Water is the primary condition for seed germination. Seeds must absorb enough water to accelerate the physiological function of seeds and promote the activity of enzymes, which is beneficial to the dissolution of storage nutrients and the growth of embryo cells, thus promoting the germination of seeds.

Temperature is also one of the necessary conditions for seed germination. After absorbing enough water and oxygen, seeds need a certain temperature to germinate, and temperature is the energy source of seed germination. The function of temperature is to promote the activity of enzyme, and the optimum temperature for seed germination is also the optimum temperature for enzyme. In addition, temperature also directly affects the speed of water absorption and respiration of seeds. In a certain temperature range, the higher the temperature, the faster the seeds absorb water, the stronger their respiration and the faster their germination.

Seed germination test needs a lot of oxygen. When seeds germinate, the respiration is enhanced, such as hypoxia respiration of seeds, which makes seeds unsuitable for germination.