PreChill – Reminder about freshly harvested seed
Why might you get a call from Customer Care asking when a sample was harvested? Are you aware that AOSA Rules For Testing Seeds requires that certain types of freshly harvested seed (approximately within 6 months) need a pre-chill before we can start testing? Examples include oats, rye, & other cereals, grasses.
What is a pre-chill? A cold, moist treatment applied to seeds to overcome dormancy prior to the germination test. The prechill method varies among species but is usually performed by holding imbibed (placed on moist planting media) seeds at a low temperature for a specified period.
Mike Stahr, Seed Lab Manager addressed this in his May 2023 Manager’s Corner on our Seed Lab website: “Adding a prechill means placing the planted seeds (on towels, blotters, sand, etc.) in a prechill chamber at 5C or 10C for five, seven or more days and then placing the tests in the correct warm temperature. In today’s world where time is money, an unnecessary prechill means adding to the days until a report of analysis is created. To that end it is important that Seed Lab staff know if incoming samples contain seeds that are “recently harvested” (Volume 1 Section 6.9e). Often there is confusion on what qualifies as recently harvested. The best bet may be for those sending seed samples to supply the month and year of harvest. If the month isn’t available, then knowing the year of harvest may be helpful.”
Please include this information on your samples or sample submission form in the future for quicker processing! |