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 10, 2013 through August 16, 2013.

Plant/SampleType, Disease/Disorder, Pathogen, County

Field Crops

Corn, Northern Corn Leaf Spot, Bipolaris zeicola, Grant

Soybean, Charcoal Rot, Macrophomina phaseolina, Dane

Soybean, Dicamba Injury, None, Walworth

Soybean, Fusarium Root Rot, Fusarium sp., Trempealeau

Soybean, Soybean Cyst, Heterodera glycines, Trempealeau

Forage Crops

Alfalfa, Aphanomyces Root Rot, Aphanomyces euteiches, Lafayette

Alfalfa, Crown Rot, Fusarium spp., Lafayette

Fruit Crops

Apple, Root/Crown Rot, Phytophthora sp., Pierce

Grape, Downy Mildew, Plasmopara viticola, Dane

Grape, Powdery Mildew, Oidium sp., Dane

Raspberry, Root/Crown Rot, Pythium sp., Rhizoctonia sp., Fusarium sp., Cylindrocarpon sp., Lincoln and Rusk


Chard (Green), Cercospora Leaf Spot, Cercospora sp., Vernon

Chard (Red), Cercospora Leaf Spot, Cercospora sp., Vernon

Kale (Green), Alternaria Leaf Spot, Alternaria brassisicola, Vernon

Kale (Green), Black Rot, Xanthomonas campestris pv. campestris, Vernon

Okra, Alternaria Leaf Spot, Alternaria sp., Vernon

Pepper, Blossom End Rot, None, Vernon

Potato , Late Blight, Phytophthora infestans, Carroll (IL)

Tomato, Bacterial Speck, Pseudomonas syringae pv. tomato Vernon

Tomato, Early Blight, Alternaria solani Vernon

Tomato, Late Blight, Phytophthora infestans Vernon

Tomato, Septoria Leaf Spot, Septoria lycopersici Vernon

Tomato, Sunscald, None, Sauk

Specialty Crops

Hop, Hop Latent Virus, Hop latent virus, Monroe


Soybean Soil, Soybean Cyst Nematode, Heterodera glycines, Eau Claire, Walworth

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