UW-Madison/Extension Plant Disease Diagnostic Clinic (PDDC) Update September 4, 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 29, 2020 through September 4, 2020.
| PLANT/SAMPLE TYPE | DISEASE/DISORDER | PATHOGEN | COUNTY |
| FRUIT CROPS | |||
| Apple | Bitter Pit (Suspected) Canker Disease Gymnosporangium Rust Transplant Shock (Suspected) Water Stress (Suspected) | None Unspecified canker pathogen Gymnosporangium sp. None None | Monroe Dane Dane, Winnebago Eau Claire Eau Claire |
| Blueberry | Cytospora Canker Phomopsis Canker Root Rot | Cytospora sp. Phomopsis sp. Phytophthora sp. | Douglas Jackson Jackson |
| Grape | Anthracnose Black Rot Fertility Issues (Suspected) Rupestris Speckle (Suspected) | Sphaceloma ampelinum Guignardia bidwellii None None | Monroe Monroe Portage Portage |
| Pear | Black Rot (Suspected) Pear Scab (Suspected) | Botryosphaeria obtusa Venturia pirina | Monroe Monroe, Portage |
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, Disease, Grapes and tagged Anthracnose, Apples, Bitter pit, Black Rot, Blueberries, canker disease, cytospora canker, disease, fertility issues, Grapes, gymnosporangium rust, PDDC, pear, pear scab, Phomopsis, Plant Disease Diagnostic Clinic, root rot, rupestris speckle, transplant shock, water stress.