From a reader who knows a lot about seeds.... some words about seed safety.

Seed Analysis and Seed Testing

Seed analysis pertains to the testing of seed that is to be sold through commercial channels to farmers, gardeners, and other seed growers. Every bag of seed that is sold has to have a "seed label" attached to it.

Because of this, each seed lot being sold has to be analyzed for certain physical and quality aspects. Each seed company has their own seed lab that does these tests and most states have a state seed laboratory that does these tests for regulatory purposes.
The Federal Seed Act and the Seed Label

The Federal Seed Act requires three seed tests be performed on every lot of seed sold that crosses state borders in the US. These are the purity analysis, the noxious weed seed exam, and the germination test.

The results of these seed tests have to appear on the seed label that accompanies each bag of seed being sold (packets exempt but not the seed lot they came from). These results of the seed analysis of a seed lot allows growers of seed to evaluate the quality of the seed they buy.

The Seed Purity Analysis Examination

The purpose of the purity analysis is to determine the physical composition and quality of a seed lot. This begins by verifying the identification of the species being sold. This requires the seed analyst to be able to identify seeds.

The seed sample being analyzed is then broken down into four components: the Pure Seed (crop being sold), other crop seed, weed seed, and inert matter (soil, insect parts, plant material, and fungal bodies, etc).

The purity test checks for (and prevents), adulteration of seed lots to protect the consumer buying the seed through fraudulent representation. There are natural variations that occur in a non-uniform product such as seeds and this needs to be taken into consideration.

Because of this, these seed tests are standardized, as much as statistically possible, by seed laboratories adhering to the AOSA "Rules for Testing Seed" and other international seed testing protocols.

The results from this seed test become a percentage of each of the four components that are separated out during the examination.

The seedsman selling the seed also are given the identity of all the weed seeds and other crops found within the seed lot. This gives them the option of further cleaning the seed and eliminating them.

The Noxious Weed Seed Examination

Sometimes, noxious weeds are found in the analysis. These seeds are defined as noxious weed seeds" by the Federal Seed Act as well as by the seed acts of each individual state. Noxious weed seeds are from plants that the various states want to prevent from growing and spreading, thus becoming a problem to agriculture.

A special seed analysis test called the noxious weed seed exam is performed on a larger sample of the seed lot to find all the noxious weed seeds that might exist.

Noxious weed seed is divided into two groups, "primary" and "secondary" noxious weeds. These are commonly known as "prohibited" and "restricted" seed.

If Prohibited seeds are found within the seed sample being analyzed, they make the seed lot un-saleable. Restricted seeds can be found in the seed lot, but they have to be identified on the seed label and the number per pound of seed indicated.

In this way, growers are aware that they are planting these weeds with the crop they are sowing and can take measures to eliminate them from their fields.
The Seed Germination Test

The third seed analysis test that is required by law is the germination test. This seed test evaluates the quality of the seed being sold by germinating the seed and getting a percentage of germination that is printed on the seed label.

This information gives the farmer an idea of what the potential crop "stand" will be when they plant the seed in their fields (and what planting rate they should use).

Not all seeds that germinate are counted in the seed germination percentage. Some seeds that germinate will not emerge from the ground or will not be able to compete and produce a favorable yield. Others will be so delayed in their growth that they will not be mature at harvest.

These seeds produce seedlings that are considered "abnormal". Abnormalities are caused by "mechanical damage" when harvested or through handling before being bagged for sale. Other abnormalities are a result of physiological problems or disease.

Deborah Peterson
I
Braham, MN

PS Each state has its own seed rulings and recommendations, so check with your local agricultural authority for further information.

Blessings. Kathleen