Disease Diagnostics

Vegetable Diseases: M. Bess Dicklow, (413) 545-3209, mbdicklo@umext.umass.edu

Nematodes: Dr. Robert Wick, (413) 545-1045, rwick@pltpath.umass.edumext.umass.edu

Contact the appropriate individual listed above to discuss your sample and to ensure that someone will be available to examine the specimen. Microscopic and laboratory identification of fungi, bacteria, viruses, and nematodes are routinely carried out. Samples can be hand-delivered (if possible) or sent overnight mail, UPS, or Federal Express. Along with your sample, you must include a completed Vegetable & Floriculture Diagnostic Form.  Be as complete as possible; accurate diagnosis depends on sufficient information about cultural practices and environmental conditions. Collect specimens that show a range of symptoms, avoiding rotted or decayed specimens. Please avoid Friday samples; Friday samples will not be examined until Monday which can lead to deterioration of the sample. Upon reaching a conclusion, the lab will send or e-mail a report on the diagnosis including complete management guidelines emphasizing cultural and biorational controls, as well as chemical control options.

Guidelines for Sending Vegetable or Floriculture Specimens:

Please submit vegetable or floriculture samples according to the following guidelines, based on the symptoms present.

Leaf Spots and Blights: Leaf spots and blights of floriculture or vegetable crops are often caused by fungi or bacteria. Certain pesticides, or environmental or nutritional factors can also cause spotting. Select leaves which show a range of symptom development. Specimens that are dead or dry are of little diagnostic value. Place leaves between sheets of paper or inside a magazine. Place the package in a plastic bag, then into the envelope for mailing. Never wrap leaves in wet paper towels.

Fruit Rots: Select early stages of disease rather than badly rotted tissue. With large fruit such as a pumpkin, cut the affected area out with a knife and submit. Wrap fruit or fruit sections in newspaper, and put into a plastic bag for mailing.

Stem Cankers: When a canker occurs on a large plant, cut a section of the stem with the symptoms, wrap in newspaper and place in a plastic bag for mailing. If the plants are small (1 foot or less), shake the soil from the roots, wrap in newspaper and put into a plastic bag for mailing.

Wilt, Crown Rot or Root Rot: If the plants are 1 foot or less, include the entire plant. Dig the plant, including a good handful of the root system. Leave the soil on the roots. Place the root/soil ball into a plastic bag and tie off at the crown to prevent soil from spilling out. Wrap in newspaper and put into a plastic bag for mailing. If the plants are large, send a portion of the plant that includes the infected tissue. For wilt diseases, we must have lower stem tissue and roots.

Scorch, Defoliation or Poor Growth: These symptoms are usually caused by nutritional or environmental factors. They may also be the result of root rot or vascular disease. Collect a specimen as for wilt (above); be sure to submit a soil sample to the UMass Soil Testing Laboratory. A tissue analysis may also be advisable. Call the Soil Testing Lab at (413) 545-2311 before sending the sample.

Diagnostic Fees (payment payable to University of Massachusetts):

Vegetable crop disease analysis - $50
Vegetable crop nematode assay - $50

Address packages to:
UMass Plant Diagnostic Lab
101 University Drive, Suite A7
Amherst, MA 01002
(413) 545-3208 - fax (413) 545-4385
Use exact address to ensure delivery.