Dormancy release in beech buds (Fagus sylvatica) requires both chilling and long days

摘要: Chilling and daylength requirements for dormancy release budburst in dormant beech (Fagus sylvatica L.) buds have been studied cuttings flushing controlled environments after different durations of outdoor chilling. Non-chilled sampled mid October required long days (LD) only budburst. Buds chilled until March still LD normal budburst, whereas November December were unable to sprout regardless conditions would do so a substantial period Four ecotypes distant latitudinal altitudinal origin responded very similarly with typical quantitative photoperiodic response. In fully shoots 13 40% took place 8-h SD three times as time continuous light. It is concluded that this dual control system ensures optimum winter stability trees under climatic warming. the closely related Carpinus betulus L. was unaffected by daylength.