Sometimes cold germination tests are conducted to simulate the cold, wet field conditions that early planted summer annual crops experience. The cold test is the most common vigor test performed.
A vigor test is defined as a test that measures the ability of a seed lot to emergence under stressful conditions.
This test is conducted very similar to the warm germination test, with two exceptions. First, a soil paste is made and smeared on the wetted thick paper towel.
Then the seed are counted and placed on the towel as in the warm germination test. The towel is covered with a wetted thin paper towel, rolled and marked as was done for the warm germination test.
The second difference is that the rolled paper towel is placed in a chamber with cold temperature, often 50F, for two or three days, then is transferred to a chamber with ideal temperature, humidity, and light. When the test is completed, seedlings that would have emerged are counted and the cold germination percentage is calculated.