• Germination
Germination is the measure of how well a seed produces a normal, healthy seedling when planted under ideal conditions. The standard germination test, evaluated under the temperature considered ideal for each species, provides an estimation of seedling emergence if soil conditions at planting and during early seedling growth are near optimum. The results of the standard germination test are printed on the seed tag.

Each species has a specific range of temperatures at which germination occurs. If temperature at planting falls outside this range, germination may be slowed or prevented, and during extreme conditions the seedlings may die.

Excessively high or low temperatures also can induce secondary seed dormancy, causing a delay in germination and establishment. It is therefore important for growers to be aware of the germination requirements of the species that is planted and to sow fields when conditions are favorable.

• Genetic purity
The genetic constitution of a variety will influence disease and insect resistance, plant response to climatic extremes, forage quality and many agronomic characteristics. Growers should purchase seed of a known variety that has been tested for their area.

In some areas, forage seed may be sold “variety not stated.” However, growers should realize that purchasing seed of an unknown variety often leads to low yields, reduced stand life and increased cost.

Genetic purity, or trueness to variety, is established and maintained by special purification and seed increase programs, by field and seed inspections and by pedigree records. The best assurance of obtaining genetically pure seed is to buy certified seed, clearly identified by the “blue tag” (Figure 1*). The blue certified seed tag is issued only to seed lots that meet specific genetic, physical and physiological standards.

• Crop purity
Seed lots with even small amounts of weed seed or other crop seed can cause serious economic losses and diminish forage quality. Weeds and other crop plants compete with the desired species for nutrients, space and soil moisture and are often difficult or expensive to control.

Seed analysis tag
The seed analysis tag or label contains information based on germination and purity analysis of a representative sample taken from the seed lot. The following information is found  on the seed tag:

• Kind and variety
The “kind” of crop refers to the species. If the variety is not given, the seed tag should bear the statement “variety not stated.” When two or more varieties or kinds are named, the word “mixture” or “mixed” must appear on the label.

• Germination
This notation tells the percentage of pure seed that germinates. The percentage is based on the number of seeds that produced normal seedlings following a specified test period (a normal seedling being one that has the essential structures necessary for plant survival). If more than one kind and variety are named, the germination percentage must be shown for each.

Some forage species are dormant when harvested, and the dormancy period may last for a few weeks to several months. When seeds are dormant, they are still viable but will not germinate when placed in the proper germination environment. Special pre-conditioning treatments must be used to break or overcome this dormancy.

It is possible to buy seeds that have high germination potential, but if dormancy has not been broken, they will not germinate in a timely fashion  when planted. Dormancy of most species can be broken by storing the seeds at room temperature for several months before planting. However, some species, especially native grasses, have a deeper dormancy that is more difficult to overcome. These species will frequently require prolonged exposure to cold, moist conditions prior to germinating.

• Origin
This label entry identifies the state or country in which the seed was grown. If the origin is unknown, the statement “origin unknown” must appear on the label.

• Lot number
Lot number allows the seed producer and buyer to identify the specific unit from which the seed were taken. The term “lot” means a definite quantity of seed that is uniform throughout for the factors that appear on the label. This information is useful in cases of performance problems.

• Net weight
This is the weight of the seeds only – minus the weight of the container. Many seeds are routinely coated with lime and various pesticides and rhizobium; the tag will indicate either weight of coating or net of seed without coating.

• Pure seed
This percentage tells the total weight of seeds of the kind and variety stated on the tag. If more than one kind or variety is named, the pure seed percentage of each component must be given.

• Inert matter
Extraneous material, such as dirt, stems, leaves, and seed parts in the seed lot, is described in this category. Inert matter reduces the value of seed. It is best to choose seed with less than 2 percent inert matter.

• Other crop seed
The percentage of the total weight from seed from a crop other than the kind and variety listed is indicated here. High-quality seed should contain no seed from other crops.

• Weed seed
Weed seed contamination is expressed as a percentage of the total weight. This classification includes seeds, bulblets or tubers of plants recognized as common weeds by official regulations or by general agreement. Weed seeds are typically very small, so a small percentage of contaminants can translate into many weed plants.

• Seedsman or vendor
The name and address of the person or company labeling the seed are given on the seed label. They are responsible for the accuracy of the label.

• Hard seed
Hard seed are viable, but have a seed coat that is impermeable to water. Where hard seeds are present, total germination percentages are customarily determined by combining germination and hard seed percentages. Hard seeds often germinate at a later date and the seedlings may or may not survive depending on the competition from associated plants.

• Test date
The law requires that the germination test must have been made within nine months of the date the seed are sold or offered for sale (not counting the month of the test). The law also requires the individual owning the seed to keep the germination test date current, so carryover seed should be retested and re-labeled before the original test date expires.

• Treated seed
Seeds that are treated with chemicals must be labeled to show the chemical used, and the words “Caution,” “Poison” or “Poison Treated” must be written on the label, depending on the harmfulness of the seed treatment to humans. In addition, the statement, “Do not use for food, feed or oil purposes,” also must be printed on labels of treated seed, and the seed must be dyed a bright color.

• Noxious seed
The name and number of all noxious weed seed must be listed on the tag.

Storing seed
High-quality forage seed can be stored successfully for more than one season if it is kept in a cool, dry environment. In general, the shelf life of grass seed stored at room temperature (77°F) is roughly two years.

Orchardgrass and tall fescue, however, are exceptions and can be stored for only about one year. Legume seed storage potential is fairly good; most can maintain germination for two years, with the exception of crimson clover, which can be stored only one year.

Avoid storing seeds in metal storage buildings or attics. Temperatures there can be extremely high during the summer, and it does not take long under these conditions for germination potential to be destroyed. Basements are well-suited for seed storage as long as moisture can be controlled.
Forage seeds may be stored in freezers; however, freezing temperatures will kill endophytes and rhizobia.

After storage, it is essential to test seed for germination at least one month before anticipated use. This will allow time to locate fresh seed if germination has declined to low levels during storage.  FG

*References and figures omitted but are available upon request at editor@progressivedairy.com

—Excerpts from North Carolina State University Extension website
J.F. Spears, Extension Seed Specialist and J.T. Green, Professor Emeritus; North Carolina State University

 J.F. Spears
Seed Specialist
North Carolina State