The idea of using quality seed in establishing or renovating a pasture seems obvious. What determines the quality of seed may not be so obvious.

Very often the phrase "You get what you pay for!" applies to purchasing seed. Seed quality is determined by genetic purity, germination and vigor. Many states have certification programs that test seeds. (Oregon Seed Services)

When purchasing certified seed, tags will state the percentage of purity meaning that the buyer is guaranteed to get seed of that specific species and variety.

Germination refers to the ability of the seed to take in water and nutrients and sprout. Not all seeds are healthy and germinate. Seeds can, in essence, be "duds". A good germination rate is one factor considered in certifying seed. The seed source has been tested and a germination percentage is provided.

Seed vigor refers to the tendency of the seed to withstand stress. Seeds need to be able to withstand less than optimal conditions to germinate.

There are certain treatments that may help for optimum seed germination.

  • scarification:
  • cold storage
  • inoculation
  • pesticide additions (fungicide, herbicide)

 

Scarification is a physical scratching of the seed coat to allow moisture in needed to begin germination. Legumes often have very hard seed coats which enable them to survive a long time within the soil. Scarifying the seeds will encourage germination.

Cold storage is a treatment that breaks the dormancy of a seed.

Inoculation is recommended when planting most legumes to assure a large number of effective rhizobia in the rhizosphere of the germination seedling. Nitrogen fixation by legumes is essential to biforous legume growth. Legumes fix nitrogen only if infected with rhizobia bacteria. These bacteria attach to legume roots producing what are called nodules. The number, size, and internal color of nodules are good indicatiors of the amount of nitrogen fixation occurring. A white-centered nodule is not fixing nitrogen. This is natural in winter but not in the growing season. A blood-red nodule is producing nitrogen. But different legumes require different strains of bacteria inoculant, so a producer cannot assume that legumes will find what they need in the soil. White clover, subclover and trefoils all are common legumes but each requires a different strain of bacteria inoculant. So use a commercially prepared strain of inoculant designed for the species planted. Inoculating your legume seeds is not difficult but can be time-consuming and messy. Thoroughly and carefully inoculate the seed and follow other careful management practices to insure viable infection of the bacteria on the newly germinated root hairs. Or you may purchase inoculated seed.

Pesticides are occasionally recommended for diseases or insects, and herbicides have been used as a seed treatment to deter competitive weed growth.

It might prove helpful to mention that seed sold in feed and seed stores labeled "Pasture Mix" should be carefully considered. Often these mixes contain a high percentage of annual ryegrass which may look promising very quickly but will not help to establish a long-term pasture. Read the species included in the contents of mixtures and look for species that will perform according to your long-range plan.