When planning their successful farming enterprise, farmers often start with buying high-quality seed. Before even reaching the marketplace, Certified Seed goes through inspection to ensure:

1. the amount of weed seeds present does not exceed allowances,
2. is the known cultivar desired to purchase, and
3. has a high germination rate, among other traits.

For this inspection to happen, independent organizations inspect the production field and resulting seed and certify these requirements before they are sold to a farmer.

There are five different classifications of seed that can occur. All states, along with the Federal Seed Act which provides rules for interstate commerce, have rules for how seed must be labeled. Regardless of the class of seed that a farmer is buying, labeling is important. It should describe the purity and germination of the seed lot, as well as other factors that may be necessary under local seed law. When purchasing seed, farmers should request to see this label, regardless of class, to ensure they understand the quality of seed they are buying.

As every state and crop has slightly different regulations for classification and labeling, we will discuss the process for small grains in the state of Washington.

Breeder Seed

Breeder seed is derived from the plant breeding program itself and is not under oversight from independent organizations. When plant breeders develop a new cultivar, they often only have limited amounts of seed. This first step in the process allows the plant breeder to increase the quantity of seed produced. More work allows a purification process to occur where the plant breeder can remove plant types that are not representative of the cultivar. Once this is done, the plant breeder releases Breeder Seed that then begins the process of increasing the seed amounts to quantities large enough for commercial production.

Foundation Seed

This level of seed typically comes after Breeder Seed, is the highest purity classification, and starts the certification oversight. Foundation Seed would look most like Breeder Seed in terms of genetic purity. It also has strict requirements for other traits, like purity. This means low or zero tolerance for Foundation Seed bins to be contaminated with weed seed, seed of other market classes, and seed of other crops.

Foundation Seed of varieties bred and released by public programs (typically universities and USDA-ARS) is usually maintained by a Foundation Seed Program. These are often housed in university programs or an independent agricultural nonprofit. Private breeding programs are also allowed to produce their own Foundation Seed stocks. Regardless of the producer of the seed, it is held to the same high standards for field and seed by the agency that handles certification.

Registered Seed

Seed companies usually plant this high-quality Foundation Seed to produce Registered Seed. Registered Seed still keeps high purification standards but is a step down from what was seen in Foundation Seed. For example, the tolerances for ‘other crop types’ in the production field and seed may be 1 in 5,000 for Registered Seed, while in Foundation Seed they may be 1 in 20,000. Growers buy some Registered Seed for production, but most advances to the final certification stage by the seed company.

Certified Seed

Certified Seed is produced after planting Registered Seed and is the certification class that most farmers would buy if they wanted a high-quality seed source. Certified Seed has a verification that it is the cultivar the farmer wants to purchase. It has been germination tested to meet a certain standard but may have some contaminates in it such as trace amounts of the same or other crop types, or small variants of the same cultivar. Although all the previously listed seed classifications are under rigorous standards, contaminants can occur. Even though equipment is thoroughly cleaned between different varieties of the same crop, a few seed may remain on this shared equipment, resulting in the contaminate. This is the last of the three classes of seed managed by the certification agency.

Common Seed

Seed that has not gone through the certification process is often referred to as Common Seed. Common Seed is held to no standard other than basic seed labeling laws. It is sold ‘as is’ and could have mixtures of other crops, market classes, or weed seeds. Although a cheaper option for growers, with no guarantees about what the seed contains, there are possibilities of crop failures because of it. To maintain high purity, some cultivars are not allowed to be sold as common seed. They can only be sold as one of the certification classes listed above.

Farmers can purchase any class of seed listed above (except usually Breeder Seed). If farmers want to purchase Foundation seed, they typically must request this from the breeding company. This typically does not happen, as Foundation seed is very expensive. Farmers usually work through a seed dealer, where they can put in a request for a certain variety. Seed dealers maintain large quantities of seed (typically Certified class) of which farmers can buy in bulk to plant on their farms. Certified Seed is always recommended for farmers as the best purchase option to guarantee a high-quality seed of known variety. Starting with this seed gives the farmer the best chance of a successful harvest at the end of the season.

Answered by Arron Carter, Washington State University and Lauren Port, Washington State Crop Improvement Association

This blog is part of Crop Science Society of America’s Seed Week celebration. Why celebrate seeds? Anyone who plants a seed is investing in hope. That’s one of the attractions of seeds. For the gardener, it could be hope for a beautiful flower, or perhaps a delicious zucchini squash. For our farmers, seeds are the hope of this year’s yields of produce, cash crops or forage. No matter the size or shape of the seed, they all can bring forth new life. At Crop Science Society of America, we hold seeds in very high regard. Please visit our Seed Week webpage for news stories, blogs and more information about seed research and facts.

Please visit our Seed Week webpage for more information.

Read the other blogs in our seed series!

How can you prevent weed seeds from germinating in your garden?

Protecting Seeds: The What, Why, and How of Seed Treatments

How does the USDA help make global seed trade safer?

The Incredible, Edible Seed

Why are seeds of different sizes and shapes?

What are seeds made of – and how can they grow into fruitful plants?!

About us: This blog is sponsored and written by members of the American Society of Agronomy and Crop Science Society of America. Our members are researchers and trained, certified, professionals in the areas of growing our world’s food supply while protecting our environment. We work at universities, government research facilities, and private businesses across the United States and the world.