North Dakota is known for vigorous, disease-free, seed potatoes produced in a climate that promotes production of high quality seed. Strict certification tolerances recommended by North Dakota seed potato growers and demanded by the commercial industry contribute to a system that produces the most consistent performing seed in the industry. The program inspects between 10,000 to 15,000 acres of different varieties of seed potatoes each year, making it the second largest seed potato program in the United States. Certification of seed potatoes in North Dakota is a function of the State Seed Department as authorized in North Dakota Century Code Chapter 4.1-55

Program administration and seedstock production operations are located in the main Seed Department office in Fargo. A regional facility located in Grafton houses supervisors and staff associated with field inspection and shipping point inspection.

General responsibilities of the Seed Potato Certification Program include:

  • Provide traceability documentation of seed lots for approval of seed stock eligibility
  • Inspect seed fields for varietal purity and disease
  • Provide shipping point inspections for physical quality factors
  • Conduct post-harvest testing of seed lots to determine eligibility for re-certification
  • Conduct disease testing for detection and symptom confirmation of prevalent pathogens
  • Implement regulations according to administrative rules
Accordion Section Title
Accordion Section Title
General Requirements


  • Field inspection applications and at least one-half of the fee must be received by June 15th each year. The remainder is due after final acreage is determined.
  • Prompt payment of fees is required in all cases, and up-to-date accounts are required for acceptance of applications.





  • An inspection may be cancelled by the applicant only if:
    • the inspection has not been completed
    • the inspector has not already incurred travel expenses to the field
  • Cancelled acres must be destroyed to reduce disease problems
  • Inspection fees, less $20 administrative cost, will be refunded to the applicant.
  • A field that has failed an inspection may not be cancelled
  • Drown-out losses, if over 25% of the field, will be credited at the discretion of the Seed Department.

Seed Farm Requirements

  • All potato fields on a farm or in a farming operation must be eligible and entered for certification. The eligibility of farming operations is determined by the Seed Department.
  • All equipment and storage facilities must be used only on the acres entered, and must be disinfected annually.
  • Field boundaries must be clearly defined and adequate separation between certified and uncertified fields must be maintained.
  • Seed potatoes may not be planted on fields planted to potatoes the previous year, unless the field has been fumigated.
  • All cull piles in the operation must be destroyed.  

Seed Source Eligibility and Documentation

  • Foundation class seed lots of North Dakota origin that passed field inspection and winter test program requirements
  • Foundation or another approved seed lots originating outside North Dakota that passed field inspection and winter test program requirements or post-harvest laboratory testing approved by the Seed Department. These seed lots may be subjected to additional testing by an approved laboratory. Additional documentation, including health certificates, field inspection reports or winter test results are required prior to acceptance.
  • Proof of purchase must accompany application to provide evidence of origin and quantity of seed. A combination of shipping point certificates, North American health certificates, affidavits or receipts are acceptable.
  • Authorization from the owner is required to produce any variety protected by patent or PVPA.
Accordion Section Title
Seed Classes - Limited Generation System

Seed potato certification programs use a Limited Generation increase system, in part, to define seed lot eligibility.  Every growing season, plants are exposed to pathogens and the diseases they cause. A disease that infects the plant may be expressed in the tubers it produces. The following season, these infected tubers may become a source of inoculum, infecting other plants or fields. Limiting the number of generations of field production for certified seed lots is important for controlling disease.

Producing disease-free sources of seed potatoes every year is essential. Annually, fresh, disease-free seed potato lots are generated in-vitro (tissue culture) and in greenhouse production. These disease-free seed lots are eventually planted in the field, starting another cycle of seed increase.

In North Dakota, certified seed is limited to seven years of reproduction in the field. Limited Generation systems identify a starting point for each seed lot, giving it some type of designation. Beginning in 2020, North Dakota will utilize Field Year to define generations and be more consistent with terminology used throughout the industry. The first field year will be FY1, followed by FY2, FY3, FY4, FY5, FY6, and C for the last possible year of the limited generation increase. The Certified class is the progeny of FY6 production, and used only for commercial planting purposes. Seed is downgraded (advanced in generation) if it does not meet tolerances for disease or varietal purity for the generation applied.

Accordion Section Title
Field Management & Inspection

Seed Department potato inspectors check fields a minimum of three times during the pre-harvest period. Inspectors perform the first inspection approximately 45 days after planting and the second approximately 10 days later to determine virus levels, presence of disease, varietal purity and other factors associated with seed quality. A third inspection is performed prior to vine-kill primarily for the purpose of detecting bacterial ring rot.

Some varieties, especially those known as potentially symptomless or that express very mild symptoms, are subjected to laboratory testing for the presence of mosaic viruses. Growers may choose to have any seed lot summer tested for virus X and other pathogens.

Growers are responsible for maintaining the quality, health and condition of seed fields in the program. Among the most important factors:

  • Insect control must begin early and be maintained until vines are desiccated. Excessive insect injury can lead to disqualification of seed lots.
  • Vine desiccation may only commence after approval from inspectors.
  • Factors such as excess weeds, hail damage or chemical damage that interfere with the inspector’s ability to determine field condition may lead to disqualification.
  • Growers are encouraged to rogue early and often, in an effort to reduce incidence and spread of serious viruses.
  • Fields are re-inspected at the discretion of the Department, if requested within three days of rejection and provided no additional roguing has occurred.
Accordion Section Title
Seed Control Areas

The seed certification program also facilitates the implementation of the Seed Potato Act (Chapter 4.1-56 of the Century Code). This act allows the creation of a seed control area in the state, with the approval of a sufficient number of landowners in the isolation area.

North Dakota has one official seed control area, near Cando. Historically, North Dakota has produced some of the finest seed in the United States due to a rotation of seed stocks from isolated areas, to the Cando control area, to the Red River Valley.

Production of nuclear and low-generation seed takes place in isolation areas near Grenora. Nuclear and low-generation lots move to the Cando or other well-isolated production areas, then on to seed farms in the state. North Dakota’s seed production occurs primarily in the northern Red River Valley, but seed is also produced in other well-isolated areas in the southeast and south-central parts of the state. Production from these farms is used primarily for seed recertification, or in commercial production of table stock and processed potatoes in North Dakota and other states.

Accordion Section Title
Post-Harvest Testing

Post-harvest testing, conducted annually, is necessary to determine eligibility for re-certification of the lot. Excessive amounts of virus make the lot unacceptable for certification. Virus is the main factor, but other factors such as mixture, herbicide damage, vigor and other diseases may cause the lot to be rejected for re-certification.

North Dakota’s post-harvest test takes place near Waialua, Hawaii, on land owned by the North Dakota Certified Seed Growers Association. Representative seed samples are shipped to Waialua during the first week of November and planted approximately 1-2 weeks later.

In early January, Department officials inspect seed lots in a manner similar to summer field inspections. Laboratory testing is also done, especially on varieties known to mask virus symptoms.

Test results, published in the Winter Test Directory, provide valuable information to North Dakota growers about the eligibility of seed lots for planting and certification the following season.


Additional Resources

Chapter 74-04-01-09  

Post Harvest Test Results

Accordion Section Title
Labeling Requirements

State and federal regulations require seed to be labeled accurately and truthfully. The requirements for certification of any lot of potatoes are not complete until properly labeled. The grower is responsible for properly labeling seed.

By law, growers must provide a purchaser a copy of the tag or certificate for each container of seed sold. Official labels (tags or bulk certificates) are provided to growers by the Seed Department at the request of the grower. Growers may request a tag or bulk certificate that contains information such as the grower’s name, variety of seed and generation passed. Each type of label will also indicate the official ND grade of seed, if it has been subject to a shipping point inspection. Tags, which may be attached to bags or tote shipments, are colored to indicate the grade of the seed labeled.

  • ”Blue Tag” seed has passed field certification and meets North Dakota standards for physical defects (based on USDA grade #1 standards).
  • “Yellow Tag” seed has passed field certification and meets a slightly lower standard for physical defects.
  • “White Tag” seed has passed field inspection and is graded according to agreement between the seller and the purchaser as to size and defects.

The physical grade of the tubers is indicated on the bulk certificate, along with other factors mentioned above. Rules state that grade inspections are compulsory for seed shipped out of state, and voluntary for seed shipped within the state of North Dakota.