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

Brian Hudelson, Sean Toporek, Ann Joy and Joyce Wu

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 8, 2015 through August 14, 2015.

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

Field Crops
Corn, Anthracnose Stalk Rot, Colletotrichum graminicola, Grant
Corn, Eyespot, Kabatiella zeae, Dane
Corn, Northern Corn Leaf Blight, Exserohilum turcicum, Dane
Soybean, Downy Mildew, Peronospora manshurica, Sauk
Soybean, Root Rot, Fusarium sp., Waupaca, Waukesha
Soybean, Sclerotinia Stem RotSclerotinia sclerotiorum, Columbia
Soybean, Sudden Death SyndromeFusarium virguliforme, Dodge
Soybean, Target Spot, Corynespora cassiicola, Waukesha

Fruit Crops
Apple, Black Rot, Sphaeropsis sp., Green
Apple, Fire BlightErwinia amylovora, Green
Apple, Root/Crown RotPhytophthora sp., Pythium sp., Sawyer
Apricot, Scab, Cladosporium sp., Waukesha
Blueberry, Gloeosporium Leaf Spot, Gloeosporium sp., Eau Claire
Blueberry, Root/Crown RotPhytophthora sp., Pythium sp., Eau Claire
Cherry,  Cherry Leaf Spot, Phloeosporella padi, Rock
Cherry, Root/Crown RotPhytophthora sp., Sawyer
Pear, Root/Crown Rot,  Phytophthora sp., Sawyer
Plum, Root/Crown Rot,  Phytophthora sp., Sawyer
Raspberry, Cane Blight, Coniothyrium fuckellii, Richland
Raspberry, Root/Crown RotRhizoctonia sp., Pythium sp., Fusarium sp., Ozaukee, Richland

Vegetables
Basil, Downy Mildew, Peronospora belbahrii, Dane
Broccoli, Crown GallAgrobacterium tumefaciens, Kenosha
Cucumber, Anthracnose, Colletotrichum orbiculare, Dane
Cucumber, Powdery MildewOidium sp., Dane
Garlic, Fusarium Stem Rot, Fusarium oxysporum, Walworth
Onion, Fusarium Basal Rot, Fusarium oxysporum, Marquette
Potato, Late BlightPhytophthora infestans, Polk
Potato, Powdery MildewOidium sp., Dane
Tomato, Late BlightPhytophthora infestans, Polk, St. Croix
Tomato, Septoria Leaf SpotSeptoria lycopersici, Rock, Kenosha
Tomato, Tobacco Mosaic, Tobacco Mosaic virus, Walworth

Specialty Crops
Hop, CarlavirusUnidentified carlavirus, Dane
Hop, Downy MildewPseudoperonospora humili, Dane

Soil
Alfalfa Soil, Aphanomyces Seedling Blight, Aphanomyces euteiches race 2, Houston (MN)

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