For seed germination, several conditions must be met to ensure that the seed can grow into a new plant. These conditions are:
1. Water:
- Role: Water is essential for the activation of enzymes that break down stored food in the seed, which is used for growth. It also softens the seed coat, allowing the seed to swell and the embryo to break through.
- Effect: Without enough water, the seed remains dormant and cannot begin the process of germination.
2. Oxygen:
- Role: Oxygen is required for cellular respiration, which provides the energy necessary for the growth of the seed. During germination, the embryo requires oxygen to break down stored nutrients and start growing.
- Effect: A lack of oxygen can prevent the embryo from developing properly, halting the germination process.
3. Temperature:
- Role: Seeds require an optimal temperature range for enzymes to function and for the germination process to occur. Different seeds have different temperature requirements, but most seeds require a moderate temperature (generally between 15°C and 30°C).
- Effect: Too cold or too hot temperatures can slow down or stop germination. Some seeds may require a period of cold (stratification) or heat (scarification) before germination can occur.
4. Light:
- Role: Some seeds require light for germination, while others need darkness. For example, small seeds (like lettuce) often require light, while larger seeds (like beans) may prefer darkness to germinate.
- Effect: Light or darkness affects the seed’s ability to begin germination, depending on the plant species.
5. Proper Soil/Medium:
- Role: The seed needs to be in a suitable medium, like soil, that provides adequate nutrients, support, and moisture for root growth. The soil should have good drainage to prevent waterlogging, which can suffocate the seed.
- Effect: Poor soil quality or an improper medium may hinder germination or lead to the death of the embryo.