germination       
noun [ U ]  biology specialized uk/ˌdʒɜː.mɪˈneɪ.ʃən/ us/ˌdʒɝː.məˈneɪ.ʃən/
 发芽
the process of a seed starting to grow, or the act of causing a seed to start growing
  Good soil moisture is required for seed germination. 种子发芽需要土壤湿润度良好。 
 The cold and frost of winter weather helps to stimulate germination. 冬季的寒冷和霜冻可刺激发芽。 
 See: germinate
 - More examples
 - When germination occurs, the covering should be removed at once.
 - Germination is slow and can take a month in cold soil.
 - The chemical kills weeds and prevents seed germination.