Diagnostics for Plant Problems

Correct diagnosis of a problem and correct identification of the pest (insect, disease, biotic 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 field or greenhouse, unique characteristics of the location. Commercial growers receive different recommendations than homeowners. 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  or your state Extension Vegetable Specialist for more information on virus screening.

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 case-history or a 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 case-history 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)

Connecticut

UConn Home & Garden Education Center (D,I,W,N)

Ratcliffe Hicks Building, Room 4
1380 Storrs Road, Unit 4115
Storrs, CT 06269-4115
(toll free) 1-877-486-6271
www.ladybug.uconn.edu
Cost:  $15

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

The Connecticut Agricultural Experiment Station
123 Huntington Street, P.O. Box 1106
New Haven, CT 06504
www.ct.gov/caes
(203) 974-8601; (877)855-2237 toll-free outside New Haven area
Cost: free

Maine

Insect Pest and Disease Diagnostic Lab (D,I)

Pest Management Office
491 College Avenue
Orono, ME 04473-1295
1-800-287-0279 (within Maine) or (207) 581-3880 (outside Maine)  fax: (207)581-3881
www.extension.umaine.edu/ipm/ipddl
Cost: free to Maine residents

Massachusetts

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

UMass Extension Plant Diagnostic Lab
#3 French Hall, 230 Stockbridge Road
Amherst, MA 01003
(413) 545-3208 fax: (413) 545-4385
http://ag.umass.edu/diagnostics
Cost: $50.00

New Hampshire

The Plant Diagnostic Lab (D,I,W)

UNH Plant Diagnostic Lab
38 Academic Way, G37 Spalding 
Durham, NH 03824
(603) 862-3200

Rhode Island

University of Rhode Island Cooperative Extension Education Center (D,I,W)

URI Plant Protection Clinic
CE Education Center
East Alumni Avenue
Kingston, RI 02881
(401) 874-2900  fax: (401)874-2259
www.uri.edu/ceoc/plantclinic
Cost: $10

Vermont

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

201 Jeffords Hall,
63 Carrigan Drive
University of Vermont
Burlington, VT 05405
(802) 656-0493 fax: (802)656-4656
http://pss.uvm.edu/pd/pdc/
Cost: $15 Vermont residents only