With much of the seed harvest wrapped up and cleaning, sizing and packaging in full swing, this is a great time to review your quality assurance standards. Producers and seed sellers should have a clear definition of what components are critical and what the specific standards are for each quality component.
Standard warm germination is the most common quality measure in seed testing. A warm germination test measures the ability of the seed lot to germinate under ideal conditions for the growth and development of the crop. A bag germ is the percent germination that you label on your seed package. Your germination percent will dictate the bag germ % that you list on your label.
Almost as important as the warm germination percent is the vigor test score. For many crop species, a cold or cool vigor assessment test will enable the seed producer to judge how the seed will emerge in less than ideal conditions for seed growth and development. Different quality standards are used by each seed company. As a rule of thumb, many producers require a cold test to be within 10 percentage points of the bag germ. For example, if germ is labeled as 95%, the minimum acceptable cold test percent should not be below 85%.
A physical seed purity analysis is also a key quality metric. A purity analysis is an evaluation of a specific weight of material that is present within the seed sample. The components of the purity analysis are pure seed percent, inert matter percent, other crop seed, weed seed, and prohibited noxious weed seed percent. All of these component percentages must be listed on the seed label. Quality standards can vary depending on species, but the vast majority of the purity component should be pure seed. Zero or a very small percent of weed seeds are generally accepted in QA standards. Absolutely no prohibited noxious weeds are acceptable within a seed lot.
The genetic purity, trait purity and adventitious presence analysis of a seed lot are also of great importance to seed producers. Quality standards should be defined for these important genetic components of the seed lots. Defining rigorous genetic standards for the production of seed will ensure that customers are receiving highly pure seed that is either free of unwanted genetic traits or, conversely, has the appropriate genetic trait present at a very high percentage.
Defining and enforcing specific quality standards for production and sale of seed products is essential to ensure that seed will meet the high expectations of our farming customers.