The objectives of this study were to trace the shift in bud burst and full bloom dates and provide a countermeasure for the suitable prediction of these representative phenological indices for citrus trees. The heat accumulation value was calculated by the growing degree day (GDD) model with six base temperatures (T_b) from 5 to 17.5℃ in 2.5℃ intervals, and the estimation accuracy of this value for both phenological stages was evaluated. The optimal T_b and heat requirement of Miyagawa Satsuma mandarin trees were 7.5℃ and 108.6℃·days for bud burst, respectively, and 10.0℃ and 196.2℃·days for full bloom, respectively. The data showed that bud burst and full bloom have advanced by 0.3−0.5 days per year since the 1960s, and this advancement was more drastic over the last 10 years, which reached 1.4 days per year. Moreover, the theoretical calculation of heat accumulation started on the date when fruit was harvested in the previous year, but the practical heat accumulation affecting bud burst started much later because of the negative effect associated with values below the T_b by the heat accumulation model. The start date of heat accumulation also gradually advanced in recent decades by 0.5 days per year. The dates of full bloom at specific study sites were predicted via the dates of full bloom at Jeju and Seogwipo, which are close to the northern and southern coasts and represent sites where recent meteorological data have been collected. The prediction equations had common components, and the value of the southernmost site could be used as a low variable threshold by dropping the coefficient; thus, the equation was dependent on the large variability of the northernmost site, which was represented by a higher coefficient.

这项研究的目的是追踪芽的爆发和盛开日期的变化，并为适当预测柑橘树的这些代表性物候指标提供一种对策。通过生长度日（GDD）模型以5到17.5℃的六个基本温度（T _b）在2.5℃的间隔内计算热量累积值，并评估了该值在物候两个阶段的估计准确性。最佳T _b宫川萨摩柑桔树的发芽旺季分别为7.5℃和108.6℃·天，盛花期分别为10.0℃和196.2℃·天。数据显示，自1960年代以来，芽的爆发和盛开的花朵每年增长0.3-0.5天，而在过去的10年中，这种增长更为剧烈，达到每年1.4天。此外，热量累积的理论计算始于上一年收获水果的日期，但是由于与低于T _b的值相关的负面影响，影响芽破裂的实际热量累积开始的时间要晚得多。通过蓄热模型。蓄热的开始日期在最近几十年中每年也逐渐增加0.5天。根据济州和西归浦市的盛开日期，可以预测特定研究地点的盛开日期，这些地区靠近北部和南部海岸，代表着已收集到最新气象数据的地点。预测方程具有共同的组成部分，通过降低系数可以将最南端站点的值用作低可变阈值；因此，该方程式取决于最北端站点的较大变异性，该变异性由较高的系数表示。