Diagnostics for Plant Problems

Correct diagnosis of a problem and correct identification of the pest (insect, disease, abiotic factor, nutrition, etc.) causing the problem are key to successful crop management and profitability. Below is a list of laboratories that offer disease diagnostics on a fee-for-service basis. When submitting a sample, remember to specify whether you are looking for insect, disease, or weed (or other) identification in case more than one organism and/or symptom is present on your sample. Also, provide as complete a description of the problem as possible including crop, symptoms, distribution within the field or greenhouse, and unique characteristics of the location. Commercial growers will receive different recommendations than home gardeners. Please indicate if you are an organic grower. In general, virus screening is limited to a small group of common viruses; further analysis is  referred to specialized laboratories. Contact your local  lab or your state Extension Vegetable Specialist for more information.

In order to submit a sample for diagnosis, some basic preparation instructions should be followed.

These include:

  • Collect specimens that show a range of symptoms (i.e., from healthy to seriously affected), usually collected from the margin of the affected area. Avoid specimens that are completely dead or decayed as they are not diagnostically useful.
  • Fill out the sample submission form (provided by lab). This is very important. Without detailed information about the problem, a correct diagnosis is very difficult.
  • Pack specimens in dry paper and place in a plastic bag (never pack with wet paper towels or add water).
  • Mail specimen and submission form using same-day or overnight delivery or deliver specimen personally the same day. If this is not possible, place in a refrigerator and mail or deliver the following day. Specimens should come to the diagnostic labs early in the week to avoid problems with weekend holdovers.

Plant Diagnostic Clinics of New England

(D = plant disease identification, I = insect identification, N = nematode analysis, W = weed identification)


UConn Plant Diagnostic Lab (D,I,N,W)

Ratcliffe Hicks Building, Room 4
1380 Storrs Road, Unit 4115
Storrs, CT 06269-4115
(toll free) 1-877-486-6271
Cost:  $20.00

The Plant Disease Information Office (D,I,N, W)

The Connecticut Agricultural Experiment Station
Jenkins-Waggoner Laboratory
123 Huntington Street, P.O. Box 1106
New Haven, CT 06511
(203) 974-8601; (877)855-2237 toll-free outside New Haven area
Cost: $20.00



Plant Disease Diagnostic Lab (D,I,N)

Pest Management Unit
17 Godfrey Drive
Orono, ME 04473-3692
800-287-0279 (within Maine) or (207) 581-3880 (outside Maine)  fax: (207)581-3881
Cost: $18.00 for Maine residents, $38.00 for out-of-state residents



Plant Disease Diagnostic Laboratory (D,I,N,W)

UMass Extension Plant Diagnostic Lab
#3 French Hall, 230 Stockbridge Road
Amherst, MA 01003
(413) 545-3208 fax: (413) 545-4385
Cost: $30.00 to $60.00


New Hampshire

The Plant Diagnostic Lab (D,I,W)

Barton Hall
34 Sage Way
Durham, NH 03824
(603) 862-3043 


Rhode Island

Plant Diagnostic Lab (D,I,W)

URI Cooperative Extension
3 East Alumni Avenue
Kingston, RI 02881
(401) 874-2900  fax: (401)874-2259
Cost: $20.00



University of Vermont Plant Diagnostic Clinic (D,I,W)

201 Jeffords Hall,
63 Carrigan Drive
Burlington, VT 05405
(802) 656-0493 fax: (802)656-4656
Cost: $15.00 (Vermont residents only)