The moisture test determines seed moisture content. Seed moisture is an important factor that affects viability, longevity in storage, and loss of vigor over time. Generally, lower seed moisture content means longer storability and better retention of germination potential and vigor.
There are several recognized methods for determining seed moisture content. At AMM Seed Testing, Inc., we use the air-oven method. With this method, the prepared seed samples are slowly dried in a laboratory oven at a specified temperature. The before-drying and after-drying sample weights are used to calculate seed moisture content.
Samples submitted for moisture tests must be contained in air-tight packaging in order to maintain the true moisture content of the seed lot. During shipping and upon arrival in the lab, the sample packets will be exposed to differing ambient conditions from where the seed lot is stored. Improperly contained samples may gain or lose moisture, and may yield inaccurate moisture test results.