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

Brian Hudelson, Ann Joy, Erin DeWinter and Joyce Wu, Plant Disease Diagnostics Clinic

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 July 13, 2013 through July 19, 2013.

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


Corn, Mosaic, Unidentified Virus, Sauk

Corn, Northern Corn Leaf Spot, Bipolaris zeicola, Dane

Corn, Root Rot,  Rhizoctonis solani, Pythium sp., Sauk

Corn, Yellow Leaf Blight, Phyllosticta maydis, Dane

Soybean, Fusarium Root Rot, Fusarium spp., Dubuque (IA)

Soybean, Herbicide Damage, None, Marinette

Soybean, Charcoal Rot, Macrophomina phaseolina, Dubuque (IA)


Alfalfa, Aphanomyces Root Rot, Aphanomyces euteiches, Vernon, Winnebago

Alfalfa, Crown Rot, Fusarium spp., Phoma medicaginis, Green Lake, Vernon, Winnebago

Alfalfa, Phytophthora Root Rot, Phytophthora megasperma f. sp. Medicaginis, Green Lake, Winnebago

Alfalfa, Pythium Root Rot, Pythium sp., Green Lake

Alfalfa Rhizoctonia Root Rot, Rhizoctonia solani, Vernon, Winnebago


Apple, Frogeye Leaf Spot, Botryosphaeria obtusa, Lafayette

Blueberry, Anthracnose, Gloeosporium sp., Waukesha

Grape, Anthracnose, Sphaceloma ampelinum, Dane, Jefferson

Grape, Downy Mildew, Plasmopara viticola, Jefferson

Grape, Poor Pollination, None, None

Grape, Rupestris Speckle, None, Dane

Pear, Anthracnose, Gloeosporium sp., Waukesha

Strawberry, Root Rot, Pythium sp., Fusarium sp., Marathon


Cabbage, Black Rot, Xanthomonas campestris pv. campestris, Outagamie

Garlic, Twister/Anthracnose, Colletotrichum gloeosporioides, Washburn

Horseradish, Fusarium Root Rot, Fusarium spp., Dunn

Pepper, Bacterial Spot, Xanthomonas campestris pv. vesicatoria, Columbia

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