Methods to improve the coloring of Red Fuji apples, making the fruit red and delicious
Red Fuji apples are known for their red color, delicious taste, and high commercial value. To bring out the inherent characteristics of Red Fuji apples and meet market demand, management during the coloring period is very necessary. Red Fuji apples begin coloring earlier than Ralls Janet, and the process is slow. From mid-to-late August until after early-to-mid September, their coloring speed is not as fast as that of Ralls Janet. To improve the degree of coloring, in addition to shaping and pruning, pest and disease control, and other work, the following measures can be implemented in early-to-mid September:
Laying plastic film for apples
1. Control nitrogen.After September, do not apply additional nitrogen fertilizer to the apples. Use frequent and shallow irrigation to maintain stable soil and air temperatures.
2. Leaf removal.Remove 1-2 old leaves shading the apples to increase the apples' use of direct sunlight.
3. Spraying.Spraying 500 PPm of rare earth on the canopy increases the rate of fully red fruit by 12%, increases anthocyanin by 1-3 times, increases the weight of 100 fruits by 6%, and increases yield by 15%. In addition, spraying vigorous trees with ethephon below 1000 PPm or 5000 PPm of monopotassium phosphate both have obvious color-enhancing effects.
4. Laying film.Laying plastic film between the rows and plants of the trees increases the intensity of reflected light, can significantly increase coloring at the top of the apple and in the calyx depression, and raises the sugar content by 1-2 degrees.
5. Root protection.During the apple coloring period, avoid frequently hoeing the tree base to prevent damage to shallow roots, which helps cytokinin synthesis and increases the sugar content of the apples.
6. Delayed harvest.The timing of harvest has a relatively large effect on apple coloring and quality. If harvested too early, the apples color poorly and have inferior quality. The appropriate harvest period for apples is generally 175-180 days after flower drop. The closer to the later stage, the greater the temperature difference between day and night, and the more favorable it is for apple coloring. Therefore, it is better to harvest Red Fuji apples somewhat later.