How much seed do I need to send?
Tests conducted by the laboratory can only evaluate
the quality of the submitted sample and it is essential that the
submitted sample represent the entire seed lot. The Association
of Official Seed Analysts (AOSA) and the International Seed Testing
Association (ISTA) have minimum working weights for purity analysis
based on 2500 seed. Samples submitted to the NSL should contain
at least 2500 seed. If a moisture content analysis is needed, extra
seed is required. Seed per pound, germination, x-ray analysis, tetrazolium,
and excised embryo tests are conducted using pure seed from the
purity analysis. If a purity tests is not required, fewer seed can
be submitted. Analysis, of seed lots, for International Seed Testing
Association (ISTA) certificates, have additional requirements. Please
contact the NSL for further information regarding ISTA certificates.
||Seed Per Pound
||Minimum Sample Size
|Small sized seed
|Medium sized seed
||10,000 - 20,000
|Large sized seed
||5-10 ounces or more depending on size
How long does it take to test tree
Depending on the tests conducted and species being tested, testing
can take a few days to several months. Moisture content, purity,
seed per pound, x-ray and tetrazolium tests can be finished within
a few days on most species. Excised embryo tests take two to three
weeks. Germination tests of tree and shrub seed requirea minimum
of four weeks. Many species require weeks or months of pretreatment
to overcome dormancy or increase speed of germination prior to the
four week minimum germination period. In addition, during certain
times of the year, the laboratory receives large numbers of samples.
There may be a delay between when we receive the sample and when
we begin the tests.
How do I pay for seed tests?
The National Seed Laboratory will send you an invoice for
services performed. We can bill you annually, quarterly, or each
time you send seed to the laboratory. Let us know what is best for
your situation. Please include the Federal ID Number of the invoice
agency on the Seed Test Request Sheet.
Does the NSL accept credit cards?
Yes. You can now pay your bill, for seed testing, online with a credit card or by check at the billpay website.
Where can I get a copy of the required
Seed Test Request Sheet?
Seed Test Request Sheet