Red color and delicious taste is the way to improve the coloring of red Fuji apples.

Red Fuji apple is famous for its red color, delicious taste and high commodity value. It is necessary to manage the coloring period to give full play to the inherent characteristics of Red Fuji Apple to meet the market. The coloring of red Fuji apples starts earlier and slower than Guoguang. From the middle and late August to the first and middle of September, the coloring speed is not as fast as that of Guoguang. In order to improve coloring, the following measures can be implemented in the first and middle of September, in addition to reshaping and pruning, prevention and control of diseases and insect pests.

Apple mulching

1. Nitrogen control. Instead of topdressing nitrogen fertilizer to apples after September, frequent and shallow irrigation should be used to keep the soil and air temperature stable.

2. Picking leaves. Remove 1 or 2 old leaves from the apple in order to improve the utilization rate of the apple in direct light.

3. Spraying. Spraying rare earths with 500PPm on the canopy increased the total red fruit rate by 12%, anthocyanin by 1-3 times, 100 fruit weight by 6%, and increased production by 15%. In addition, Wangshu sprayed ethephon below 1000PPm or potassium dihydrogen phosphate of 5000PPm had obvious color enhancement effect.

4. Laying film. Covering plastic film between rows and trees and increasing the intensity of reflected light can significantly increase the coloring of apple fruit top and calyx depression, and the sugar content can be increased by 1-2 degrees.

5. Root protection. During the coloring period of apple, we should avoid hoeing frequently and destroy the shallow root system, which is beneficial to the synthesis of cytokinin and improve the sugar content of apple.

6. Late harvest. The time of harvest has a great influence on the coloring and quality of apples. If the apple is harvested too early, the color and quality of the apple is poor. The timely harvest time of apple is generally 175-180 days after flowering. The closer to the later stage, the greater the temperature difference between day and night, the more conducive to apple coloring. Therefore, it is better to harvest red Fuji apples later.