The growth process of apple must go through four periods: 1. flowering, 2. physiological fruit drop, 3. fruit expansion, and 4. ripening period.

After flowering, it enters the first physiological fruit drop (with fruit stalk shedding), and then enters the second physiological fruit drop (without fruit stalk shedding), and then enters the period of young fruits, to the period of fruit expansion, and then to the period of growth and maturity.?

Color and shape changes, now take Hua Guan varieties as an example: fruit nearly conical, high pile, young fruit thick green, then turned light green, after maturity, the bottom of the fruit color golden, more than two thirds of the fruit surface bright red, smooth, glossy, yellow flesh, flesh is fine, brittle and hard, juicy, fragrant.

Flower bud differentiation period Apple's flower bud differentiation, most varieties are from the beginning of June to the completion of the winter, the whole process is divided into physiological differentiation, morphological differentiation and sex cell maturation of three periods.

Fruit expansion period Apple fruit is a pseudo-fruit developed by the ovary and receptacle, in which the ovary develops into a fruit heart, the receptacle develops into fruit flesh, and the embryo develops into a seed.

The expansion of the fruit, which is divided into the early, middle, ripe, not yet period, the time of fruit expansion is generally early varieties of 65-87 days, medium-ripe varieties of 90-133 days, late varieties of 137-168 days.

Flowering period Apples from the appearance of buds to fruit harvest, there are generally four times to fall flowers and fruits.

The first time is during the final flowering period, when the flower stalks fall off together with the flowers, usually called blossom drop.

The second time, about a week after flower drop, the ovary is slightly enlarged, which can last for 5-20 days, and is called pre-fruit drop.

The third in the second 7-14 days after the fruit drop, the fruit has reached the thumb to yuan large, a greater impact on yield, known as physiological fruit drop, Yunnan generally occurs in May, the north of the climatic period later than Yunnan, occurred in June, so called "June fruit drop".

Fourth in the fruit before harvest, fall ripe or nearly ripe fruit, so called pre-harvest fruit drop.

The first and second drop flower and fruit, mainly due to nutritional deficiencies and poor fertilization caused by pollination, the third drop fruit, in addition to the competition for nutrients between the fruit, the lack of intra-embryonic growth hormone, is the tip of the fruit to compete for nutrients due to intense.

Because the osmotic pressure of the leaves is greater than that of the young fruit, the power to compete for nutrients is stronger than the young fruit, so in addition to timely and good centering, cutting the tips and other suppression of the growth of the new shoots, should also be timely application of flower fertilizer, supplemental nutrients.