The Germination Process
Planting pure seeds
Seeds vary in size, so there are different ways to plant them. Small seeded kinds are planted on blotter paper in boxes while larger seeded kinds are planted on germination paper. Round and other uniformly shaped seeds like wheat can be planted with a vacuum planter, while others have to be counted and planted by hand.
After planting, the prepared seeds are placed in a growth chamber. Different seeds have different optimal temperatures, so we have a variety to choose from. We use both static temperatures and alternating temperatures, to mimic day and night temperature fluctuations. Some seeds will spend time in a pre-chill chamber first, which mimics the effects of winter. After a specified period of time they are moved to a warmer chamber, where they will sprout.
Once the seeds have been in the germinator for the specified period of time, they are removed and evaluated. We look for normal and abnormal seedlings as well as dormant and dead seeds.
Seeds that do not germinate in the allotted period of time might still be viable. We can determine this by using a TZ test. TZ is short for Tetrazolium Chloride, which is a chemical compound that will stain the respiring, living tissue of a seed a red color. This is a tedious process, by where the seed is cut with a sharp blade, then placed in the TZ solution. After a designated period of time, usually overnight, the test is complete. The seeds are inspected with a microscope and all seeds with the appropriate structures stained red are considered to be viable for the purpose of a germination result.