**4.3 Seed stratification**

Stratification is used mainly to alleviate dormancy in temperate plant species. The stratification approach depends on the cause of dormancy in a species. For example dormancy due to immature embryos is broken via warm stratification; physiological dormancy is relieved by cold stratification while combined warm and cold stratification is effective for seeds that have both immature embryos and physiological dormancy [76].
