桃果实品质动态变化及其对气象因子的响应

为提高桃品质并确定最佳采收期，以‘久保’为供试材料，分析果实的单果重、果径、硬度、可溶性固形物含量和可滴定酸含量的变化规律，并利用多元回归法建立果实品质与关键气象因子的综合模型。结果表明：桃果实单果重和果径生长发育动态呈现“慢—快—慢”阶段性特征，且均符合Logister曲线，单果重增长极大值出现在花后91 d，纵径增长极大值出现在花后66 d，横径增长极大值出现时间比纵径推迟5 d；随着果实的成熟，硬度逐渐下降，可溶性固形物含量呈上升趋势，上升幅度逐渐加快，可滴定酸含量先小范围波动后迅速下降。结合回归分析结果可判定，果实品质主要受≥18℃积温、≥24℃积温、日均气温和累计日照时数的共同影响。在≥18℃积温≥1170.21℃、≥24℃积温≥769.23℃、日均气温≥27.00℃、累计日照时数≥318.89 h条件下，果实品质达到最佳成熟度。

Quality Dynamic Variation and Response to Meteorological Factors in the Development of Peach Fruits

In order to improve the quality of peach fruits and determine the best harvest time, ‘Jiubao’ was used as the material. The variations of single fruit weight, diameter, hardness, soluble solids content and titratable acid content were analyzed in this study. The models of fruit quality and main meteorological factors were established with the multiple regression method. The results showed that the growth and development dynamics of single fruit weight and diameter presented ‘slow-fast-slow’ stage characteristics, and conformed to the Logister curve. The single fruit weight maximum value appeared at 91 days after flowering, the vertical diameter growth maximum value appeared at 66 days after flowering, and the horizontal diameter growth maximum value appeared 5 days later. With the ripening of peach fruits, the fruit hardness gradually decreased, and the soluble solids content increased with a gradually accelerated rate. The titratable acid content fluctuated in a small range at first and then decreased rapidly. Combined with the regression analysis results, the fruit quality was mainly affected by ≥18℃ cumulative temperature, ≥24℃ cumulative temperature, daily average temperature and cumulative sunshine hours. Under the conditions of ≥18℃ cumulative temperature ≥1170.21℃, ≥24℃ cumulative temperature ≥769.23℃, daily average temperature ≥27.00℃, and cumulative sunshine hours ≥318.89 h, the fruit quality could reach the best maturity.