The laboratory germination test determines the germination potential of a seed lot by growing the seeds under carefully controlled conditions. Temperature, moisture, and light are all maintained at the optimum levels for germination. After the prescribed growth period, the seedlings are evaluated and the results are reported as percentage of germination. Only healthy seedlings that have all critical structures sufficiently developed and intact are counted as normal.
Most commercially produced crop kinds have one or more prescribed methods for germination testing in the rules applicable to seed testing:
AOSA (Association of Official Seed Analysts) Rules for Testing Seeds
ISTA (International Seed Testing Association) International Rules for Seed Testing
Canada Canadian Methods and Procedures for Testing Seed (M&P)
Seeds are tested in the lab using artificial growth media, such as germination paper, blotter paper, and/or creped cellulose paper. Sand or soil mixtures can also be used. These materials eliminate most of the variables caused by natural soils, such as organic matter, microbes, fungi, and other factors. It also allows for easier examination of the seedling structures.
Although crops are not usually grown under absolutely perfect conditions in the field or greenhouse, testing seeds under optimum conditions shows the maximum germination potential of a seed lot. It is also the best way to obtain consistent results which can be duplicated within the laboratory, or between different laboratories. It establishes a consistent value for the seed lot.