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

Brian Hudelson, Ann Joy, Amy Gibbs, and Brooke Weber, Plant Disease Diagnostics Clinic

The PDDC receives samples of many plant samples from around the state. The following diseases/disorders have been identified at the PDDC since July 22, 2009:

 

PLANT/SAMPLE TYPE	DISEASE/DISORDER	PATHOGEN	COUNTY
FIELD CROPS
Corn (Seed)	Yellow Leaf Blight	Phyllosticta maydis	Dane
Corn (Unidentified)	Eyespot   Yellow Leaf Blight	Aureobasidium zeae   Phyllosticta maydis	Iowas   Iowa
Soybean	Root Rot     Soybean Cyst Nematode	Fusarium sp., Phytophthora sojae, Rhizoctonia sp.   Heterodera glycines	Columbia, Jefferson, Trempeauleau   Brown
Wheat	Black Stem Rust	Puccinia graminis	Jefferson
FRUIT CROPS
Apple	Cedar-Apple Rust	Gymnosporangium sp.	Dane
Grape (Concord)	Anthracnose   Downy Mildew   Guignardia Leaf Spot/ Black Rot	Sphaceloma ampelinum   Plasmopara viticola   Guignardia bidwellii	Brown   Sheboygan   Sheboygan
Plum	Bacterial Canker	Pseudomonas syringae	Outagamie
Raspberry	Raspberry Leaf Spot   Root/Crown Rot	Cylindrosporium rubi   Phytophthora sp., Pythium sp.	Dane   Dane
Strawberry	Root/Crown Rot	Cylindrocarpon sp., Fusarium sp., Phomopsis sp., Pythium sp., Rhizoctonia sp.	Brown, Clark
VEGETABLES
Beet	Cercospora Leaf Spot	Cercospora beticola	Waushara
Cabbage	Growth Regulator Herbicide Damage	None	Chippewa
Onion	Purple Blotch	Alternaria porri	Dane
Tomato	Growth Regulator Herbicide Damage	None	Jefferson

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