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Adoption. If grapes are grafted with cold-resistant rootstocks (such as Peking University and Beichun). ), it will be easier to bury them underground to keep out the cold. The depth of covering soil is generally thinner in loam and flat vineyards, and thicker in sandy soil and mountain vineyards. For some plants grafted and transplanted that year, although the lowest temperature in winter can't reach-17℃, the plants grow vigorously, fall leaves late and have many fruits, so they should be buried in time to prevent cold.
Grape root system is developed, which is fleshy root and stores a lot of nutrients, including water, vitamins, starch, sugar and other organic and inorganic components.
The function of grape root system is not only to fix the plant, but also to absorb water and nutrients from the soil and accumulate stored nutrients, which becomes the material basis for the regeneration and rejuvenation of aboveground parts.
Root characteristics of grapes
Root species
The composition and distribution of grape roots are slightly different due to different propagation methods.
Rooting line: a plant propagated by seeds, with vertical main roots and lateral roots at all levels. The taproot is developed, the root system is deep, there are obvious rhizomes and the branching angle is small.
Stem root system: Branched plants have no vertical straight roots and are mainly composed of lateral roots at all levels. There is no true rhizome, the lateral roots are developed, and the root branching angle is large.
Root distribution
Grape roots are generally distributed in soil with a depth of 20~60 cm, and the deepest part can reach about 2 meters, but the depth is directly related to fertilization depth, soil quality and variety. Because the growth of roots is water-oriented, fertilizer-oriented and geotropic, the deeper the fertilization, the deeper the roots will be, and vice versa.
Growth characteristics
Grape roots can grow all year round when the soil temperature is kept at 13 ~ 25℃ and the water content is suitable. Generally speaking, grapes have a rooting peak in spring, summer and autumn, and roots and new shoots grow alternately.
The first peak: before and after grape germination, when the soil temperature is low, the root system grows slowly by absorbing water and nutrients, reaches the growth peak after leaf spreading, and then gradually decreases, reaching the lowest point in the first half of flowering.
The second peak: after the grapes set, the demand for nutrients of the whole fruit tree reached the peak of the annual demand, so the corresponding root growth also reached the peak of the annual growth, and then gradually decreased to a low peak with the maturity of the grapes.
The third peak: after the grapes are picked, the vines start to grow again, and the corresponding roots gradually resume to grow, reaching a new peak, and then gradually decrease and enter the winter dormancy period.
Factors affecting the growth of grape root system
Grape root growth is related to temperature, light, moisture, nutrition, soil pH and organic matter content.
temperature
The optimum temperature for grape root activity is 2 1~24℃. When the soil temperature reaches 8~ 10℃, the roots begin to move and grow at 12~ 13℃. When the soil temperature reaches 20~25℃, the root system enters the vigorous growth period. When the soil temperature exceeds 25℃, the root system growth is inhibited, and it stops growing when it exceeds 28℃, and it quickly becomes cork with the continuous increase of temperature.
Grape roots are weak in cold resistance and stop growing at 10℃. Generally, the roots are slightly frozen at -4℃ to -5℃ and freeze to death at -6℃ for about two days. Different populations have different resistance to low temperature, and the order is:
East Asian population (Vitis amurensis):-15℃ ~-16℃;
North American population (Peking University):-12℃ ~-13℃;
Mixed species of Europe and America (Kyoho):-7℃ ~-8℃;
European species (red soil):-4℃ ~-5℃;
moisture
The soil moisture suitable for root growth is 60%~80% of the maximum field capacity. Soil moisture and nutrient status and their related physical and chemical characteristics play a decisive role in root growth.
Excessive soil drought: it is difficult for roots to absorb water and nutrients from the soil, photosynthesis is weakened, old leaves are easy to turn yellow and fall off, and even plants wither and die.
Soil waterlogging or high water content: causing soil hypoxia, forcing roots to supplement oxygen by leaves. Over time, the roots have difficulty breathing and lack oxygen to rot. At the same time, soil hypoxia affects microbial activities, making it difficult for roots to absorb nutrients, making trees gradually weak, and root growth tends to stop or wither or even die.
Tree nutrition
The growth of grape root system is related to the nutrient supply of the tree, and the balance of leaf-fruit ratio or light load is beneficial to rooting; The heavy load consumes a lot of nutrients, which is not conducive to rooting.
If the high yield meets the weak tree stage, the yield must be reduced first, and then the nutrition should be supplemented appropriately. At the same time, the sea elf biostimulant should be applied to promote the root growth and balance the nutrient absorption.
Fertilize soil or land
The roots of any plant have a procreation tendency. Generally speaking, fertilization on grapes is beneficial to rooting. However, if we do not pay attention to fertilization methods, it will not only promote the growth of roots, but also damage the roots.
Excessive fertilizer concentration: physiological water in the tree oozes out to the periphery of the root system to balance the physiological concentration inside and outside the root system. If too much physiological water seeps out, the tree will wither or die due to physiological dehydration, which is often called "fat burning root".
Fertilization: It is easy to cause the root system to float. The soil surface layer at 20cm is rich in microorganisms and various pathogenic bacteria, and the probability of root infection will greatly increase after the root system floats. At the same time, the ability of cold tolerance, drought tolerance and waterlogging tolerance of root system decreases, which affects the tree potential, causes the quality of fruit trees to decline and is easy to crack.
Timing of fertilization: At the peak of grape root growth, timely fertilization can promote root growth and enhance tree potential. It is worth noting that after spring germination, the soil temperature is low and the root activity is poor, so it is not suitable for a large number of topdressing. A small amount of available nitrogen fertilizer can cooperate with sea elf biostimulant to restore root activity. At the same time, spraying sea elf (foliar type) on the leaves after unfolding can quickly supplement the nutrition of trees and improve the photosynthesis of leaves.
soil acidification
Soil acid damage is characterized by stiff plants, slow root growth, slow leaf emergence, small and few leaves, increased soil-borne diseases and easy occurrence of nematodes.
Root growth is poor in acidic environment, including black root, rotten root, dead root and no white root.
After soil acidification, the absorption efficiency of grapes to nitrogen, phosphorus, potassium, calcium, magnesium, boron and other nutrients becomes low. Cause nutrient loss or waste, and still lack fertilizer after fertilization.
It is easy to cause soil hardening, resulting in less air and more gaps in the soil, which is not conducive to root growth and nutrient absorption.
The number of beneficial bacteria and organisms is reduced, which is easy to breed pathogenic bacteria and nematodes.
To reduce acid damage, it is necessary to control the amount of nitrogen fertilizer and reduce the use of other acid fertilizers, such as calcium superphosphate, phosphogypsum and immature organic fertilizer. In view of soil acidification, grapes can use sea elf biostimulant containing mineral humic acid and seaweed extract in the growing period to balance soil pH value and improve soil microenvironment.
organic matter
Soil with high organic matter content and good aggregate structure has good permeability, high fertility and vigorous microbial activity, which is most conducive to root activity and growth.
For the soil with heavy clay, less organic matter and poor permeability, organic fertilizer should be added to improve it, combined with biological bacterial fertilizer and sea elf biological stimulator, and ditch drainage should be carried out to promote root growth. ? [ 16]?
Fresh storage
Modern storage mostly adopts controlled atmosphere refrigeration, and the equipment is more complicated. At present, simple storage methods are mainly used in rural areas, such as cellar storage, cylinder storage, sulfur dioxide fumigation storage, micro-cold storage and so on.
(1) The experience of storing grapes in northern China is harmful. Generally, a cellar is built on the hillside or the source bank, with 4-6 layers of wooden scaffolding, and L layers of grape ears are gently placed on each layer. The specific methods of cellar management are as follows: ① Pre-cooling grapes in the shade for 2 days after harvest, and the pre-cooling temperature must be controlled below 65438 00℃ to fully radiate the heat in the field. Then carefully put the grapes on the shelf in the cellar. ② Control the temperature and humidity in the cellar. Due to the high outdoor temperature in the early stage of cellar, ventilation measures can be taken to keep the temperature below 65438 00℃. After winter, when the temperature drops, it can be kept at 0- 1℃ during the day and closed at night. The relative humidity should be 80%-90%, and when the humidity is insufficient, water can be sprayed on the ground to moisturize. When the outside temperature drops below 10℃, the cellar door should be closed. (3) Strengthen inspection, and timely eliminate rotten grains of diseased ears.
⑵ When the number of grapes stored is small or the grapes are stored in the courtyard, the storage method can be adopted. In the north, household urns are commonly used or stored by themselves. Before storage, wash the jar, dry it, and then put in the grapes. The method of filling the ear is as follows:
1. Young trees should be pruned according to the principle of "giving priority to lightness, paying equal attention to modeling and results, and promoting early yield increase". (1) 2-4-year-old young trees, under the premise of arranging backbone branches, the key point of pruning is to clean up a layer of tightly squeezed branches and straighten the tree shape. According to the planting density, the small crown sparse layer shape (less than 80 plants per mu) and free spinning cocoon shape (more than 80 plants per mu) can be popularized. Small crown and sparse layer shape: select 3-4 main branches in the first layer, clean up the dense branches that affect the growth of the main branches after selection, and clean up 1-2 branches every year, and strive to clean them up in 2 years. Free-spinning reeling shape: 3-4 small main branches are selected every year, and the spacing between the main branches is about 20 cm, and the branches that are too dense are properly loosened. (2) 5-8-year-old young trees have entered the fruiting stage, and the key point of pruning is to clean up the dense branches between layers, improve the lighting conditions of the trees, and make the fruiting parts gradually transition to the backbone branches. Clean up 2-3 crowded places every year, and strive to clean them up in 3 years. After several years of adjustment and cleaning, five main branches, 1-2 auxiliary branches and 10- 13 main branches were preserved in the sparse layer of small crown.
2. Pruning of adult trees The purpose of pruning of adult trees is to "improve the illumination, improve the quality of branches, stabilize the quality and increase the yield". The key point of pruning is to remove two layers of excessively dense large auxiliary branches, large lateral branches and large branches in batches, so that the large branches remaining in two or more layers extend outward as much as possible in a whip shape, and the total branches account for less than 20% of the total branches of the whole tree, which is beneficial to the illumination in the inner room of the first floor. If the crown of the tree is on the high side, it is necessary to gradually bow your head and be happy by the strength of the tree, and the height of the tree should be controlled below 3.5 meters; If the crown has crossed, the densely packed branches should be drained or transformed into small branches, and the branches should be shortened to slow down the outside and promote the inside, or the direction and angle of the main branches should be changed by changing the main branches, so that the crown distance should be kept at about 1 m to improve the lighting conditions of the population and individuals.
Second, cut off the diseased branches and insect branches. According to the survey, many diseases and insect pests that harm apples overwinter on the branches. For the diseases and pests that overwinter in trees, combining with winter shears, all branches of diseases and pests are cut off, burned or buried deeply, which can obviously reduce the harm in the coming year.
Third, the rough old bark in the gap between the rough old bark and trunk of fruit trees, there are often a large number of overwintering bacteria and pests. Scraping rough old bark, burning or burying it deeply has a good control effect on many kinds of pests and diseases, and sometimes even completely eliminates some pests.
Apple is a beauty product, which can not only lose weight, but also make the skin smooth and tender. Apple is a low-calorie food, every 10.
0 g only produces 60 kilocalories; The nutrients in apples are soluble and easily absorbed by the human body, so they are called "living water", which is beneficial to dissolve sulfur and make the skin smooth and tender. Apple contains copper, iodine, manganese, zinc, potassium and other elements. Without these elements, the skin will be dry, fragile and itchy.
Vitamin C in apples is a protector of cardiovascular system and a healthy element for patients with heart disease.
People who eat more apples are much less likely to catch a cold than those who don't eat or eat less apples. Therefore, some scientists and doctors call apples "all-round healthy fruits" or "general practitioners". The air pollution is serious. Eating more apples can improve the respiratory system and lung function and protect the lungs from dust and smoke in the air. ? [7]?
Pectin: It belongs to soluble fiber, which promotes cholesterol metabolism, lowers cholesterol level and promotes fat excretion.
Trace elements: potassium dilates blood vessels, which is beneficial to patients with hypertension; Zinc deficiency will lead to disorder of blood sugar metabolism and decline of sexual function.
Can regulate the stomach: fiber helps to excrete; It also has astringent effect on diarrhea.
Apple peel+a few slices of ginger boiled water: it can stop vomiting.
Binding: connect the cut scion to the other end of the thorn, and connect the scion with the thorny rootstock. Rootstock and scion should be as close as possible without gaps, so as to avoid poor healing caused by bacterial infection. Then, each side is fixed with a thorn, and then a thin thread is tightly wound around the base.
B. wedging method
Cut a slit longitudinally at the top of the rhizome with a sterilized knife, but not too deep. Then cut the lower part of the scion into a duckbill shape with a sterilized blade, insert it into the crack of the rootstock immediately after cutting, fix it with plastic tape, and cover it with a plastic bag to keep the air humidity, which is beneficial to survival. After 20 days, the growth of grafting was observed. If it can keep fresh and bright green, it will survive. You can leave the nursery in a month.
pot culture
The germination temperature of pitaya seeds is about 25℃.
To choose culture soil with fine particles, you can also use commercially available sowing soil instead.
Be sure to remove the pulp and gum attached to the seeds, otherwise mold will easily grow when sprouting.
To make a small potted plant, the seeds should be spread densely, especially at the edges, otherwise it will be scattered loosely and lose its aesthetic feeling.
If there is no bottom hole in the basin, don't water it directly with the kettle, so as not to water it too much. Just spray water with the watering can once every 2-3 days. ?
Including peaches, plums, apricots and cherries. The outer wall of the ovary forms exocarp, the middle wall develops into fruit meat, and the inner wall forms lignified stone. There is usually a seed in a stone. The edible part is mesocarp.
3. Berry fruit trees
Include kiwi fruit, raspberry, pomegranate, grape, etc. The fruit is juicy, and the seeds are small and numerous, which are distributed in the pulp, and most of them are not resistant to storage. This kind of fruit has great differences in fruit structure due to different tree species. Its representative tree species is grape, the fruit develops from ovary, the exocarp is membranous and the mesocarp is soft and juicy. The edible part is mesocarp.
4. Nut fruit trees
Including walnuts, chestnuts, hazelnuts, ginkgo, etc. It is characterized by a hard shell outside the fruit and seeds in the shell. Edible parts are mostly seeds, which have low water content and are resistant to storage and transportation, commonly known as dried fruits.
5. Persimmon and jujube trees
Exocarp membranous, mesocarp fleshy. The endocarp of jujube forms a nucleus, and the edible part is mesocarp; Persimmon endocarp is tough, and the edible part is the middle endocarp.
Including oranges, oranges, oranges, grapefruit and so on. The fruit developed from ovary, the exocarp was leathery with oil cells, the endocarp was a white sponge and the endocarp was a juicy sac. The edible part is endocarp capsule. Most fruits are resistant to storage and transportation.
2. Others
Include litchi, longan, loquat, bayberry, coconut, mango, avocado, etc.
Perennial herbaceous fruit trees
Include bananas, pineapples, strawberries and the like.
(1) Nutrition and health functions of fruits are rich in nutrients, including vitamins and inorganic salts, as well as sugar, starch, protein, fat, organic acids and aromatic substances, which are necessary for human growth, development and nutrition. According to nutritionists, each person needs 70 ~ 80 kilograms of fruit every year to meet the normal needs of the human body.
(2) Medicinal functions of fruits Many fruits and seeds can be used as medicine and have therapeutic effects. Such as walnuts, lychees and longan are all good tonics; Pear cream and persimmon cream are often used as medicine; Almond, peach kernel and orange complex are important Chinese herbal medicines. Guava can treat diabetes and lower cholesterol.
(3) The eco-environmental benefits of fruit trees have universal adaptability. Fruit trees can be planted not only in plains, rivers, roads and rural gardens, but also in deserts, hills and beaches. Choosing suitable fruit trees can not only increase economic income, but also prevent soil erosion, increase green coverage area and adjust climate, thus greening, beautifying and purifying the environment.
(4) Fruit trees are important raw materials for food industry and chemical industry. In addition to fresh food, fruits can also be processed into preserved fruits, fruit juices, preserves, jams, cans, fruit wine, fruit vinegar and so on. The hard shell of some fruits can be used to make activated carbon, the leaves, bark and peel of some fruit trees can be used to extract dyes or tanning materials, and orange peel and neroli can be used to extract essential oils. The wood of many fruit trees is an excellent material for national defense industry, construction industry and carving technology.
(5) The economic benefits of fruit trees are an important part of agriculture. With the adjustment of rural industrial structure and the liberalization of agricultural products market, especially in hilly, mountainous and desert areas, developing fruit tree production according to local conditions can bring considerable benefits to farmers. China fruit is rich in resources, and fruit tree production is highly competitive in the international market, which is an important source of foreign exchange earned by agricultural products export.
First, the selection of excellent varieties of saplings should be pure and adapt to local natural environmental conditions. To develop new varieties of fruit trees, it is necessary to consult relevant scientific research departments and experts, and never trust advertisements and choose seeds by ear. The seedlings supplied by general scientific research units and competent departments are more reliable. For seedlings sold by individuals, the source of seedlings or scions must be made clear before purchase. [ 1]
Second, the root system of fruit tree seedlings with excellent roots should have more lateral roots and fibrous roots, which are evenly distributed. The first-class and second-class seedlings should have more than three lateral roots, and the roots should not lose water.
3. Selection of superior specifications: The height of fruit seedlings should be 1 ~ 1.3 m, and the ground diameter (above the interface 10 cm) should be 0.8 ~ 1 cm. Grape Miao Di diameter is not less than 0.6 cm.
4. Germination conditions: the plastic belt below the fixed stem position must have more than 6 full and full leaf buds, so that good branches can be issued after the fixed stem position. Grape seedlings must have 3 ~ 4 full buds with high maturity.
Five, whether there are pests and diseases, choose the seedlings without pests and diseases, and the seedlings belonging to the quarantine scope should have quarantine certificates. Never introduce diseases, insects and weeds into quarantine objects, otherwise, at this time, almost all fruit tree pests and diseases will start to hide in the wintering nest, unable to eat or move, and enter hibernation. Therefore, this is the best time to control fruit tree diseases and insect pests once a year. First, clean the garden. Some diseases such as soft rot, gray mold and downy mildew, as well as some pests such as red spider, borer and caterpillar, mostly hide in dead branches, fallen leaves, weeds and garden debris for the winter. Therefore, orchards should be cleaned in time after fruit picking or defoliation. First, cut off branches, dead branches, insect buds, dead fruits, etc. In the tree; Then clean up the fallen leaves and fruits under the tree, and at the same time clean up and bury the sundries around the garden, destroy them or make compost, which can basically eliminate pests or germs that overwinter in these sundries.
Second, the garden soil has been deeply ploughed over the fruit trees, such as scarab, peach moth, ship caterpillar and oblique 15 ~ 50 years, with poor soil and extensive management, only 20 ~ 30 years. Due to the combined effect of apical dominance and bud heterogeneity, apples usually have strong dryness and obvious stratification. Due to the differences in germination and branching ability among varieties, the obvious stratification degree is also different. [4] Apple buds are divided into leaf buds and flower buds according to their properties. Leaf buds are triangular, long and curved, and grow into branches after spreading leaves, which are called new shoots or vegetative branches. Branches can be divided into long branches, common branches, slender branches and leafy branches according to their growth. The flower buds of apples are mixed buds. Axillary flower buds are buds formed in the axils of leaves of branches of the same year, and those that can blossom and bear fruit in the next year are called axillary flower buds. 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. 5-7 flowers per inflorescence.
bloom and bear fruit—yield positive results
Flowering: The flowering period of apples varies greatly due to different climates. Usually from April to May,
There are 3 ~ 7 flowers in each bud, and the central flower blooms first. Apple is a cross-pollinated plant, and most varieties cannot bear fruit by themselves. The proportion of various fruiting branches varies with the age and species of trees. Usually, young trees have more long fruit branches and middle fruit branches. With the increase of tree age, the proportion of short fruit branches increased rapidly, reaching more than 70% in the full fruit period, and almost all of them were short fruit branches in the aging period. From the variety point of view, Jin Shuai and other varieties have more long fruit branches and medium fruit branches, and varieties such as Starkrimson and Red Fuji have a large proportion of short fruit branches, and varieties such as Liaofu are easy to form axillary buds.
Fruit setting: the normal fruit of apple, each fruit has 5 ventricles, and each ventricle has 2 seeds. During fruit development, seeds secrete hormones to stimulate pulp growth, so pollination is good, seeds are full and full, fruit shape is correct, and pulp is full; 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. [ 1]
Fruit quality
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 volume expansion of cells in the later stage.
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 and 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. 7 ~ 14 days after the third and second fruit drop, the fruit has reached the size of thumb nail, which has a great influence on the yield, so it is called physiological fruit drop. Yunnan usually occurs in May, and the phenology in the north is later than that in Yunnan, which occurs in June, so it is called "June 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. [ 1]
Fruit development
Apple peel color can be divided into background color and surface color. When the fruit is immature, the background color of the peel is generally dark green, and there are three situations when the fruit is mature:
1. Green fades or even disappears completely, and the background color is red.
2. Green will not fade completely, resulting in yellow-green or yellow-green background color.
3. Green doesn't fade at all, it is still dark green.
When the fruit is ripe, the surface color of the peel is generally red, green and Huang San, and there are other colors, but they are rare.
The main pigments that determine the color of fruits are chlorophyll, carotene, anthocyanins and flavonoids. Anthocyanin is an extremely unstable water-soluble pigment, which mainly exists in cell fluid or cytoplasm. It is red at low pH, lavender at neutral and blue at alkaline. When it is combined with different metal ions, it will also show various colors, so fruits can show various complex colors.
Factors affecting the formation of anthocyanins
In addition to the heredity of varieties, the sugar content in fruits is the main factor affecting the formation of anthocyanins in apples. Anthocyanins are proanthocyanidins formed when pentose breathes violently. In addition, anthocyanins often combine with sugar to form anthocyanins in fruits. Therefore, the development of anthocyanins is closely related to the sugar content. Any factors that affect the synthesis and accumulation of sugar will affect the development of anthocyanins. Higher tree nutrition level, reasonable load, suitable ratio of phosphorus, potassium and nitrogen fertilizer and proper water control are all beneficial to the red development of fruit.
The effect of temperature on coloring is also related to the accumulation of sugar. When the temperature of mid-late mature apple varieties is above 20℃ at night, it is not conducive to coloring.
The firmness of pulp is also one of the important indexes of fruit quality. The hardness of pulp not only affects the taste of fresh food, but also relates to the storage and processing characteristics of fruit. The hardness of apple pulp is closely related to the cellulose content in the cell wall, the kind and quantity of pectin in the glue layer in the cell wall and the swelling pressure of pulp cells. [ 1]
Apple tree 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 ≥ 10℃, and the average temperature in the growing season (April ~ 10) is about 5000℃. It is generally believed that apples can be planted in areas where the annual average temperature is 7.5 ~ 14℃. The natural dormancy period of apples is very long. If the temperature in winter is too high to reach the low temperature required for winter dormancy, the germination in spring will be uneven.
Judging from the areas with the most apples in the world, the average temperature in Leng Yue in winter (65438+ 10 in the northern hemisphere and July in the southern hemisphere) is between-10 ~ 10℃, which can meet the requirements of low temperature for apples. The average temperature of the main apple producing areas in China 1 month is within this range. The average temperature 12 ~ 18℃ in the growing period (4 ~ 65438+ 10 month) and 18 ~ 24℃ in the summer (June ~ August) are the most suitable for apple growth. In autumn, the temperature is high during the day and low at night, and the fruit has high sugar content, good coloring, thick peel, more fruit powder and storage resistance. [ 1]
deposit
The precipitation per mu during the apple growing period is about 180mm. Generally, natural precipitation can actually be absorbed by fruit trees, which is about 1/3, so it is enough to have a precipitation of 540 mm during the growing period. Areas with rainfall below 450 mm from April to September need irrigation. The distribution of precipitation in northern China is uneven, with 70-80% concentrated in July and August, and the amount of water is insufficient in spring. There is little precipitation and water shortage in inland areas, so irrigation conditions and soil and water conservation measures must be considered when building gardens and selecting land, and drainage measures should also be paid attention to in rainy season.
sunlight
Apple tree is a light-loving tree, and it can grow normally only when there is enough light. According to the measurement of Shandong Agricultural University, the light compensation point of Jinguan and emerging areas in Tai 'an is 600 ~ 800 m candle, and the saturation point is 3500 ~ 4500 m candle. In this range, the light intensity increases and photosynthesis is also strengthened. Insufficient sunshine causes a series of reactions, such as excessive growth of branches and leaves, weak resistance to pests and diseases, less flower bud differentiation, less nutrient storage, yellow color and so on, but they are rare.
The main pigments that determine the color of fruits are chlorophyll, carotene, anthocyanins and flavonoids. Anthocyanin is an extremely unstable water-soluble pigment, which mainly exists in cell fluid or cytoplasm. It is red at low pH and lavender at neutral.