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 August 3, 2013 through August 9, 2013.

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


Corn, Fusarium Stalk Rot, Fusarium oxysporum, Walworth

Corn, Gibberella Stalk Rot, Fusarium graminearum, Walworth

Corn, Purple Leaf Sheath, None, Dane

Soybean, Brown Spot, Septoria glycines, Outagamie

Soybean, Charcoal Rot, Macrophomina phaseolina, Adams

Soybean, Dicamba Injury, None, Outagamie

Soybean,  Fusarium Root Rot, Fusarium sp., Adams

Soybean, Soybean Cyst, Heterodera glycines, Outagamie


Blueberry, Phomopsis Canker, Phomopsis sp., Brown

Blueberry, Red Ring Spot, Red Ringspot Virus, Brown

Chokeberry, Cercospora Leaf Spot, Cercospora sp., Dane

Chokeberry, Phomopsis Canker, Phomopsis sp., Dane

Chokeberry, Rhizoctonia Stem Blight, Rhizoctonia sp., Dane

Grape, Growth Regulator Herbicide Injury, None, Dane

Grape, Oxidant Stipple, None, Dane

Grape, Brown Rot, Monilinia fructicola, Dane

Grape, Plum Pockets, Taphrina communis, Dane

Raspberry, Root/Crown Rot, Phytophthora sp., Pythium sp., Rhizoctonia sp., Columbia


Potato , Late Blight, Phytophthora infestans, Adams, Brown

Squash, Root Rot, Rhizoctonia solani, Dane

Tomato, Late Blight, Phytophthora infestans, Brown, Racine

Tomato, Unidentified Viral Disease, Not identified, Polk

Tomato, Walnut Toxicity, None, Wood


Soybean Soil, Soybean Cyst Nematode, Heterodera glycines, Rock

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