Abstract: Experiment was conducted with 72year-old sweet cherry (Prunus avium L. ) ‘Hongdeng’and ‘Zaohongbaoshi’ trees, the effect of bud-scale removing and chemical treatments on phenolics content and germination rate were analyzed and studied. Results showed that phenolics in dormant flower buds were distributed primarily in scales, phenolics content in scaleswas far higher than that in de-scaled buds and whole buds. The content of phenolics in flower buds fall down sharply after shelling scales. The effects of bud-scale removing
were differerent during differerent stage of endodormancy: the effect of bud-scale removing in the early stage of endodormancy was better; In the middle stage of endodormancy, because of the deepest time of endodormancy,
bud-scale removing could not break the endodormancy; In the last stage of endodormancy, bud-scale removing could also break endodormancy. The effects of different chemical treatments on the content of phenolics at different stage of endodormancywere different: KNO₃ and sulfourea treatment slowed the speed of phenolics accumulation speed, while H₂O₂ treatment accelerated the accumulation of phenolics content in the primary stage of endodormancy. In the middle stage of endodormancy, the effects of these three chemical treatments on phenolics contentwere similar to those in the early stage of endodormancy. In the last stage of endodormancy, KNO₃ treatment reduced phenolics content while sulfourea treatmentmade it increased slightly, H₂O₂ treatment remarkably increased phenolics content. In the aspect of breaking endodormancy, KNO₃ treatment was 2 - 3 days earlier than the control, there were no remarkable changes on breaking endodormancy after sulfourea reatment, while H₂O₂ treatment remarkably inhibited the breaking of endodormancy.

Key words: Sweet cherry, Chemical treatment, Flower bud, Phenolic, Endodormancy