty Crops
Miscellaneous

Broad-Leafed Woody Ornamentals

No New Diseases

(Back To Menu)

Field Crops

No New Diseases

(Back To Menu)

Forage Crops

No New Diseases

(Back To Menu)

Fruit Crops

No New Diseases

(Back To Menu)

Herbaceous Ornamentals

Plant: Vinca
Disease/Disorder: Winter Burn (Suspected)
Pathogen: None
County: Dane

(Back To Menu)

Houseplants

No New Diseases

(Back To Menu)

Needled Woody Ornamentals

Plant: Juniper
Disease/Disorder: Cedar-Quince Rust (Suspected)
Pathogen: Gymnosporangium clavipes
County: Ozaukee

Plant: Pine (Red)
Disease/Disorder: Brown Spot (Suspected)
Pathogen: Lecanosticta acicola
County: Waukesha

Plant: Pine (Red)
Disease/Disorder: Ozone Damage (Suspected)
Pathogen: None
County: Waukesha

Plant: Spruce (Norway)
Disease/Disorder: Spruce Needle Drop
Pathogen: Setomelanomma holmii
County: Jefferson

(Back To Menu)

Vegetable Crops

Plant: Garlic
Disease/Disorder: Aerial Blight
Pathogen: Rhizoctonia sp.
County: Richland

Plant: Garlic
Disease/Disorder: Root Rot
Pathogen: Pythium sp.
County: Richland

Plant: Tomato
Disease/Disorder: Edema
Pathogen: None
County: Taylor

Plant: Tomato
Disease/Disorder: Ethylene Damage (Suspected)
Pathogen: None
County: Taylor

(Back To Menu)

Specialty Crops

No New Diseases

(Back To Menu)

Miscellaneous

No New Reports

(Back To Menu)

Monthly Column

April 2025: The Root of the Problem

April 28, 2025 hudelson

As I commented in my March 2025 web article, the 2024 growing season was incredibly wet, and as a consequence, I observed an uptick in foliar diseases such as apple scab and Septoria leaf spot of lilac. But, it wasn’t only leaves that had problems due to the wet weather. A lot of last year’s rain ended up in the soil, and the resulting wet soil conditions contributed to an increase in root rots and related diseases.

Rot roots

Root rots are caused by a wide variety of organisms including (but not limited to) Rhizoctonia, Pythium, and Phytophthora,. Rhizoctonia is a true fungus, while Pythium and Phytophthora fall into a group of fungi-like organisms called the water molds. Water mold root rot pathogens tend to be particularly aggressive and also tend to be long-lived. They produce thick-walled resting spores (called oospores) that can survive for years, if not decades, in the soil. Under hotter, drier conditions, these spores germinate to form hyphae (i.e., fungal threads) that can directly infect plant roots. Under cooler, wetter conditions, oospores germinate in a different manner, eventually producing numerous smaller, swimming spores called zoospores. These spores swim to plant roots where they infect. Production of zoospores significantly increases a water mold’s ability to infect, leading to an increase in the number of infections and subsequent disease severity.

Browning of the lower trunk and roots of a tree typical of root and crown rot.

Root rot pathogen infections directly lead to root decay and deterioration. Roots are typically discolored (e.g., brown, black), as well as soft and mushy. This decay interferes with a plant’s ability to take up water and nutrients. Indirect effects due to root rots include leaf symptoms that might be misidentified as being due to poor fertility (e.g., yellowing or reddening), symptoms that might be mistaken for drought stress symptoms (e.g., marginal leaf browning), wilting and branch dieback, and, ultimately, plant death.

Once symptoms of root rots are observed, often there is little one can do to correct the problem. Root rots are best managed preemptively at the time that gardens and landscapes are established. Modifying soils to improve drainage (e.g., by adding organic matter), and choosing plants that are adapted to the soil moisture conditions at a particular site are two ways to prevent root rot issues. There are potentially fungicides that can be used for management of root rots. However, for these treatments to be effective, early diagnosis of the problem (i.e., before there is extensive root damage) is critical. Fungicides, for the most part, do not cure existing infections, but help protect new roots from being infected. Before applying fungicides, proper identification of the organism(s) involved in a root rot problem is extremely important; the fungicides needed to manage fungal vs. water mold root rot pathogens are quite different. Often, plants have problems with both fungal and water mold root rotters simultaneously, so use of multiple active ingredients is needed for control. Note that root rot fungicides typically are not readily available to homeowners, so contracting with a professional pesticide applicator to make treatments will likely be necessary. As you can imagine, using fungicides for root rot control can get very expensive, very quickly.

Related diseases

A variant of root rots that I encountered several times last summer and have already encountered in 2025, is bleeding cankers on trees (e.g., maple, beech, birch). Typical symptoms of bleeding cankers are a series of wet, oozy spots on tree trunks. Sometimes these areas are near the soil surface; other times, the oozing occurs farther up on the trunks. The most typical cause of bleeding cankers on common landscape shade trees is Phytophthora (which I mentioned above in the context of root rots). When people contact me about bleeding cankers, I request that they send me blobs of the ooze and/or small bits of the ooze-soaked bark (about the equivalent of a 2 inch by 2 inch bark piece). I test this material with a dipstick serological test for Phytophthora. This test uses similar technology to that used in home pregnancy tests and home COVID-19 tests.

Bleeding cankers caused by Phytophthora cactorum on a beech tree trunk. Photo courtesy of John Hartman, University of Kentucky, Bugwood.org.

The real fun begins if I get a positive reaction from my initial testing (and many of the samples I have received have tested positive). At that point, I have to forward the sample to the WI DATCP Plant Industry Lab for further testing. One of the species of Phytophthora that can cause bleeding cankers is Phytophthora ramorum. This organism causes sudden oak death/Ramorum blight and is highly regulated at both the state and federal level, because of how destructive it can be. I need to make sure that samples that test positive for Phytophthora are not infected with Phytophthora ramorum. Phytophthora ramorum has occasionally be detected by WI DATCP in nursery stock brought into Wisconsin from other states. However, Phytophthora ramorum has never been detected in Wisconsin in established landscapes plants. Luckily, none of the samples that I have submitted to WI DATCP has tested positive for Phytophthora ramorum. Typically, the Phytophthora species present in my samples has been Phytophthora cactorum, a common Phytophthora species that can cause root rots on a wide range of plant species.

Need help?

Hopefully, you will never have problems with root rots or bleeding cankers in your gardens and landscapes. If you do however, I encourage you to submit samples for a proper diagnosis. If you have questions about any plant disease that you are seeing or questions about sample submission, please feel free to contact me at (608) 262-2863 or pddc@wisc.edu. For additional information on plant diseases and their management, be sure to check out the UW-Madison PDDC website (https://pddc.wisc.edu/). To keep up to date on clinic activities and resources, follow the PDDC on Facebook, Twitter (X), or Bluesky (@UWPDDC), or subscribe to the clinic’s listserv, UWPDDCLearn (by emailing or phoning the clinic to subscribe).

Keep on gardening, and have a great spring and summer!

WI Disease Almanac

Wisconsin Disease Almanac – April 25, 2025

April 26, 2025 hudelson

Compiled by Brian Hudelson and Dante Tauscheck

The following diseases/disorders were identified at the Plant Disease Diagnostics Clinic from April 19, 2025 through April 25, 2025.

Page Table of Contents

Click the links below to jump to the document section.

Broad-Leafed Woody Ornamentals
Field Crops
Forage Crops
Fruit Crops
Herbaceous Ornamentals
Houseplants
Needled Woody Ornamentals
Vegetable Crops
Specialty Crops
Miscellaneous

Broad-Leafed Woody Ornamentals

No New Diseases

(Back To Menu)

Field Crops

No New Diseases

(Back To Menu)

Forage Crops

No New Diseases

(Back To Menu)

Fruit Crops

Plant: Blueberry
Disease/Disorder: Cold Injury (Suspected)
Pathogen: None
County: Vernon

Plant: Blueberry
Disease/Disorder: Lichens
Pathogen: None
County: Vernon

(Back To Menu)

Herbaceous Ornamentals

Plant: Astilbe
Disease/Disorder: Tobacco Rattle
Pathogen: Tobacco rattle virus
County: Jefferson

Plant: Pachysandra
Disease/Disorder: Volutella Blight
Pathogen: Volutella pachysandricola
County: Waukesha

Plant: Pachysandra
Disease/Disorder: Winter Burn
Pathogen: None
County: Waukesha

Plant: Tradescantia
Disease/Disorder: Tobacco Rattle
Pathogen: Tobacco rattle virus
County: Jefferson

(Back To Menu)

Houseplants

Plant: Hibiscus
Disease/Disorder: Fertility Issues (Suspected)
Pathogen: None
County: Waukesha

(Back To Menu)

Needled Woody Ornamentals

Plant: Arborvitae
Disease/Disorder: Root Rot
Pathogen: Phytophthora sp.
County: Waukesha

Plant: Pine (Japanese White)
Disease/Disorder: Artillery fungus
Pathogen: None
County: Dane

Plant: Spruce (Norway)
Disease/Disorder: Hail Damage
Pathogen: None
County: Dane

Plant: Spruce (Norway)
Disease/Disorder: Spruce Needle Drop
Pathogen: Setomelanomma holmii
County: Racine

Plant: Spruce (Unspecified)
Disease/Disorder: Rhizosphaera Needle Cast
Pathogen: Rhizosphaera kalkhoffii
County: Waukesha

Plant: Spruce (Unspecified)
Disease/Disorder: Water Stress (Suspected)
Pathogen: None
County: Waukesha

(Back To Menu)

Vegetable Crops

No New Diseases

(Back To Menu)

Specialty Crops

No New Diseases

(Back To Menu)

Miscellaneous

No New Reports

(Back To Menu)

WI Disease Almanac

Wisconsin Disease Almanac – April 18, 2025

April 19, 2025 hudelson

Compiled by Brian Hudelson and Dante Tauscheck

The following diseases/disorders were identified at the Plant Disease Diagnostics Clinic from April 12, 2025 through April 18, 2025.

Page Table of Contents

Click the links below to jump to the document section.

Broad-Leafed Woody Ornamentals
Field Crops
Forage Crops
Fruit Crops
Herbaceous Ornamentals
Houseplants
Needled Woody Ornamentals
Vegetable Crops
Specialty Crops
Miscellaneous

Broad-Leafed Woody Ornamentals

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

Plant: Honey Locust
Disease/Disorder: White Rot
Pathogen: Ganoderma applanatum, Ganoderma sessile
County: Milwaukee

Plant: Oak (Bur)
Disease/Disorder: Bur Oak Blight
Pathogen: Tubakia iowensis
County: Dane

(Back To Menu)

Field Crops

No New Diseases

(Back To Menu)

Forage Crops

No New Diseases

(Back To Menu)

Fruit Crops

No New Diseases

(Back To Menu)

Herbaceous Ornamentals

Plant: Checkerbloom (Sidalcea)
Disease/Disorder: Potyvirus Disease
Pathogen: Unspecified potyvirus
County: Jefferson

(Back To Menu)

Houseplants

No New Diseases

(Back To Menu)

Needled Woody Ornamentals

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

(Back To Menu)

Vegetable Crops

Plant: Broccolini
Disease/Disorder: Root Rot
Pathogen: Pythium sp.
County: Waukesha

Plant: Broccolini
Disease/Disorder: Wire Stem
Pathogen: Rhizoctonia solani
County: Waukesha

Plant: Pepper
Disease/Disorder: Anthracnose
Pathogen: Colletotrichum sp.
County: Jefferson

Plant: Pepper
Disease/Disorder: Sunburn
Pathogen: None
County: Jefferson

Plant: Tomato
Disease/Disorder: Bacterial Speck (Suspected)
Pathogen: Pseudomonas syringae pv. tomato
County: Waukesha

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

(Back To Menu)

Specialty Crops

No New Diseases

(Back To Menu)

Miscellaneous

No New Reports

(Back To Menu)

WI Disease Almanac

Wisconsin Disease Almanac – April 11, 2025

April 12, 2025 hudelson

Compiled by Brian Hudelson and Dante Tauscheck

The following diseases/disorders were identified at the Plant Disease Diagnostics Clinic from April 5, 2025 through April 11, 2025.

Page Table of Contents

Click the links below to jump to the document section.

Broad-Leafed Woody Ornamentals
Field Crops
Forage Crops
Fruit Crops
Herbaceous Ornamentals
Houseplants
Needled Woody Ornamentals
Vegetable Crops
Specialty Crops
Miscellaneous

Broad-Leafed Woody Ornamentals

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

Plant: Crabapple
Disease/Disorder: Cedar-Apple Rust
Pathogen: Gymnosporangium juniperi-virginianae
County: Washington

Plant: Oak (Bur)
Disease/Disorder: Diplodia Canker
Pathogen: Diplodia sp.
County: Eau Claire

(Back To Menu)

Field Crops

No New Diseases

(Back To Menu)

Forage Crops

No New Diseases

(Back To Menu)

Fruit Crops

No New Diseases

(Back To Menu)

Herbaceous Ornamentals

Plant: Astilbe
Disease/Disorder: Tobacco Rattle
Pathogen: Tobacco rattle virus
County: Dane

Plant: Geranium
Disease/Disorder: Black Leg
Pathogen: Pythuim sp.
County: Winnebago

Plant: Geranium
Disease/Disorder: Cucumber Mosaic
Pathogen: Cucumber mosaic virus
County: Jefferson

Plant: Geranium
Disease/Disorder: Root Rot
Pathogen: Pythuim sp., Rhizoctonia sp.
County: Winnebago

Plant: Ranunculus
Disease/Disorder: Tobacco Rattle
Pathogen: Tobacco rattle virus
County: Jefferson

(Back To Menu)

Houseplants

No New Diseases

(Back To Menu)

Needled Woody Ornamentals

Plant: Spruce (Unspecified)
Disease/Disorder: Phomopsis Canker
Pathogen: Phomopsis sp.
County: Winnebago

Plant: Spruce (Unspecified)
Disease/Disorder: Rhizosphaera Needle Cast
Pathogen: Rhizosphaera kalkhoffii
County: Winnebago

(Back To Menu)

Vegetable Crops

Plant: Potato
Disease/Disorder: Bacterial Soft Rot
Pathogen: Pectobacterium carotovorum subsp. carotovorum, Pectobacterium parmentieri
County: Waushara

Plant: Potato
Disease/Disorder: Common scab
Pathogen: Streptomyces scabies
County: Waushara

(Back To Menu)

Specialty Crops

No New Diseases

(Back To Menu)

Miscellaneous

No New Reports

(Back To Menu)

WI Disease Almanac

Wisconsin Disease Almanac – January 1, 2025 through April 4, 2025

April 5, 2025 hudelson

Compiled by Brian Hudelson and Dante Tauscheck

The following diseases/disorders were identified at the Plant Disease Diagnostics Clinic from January 1, 2025 through April 4, 2025.

Page Table of Contents

Click the links below to jump to the document section.

Broad-Leafed Woody Ornamentals
Field Crops
Forage Crops
Fruit Crops
Herbaceous Ornamentals
Houseplants
Needled Woody Ornamentals
Vegetable Crops
Specialty Crops
Miscellaneous

Broad-Leafed Woody Ornamentals

Plant: Beech (European)
Disease/Disorder: Phytophthora Canker
Pathogen: Phytophthora cactorum
County: Milwaukee

Plant: Hornbeam
Disease/Disorder: Root/Crown Rot
Pathogens: Phytophthora sp.
County: Dane

Plant: Maple (Norway)
Disease/Disorder: White Rot (on dead wood)
Pathogen: Dryad’s saddle (Polymorphus squamosus)
County: Dane

Plant: Oak (Bur)
Disease/Disorder: Coryneum Canker
Pathogens: Coryneum sp.
County: Dane

Plant: Oak (Pin)
Disease/Disorder: Jelly Fungus (Unidentified)
Pathogens: None
County: Dane

Plant: Oak (Red)
Disease/Disorder: Brittle Cinder (Suspected)
Pathogen: Kretzschumaria deusta
County: Dane

Plant: Oak (White)
Disease/Disorder: Brittle Cinder (Suspected)
Pathogen: Kretzschmaria deusta
County: Dane

Plant: Oak (Unspecified)
Disease/Disorder: Armillaria Root Disease (Suspected)
Pathogen: Armillaria sp.
County: None (Republic of Singapore)

Plant: Serviceberry
Disease/Disorder: Lichens
Pathogen: None
County: Dane

Plant: Tree (Unspecified)
Disease/Disorder: Phomopsis Gall
Pathogen: Phomopsis sp.
County: Dane

(Back To Menu)

Field Crops

No New Diseases

(Back To Menu)

Forage Crops

No New Diseases

(Back To Menu)

Fruit Crops

Plant: Grape
Disease/Disorder: Phomopsis Cane and Shoot Spot
Pathogen: Phomopsis sp.
County: Sauk

(Back To Menu)

Herbaceous Ornamentals

Plant: Begonia
Disease/Disorder: Impatiens Necrotic Spot
Pathogen: Impatiens necrotic spot virus
County: Clark

Plant: Calibrachoa
Disease/Disorder: Powdery Mildew (Suspected)
Pathogen: Oidium sp.
County: Taylor

Plant: Coleus
Disease/Disorder: Aerial Pythium
Pathogen: Pythium sp.
County: Waushara

Plant: Coleus
Disease/Disorder: Downy Mildew
Pathogens: Peronospora lamii
Counties: Columbia, Dane

Plant: Geranium
Disease/Disorder: Gray Mold/Botrytis Blight
Pathogen: Botrytis cinerea
County: Clark

Plant: Geranium
Disease/Disorder: Root Rot
Pathogen: Pythium sp.
County: Clark

Plant: Gladiolus
Disease/Disorder: Leafy Gall
Pathogen: Rhodococcus faciens
County: Clark

Plant: Hosta
Disease/Disorder: Physical Abrasion (Suspected)
Pathogen: None
County: Jefferson

Plant: Pachysandra
Disease/Disorder: Volutella Blight
Pathogen: Volutella pachysandricola
County: Waukesha

Plant: Pachysandra
Disease/Disorder: Winter Burn
Pathogen: None
County: Waukesha

Plant: Pericallis
Disease/Disorder: Impatiens Necrotic Spot
Pathogens: Impatiens necrotic spot virus
County: Jefferson

(Back To Menu)

Houseplants

Plant: Fig (Weeping)
Disease/Disorder: Crown Gall (Suspected)
Pathogen: Agrobacterium tumefaciens
County: Dane

Plant: Money Tree
Disease/Disorder: Anthracnose
Pathogen: Colletotrichum sp.
County: Fond du Lac

(Back To Menu)

Needled Woody Ornamentals

Plant: Arborvitae
Disease/Disorder: Phomopsis Canker
Pathogen: Phomopsis sp.
County: Waukesha

Plant: Arborvitae
Disease/Disorder: Water Stress (Suspected)
Pathogen: None
County: Kenosha

Plant: Pine (Austrian)
Disease/Disorder: Diplodia Shoot Blight and Canker (Suspected)
Pathogen: Diplodia sp.
County: Racine

Plant: Pine (Austrian)
Disease/Disorder: Water Stress (Suspected)
Pathogen: None
County: Racine

Plant: Pine (Japanese Umbrella)
Disease/Disorder: Needle Spot
Pathogen: Colletotrichum sp.
County: Dane

Plant: Pine (Scots)
Disease/Disorder: Brown Spot
Pathogens: Lecanosticta acicola (Mycosphaerella dearnessii)
County: Clark

Plant: Spruce (Blue)
Disease/Disorder: Diplodia Shoot Blight and Canker
Pathogen: Diplodia sp.
County: Dane

Plant: Spruce (Blue)
Disease/Disorder: Phomopsis Canker
Pathogen: Phomopsis sp.
County: Dane

Plant: Spruce (Unspecified)
Disease/Disorder: Rhizosphaera Needle Cast
Pathogen: Rhizosphaera kalkhoffii
County: Dane

Plant: Spruce (Unspecified)
Disease/Disorder: Water Stress (Suspected)
Pathogen: None
Counties: Dane, Milwaukee

(Back To Menu)

Vegetable Crops

Plant: Cabbage
Disease/Disorder: Black Rot
Pathogen: Xanthomonas campestris pv. campestris
County: St. Johns (FL)

Plant: Cabbage
Disease/Disorder: Cucumber Mosaic
Pathogen: Cucumber mosaic virus
County: Flagler (FL)

Plant: Cabbage
Disease/Disorder: Impatiens Necrotic Spot
Pathogen: Impatiens necrotic spot virus
County: Flagler (FL)

Plant: Carrot
Disease/Disorder: Fusarium Dry Rot
Pathogen: Fusarium sp.
County: Dane

Plant: Collards
Disease/Disorder: Fertility Issues (suspected)
Pathogen: None
County: Dane

Plant: Kale
Disease/Disorder: Fertility Issues (suspected)
Pathogen: None
County: Dane

Plant: Potato
Disease/Disorder: Bacterial Soft Rot
Pathogens: Pectobacterium atrosepticum, Pectobacterium carotovorum subsp. carotovorum, Pectobacterium parmentieri
Counties: Portage, Waushara

Plant: Potato
Disease/Disorder: Corky Ringspot
Pathogens: Tobacco rattle virus
County: Portage

Plant: Potato
Disease/Disorder: Dry Rot
Pathogens: Fusarium sp.
Counties: Portage, Waushara

Plant: Potato
Disease/Disorder: Powdery Scab
Pathogen: Spongospora subterranea subsp. subterranea
County: Adams

Plant: Radish (Watermelon)
Disease/Disorder: Root Rot
Pathogens: Fusarium sp., Rhizoctonia sp.
County: Crawford

Plant: Radish (Watermelon)
Disease/Disorder: Root Spot
Pathogen: Xanthomonas sp.
County: Crawford

Plant: Rosemary
Disease/Disorder: Powdery Mildew (Suspected)
Pathogen: Oidium sp.
County: Fond du Lac

Plant: Tomato
Disease/Disorder: Edema
Pathogen: None
County: Rock

(Back To Menu)

Specialty Crops

No New Diseases

(Back To Menu)

Miscellaneous

No New Reports

(Back To Menu)