UW-Madison/Extension Plant Disease Diagnostic Clinic (PDDC) Update June 26, 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 June 20, 2020 through June 26, 2020.
| PLANT/SAMPLE TYPE | DISEASE/DISORDER | PATHOGEN | COUNTY |
| Apple | Apple Scab (Suspected) Bacterial Wetwood Fertility Issues (Suspected) Frost Crack Graft Union Failure Gymnosporangium Rust Root/Crown Rot (Suspected) Overly Deep Planting | Venturia inaequalis Miscellaneous bacteria None None None Gymnosporangium sp. Pythium sp., Fusarium sp. None | Monroe Sauk Price Sauk Ozaukee La Crosse Dane Sauk |
| Cherry | Cherry Leaf Spot (Suspected) Phytoplasma Disease (Suspected) | Blumeriella jaapii Unspecified phytoplasma | Rock Brown |
| Peach | Peach Leaf Curl | Taphrina deformans | Dane |
| Pear | Frost Crack Wood Rot (Suspected) | None Unspecified rot fungus | Vernon Vernon |
| Raspberry (Black) | Root Rot (Suspected) | Unspecified root rot fungi/water molds | Richland |
| MISCELLANEOUS | |||
| Fungus ID | King Stropharia (Stropharia rugosoannulata) | None | Langlad |
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 Disease and tagged Apple Scab, Apples, bacterial wetwood, Cherry, fertility issues, frost crack, graft union failure, gymnosporangium rust, king stropharia, overly deep planting, PDDC, Peach, peach leaf curl, pear, phytoplasma disease, Plant Disease Diagnostic Clinic, Raspberries, root rot, wood rot.