Seed Sampling and Testing
No matter how accurate the seed analysis, it reveals only the quality of the sample submitted. It is important, therefore, that certain procedures be followed in collecting seed samples for testing purposes which most nearly represent the bulk of the seed in a given lot.
General Procedures
- Take equal portions from evenly distributed parts of the quantity of seed to be sampled.
- For free-flowing seeds, use a probe or trier long enough to sample all portions whether seed is in bags or bulk.
- For non-free-flowing seed, such as chaffy seeded grasses, thrust the hand into the bulk and withdraw representative portions.
Obtaining a Representative Sample for Laboratory Analysis
- When more than one core or handful is drawn, follow different paths.
- For lots of one to six bags, obtain a sample from each bag.
- For lots of more than six bags, sample five bags plus at least 10% of the number of
bags in the lot. Regardless of the lot size, it is not necessary to sample more than
30 bags.
For example, seed lots consisting of 7, 100 and 400 bags, each would require 6, 15, and 30 bags to be sampled, respectively. For bulk seed, a composite sample may be obtained by taking many cores or handfuls as if the same quantity of seed were in bags of an ordinary size. Take samples from well distributed points throughout the bulk. - For samples taken during cleaning/conditioning sub samples should be taken periodically from the clean seed stream and combined to form a composite sample.
Downgrading Seed
Foundation or Registered seed may be downgraded to lower classes at the discretion of the grower.
Substandard Seed
Certain seed quality factors other than genetic may be affected by environmental or other conditions which make it impossible or unfeasible for the seed to meet the minimum certification standards for those factors. Seed in this category may be certified upon request of the grower. The cause for the substandard classification will be stated on the certification label.
Carry-over Seed
Certain seed quality factors other than genetic may be affected by environmental or other conditions which make it impossible or unfeasible for the seed to meet the minimum certification standards for those factors. Seed in this category may be certified upon request of the grower. The cause for the substandard classification will be stated on the certification label.
Blending of Seedlots
It is permissible to blend seed lots of the same variety or hybrid. When blending two or more lots, the blended lot assumes the certified class of lowest class utilized in the blend. The production year will be the year of the oldest component utilized in the blend. Seed lots rejected for certification because of prohibited weed seeds cannot be used in the blended seed lot. A “Blend of Certified Seed” refers to a planned mixture of certified seed of different varieties on one or more crop kinds. The label, Plant Variety Protection Acknowledgement Form, and other documentation must specify that it is a blend of certified seed.
- Each blend must be approved by OCIA prior to blending.
- Blending may only be done by an OCIA Approved Conditioner. The conditioner must demonstrate the ability to blend within specified tolerances.
- Only Registered or Certified seed of each component variety may be used in the blend. Both will be designated “Blend of Certified Seed”.
- Formulas for each blend must be recorded with OCIA and shall not vary between lots and between years.
- Several components are acceptable, however, each component must be greater that 15% of the whole by weight. The tolerance for each component must be no greater than plus of minus 5% of the whole.
- Permission to use a protected or private variety in the blend must be obtained from the owner and submitted to OCIA.
- A blending report must be provided to OCIA prior to blending.
- For each component of the blend
- Lot Number
- Crop Kind
- Variety Name
- Grower
- Pounds of seed of this lot in blend
- Certification Number
- For the blend
- Name assigned to this blend
- Total pounds of seed in blended lot
- Lot Number of blended lot
- Conditioner Name and address
- For each component of the blend
- The certification tag on each bag of the blend will state: “Blend of Certified Seed”. The following information will also be on each tag: Blend name of number, crop kind(s), lot number, approved conditioner name or number. If no blend name or number is selected, the names of the component varieties will be used. This information must be written on the “Plant Variety Protection Acknowledgement” form (or receipt) for small grains sold in bulk.
- An analysis tag to meet State and Federal Seed Laws must be attached to each bag of the blend. This information must be written on the “Plant Variety Protection Acknowledgement” (or receipt) for small grains sold in bulk.