UW-Madison/Extension Plant Disease Diagnostic Clinic (PDDC) Update August 28, 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 22, 2020 through August 28, 2020.
| PLANT/SAMPLE TYPE | DISEASE/DISORDER | PATHOGEN | COUNTY |
| FRUIT CROPS | |||
| Apple (‘Honeycrisp’) | Gymnosporangium Rust Zonal Leaf Chlorosis | Gymnosporangium sp. None | Vernon Vernon |
| Apple (Unspecified) | Fire Blight (Suspected) Gymnosporangium Rust Water Core (Suspected) | Erwinia amylovora Gymnosporangium sp. None | Vernon Vernon Barron |
| Cherry | Cherry Leaf Spot | Blumeriella jaapii | Monroe |
| Cranberry | Cranberry False Blossom | Cranberry false blossom phytoplasma | Wood |
| Grape (Unspecified) | Anthracnose Downy Mildew Virus Disease (Suspected) | Sphaceloma ampelinum Plasmopara viticola Unidentified virus | Dane, Langlade Dane Langlade |
| Pear (Unspecified) | Pear Scab (Suspected) | Venturia pirina | Monroe |
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, Cranberry, Disease, Grapes and tagged Anthracnose, Apples, Cherry, Cherry Leaf Spot, Cranberries, cranberry, cranberry false blossom, disease, Downy mildew, Fire Blight, Grapes, gymnosporangium rust, Honeycrisp, PDDC, pear, pear scab, Plant Disease Diagnostic Clinic, water core, zonal leaf chlorosis.