The criteria used to determine a seed lots viability is termed standard germination.

Standard germination is the percentage of a seeds in a seed lot that produce a normal seedling under optimal germination conditions.

Photo showing petri dishes being used to conduct standard germination tests.

Germination conditions and normal seedling characteristics are described by the Association of Official Seed Analysts.

A normal seedling must have an actively growing root and shoot meristem and at least one cotyledon.

Photo showing four variations of abnormal bean seedlings.

Abnormal seedlings of bean.

For the rolled towel test, the seed analyst places a precise number of seeds on several sheets of germination paper.

The seeds are rolled in the paper and placed upright in the growth chamber.

The number of normal seedlings will be determined after first and second counts.

Photo of seeds germinating in trays of upright, rolled, germination papers.

Rolled towel test. Click on the buttons below to see the Seed Rolled Towel Planter Board, and Seed Rolled Towel Small Seed videos.

The Petri dish germination test is used for crops with small seeds or those requiring light.

Seeds are placed on a vacuum template to get the correct number of seeds for insertion into the Petri dish.

The Petri dish contains a moistened paper substrate (blue blotter).

Dishes are placed in an incubator and normal germination is counted.

Photo of a petri dish with moistened, blue blotter, paper substrate. Seeds are germinating in it.

Petri dish germination test.

Click on button below to see video.