In addition to the heredity of apple varieties, the sugar content in the fruit is the main factor affecting the formation of apple anthocyanins. Anthocyanins are chromogens formed when pentose respiration is vigorous; in addition, anthocyanins are often combined with sugars to form anthocyanin glycosides that are present in fruits. Therefore, the development of anthocyanins is closely related to sugar content. Any factor that affects sugar synthesis and accumulation affects the development of anthocyanins. Higher tree nutrient level, reasonable load, appropriate ratio of phosphorus and potassium fertilizer to nitrogen fertilizer, and proper water control are all conducive to the red development of the fruit. The effect of temperature on coloring is also related to the accumulation of sugar. When the night temperature of mid-late ripening apple varieties is above 20℃, it is not conducive to coloring. The firmness of the pulp is also one of the important indicators of fruit quality. The firmness of the pulp not only affects the taste and taste when eaten fresh, but is also related to the storage and processing properties of the fruit. The hardness of apple pulp is closely related to the cellulose content in the cell wall, the type and quantity of pectin in the glue layer of the cell wall, and the turgor pressure of the pulp cells. Absorption and distribution of calcium in fruit bagging Apple bagging cultivation has the advantages of significantly improving the appearance and quality of the fruit, reducing the pesticide residues in the fruit, and improving the drug structure of the orchard. However, after the fruit is bagged, the temperature, humidity, and light conditions of the fruit are changed, which affects the absorption of mineral elements during the growth and development of the fruit, resulting in some physiological metabolic disorders. Many studies have shown that the occurrence of physiological diseases in apple fruits is closely related to the calcium in the fruits. Apple fruit can continue to take in calcium throughout the growth and development process. Before bagging, the fruit can absorb about 20% of the calcium of the whole fruit; the calcium absorption of the whole fruit of the control fruit in July and August is 66.1%, while that of the bagged fruit is 73.8%; in addition, there is still a certain amount of calcium in the mature period. absorb. After debagging, the calcium absorption of bagged fruits was higher than that of control fruits. After the fruit is bagged, calcium absorption is inhibited, which is mainly manifested in the peel. The calcium content of the bagged apple peel is significantly lower than that of the control during the whole growth and development period. The calcium content in the core and pulp of the fruit was not much different from that of the control fruit, even slightly higher than that of the control fruit, especially the core calcium was significantly higher than that of the control fruit 40 to 90 days after flowering.