The main parameters for measuring and describing seed quality are germination percentage, including warm germination, cool germination (or vigor) tests, mechanical damage, and foreign material. The standard (warm) germination test is conducted at an alternating temperature regime of 86 and 68 degrees F, while the "cool germ" germ or vigor test employs a constant temperature of 64 degrees F. Other analytical tools for measuring seed soundness and viability include the tetrazoleum test, the accelerated aging test, and a short-term germination test. Most state laws require field corn seed to have a tag on each bag stating the percentage of viable (live) seeds and the germination of those viable seeds. In addition, most seed tags will state how much foreign matter is in the bag.
Seed germination is often above 90 percent, and viable seeds are often above 95 percent. Foreign matter is often less than 0.05 percent. Seedling vigor is difficult to quantify at a level of accuracy sufficient to base hybrid comparisons on.
For more information on this and other topics related to corn production, contact your state extension soybean specialist or your local extension educator/agent.
Following is the link to the soybean extension specialists: state extension soybean specialist.
