Farmers use results of vigor tests to determine planting rates, select the lots of seed to be planted a various times in the production season and insure the purchase of high-quality seed. When seed quality is good, the need for vigor tests diminishes. When harvesting conditions are poor and seed quality is poor, the need for vigor tests increases.
The seed laboratory uses three vigor tests to measure performance of seed under adverse planting conditions. (If a measure of seed performance under favorable planting conditions is desired, a standard germination test is used.) Vigor testing requires more time and skill of the seed analyst than standard germination testing.