How to Collect Plant Samples for Plant Disease Identification

The Plant Disease Diagnostic section of PEI Analytical Laboratories is now open and accepting samples for the 2022 season. Samples may be dropped off directly to the lab, or at PEI Access sites outside of Charlottetown.

The Plant Disease Diagnostic Service provides farmers, agri-business and agricultural extension staff with a disease identification and control advisory service.  Diagnoses are based on visual examination of symptoms, microscopic observation and explicit laboratory techniques.  

What is the objective of the Plant Disease Diagnostic service?

The objective of this program is to provide clients with a fundamental service, identifying the problem and providing information to control the problem if possible, and to prevent any reoccurrence.  All sample results are followed up with a written disease diagnostic report, fact sheet on the disease and a Crop Specialist visit if needed. 

How is the diagnostic information used to assist agriculture on PEI?

The collection of data is recorded using Plant Health Reporting System (PHRS).  This computer program can be utilized to query information on specific diseases, and to monitor disease status for new and existing diseases.   Through the collection of data (PHRS), all pest levels are recorded for the Crop Specialists, Pest Hotlines and the farmers. Timely information on pest levels help farmers make informed decisions on the utilization of appropriate control measures and management practices.

How can I identify a potential plant disease problem?

When investigating a potential plant disease problem, good observational and detective skills are necessary. The sample should be fresh material with several examples of visual symptoms expressed from healthy to infected tissue.

Examples of observations a collector should make include:

  1. pattern of disease in the crop;
  2. frequency of the disease symptoms; and
  3. inspect the interior of roots and stems to identify if internal symptoms exist.

Procedure For Sample Collection, Packaging and Submission

The following procedures for obtaining, packaging and submitting the sample are suggested.

  1. Obtain a fresh sample with several examples ranging from healthy to infected tissue.
  2. Include as much of the plant as is practical, especially the root system. Place root system in a separate plastic bag to avoid drying out and soil contaminating the leaves.
  3. A leaf and potato tuber sample should be large enough to give a good indication of the problem: approximately 10 to 20 leaves or 15 to 20 pounds of tubers.
  4. Place samples in appropriate bags: tubers in paper bags and leaf tissue in plastic bags with a moist paper towel and air.
  5. Keep samples cool and moist, protected from crushing, freezing and heat.
  6. Label the sample with the pertinent information required.
    1. Name of Grower
    2. Date of Collection
    3. Variety
    4. Statement of Problem
    5. Growers' Telephone Number

What information is required when submitting the sample?

Background Information

  1. Identify the crop, variety and any information on management practices that may have adversely affected the plant; for example fertilizer rates, pesticides applied.
  2. Identify environmental conditions preceding and during disease development: temperature, humidity, ventilation.
  3. Note the rate of disease development, coincident with any treatment or environmental event.

Remember: A concise, accurate plant diagnosis can only be completed when a fresh, representative sample of the disease problem is submitted to the laboratory.

When and where can samples be submitted?

Samples can be submitted at the Plant Health Lab  until November 30, 2022:

Plant Health Lab
c/o Marleen Clark
Phone: (902) 368-5261

PEI Analytical Laboratories
23 Innovation Way, Charlottetown

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Published date: 
July 29, 2022
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General Inquiries

PEI Analytical Laboratories
23 Innovation Way,
BioCommons Park,
Charlottetown, PE C1E 0B7

Phone: 902-620-3300
Fax: 902-569-7778

Hours of Operation:
Summer (June - September) 8:00 a.m. to 4:00 p.m.
Winter (October - May) 8:30 a.m. to 5:00 p.m.