Plant Disease Clinic Update

Sandra Gould, Plant Pathology Extension, University of Minnesota, St. Paul, Minn.

The University of Minnesota’s Plant Disease Clinic provides prompt, accurate information on plant diseases for commercial growers in Minnesota.

Services Offered

Routine Diagnosis - $20-25
We provide routine diagnosis of samples that require traditional methods of symptom analysis, culturing, or microscopic examination. These include leaf spot and root rot diseases of field crops, trees, or greenhouse crops and diagnosis of oak wilt and Dutch elm disease. Fees may vary if additional specialized media is required.
Nematode Analysis - $15
Identification and count of plant parasitic nematodes for all commercial crops Note: Samples specifically for soybean cyst nematode (SCN) should be sent directly to the Nematology Laboratory, Southern Research Experiment Station, 35838 120th St., Waseca, MN 56093.
Virus Analysis ELISA testing - $25
ELISA (enzyme-linked, immunosorbent assay) testing is done for these and other viruses: Tomato spotted wilt , Barley yellow dwarf, Impatiens necrotic spot. Other viruses may be identified using biological or serological techniques. Fees vary depending on the virus to be identified.
Seed Quality Testing, includes: Soybean: Phomopsis pod test - $25; Corn and Grain: Identification of storage molds - $30; and Dilution plating of silage, haylage or feed for storage molds - $35
Verticillium sp. Testing includes: Pinch-squeeze test of potato stem tissue - $20; Soil assay - $30; and Culture of plant tissue - $25
Aphanomyces sp. Testing - $100; This is a biological assay on sugarbeet soil for the presence of Aphanomyces sp. Soil samples should be collected after harvest and will be processed in the greenhouse during the winter months. Contact the Plant Disease Clinic for specific information.
Rhizomania Testing - $45; A 9-10 week bioassay performed on sugarbeet soil for the presence of beet necrotic yellow vein virus (Rhizomania). Samples are processed during the winter months.

How To Submit Samples For Disease Diagnosis

1. Collect living plants that exhibit varying stages of decline. Do NOT submit dead plants.
2. For herbaceous plants, collect the entire plant, including as much of the root system as possible. Dig out (don't pull) several symptomatic plants and shake excess soil from roots. Bundle plants together and wrap roots only in a plastic bag, allowing stems and leaves to hang out of the bag. Wrap the entire bundle of plants in newspaper and place it in a cardboard box.
3. For tree wilts, collect branches 1/2 -inch to 1-inch in diameter from branches which are actively wilting, but not totally dead. Wrap in plastic to retain moisture, and keep cool until delivery to the lab. 4. For virus testing, collect symptomatic leaves, stems, or entire plants. Wrap in plastic. It is very important that these samples do not dry out during shipment. Do not add extra water to the bags.
5. For nematode analysis, ship soil in plastic bags and keep refrigerated until shipped. It is important that nematode samples are not exposed to high temperatures. Specific guidelines for sample collection are available upon request.
6. Submit a completed Information Request Form with each sample.
7. Ship samples immediately after collection.
8. Ship samples by overnight delivery or mail early in the week to insure fast delivery. Plant samples often decompose if left in the post office over the weekend.
9. Please submit payment with each sample. Make checks payable to the University of Minnesota.

Shipping Address:
Plant Disease Clinic
495 Borlaug Hall
1991 Upper Buford Circle
University of Minnesota
St. Paul, MN 55108-6030
(612) 625-1275 – Phone
(612) 625-9728 - Fax

In-person, delivery address:
105 Stakman Hall
1519 Gortner Ave
University of Minnesota, St. Paul campus

Click here (http://www.plpa.agri.umn.edu/extension/images/clinic.pdf) (requires Adobe Acrobat) to download the form for submitting samples to the Plant Disease Clinic. For more information on the clinic, see their web site at: http://www.plpa.agri.umn.edu/extension/plantdiseaseclinic.htm

Co-Editors: Bill Hutchison, Department of Entomology, University of Minnesota, hutch002@tc.umn.edu
Jeanne Ciborowski, IPM Program, Minnesota Department of Agriculture, jeanne.ciborowski@state.mn.us
Cindy Tong, Department of Horticulture, University of Minnesota, c-tong@tc.umn.edu
Production Editor: Suzanne Wold, Graduate Research Assistant, University of Minnesota, woldx018@tc.umn.edu

Disclaimer
Reference to products in this publication is not intended to be an endorsement to the exclusion of others which may have similar uses. Any person using products listed in this publication assumes full responsibility for their use in accordance with current directions of the manufacturer

Last Revised July 12, 2001.
The University, including the Minnesota Extension Service, is an equal opportunity educator and employer.©2001 Minnesota Extension Service, University of Minnesota. All rights reserved. Contact copyright@extension.umn.edu for information on reproduction or use of this material.