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

Brian Hudelson, Sean Toporek, Jake Kurczewski and Ann Joy

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 20, 2016 through August 26, 2016.

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

Field Crops
Corn, Common Rust, Puccinia sorghi, Dodge
Corn, Southern Rust, Puccinia polysora, Rock
Soybean, Bacterial Blight, Pseudomonoas syringae pv. glycinea, Trempealeau
Soybean, Brown Spot, Septoria glyinces, Trempealeau
Soybean, Sclerotinia Stem Rot, Sclerotinia sclerotiorum,Trempealeau
Soybean, Soybean Cyst Nematode, Heterodera glyinces, Trempealeau
Soybean, Stem and Pod Blight, Diaporthe phaseolorum, Trempealeau
Soybean, Stem Canker, Diaporthe phaseolorum, Trempealeau
Soybean, Sudden Death Syndrome, Fusarium virguliforme, Pierce

Forage Crops
Alfalfa, Crown/Root Rot, Pythium sp. Fusarium oxysporum, Washington
Alfalfa, Spring Black Stem and Leaf Spot, Phoma medicaginis, Columbia
Alfalfa, Stemphylium Leaf Spot, Stemphylium sp., Columbia
Alfalfa, Summer Black Stem and Leaf Spot, Cercospora sp., Columbia

Fruit Crops
Apple (‘Honeycrisp’), Honeycrisp Leaf Chlorosis, None, Jo Daviess (IL)
Apple (Unspecifified), Bitter Rot, Colletotrichum gloeosporioides, Dane
Pear, Fire Blight, Erwinia amylovora, Waukesha

Vegetable Crops
Pepper, Herbicide Damage, None, Jackson
Tomato, Bacterial Canker, Clavibacter michiganensis subsp. michiganensis, Wood
Tomato, Cucumber Mosaic, Cucumber mosaic virus, Portage
Tomato, Late Blight, Phytophtora infestans, Polk
Tomato, Tobacco Mosaic, Tobacco mosaic virus, Portage

Specialty Crops
Hop, Alternaria Cone Disorder, Alternaria sp., Dane
Hop, Cone Tip Blight, Fusarium sp., Dane

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