Seed Testing

Tests offered are germination, purity, seed weight, moisture content, tetrazolium and excised embryo (for quick estimates of viability, and x-ray analysis of internal seed structures). Each year the FSNSL tests approximately 180 different species of seeds. The lab is the only seed laboratory in the US accredited by the ISTA to conduct seed tests on forest seeds. This accreditation assures that the test results are as reliable as possible by requiring a rigorous quality assurance program.

Seed Test Request Sheet

Dickey John Tri-Grain Chart 

Dole Chart 

Dole Instructions 

Dear Customers:

Thank you for using our services. It is a rewarding partnership, to work with each of you. We try as hard as possible to provide high quality service at an affordable price. Our last price increase was approximately 4 years ago. Since then, costs for everything have increased to the extent that we must raise prices on December 1, 2011. Furthermore, with the expansion of our program to include all native plants, we have had to broaden our price schedule to cover a wider range of species. Therefore, you will see new items on the price schedule. All the traditional services are still offered, except for un-scored x-ray; due to decreased request. So, although we have changed to serve a wider mission, you will still find the testing services you have relied upon.

By considering these points and planning your seed needs for the upcoming year as soon as possible, you will help us avoid any delays that could occur in starting your tests and will enable us to get the test results to you as quickly as we can.

Seed Test Definitions

Germination of seed in a laboratory test is used to predict the probability that the seed will produce a normal plant under favorable conditions. The test measures the percentage of seeds that germinate and the speed of germination.

Moisture content is the percentage of water held by the seed. It is calculated by measuring the loss of weight by the seed when it is dried at a constant temperature for a specific period of time. Moisture content is a critical factor in storing seed because seed that is too moist cannot be stored and will deteriorate rapidly.

Purity distinguishes the amount and type of impurities in a seed sample. The impurities are physically removed from the seed sample in the laboratory leaving only the pure seed. A minimum weight that contains 2500 seeds is needed to conduct the test.

Seeds per pound determines the number of individual seeds in a pound. This value is used with the germination percentage and purity percentage to predict the number of seedlings expected to be produced by a given weight of seeds.

Estimated viability tests are for quickly determining the number of live seeds in a sample. The tetrazolium, excised embryo, and x-ray tests are the viability tests used most frequently at the laboratory. They are the preferred tests for very dormant seeds (seeds that are difficult to germinate).

In the tetrazolium test, a colorless solution of tetrazolium chloride is imbibed by the seed. Living tissues then stain red while dead tissues retain their natural color. Properly stained seeds are considered viable while improperly stained or unstained are generally considered non-viable seeds.

In the excised embryo test, the embryos are excised and incubated under prescribed conditions for 5 to 14 days. Viable embryos remain firm or exhibit evidence of growth while non-viable embryos show signs of decay.

X-radiography is used to examine the internal structures of the seed. It provides a quick, nondestructive method of differentiating between filled, empty, insect damaged, and physically damaged seed.

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