UW-Madison/Extension Plant Disease Diagnostic Clinic (PDDC) Update July 31, 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 July 25, 2020 through July 31, 2020.
| PLANT/SAMPLE TYPE | DISEASE/DISORDER | PATHOGEN | COUNTY |
| FRUIT CROPS | |||
| Apple | Fire Blight (Suspected) Gymnosporangium Rust | Erwinia amylovora Gymnosporangium sp. | Brown, Vernon Milwaukee |
| Blueberry | Overly High Soil pH (Suspected) Transplant Shock (Suspected) | None None | Milwaukee Milwaukee |
| Cherry | Cherry Leaf Spot (Suspected) | Blumeriella jaapii | Dane |
| Grape | Anthracnose Anthracnose (Suspected) Black Rot | Sphaceloma ampelinum Sphaceloma ampelinum Guignardia bidwellii | Dodge Douglas Dodge |
| Raspberry | Fertility Issues (Suspected) Raspberry Leaf Spot (Suspected) Transplant Shock (Suspected) | None Cylindrosporium rubi None | Sheboygan Sheboygan Waukesha |
| Strawberry | Angular Leaf Spot Common Leaf Spot Phomopsis Leaf Blight Root/Crown Rot | Xanthomonas fragariae Mycosphaerella fragariae Phomopsis obscurans Rhizoctonia sp., Pythium sp. | Columbia Columbia Columbia Columbia |
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 angular leaf spot, Anthracnose, Apples, Black Rot, Blueberries, Cherry, Cherry Leaf Spot, common leaf spot, disease, fertility issues, Fire Blight, Grapes, gymnosporangium rust, overly high soil pH, PDDC, Phomopsis, Plant Disease Diagnostic Clinic, Raspberries, raspberry leaf spot, Root/Crown Rot, Strawberries, transplant shock.