Abstract:

To investigate the effect of temperature on the quality of red Fuji apples in east Gansu, and carry out apple quality regionalization, the maturity of red Fuji apple in 19 townships of Qingyang City from 2016 to 2017 was sampled, the sugar content and hardness were determined, and the aero-meteorological statistical method was used to analyze the sugar content, hardness with temperature. The results showed that the main factors that had positive contribution effects on sugar content were the average maximum temperature, average minimum temperature and average temperature after mid-September, the increasing effect of the average temperature in the early and middle October on sugar content was obvious, and the sugar content increased 0.265%-0.304% by each 1℃ increase. The main factors that had a positive contribution effect on hardness were the highest temperature in September, the lowest temperature in August, and the diurnal range from late July to mid-August and mid-October. Diurnal range in mid-October had greater effects on the hardness, the hardness increased 0.258 kg/cm ² with each 1℃ rising. The sugar content of apple showed a quadratic curve with the average temperature from late September to early October. The hardness and the average diurnal range from July to September showed a cubic curve. Apple with sugar content less than 10.5% and hardness less than 6.43 kg/cm ² belonged to poor quality zone. Apple with sugar content higher than 13.6% and hardness greater than 6.72 kg/cm ² belonged to superior quality zone. Apple with sugar content of 11.2%-13.0% and hardness greater than 6.44 kg/cm ² belonged to moderate quality zone. The quality of red Fuji apple is the best in Dongzhi tableland, central Qingyang.

Key words: red Fuji apple, quality regionalization, temperature, east Gansu