The flower bud differentiation of hawthorn is later than that of apple, pear and peach 1 ~ 2 months, which is related to the characteristics that hawthorn inflorescence is a mixed bud, and the terminal inflorescence and each flower bud contain more florets. According to observation, the morphological differentiation of flower buds is the earliest in the middle of July, mostly in the middle and late August, but some of them can be delayed until the beginning of September (Li Yongze, Shandong). The prophase of inflorescence differentiation was completed within half a month in mid-September, and the anaphase of inflorescence differentiation lasted from late September to 65438+February. The dormancy period was carried out slowly, and it was not completed until the middle of March of the following year. The differentiation of petals and stamens is completed quickly before the first growth peak of root system in spring, that is, from late March to early April. Therefore, it takes a long time for hawthorn differentiation to alternate with branch growth and fruit development.