关中地区不套袋栽培‘瑞雪’苹果适宜采收期的确定

为确定关中地区不套袋栽培‘瑞雪’苹果的适宜采收期，为新品种‘瑞雪’苹果不套袋栽培及适时采收提供理论依据。以6 a生M9自根砧的不套袋‘瑞雪’品种苹果为试材，于10月7日（盛花后180 d）开始，每间隔7 d采收一次，分别测定其果实单果重、纵横经、果面L值和b值、果肉硬度、可溶性固形物含量、可滴定酸含量、淀粉染色指数，分析这些生理指标与淀粉指数的相关性，来判断不套袋栽培‘瑞雪’苹果的适宜采收期，并制作不同采收日期对应的染色图谱，为关中地区不套袋栽培‘瑞雪’苹果的适时采收提供理论参考。在10月23日至11月1日期间，不套袋栽培 ‘瑞雪’苹果果实的大小基本达到最大，果面亮度和褪绿变黄程度适中，果肉硬度达到生理成熟度，可溶性固形物含量基本达到最高，可滴定酸含量基本降至最低，果实的整体品质、口感和风味达到最佳状态。经过多项指标综合判断，可知关中地区不套袋栽培 ‘瑞雪’苹果的适宜采收期在10月23日至11月1日期间（或参考染色指数在5.1至5.7之间），同地区或地理、气候条件相似地区的不套袋栽培 ‘瑞雪’苹果采收期可参考该范围。

Determination of Optimal Harvest Period for ‘Ruixue’ Apple Cultivated without Bagging in Guanzhong Area

In order to ascertain the optimal harvest peiod for non-bagged new apple variety ‘Ruixue’ in Guanzhong area, and to provide a theoretical foundation for its cultivation and appropriate harvesting period.Non-bagged ‘Ruixue’ apple from a six-year-old M9 rootstock was harvested every 7 days started from October 7 (180 d after flowering). Various parameters including fruit weight, vertical and transverse longitude, L and b values of fruit surface, pulp hardness, soluble solid content, titrable acid content and starch staining index were measured. The correlation between these physiological indexes and starch index was analyzed to determine the appropriate harvesting period for non-bagged ‘Ruixue’ apple, and the staining maps corresponding to different harvesting period were created, offering a theoretical reference for the timely harvest of non-bagged ‘Ruixue’ apple in the Guanzhong area. The results showed that between October 23 to November 1, non-bagged ‘Ruixue’ apple exhibited the maximum fruit, moderate fruit surface brightness, and chlorosis and yellows levels. During this period, pulp hardness reached physiological maturity, soluble solid content essentially reached its peak, titratable acid content dropped to a minimum, and the overall quality, taste, and flavor of the fruit reached their optimal state. After a comprehensive evaluation of multiple indexes, it was determined that the appropriate harvesting period for non-bagged ‘Ruixue’ apple in Guanzhong area is from October 23 to November 1 (or when the reference dyeing index falls between 5.1 and 5.7), and the harvesting period of non-bagged ‘Ruixue’ apple in the same area or the area with similar geographical and climatic conditions can can be guided by this timeframe.