Submitting enough seed is important to ensure that your sample is representative of the seed lot and that sufficient seed is available to complete the requested testing.
The minimum submitted sample size is not the same as the amount of seed used in an individual test. Official testing procedures require a larger submitted sample from which representative portions are taken for analysis.
Minimum Sample Size
For most Quality Lab testing, use the following as a guide:
| Type of Seed | Minimum Amount to Submit |
|---|---|
| Grasses and similarly small seeds | 60 g (approximately 2 oz) |
| Alfalfa, clovers, flax, lespedeza, millet, rape, ryegrasses, and seeds of similar size | 150 g (approximately 5 oz) |
| Proso millet, sudangrass, and seeds of similar size | 500 g (approximately 1 lb) |
| Cereals, vetches, sorghums, and seeds of similar or larger size | 1,000 g (approximately 2 lb) |
| Vegetable and flower seed | At least 800 seeds |
| Tree and shrub seed | At least 600 seeds |
| Coated, encrusted, or pelleted seed | See requirements below |
Vegetable, Flower, Tree & Shrub Seed
When Purity Analysis or Noxious Weed Seed Examination is requested, additional seed may be required. The sample must contain enough seed to meet the minimum working weights required for the species and tests requested.
Coated, Encrusted & Pelleted Seed
Please submit at least:
- 7,500 coated units for Purity Analysis
- 30,000 coated units for a Noxious Weed Seed Examination up to 2,000 grams
- 1,000 coated units for Germination testing only
Germination-Only Samples
Smaller samples may be sufficient when only Germination is requested. The amount required depends on the species and type of seed.
For example, vegetable and flower samples submitted for Germination only should contain at least 400 seeds, although submitting additional seed is recommended whenever possible.
Contact Customer Care if you have a limited quantity of seed or are unsure how much to submit.
Why Do I Need to Send More Seed Than the Lab Tests?
The amount listed for a test method is often the working sample—the portion actually used to conduct that test.
The submitted sample is the larger amount you send to the laboratory. The laboratory mixes and divides the submitted sample to obtain smaller, representative working samples for testing.
Requiring a larger submitted sample helps ensure that the portion tested accurately represents the seed lot and provides enough seed to conduct all requested analyses.
For example, a Purity Analysis uses a working sample representing approximately 2,500 seeds, but the recommended submitted sample may be considerably larger. The additional seed allows the laboratory to obtain a representative working sample and provides sufficient material for other examinations that may be requested.
What If I Have Less Seed Available?
If you do not have the recommended amount of seed available, contact Customer Care before submitting your sample. In many cases, testing may still be possible with a smaller sample, depending on the species and tests requested.
These sample recommendations are based on the AOSA Rules for Testing Seeds. Sample requirements may vary depending on the species, tests requested, and intended use of the results.