UW-Madison/Extension Plant Disease Diagnostic Clinic (PDDC) Update September 18, 2020
The PDDC is now once again accepting physical samples for diagnosis, but due to COVID-19, only with limited hours and limited sample processing capacity. Click here for the current submission policy. The PDDC is continuing to provide diagnoses through examination of digital photographs. Digital diagnoses have not traditionally been included in the Wisconsin Disease Almanac, because such diagnoses are not verified through lab testing (critical in most situations for a diagnosis to be accurate). However, in an attempt to keep clients as informed as possible, digital diagnoses will be included in the Almanac until normal PDDC operations resume. For Almanac entries below, when a digital diagnosis would normally require a lab confirmation, the disease/disorder will be labeled as “suspected”. The following diseases/disorders have been identified at the PDDC from September 12, 2020 through September 18, 2020.
| PLANT/SAMPLE TYPE | DISEASE/DISORDER | PATHOGEN | COUNTY |
| FRUIT CROPS | |||
| Apple (‘Honeycrisp’) | Zonal Leaf Chlorosis | None | Milwaukee |
| Apple (Unspecified) | Chlorosis Cork Spot (Suspected) Fire Blight (Suspected) Root-Bound Water Stress (Suspected) | None None Erwinia amylovora None None | Milwaukee Barron Jefferson Jackson Jackson, Milwaukee |
| Blueberry | Phomopsis Canker (Suspected) | Phomopsis sp. | St. Croix |
| Cranberry (Unspecified) | Bitter Rot Black Rot Blotch Rot Early Rot Ripe Rot Upright Dieback | Colletotrichum acutatum, Colletotrichum gloeosporioides Allantophomopsis lycopodina Physalospora vaccinii Phyllosticta vaccinii Coleophoma empetri Phomopsis sp. | Wood Wood Wood Wood Wood Wood |
| Pear | Stony Pit (Suspected) | Stony pit virus | Eau Claire |
| Raspberry | Root/Crown Rot (Suspected) | Unspecified root rot fungi/water molds | Waupaca |
To learn more about plant diseases and their control, as well as PDDC educational resources and activities, visit the PDDC website at pddc.wisc.edu, follow the clinic on Facebook and Twitter @UWPDDC or email pddc@wisc.edu to subscribe to the PDDC listserv “UWPDDCLearn”.
This article was posted in Apples, Berries, Cranberry, Disease and tagged Apples, Bitter Rot, Black Rot, blotch rot, Blueberries, chlorosis, cork spot, Cranberries, disease, Early Rot, Fire Blight, Honeycrisp, PDDC, pear, phomopsis canker, Plant Disease Diagnostic Clinic, root-bound, Root/Crown Rot, stony pit, upright dieback, water stress, zonal leaf chlorosis.