Preparing for post-harvest virus testing

  • before harvest begins provincial field staff will visit your farm
  • you will be asked to sign a Grower Waiver so attending staff can get required information from CFIA
  • once CFIA information is received and seed lots are identified and killed down, sampling will begin
  • you must clearly communicate what testing you require before sampling arrangements are finalized
  • if requested, Bacterial Ring Rot (BRR) sample can be collected with the post-harvest sample
  • the sample size (size chart below) is based on the size of your field and number of tests you require
  • the lab destroys all samples after testing to prevent any contamination
  • growers may request to receive test results by e-mail, Canada Post, fax or phone

Convert acres to hectares
Divide the number of acres by 2.4710
(for example: 200 acres ÷ 2.4710 = 80.94 hectares)
or
Multiply the number of acres by 0.4047
(for example: 200 acres × 0.4047= 80.94 hectares)


Bacterial Ring Rot (BRR)

Provincial field staff will collect samples for BRR testing on your behalf while collecting for post-harvest virus sample. You must identify the fields that require BRR testing so that enough tubers are collected for the combined BRR and virus tests.

It’s mandatory for Federal CFIA inspectors will collect samples from:

  • new seed growers who began growing within the past two years
  • farms affected by BBR within the past six years, and
  • seed lots destined for export markets in Uruguay, Brazil, Thailand and EU

CFIA minimum testing requirement: For replanting on your farm and/or for sales purposes, a minimum of two (2) seed lots per grower (identified by specific grower number) must be tested and found free of BRR before any tags or other forms of proof will be issued. Select the two sampling lots in consultation with your local CFIA inspector.

If the above minimum testing requirement is met, pre-shipment testing of each lot of Pre-Elite, Elite I and/or Certified class stock is not mandatory.

For sales purposes, a sample of each lot of Elite II, Elite III, Elite IV and/or Foundation class seed must be tested and found free of BRR.


Post-harvest testing

All seed lots intended for planting on PEI require Potato Virus Y (PVY) and Potato Leafroll Virus (PLRV) testing in an accredited laboratory. Any seed lots that exceed the total virus tolerance level will not be eligible for planting on PEI.

Post-harvest virus testing is mandatory for:

  • Elite II, Elite III, Elite IV and/or Foundation seed lots that will be replanted the following growing season on PEI.
  • Pre-Elite and Elite I seed lots, if any or all of the seed lot is to be sold off the farm on which it has grown. If all PE and EI seed is to be replanted on the originating farm, it is exempt from mandatory testing.

Improve accuracy
Multiple samples from a single seed lot will improve the accuracy of the post-harvest virus test, especially in large lots with multiple fields, lots with long distances between fields and situations such as multiple seed sources or different virus pressure around individual fields.

Post Harvest Virus Limit

The post-harvest level of seed lots planted cannot exceed 2% Potato Leafroll Virus (PLRV) or 3% total virus (PLRV+PVY).


Retesting

 

View sample submission tag at full size.


Please contact us if you have any questions about testing.