When Should I Use This Test?
The Saturated Cold test is used to further separate the quality levels of seed lots - particularly questionable lots. The saturated cold test is potentially more stressful than the shoebox cold test. This test is conducted on corn and soybeans.
What Technique is Used?
A ¼" of soil is layered on top of two germ towels wrapped around a plastic grid and laid in a a tray - to which, 500 mL of water is added, keeping the soil at 100% saturation. Two hundred seeds are split between 2 trays, planted with the embryo facing down - careful not to push the seed too far into the soil. The trays are kept in a cold room for 7 days at 10ºC (50ºF) and then in the warm germinator for 4 days at 23ºC (73ºF).
What Do the Results Mean?
Results are reported as a percentage, which represent the number of seedlings categorized as "normal" out of the 200 seed test. During analysis, technicians record the number of normal, abnormal and dead seedlings. Saturated cold test results generally are lower than the shoebox cold test result.