Growing high-quality vegetable seed is crucial for seed production success. When selling seed commercially you want to ensure you understand and meet quality standards as well as seed regulations. Basic terms, protocols and regulations are explained below and the resource section will link you to further information.
Common Terms for
Seed Quality Assurance
POPULATION SIZES AND ISOLATION
Self-pollinated plants need be only a few feet apart to prevent the pollen of one plant from pollinating nearby plants of another variety. A small number of self-pollinated plants will make viable seed. Cross-pollinated species may need to be separated by several hundred feet to isolate them from plants of different varieties. Cross-pollinated species may require a population of hundreds or thousands of plants to produce quality seed and reduce the risk of inbreeding.
Before growing seed for commercial sale familiarize yourself with recommended population sizes and isolation distances for the crops you plan to grow. Check with seed companies you plan to sell to see if they have specific requirements.
Download the Seed Viability Assessments and Best Management Practices for Small Scale Seed Savers for guidelines on isolation distances and population sizes.
A germination test is essential for selling seed. Knowing the germination rate of a particular seed lot is key to understanding how well that seed will perform in the field. If your seed has a 90% germination rate, it means 90 out of 100 seeds are likely to germinate under good growing conditions.
You can use this information to better understand the quality of the seed you are producing. Seed companies will want to know how well your seed germinates–they may require you to do your own testing, send your seed to an accredited lab for testing or will do their own germination test.
How to do it
Germination tests can be conducted at home to inform you of how well your seed performs. UBC Farms’ guide to Seed Viability Assessment walks you through the necessary steps. For commercial sale of seed a germination test completed by an accredited seed testing labs is recommended, and may be a requirement for contract growing. Accredited seed labs in Canada follow germination test methods approved by the Canadian Food Inspection Agency. To conduct the test, 200 seeds are taken at random from the seed lot being tested and evenly spaced on a blotter so they’re not touching, moistened then left for a prescribed amount of time to germinate.
PHYSICAL PURITY TEST
A physical purity test or physical purity analysis measures the proportion of pure seed component in the seed lot as well as the proportion of other crop seed, weed seed, and inert matter. The measurements are taken by weight and given in percentages. The percentage of physical purity is one of the measures used to determine seed grades—explained further below.
A purity test is typically completed by a lab, but it may be done outside of a lab by following the methods recommended by CFIA. The analyst takes a representative sample from the seed lot and physically looks through all of the seeds present, removing the species that are not labeled on the submitted bag. These seeds are identified, classified, and reported according to the applicable Grade Table in CFIA’s seed regulations (discussed below).
Disease testing is often not required for commercial sale of vegetable seed in Canada, but if there is a problematic disease present on your farm or in the region that affects the seed crop you are growing disease testing may be required or recommended to prevent the spread of disease.
The objective of seed disease (pathology) testing is to determine the health of the seed lot for use in planting. Not all plant diseases are contained in or on seed but it is important to know if you have one or more that is. Seed may contain plant pathogens or agents that may affect storage, vigour, germination, market availability, harvest yield, seed appearance, or contain toxins. Plant pathogens include: fungus, bacteria, viruses, and nematodes. When infected seed is planted the pathogens spread. Many of these can persist in soil and become a problem for many years.
There are many ways to test seed health in the laboratory. The most common and reliable are incubation tests. The seed is pretreated and plated on specialized media, which favour the growth of the organism being looked for. The plates are then incubated and examined by a seed pathologist for specific traits. Visual tests can be used to spot disease bodies in seed lots. DNA and Immunoassay tests, which look for genetics of a pathogen, can also be used.
Most Canadian seed labs focus on grain and legume seed, but can also test vegetable seeds.
for Sale of Vegetable Seed
The Canadian Food Inspection Agency (CFIA) is responsible for the administration of the Seeds Act and Regulations to help ensure that seeds sold in, imported into and exported from Canada meet established standards for quality and are labelled so that they are properly represented in the marketplace, and are registered prior to sale in Canada (most agricultural crop varieties).
Seed imported into or offered for sale in Canada must meet the quality standards established in the Seeds Regulations (the Regulations). The Regulations specify how the seed is sampled, how it is tested and who is qualified to conduct the sampling and testing to determine if the seed meets those standards.
The sampling and testing methods established by the Regulations are minimum requirements. Seed sampled and tested by more rigorous methods will also satisfy the conditions in the Regulations.
Canadian seed regulations primarily focus on grain and legume crops, but requirements for purity and germination testing do apply to vegetable seed crops and minimum standards for many vegetable seed crops are listed in the regulations. All commercial seed growers should be aware of these regulations and standards.
REQUIREMENTS FOR SALE OF “COMMON” SEED
In Canada there is not a registration systems for vegetable seed crops. Vegetable seed crops are considered non-pedigreed (common) seed. All non-pedigreed (common) seed that has been advertised for sale must be tested for purity and germination prior to labelling with a grade name for sale in Canada.
According to CFIA requirements, if requested by a purchaser, every vendor of seed must supply purity and germination test results, in writing, within 30 days of the request. Seed must be tested using recognized standard procedures such as the Canadian Methods and Procedures for Testing Seed—this can be done in an accredited lab or outside a lab following the same testing methods.
Many medium to large scale seed companies include statements about seed grades on the packaging and only purchase graded seed. Seed grade names indicate that the seed lot has been sampled, tested and graded according to Regulations and has met the quality standards established in the Grade Tables.
A grade name (e.g., Canada Certified No. 1) has two components:
- the first component indicates the pedigreed status of the seed (e.g., Foundation, Registered, Certified or Common status); and
- the second component (e.g., No. 1 or No. 2) indicates the prescribed standards that the seed meets for percentage germination, weed seeds, seeds of other kinds and disease.
To establish the grade name each seed lot needs to be tested for germination and purity. Additional disease testing may be required in some cases.
Selling seed without a grade
Small-scale vegetable seed producers may sell their seed in Canada without a grade name if:
- The seed package is labelled according to Section 30 of the Regulations
- The seed meets weed seed and crop seed standards
- Seed testing is undertaken and recorded according to recognized methods, e.g.,
b. Germination tests
c. Purity tests
4. Seed is labeled using the proper variety name
Resources for More Information
Seed Viability Assessment and Best Management Practices for Small-Scale Seed Savers. By Julian Napoleon, Mel Sylvestre, Andrew Riseman – Centre for Sustainable Food Systems, UBC Farm