The flower bud differentiation of most apple varieties began in early June and ended before winter. The whole process is divided into three stages: physiological differentiation, morphological differentiation and sexual cell maturation. The flower buds are mixed buds and the inflorescences are corymbose cymes. Each inflorescence has 5-8 flowers, mostly 5. The central flower blooms first, and the marginal flower blooms later. The central flower has the best quality, stable fruit and large fruit. When thinning flowers and fruits, the central flowers and fruits should be kept, and the marginal flowers and fruits should be thinned more. The bud leaves first, then blooms, and shoots from the fruit table. The number and length of branches on the fruit table vary with varieties and nutritional conditions of fruiting mother branches. Varieties with strong secondary branches and long and strong branches, such as Zhuguang, have small fruits, low yield and loose fruiting branches.
Second, the fruit:
Apple fruit is a fake fruit developed from ovary and receptacle, in which ovary develops into heart, receptacle develops into meat and embryo develops into seed. The volume expansion of fruit depends on the increase of the number of rapidly dividing cells in the early stage and the number of cell bodies in the later stage.
The expansion of products. The volume expansion of fruit is faster in the middle period to before ripening, slower in the early and late period, and the fruit weight increases fastest in the month before ripening. The length of fruit development period is generally 65-87 days for early-maturing varieties, 90- 133 days for middle-maturing varieties and 137- 168 days for late-maturing varieties.
Fruit color is an important indicator of commodities. The quality of apple coloring is closely related to the accumulation of sugar, the coordination of mineral elements, environmental conditions, and the types and contents of hormones. Controlling application of nitrogen fertilizer, increasing application of potassium fertilizer, reducing chlorophyll in peel, improving ventilation and light transmission conditions, improving sunshine, good drainage, reducing air humidity, spraying NAA and 2.4-D hormone can all promote apple coloring.
From the appearance of buds to the harvest of fruits, apples usually have four flowers and fruits. The first time in the final flowering period, the pedicel falls off with withering, which is usually called falling flower. The second time, about a week after flower dropping, the ovary is slightly enlarged and lasts for 5-20 days, which is called early fruit dropping. The third time, 7- 14 days after the second fruit drop, the fruit has reached the size of thumb nail, which has a great influence on the yield, and is called physiological fruit drop. The fourth time, before the fruit is harvested, the mature or nearly mature fruit is dropped, so it is called pre-harvest fruit drop.
The first and second falling flowers and fruits are mainly caused by insufficient nutrition and poor pollination and fertilization. The third fruit drop is caused by the fierce competition for nutrients among fruits and the lack of auxin in embryos. Because the osmotic pressure of leaves is greater than that of young fruits, the power to compete for nutrients is stronger than that of young fruits. Therefore, in addition to pinching and pruning branches to inhibit the growth of new shoots, it is necessary to apply huafei to supplement nutrients in time.
Third, seeds:
Developed from fertilized eggs in embryo sacs. The normal fruit of apple has five ventricles, and there are two seeds in each ventricle. In the process of fruit development, seeds secrete hormones to stimulate the growth of pulp, so those with good pollination and fertilization, full seeds, correct fruit shape and full pulp; On the other hand, on the side with poor seed development or no seed, the pulp becomes thin and deformed, so pollination trees must be arranged to improve the pollination effect. First, the temperature:
Apple is a temperate fruit tree that likes low temperature and dryness. It requires no cold in winter and no heat in summer. The suitable temperature range is the annual average temperature of 9- 14℃, the extreme low temperature in winter is not lower than-12℃, the highest monthly average temperature in summer is not higher than 20℃, the annual accumulated temperature is about 5000℃ ≥ 10℃, and the average temperature in the growing season (April-10)/ Low temperature time is not enough, leaves and flowers are delayed irregularly, and some flower buds don't even germinate. In May, the scales became loose and fell off, which became a dead pile and seriously reduced production. When the absolute low temperature is lower than -30-32℃, freezing injury occurs again.
Second, the rainfall:
Although apple is native to the dry inland climate zone in summer, and prefers dry environment, it still needs sufficient water and suitable air humidity to grow and develop normally during the growing period. However, excessive rainfall and humidity will lead to dense branches and leaves, serious pests and diseases, large color difference of fruits and low acid concentration of sugar. Generally, the annual rainfall is 500- 1000mm and the air humidity is 60%-70%.
Third, the light:
Apple is a kind of fruit tree that avoids light. According to the determination, the light compensation point of most varieties is 600-940 lux, and the saturation point is 24,000-75,000 lux. Insufficient light directly reduces photosynthesis and tree nutrition, and affects fruit coloring and sugar conversion; Too strong direct light and too long exposure time can easily cause burns to branches and fruits. Therefore, it is necessary to choose a good garden, do a good job of styling pruning, improve ventilation transparency, and have a reasonable number of curtains in order to avoid the above disadvantages.
Fourth, the terrain:
Flat land, mountains, beaches and floodplains can all be planted, but gentle slopes with abundant sunshine, openness, leeward and good surrounding vegetation are the most suitable for planting. Depression, gully, although the soil layer is deep, but the illumination is poor, it is easy to accumulate water in rainy season, and the air humidity is too high; The steep slope, shallow soil layer, thin soil and heavy soil erosion are not conducive to the growth of fruit trees.
Verb (short for verb) soil:
The requirements for soil are not strict, and clay, sandy soil and loam can be used, but sandy loam with deep soil layer and loose and fertile soil is the best. Thick soil with shallow soil layer and many gravels must be improved before planting. The adaptive PH range is pH 5.3-8.2, and the optimum pH is 5.4-6.8. If it is lower than 5.4, the acidity is too strong, and it is easy to produce fruit shrinkage and bitter pox due to boron and calcium deficiency; Above 7.8, it is alkaline, and it is easy to lack iron, which leads to the loss of green leaves.
Sixth, specific management.
(A) Garden and rootstock selection
Red Fuji apple should be cultivated in a well-drained place, on the leeward and sunny slopes in hilly and mountainous areas, and in neutral-slightly acidic soil. At the same time, we should choose rootstocks with strong resistance, such as begonia rotundifolia. M26, MMI06 and M7 can be used as intermediate rootstocks for dwarfing and close planting, and can be grafted on 2-5-year-old Guoguang trees to increase cold resistance.
(2) Planting density
405 ~ 660 plants per hectare (27 ~ 44 plants per mu) are planted with common red Fuji, and the spacing between plants is 3 ~ 4m× 5 ~ 6m. Dwarf intermediate stock (M26, MM 106, M7) is planted with 660 ~ 990 plants per hectare (40 ~ 66 plants per mu), and the plant spacing is 2.5 ~ 3m× 4 ~ 5m.
(3) shaping and pruning
Red Fuji young trees should pay attention to the opening angle, the central trunk and extended branches should be appropriately cut short, and other branches that do not affect the tree shape should be lightly cut and lengthened. Pay attention to cultivate a loose and clear tree structure, remove the over-dense developing branches and competing branches in time, keep the indoor room fully illuminated, and pay attention to the shortening of the fruiting branches.
(D) Rational allocation of pollination trees
The self-pollination and seed setting rate of Red Fuji is extremely low, so it is necessary to allocate pollination trees reasonably when building the garden. When planting common red Fuji, Jinguan, Wanglin, Hongxing, Tsutsugaru and World No.1 can all be used as pollination trees, while short-branched red Fuji should be pollinated by short-branched varieties Jin Aisheng, Xinxing, Brilliant Red, Super Red and Shouhong.
In the case of close planting, the arrangement of pollinated trees among plants is better, generally, 1 pollinated tree is arranged every 4 ~ 5 plants. If it is arranged between rows, a row of pollination trees should be arranged every 4 ~ 5 rows, and the proportion of pollination trees is generally around 15% ~ 20%.
(5) artificial pollination and fruit thinning
The self-flowering and fruit-setting rate of Red Fuji is very low. Even if there are pollinated trees, artificial pollination should be carried out without losing time. After fruit setting, the fruit should be thinned strictly according to the branch-fruit ratio of 4 ~ 5: 1, and only the middle fruit should be left to prevent the excessive load from affecting the tree vigor and fruit quality.
(6) Pay attention to cold protection
In the northern Red Fuji cultivation area, there are often different degrees of freezing damage and peeling, which may affect the yield and even cause the trees to die. Therefore, in addition to choosing a place with good microclimate conditions, we should also protect the young trees under cultivation.
Measures, such as planting grass and sealing mounds. (seven) pay attention to the prevention and control of pellagra and ring rot.
Red Fuji apple is not resistant to rough skin disease and ring rot, which is a big obstacle to popularize red Fuji cultivation. The fundamental measure to control pellagra is to improve soil and enhance tree vigor. Apply more organic fertilizer, dig deep into the soil, or cover the orchard with grass to alleviate the disease; Selecting rootstocks resistant to pellagra, such as begonia rotundifolia, can also reduce the occurrence of pellagra. The intermediate rootstock has strong light resistance, so the diseased branches should be scraped off and coated with the original solution of sulfur mixture for disinfection. Ring rot is caused by weak parasitic bacteria infection, and the incidence of strong trees is less. Therefore, it is necessary to strengthen the cultivation management and enhance the tree potential. Special attention should be paid to the reasonable collocation of nitrogen, phosphorus and potassium fertilizer, and more organic fertilizer should be applied to avoid partial application of nitrogen fertilizer. The ringspot on the branches is the initial source of infection, so it should be pruned in winter and spring, scrape off the rough and old skin of the branches, cut off the diseased dead branches and burn them centrally outside the garden. After scraping, apply 5 waves of smectite sulfur mixture or 1% copper sulfate solution for disinfection. During the growth period of fruit trees, spray 20% fenxiuning EC 1 500 times of15 days after flowering, and then spray it every 15 ~ 20 days from mid-late May to August, * * * 4. In order to improve the control effect, the following pesticides can be used alternately: 100 times 80% Dijundan WP, 500 times 25% carbendazim WP, 600 times 50% carbendazim WP and 800 times 50% thiophanate-methyl WP.