The future impacts of climate change on the yields of staple crops have been widely investigated. However, owing to insufficient data compared to that available for staple crops and the complexity of the quality determination process, the relationship between quality changes in horticultural crops and climate change has not been quantified, and potential future changes in fruit quality are not well understood. We conducted temperature treatment experiments to quantify the sensitivity of apple quality to air temperature and collected quality indices records through field observations to propose a model for estimating apple quality indices from the air temperature. In the temperature treatment experiment, ‘Fuji’ apple trees were placed in glass chambers set at a constant temperature of 17.3–25.6°C from 110 days after full bloom (DAFB). The fruits were harvested at 170 DAFB to measure the quality indices. The results indicated that the acidity and ratings for blush, peel ground color, starch disappearance, and watercore were all significantly lower at higher air temperatures. The relationship between these quality indices and air temperature could be linearly approximated. Sugar content and fruit firmness were not clearly affected by the air temperature. In addition, data from field observations conducted at experimental orchards in Aomori and Nagano Prefecture over 50 years (1970–2019) were analyzed. The relationship between fruit quality indices at 170 DAFB and the mean temperature in the 60 days from 110 DAFB in Aomori and Nagano was similar to that observed for the chamber experiment results, and no significant difference was observed in the slope of the linear regression equation between the chambers and orchards. A model was developed to estimate the fruit quality indices based on air temperature by accumulating daily amounts of change in quality indices calculated from daily mean temperatures using the results of experimental and field observations. The model could be used to assess the impact of future long-term temperature increases on apple quality indices.

气候变化对主要农作物产量的未来影响已得到广泛研究。然而，由于与主要作物相比数据不足，且质量测定过程复杂，园艺作物质量变化与气候变化之间的关系尚未量化，未来水果质量潜在的变化尚不清楚。我们进行了温度处理实验，量化了苹果品质对气温的敏感性，并通过现场观察收集了品质指标记录，提出了根据气温估算苹果品质指数的模型。在温度处理实验中，“富士”苹果树从盛花后 (DAFB) 110 天起被放置在恒温在 17.3–25.6°C 的玻璃室中。果实在170 DAFB下采收，测定品质指标。结果表明，在较高的气温下，酸度和腮红、果皮底色、淀粉消失和水核的评分均显着降低。这些质量指数与气温之间的关系可以近似线性。糖含量和果实硬度不受气温的明显影响。此外，还分析了 50 年来（1970 年至 2019 年）在青森县和长野县实验果园进行的实地观察数据。青森县和长野县170 DAFB下的果实品质指标与110 DAFB 60 d平均温度之间的关系与箱式实验结果相似，并且线性回归方程的斜率没有观察到显着差异。房间和果园。开发了一个模型，通过使用实验和现场观察的结果，根据日平均温度计算出的质量指数的日变化量的累积来估计基于气温的水果质量指数。该模型可用于评估未来长期气温升高对苹果品质指数的影响。