Having the lab perform a 1000 seed weight can help you to determine your ideal seeding rate which will allow you to get the most out of your seed. We calculate the 1000 seed weight in the lab using the International Seed Testing Association (ISTA) rules. The sample is mixed down to obtain an accurate working sample and then pure seeds are selected for weighing.
Changes in moisture content will affect your 1000 seed weight; therefore to obtain the most accurate result, have your seed tested as close to seeding as possible and send your seed in a moisture proof container.
For more information on seeding rates go to Agriculture, Food and Rural Development: