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 September 3, 2016 through September 23, 2016.

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

Field Crops
Corn, Anthracnose Leaf Blight, Colletotrichum graminicola, Portage
Corn, Anthracnose Stalk Rot, Colletotrichum graminicola, Kenosha
Corn, Common Rust, Puccinia sorghi, Dodge, Grant
Corn, Eyespot, Kabatiella zeae, Grant, Portage
Corn, Giberella Stalk Rot, Fusarium graminearum, Kenosha
Corn, Goss’ Wilt, Clavibacter michiganensis subsp. nebraskensis, Buffalo, Sawher
Corn, Northern Corn Leaf Blight, Exserohilum turcicum, Dodge, Portage, Shawano
Corn, Northern Corn Leaf Blight, Bipolaris zeicola, Portage
Corn, Southern Rust, Puccinia polysora, Grant
Corn, Tar Spot, Phyllachora maydis, Iowa
Sunflower, Alternaria Head Rot, Alternaria spp., Marathon
Sunflower, Alternaria Leaf Blight, Alternaria spp., Marathon
Sunflower, Botrytis Head Rot, Botrytis cinerea, Marathon

Fruit Crops
Apple, Bitter Rot, Colletotrichum gloeosporioides, Fond du Lac
Apple, Elsinoe Fruit Spot, Sphaceloma pirinum, Lafayette
Grape, Phomopsis Fruit Rot, Phomopsis viticola, Marinette
Strawberry, Root/Crown Rot, Phytophthora sp., Pythium sp., Fusarium sp., Dane

Vegetable Crops
Basil, Downy Mildew, Peronospora belbahrii, Jefferson, Outagamie
Cabbage, Alternaria Leaf Spot, Alternaria sp., Portage
Cabbage, Black RotXanthomonas campestris pv. campestris, Rock
Cauliflower, Verticillium Wilt, Verticillium sp., Rock
Potato, Black Leg, Dickeya sp., Rock
Rutabaga, Black Rot, Xanthomonas campestris pv. campestris, Rock
Pumpkin, Phytophthora Fruit Rot, Phytophthora capsici, Portage
Squash (Butternut), Alternaria Leaf Blight, Alternaria sp., Portage
Squash (Butternut), Powdery Mildew, Oidium sp., Portage
Tomato, Septoria Leaf Spot, Septoria lycopersici, Dane

Specialty Crops
Hop, Alternaria Cone Disorder, Alternaria sp., Sauk
Hop, Carlavirus, Unidentified carlavirus, Sauk
Hop, Cone Tip Blight, Fusarium sp., Sauk
Hop, Downy Mildew, Pseudoperonsopra humuli, Sauk


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