Seed Potato Production Pyramid

Seed potato production in Canada uses a limited generation system, which means that seed passing inspection must advance to a lower class with each generation of production. A seed crop for each production generation cannot be maintained at a specific class or move to a higher class.

Nuclear seed is at the top of the seed potato production pyramid is Nuclear Seed. Nuclear seed must be produced from disease free parent stock in a protected environment (a growth room, greenhouse or screenhouse). The parent stock has been extensively tested to confirm the absence of potato pathogens. Nuclear stock production is subjected to a series of laboratory tests to confirm freedom from certain potato pathogens. These pathogens include: potato virus X (PVX), potato virus S (PVS), potato virus M (PVM), potato virus A (PVA), potato mosaic virus (PVY), potato leaf roll virus (PLRV), potato spindle tuber viroid (PSTV), and bacterial ring rot (BRR).

In the field, seed can be increased for seven years. There are therefore seven sequential classes of seed potatoes in the Canadian Seed Potato Certification system

Seed Potato Production Pyramid.

Class	Field generation
Pre-elite	1st generation seed
Elite 1	2nd generation seed
Elite 2	3rd generation seed
Elite 3	4th generation seed
Elite 4	5th generation seed
Foundation	6th generation seed
Certified	7th generation seed

Each class has a defined tolerance level for the presence of certain diseases and foreign varieties. All classes must be completely free of spindle tuber and bacterial ring rot. The tolerance levels for the other diseases increase slightly with each class produced. Therefore, the class designation describes a precise seed quality based on parentage and the amount of disease detected in the growing crop. Parallel to the schedule of classes is a field generation designation. Contrary to the class designation, the field generation does not involve disease tolerance levels and is not a quality designator. Generation is a term that identifies only the number of years that the seed has been grown in the field or the number of field production generations after Nuclear Seed.

Application to become a new seed grower
Anyone interested in becoming a seed potato grower should contact the local office of the CFIA. This should be done at least three months prior to receiving seed supplies for the spring planting.

An application made by a new grower will only be approved when cleanup and an inspector of CFIA has verified disinfection of the premises and equipment. This must be carried out before the grower can receive seed potatoes. A new applicant should also be aware that land used for seed potato production must not have been in potato production during the previous two years.

Application for crop inspection
Applications for field inspection should be made on forms supplied by CFIA. The completed application, payment of assessed fees and other required information should be delivered to the address given in the application package for all interested seed potato growers. The application deadline for seed potatoes is June 15 of the current crop year. The following information must be provided for each potato field planted:

1. Variety
2. Hectares
3. Seed Potato Class and certification number
4. Weight planted (in cwt or kg)
5. Location of the field
6. Previous crop grown on the field

1. An official tag from one container of those potatoes purchased in containers (The remainder of the tags from bagged seed must be retained by the applicant for inspection by the inspector).
2. A copy of the bulk-movement certificate in the case of seed potatoes purchased in bulk.
3. A copy of a nuclear stock certificate in cases where nuclear stock is planted.
4. An Import Permit from CFIA headquarters and a Phytosanitary certificate from the USA are necessary to import seed potatoes. In addition, for certification eligibility a Bacterial Ring Rot test from an accredited Canadian laboratory is required and a North American Seed Potato Health certificate from the state of origin is recommended to determine class eligibility of the seed potatoes in the Canadian system.

The total area entered for certification is less than 0.25 acres (or 0.1 ha) in size.
Bacterial ring rot infected potatoes were found in the field, buildings, or on equipment used by the grower.
An inspector did not verify cleanup and disinfection of the buildings and equipment.
Non-eligible potatoes have been planted on the farm. The following are identified to be non-eligible potatoes:
	Certified class seed potatoes
	US seed potatoes that do not have any Canadian class equivalency.
	Non-certified (table) potatoes
	Seed potatoes exposed to contamination by ring rot
The crop is growing in a field where there has been an occurrence of bacterial ring rot. (Unless the inspector has verified that the field has been free of potatoes, including volunteers for the previous two years.)
The certification fee has not been paid.

1. A condition exists that interferes with an inspector's ability to conduct a visual inspection of the crop. This can include poor growth, lack of vigor or leaf injury brought about by late planting, lack of cultivation, the existence of excessive weeds, weather conditions, soil conditions, chemical injury, insect damage or pesticide damage.
2. The field is located within 197 feet (60 metres) of another field that has visible symptoms of a virus disease that exceeds the tolerance limits for the class of seed being produced.
3. The distance between adjacent seed potato fields is less than one blank row.
4. The crop is growing in a field where non-certified potatoes were planted in the previous two years.

1. Class and variety,
2. Number of hectares that passed inspection, and
3. Certificate number.

1. An inspector learns that any one of the lots are infected with Clavibacter michiganensis subsp sepedonicus (Bacterial Ring Rot).
2. An inspector has determined that the crop does not meet the standards for any class of seed.
3. An inspector has determined that the crop has been infected with the potato spindle tuber viroid.
4. The crop has been treated with or exposed to a sprout inhibitor.
5. Any one of the lots has come into contact with used, shared or custom equipment that was used in the harvesting, storing or grading of a lot that was infected with ring rot bacteria.
6. The seed potatoes have lost their identity.
7. The seed has lost its ability to propagate.
8. The inspector determines that non-certified potatoes from another farm are stored with the certified seed potatoes or that the certified seed potatoes were stored, graded or handled with common equipment.

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