Plant Disease Clinics

Several plant disease diagnostic clinics in the Pacific Northwest can help determine plant problems. Publicly supported clinics are listed below. A listing of other laboratories (mostly private) that provide a similar service can be found at http://www.puyallup.wsu.edu/analyticallabs/services

For best service, the most useful returns on your efforts, and for efficient use of our time, please read and observe these instructions before submitting specimens.

Collecting

1. Select material showing the symptoms you are concerned about. Send several samples showing various stages of disease, especially early symptoms. If possible also send a healthy plant.
2. Get all parts of plants including roots where practical. Enclose roots and soil in a plastic bag. Use another bag to enclose the rest of the plant.
3. If it is not practical to send the entire plant, include several affected portions of the plant. With stem or branch disorders, also include a section of live material attached to the diseased portion.
4. If a vascular wilt such as Verticillium wilt or Dutch elm disease is suspected, send several branch sections 0.75 to 1 inch in diameter and about 6 inches long from branches with dying, wilted, or yellowed leaves. Do not send dead wood. Put samples in a plastic bag to prevent drying.
5. Turfgrass samples should be taken from the edges of affected areas that include dying and also apparently healthy plants. Send one or two 3-by-3-inch squares of sod containing 1 inch of attached soil. Wrap each sample in one thickness of slightly dampened toweling, then in dry newspaper. Send as much information as possible.
6. Fleshy specimens such as vegetables, fruit, or mushrooms should be as firm as possible and show early and intermediate symptom development. Wrap specimens separately in paper towels or newspaper. Do not put in plastic. Pack with sufficient padding to avoid crushing.

Packing

1. Keep plants cool and moist before shipping. Mail as soon as possible after collection. Mail specimens early in the week to avoid delay in the post office over weekends or holidays.
2. Pack in a sturdy container to prevent crushing in transit. Use paper to pack the specimen firmly in the container.
3. Identify package with labels both outside and inside. Put the label and the Plant Clinic Disease Form in a waterproof barrier such as plastic.

Addressing Packages

Oregon (from any location)

Plant Clinic, Cordley Hall 1089, 2701 SW Campus Way, Oregon State University, Corvallis, OR 97331-2903 (Fees required; see below.)

Oregon (North central and Northeast Oregon only)

Extension Plant Pathology Laboratory, 2121 S. First, OSU, Hermiston, OR 97838.

Idaho

Plant Samples, Kimberly Research and Extension Center, Kimberly, ID 83341 Plant Samples, Parma Research and Extension Center, University of Idaho, Parma, ID 83660

Western Washington

WSU Puyallup Plant Clinic, 2606 W. Pioneer, Puyallup, WA 98371-4998. (Fees required.)

British Columbia

Plant Diagnostic Laboratory, British Columbia Ministry of Agriculture, Fisheries, and Food, 1767 Angus Campbell Rd., Abbotsford, BC V3G 2M3 Canada (Fees required).

Information

Fill out the appropriate Plant Disease Form or Plant Disease Identification Request sheets with as much information as possible. These forms are available in your County Extension offices, the labs listed above and on the web at http://www.bcc.orst.edu/bpp/Plant%20disease%20form%202004.pdf This information is valuable as an aid for diagnosis. Some labs will not process samples unless a form has been filled out. Photographs or video tapes convey a lot of information that may be useful. The more information you provide, the more accurate the diagnosis will be.

OSU Plant Clinic Fees

Services and fees

Insect/mite and other arthropod identifications are currently provided free of charge.

Disease Diagnosis Services

Plant disease diagnosis = $45.00 per sample. (Note - fees and services in 2010 are likely to change but were not available at this writing.)

This is our most frequently requested service. The service includes overall evaluation, including microscopic exam, leaf dip with an electron microscope or ELISA assay (for suspected virus infection), results from a moist chamber incubation, isolations onto artificial nutrient media, and identification of fungi or bacteria to genus. Viral inclusion analysis and measurement of soil pH and total soluble salts will be performed if necessary. Control recommendations are included.

Special Identification Services

Bacterial identifications

Identification of purified bacterial cultures = $25.00

This service identifies purified plant related bacterial cultures using Biolog. This method uses a microtitre plate filled with different carbon sources and identifies bacteria according to their metabolic profile; ID will be to species when possible.

Isolation for and identification of Agrobacterium species. = $50.00 per sample. This procedure also checks for the bacterium Rhodococcus at the same time. A sample consists of one or more plants of the same species and cultivar with the problem. Plants of different species or of different cultivars are considered separate samples.

Viral identifications

Virus identification via ELISA (enzyme-linked immunosorbent assay).

These fees are for those plant samples that are submitted specifically with a request to test for viruses. The cost of virus testing is based on the number of samples submitted and the number of viruses for which the samples are to be tested.

$40 for the first sample. Bulk samples have a discounted rate:

2 - 4 additional samples = $15.00 each

5 - 24 additional samples = $10.00 each

25 + additional samples = $7.00 each

Virus testing done by an outside company = Cost of testing + postage

It is occasionally necessary to send a sample out to a third part for testing. The fees associated with doing so are dependent on the fees charged by the testing service. That fee is passed along to our client without any additional charge.

Seed assays

Seed tests for blind seed or stripe smut = $30.00/ seed sample.

Seed tests for Kabatiella and Phoma (clover seed); or Ascochyta (pea) = $50/seed sample.

Water assays

Testing water for the presence of Phytophthora or Pythium = $40 for the first sample, and $15 for each additional sample. Identification of the organisms obtained will be to genus only. In some cases Phytophthora species may be identified to species. Call first for instructions on how to sample and how to ship samples.

The Plant Clinic requires 3 days notice for this service so we can have the necessary materials prepared and ready, so please call in advance. We also must have the water 24 hours after it has been sampled.

Soil assays

Verticillium wilt is a disease of many crops and landscape plants in the Pacific Northwest. The fungus Verticillium dahliae can survive long periods of time in soil in the absence of a susceptible host. Sampling the soil for V. dahliae can help avoid future disease losses or determine the need for specific soil treatment. This assay will not detect V. albo-atrum.

Sampling Procedure

Soil Collect about 20 soil samples for every 5 acres, sampling from across the field or subsection. Sample from the top 12 inches of soil with a shovel or soil core. Place each sample in a separate bag, and label each bag with the grower’s name and field identification and location. Each soil sample should be around 2 cups in volume.

Each field or subsection should represent no more than 5 acres. Further, collect samples from areas with different cropping histories, soil types, or any other distinguishing characteristics. Keep samples cool and ship as soon as possible. Soil samples will be air-dried before testing and results are available in 4 to 6 weeks.

Assaying field soil for the presence of Verticillium = $20.00/soil sample.

Soil pH and total soluble salts = $10.00

Soil submitted with a plant sample will automatically have these measurements taken, when requested, at no additional charge. This service is for soils submitted specifically for this analysis.

Rush samples

Plant samples to be done on a "rush" basis = $100.00 per sample

This includes an extremely thorough investigation, with results available in most cases in 24 hours. This includes evaluation for fungal and other diseases; no additional fees are assessed for culturing or other methods needed to reach a diagnosis. This service is not available at all times. Please call to confirm it is available before submitting a sample.

Other services

Other services not listed here may be available. Call for information.

Out of state samples

ALL SAMPLES received from out-of-state will be assessed an additional 50% surcharge.

Factors used to set fees include cost of materials, supplies, clerical support, and a portion of the labor required to perform the tests. The remainder of the costs are paid by the OSU Extension Service as part of its education mission.

For more information, contact:

Melodie Putnam
Director
OSU Plant Disease Clinic
Cordley Hall, Room 1089
2701 SW Campus Way
Corvallis, OR 97331-2903
Tel. 541-737-3472
Fax 541-737-2412
E-mail: putnamm@science.oregonstate.edu