UW-Madison/Extension Plant Disease Diagnostic Clinic (PDDC) Update August 21, 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 August 15, 2020 through August 21, 2020.
| PLANT/SAMPLE TYPE | DISEASE/DISORDER | PATHOGEN | COUNTY |
| FRUIT CROPS | |||
| Apple (‘Honeycrisp’) | Zonal Leaf Chlorosis | None | Pierce |
| Apple (Unspecified) | Fire Blight | Erwinia amylovora | Sheboygan |
| Cherry | Powdery Mildew | Oidium sp. | Brown |
| Cranberry | Bitter Rot Blotch Rot | Colletotrichum gloeosporioides Physalospora vaccinii | Wood Wood |
| Fruit Trees (Miscellaneous) | Chemical Burn (Suspected) | None | Jefferson |
| Pear | Pear Scab (Suspected) Pear Stony Pit (Suspected) | Venturia pirina Unspecified virus (Suspected) | Dunn Washington |
| Plum | Brown Rot | Monilinia sp. | Dunn |
| Raspberry | Raspberry Leaf Spot (Suspected) Root/Crown Rot (Suspected) | Septoria darrowii Unspecified root/crown rot fungi/water molds | Brown Richland |
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 apple, Bitter Rot, blotch rot, Brown Rot, chemical burn, Cherry, Cranberries, Fire Blight, Honeycrisp, PDDC, pear, pear scab, pear stony pit, Plant Disease Diagnostic Clinic, plums, Powdery mildew, Raspberries, raspberry leaf spot, Root/Crown Rot, zonal leaf chlorosis.