Seed dormancy is a mechanism that prevents seeds from germinating under unfavorable conditions such as low temperatures, insufficient moisture, or lack of light. Here are some factors:
Scarification: This refers to the process of breaking or weakening the seed coat, which can be done through mechanical means (such as scratching or filing the seed coat) or chemical means (such as soaking in acid). Scarification can help to permeate water and oxygen into the seed, which can trigger germination.
Stratification: This refers to the process of exposing seeds to a period of cold and moist conditions, such as in a refrigerator or outdoors during winter. This mimics the natural winter conditions that some seeds require in order to germinate.
Fire or smoke: Some seeds, particularly those from plants that grow in fire-prone areas, require exposure to heat or smoke in order to break seed dormancy.
Light: Some seeds require exposure to light in order to germinate. This is known as photodormancy.
Hormonal changes: The plant hormone gibberellin is often involved in breaking seed dormancy, either by being produced naturally by the seed or by being applied externally to the seed.
Aging: Some seeds require a period of time to pass before they can germinate, as the seed coat may harden and become impermeable to water and oxygen. This is known as after-ripening.
All seeds have the same dormancy requirements, and some seeds may require multiple factors to trigger germination.