UW Madison/ Extension Plant Disease Diagnostic Clinic (PDDC) Update

Brian Hudelson, Sean Toporek, Catherine Wendt, Claire Wisniewski, and Ann Joy

The PDDC receives samples of many plant and soil samples from around the state. The following diseases/disorders have been identified at the PDDC from August 15, 2015 through August 21, 2015.

Plant/Sample Type, Disease/Disorder, Pathogen, County

Field Crops
Corn, Anthracnose Stalk Rot, Colletotrichum graminicola, Columbia
Corn, Fusarium Stalk Rot, Fusarium sp., Lafayette
Corn, Goss’ Wilt, Clavibacter michiganensis subsp. nebraskensis, Columbia
Corn, Gray Leaf Spot, Cercospora sp., Dane
Corn, Northern Corn Leaf Blight, Exserohilum turcicum, Dane
Soybean, Root Rot, Pythium sp., Fusarium sp., Dane, Marquette, Monroe
Soybean, Stem Canker, Phomopsis sp., Dodge

Fruit Crops
Apple, Bitter Pit/Cork Spot, None, Polk
Apple, Russeting, None, Polk
Grape, Downy MildewPlasmopara viticola, Dane

Potato, Cercospora Leaf Blotch, Cercospora sp., Dane
Early BlightAlternaria solani, Dane
Potato, Late BlightPhytophthora infestans, La Crosse, Portage
Sweet Corn, Antracnose Stalk Rot, Colletotrichum graminicola, Rock
Sweet CornGibberella Stalk Rot, Fusarium graminearum, Rock
Tomato, Bacterial Speck, Pseudomonas syringae pv. tomato, Dunn
Tomato, Late BlightPhytophthora infestans, La Crosse, Marathon, Portage, Walworth, Wood
Tomato, Septoria Leaf SpotSeptoria lycopersici, Florence, La Crosse

Alfalfa Soil, Aphanomyces Seedling Blight, Aphanomyces euteiches race 2, Wood

For additional information on plant diseases and their control, visit the PDDC website at pddc.wisc.edu