Flowering phenology characteristics and climate adaptability of ornamental crabapple

Abstract [Objective] Ornamental crabapple is an excellent spring flowering tree species. Studying its flowering phenology characteristics and stability and change rules, and exploring its relationship with climate change are of great significance for the prediction and regulation of the flowering period of crabapple. [Methods] Based on the phenological observation data of 67 varieties for 8 years, the flowering date, length, and stability of crabapple were divided, and the adaptability of each variety to climate change was analyzed in combination with meteorological data. [Results] (1) The stability of the initial flowering time of the crabapple variety group was high, and the fluctuation range of the initial flowering time of most varieties (68.7%) was 0-0.04. (2) The flowering life of crabapple was highly sensitive to climate, and only some varieties (18%) had a relatively stable flowering length, with a fluctuation range of 1-2 months. (3) Ornamental crabapple flowering required a certain low temperature stimulation, and different varieties had different low temperature requirements for flowering. (4) When daily maximum temperature ≥25 ℃, daily precipitation≥5 mm, or daily relative humidity ≥80%, the flowering period of crabapple was shortened. [Conclusion] Low temperature before flowering significantly affects the stability of the initial flowering period of crabapple, and maintaining a suitable climate during flowering is of great significance for prolonging the flowering period of crabapple.