Apple plant Malus pumila Mill. Related English: apple: apple ◇apple jam apple honey apple butter apple peeler apple grunt apple sauce applesauce apple roast (wine) ) applejack apple tree apple (tree) apple oil apple oil apple juice cider This is a common fruit family, Rosaceae, apple genus Morphology and habits: deciduous tree, tree height can reach 15 meters, generally 3 to 5 meters high under cultivation conditions . The trunk is grey-brown, the old bark has irregular longitudinal cracks or flakes peeling off, and the branchlets are smooth. The single leaves are alternate, elliptical to oval, with serrated margins. Corymb inflorescence, petals white, pink when in bud, 20 stamens, 5 styles. The fruit is a pome, and the color and size vary depending on the variety. It likes light and slightly acidic to neutral soil. It is most suitable for sandy soil with deep soil layer, rich in organic matter, and good ventilation and drainage. Propagation and cultivation: Propagation by grafting. Rootstocks include arborizing rootstocks and dwarfing rootstocks. Commonly used arborizing rootstocks include: Catalpa japonica, Begonia chinensis, and Vitex japonica. The dwarfing rootstocks are mainly imported British varieties. Use wide rows of dense planting, with the rows facing north and south. Plant in autumn and winter before the soil freezes in southern areas, and when it thaws in spring in northern areas. Apples have poor self-flowering ability and must be planted with pollinating trees. Resource distribution: native to southeastern Europe, Asia Minor and the South Caucasus. It was introduced to Yantai, my country, around 1870. In recent years, it has been widely cultivated in southern Northeast China, North China, and Northwest China. Most of the fruits we eat daily have a long history of cultivation in China, and their names have been recorded in history for a long time. The case of apples is an exception. Although there were fruits very similar to it in ancient China, the name apple did not officially appear until the Ming Dynasty. Investigating its origin, apple is the abbreviation of "Ping Po Fruit". "Ping Po" was originally written as "Pin Po", and "Pin Po" had other phonetic variations such as "Ping Bo" and "Ping Po". This article intends to start from the investigation of the "Pinpo" fruit, discuss the origin of the word "apple" in Chinese, and provide some literature for the study of the history of apple cultivation in ancient China. We welcome the criticism and correction of relevant experts. Fruiting habits of apples 1. Flower buds and flowers: Flower bud differentiation of apples begins in early June and is completed before winter in most varieties. The entire process is divided into three stages: physiological differentiation, morphological differentiation and sex cell maturation. The flower buds are mixed buds and the inflorescences are corymbose cymes. Each inflorescence blooms 5-8, mostly 5. The central flower blooms first, and the side flowers bloom later. The central flower has the best quality, stable fruit setting, and large results. When thinning flowers and fruits, the central flower and central fruit should be retained. Many sparse edging flowers and edging fruits. Flower buds first produce leaves and then bloom, and produce secondary shoots from the fruit stand. The number and length of secondary shoots from the fruit stand vary with the variety and the nutritional conditions of the fruiting mother branch. Varieties with strong (two) secondary shoots and long and strong branches, such as Zhuguang, have small fruits, low yields, and loose branch clusters. For this type of species, methods such as thinning one and leaving one and pinching and twisting should be used to control the growth of secondary shoots. Varieties with medium secondary shoot growth (1 or 2), short and thick branches (less than 10 cm), such as Jinshuai, Jonagold, etc., have large fruits, high yields, compact branch groups, easy renewal, and continuous fruiting ability powerful. Varieties with weak secondary shoot growth (1) and short branches (less than 3 cm), such as Marshal series, Entai, etc., have large fruits and compact branch groups, which are easy to form chicken-foot branch groups. They are easy to renew, but have many fruit sets. In order to bear fruit every other year, more preparation branches should be left to reduce the number of bears in the next year. 2. Fruit: Apple fruit is a false fruit developed from an ovary and a receptacle. The ovary develops into the fruit core, the receptacle develops into the flesh, and the embryo develops into a seed. The expansion of fruit volume depends on the increase in the number of rapidly dividing cells in the early stage and the expansion of cell volume in the later stage. The expansion of fruit size is faster in the middle stage and before maturity, and slower in the early and final stages. Fruit weight increases fastest in the month before maturity. The length of fruit development period is generally 65-87 days for early-maturing varieties, 90-133 days for mid-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, coordination of mineral elements, environmental conditions and hormone types and contents. In the later period, controlled application of nitrogen fertilizer, increased application of potassium fertilizer, reduction of chlorophyll in the peel, improvement of ventilation and light transmission conditions, increase of sunlight exposure, good drainage, reduction of air humidity, and spraying of hormones such as naphthyl acetic acid and 2.4-D can all promote apple growth. Color. From the time the flower buds appear to the time the fruit is harvested, apples generally fall off four times. For the first time, during the final flowering period, the pedicels fall off together with the flowers, which is usually called flower drop. The second time, about a week after the flowers fall, the ovary slightly enlarges and lasts for 5-20 days, which is called early fruit drop. The third time, 7-14 days after the second fruit drop, the fruit has reached thumb to yuan size, which has a greater impact on yield. It is called physiological fruit drop. It usually occurs in May in Yunnan, and the phenological period in the north is later than that in Yunnan. In June, it is called "June Fruit Falling". The fourth time before the fruit is harvested, mature or nearly mature fruits fall, so it is called preharvest fruit drop. The first and second flower and fruit drop are mainly caused by nutritional deficiencies and poor pollination and fertilization. The third fruit drop is caused by intense competition for nutrients between fruits and shoots, in addition to competition between fruits and lack of growth hormone in the embryo.

Because the osmotic pressure of the leaves is greater than that of young fruits, the competition for nutrients is stronger than that of young fruits. Therefore, in addition to timely topping and cutting of new shoots to inhibit the growth of new shoots, topdressing of flower-bearing fertilizers should also be applied in a timely manner to supplement nutrients. 3. Seed: It develops from the fertilized egg in the embryo sac. The normal fruit of apple has 5 ventricles and 2 seeds in each ventricle. During the fruit development process, the seeds secrete hormones to stimulate the growth of the pulp. Therefore, those with good pollination and fertilization and plump seeds will have a correct shape and plump flesh. On the contrary, those with poorly developed seeds or no seeds will have sunken and thin flesh, resulting in deformed fruits. Therefore, Be sure to configure pollinating trees and improve pollination. Requirements for external environmental conditions 1. Temperature: Apple is a temperate fruit tree that likes cool, cool and dry conditions. It requires no severe cold in winter and no severe cold in summer, with small annual range and large daily range. The suitable temperature range is the annual average temperature of 9-14℃, the extreme minimum temperature in winter is not lower than -12℃, the highest monthly average temperature in summer is not higher than 20℃, the annual accumulated temperature of ≥10℃ is about 5000℃, and the growing season (4-10 The average temperature per month is 12-18°C, and in winter it takes 1200-1500 hours of low temperature below 7.2°C to successfully pass natural dormancy. Insufficient low-temperature time leads to delayed and irregular leaf development and flowering, and some flower buds do not even sprout. In May, the scales loosen and fall off, becoming dead piles, seriously reducing yields; the absolute low temperature is lower than -30--32℃, and frost damage occurs again. . According to the survey, the performance of apples in different altitude and temperature areas of Yunnan Province is as follows. Table 1 Performance of apples in different altitude and temperature zones in Yunnan Altitude (meters) Annual average temperature () High yield Fruit quality Pests and diseases Growth pattern Suitability 1800 Below 15 Above `Difference Weight difference Abnormal Unsuitable 1800-2000 14-15 Medium Heavier than normal, suitable for 2000-2200, 13-14, rich, light, normal, suitable for 2400-2500, 12-12.5, 2200-2400, 12-13, high, excellent, extremely light, normal, suitable for 2200-2400 meters, average temperature 12-13℃, apples perform well The reasons are mainly due to the temperature difference between day and night in summer and autumn, sufficient accumulated temperature, and strong ultraviolet light. Apples show high and stable yields, bright fruit colors, high fruit shapes, five-ridged edges, high sugar and vitamin C content, low acid content, and pectin viscosity. Large, good flavor, strong storage and cold resistance. The low temperature in winter allows fruit trees to pass through natural dormancy smoothly. The flower buds are of good quality and will germinate on time in the following spring. The germination and flowering are neat, the fruit setting rate is high, and there are few and mild pests and diseases, so it is the most suitable area for apples. The areas with an altitude of 2000-2200 meters and an average annual temperature of 13-14°C and an altitude of 2400-2500 meters with an average annual temperature of 12-12.5°C, immediately following the lower and upper zones of the most suitable zones, are the suitable zones for apples. In areas with an altitude of 1800-2000 meters and an average annual temperature of 14-15°C, the winter temperature is relatively high. In "cold winter" years, it can basically pass dormancy smoothly, and the performance will be normal the next year; in "warm winter" years, it cannot break dormancy smoothly, so it will Delayed germination, irregular flowering, and reduced yield will occur, so it is a sub-suitable area for apples. In areas with an altitude below 1,800 meters and an average annual temperature above 15℃, the temperature in summer and autumn is too high and the cooling is late. Not only is the fruit color poor, the sugar is low and the acid is high, but the branches and leaves are very long, the vegetative growth period is long, the leaves are delayed, and the flower buds are poorly differentiated; The temperature in winter is too high, and the low temperature hours during the dormant period are insufficient. Flower buds cannot go through dormancy, which disrupts normal life patterns and leads to physiological disorders. Germination and flowering in the next spring are irregular, the fruit setting rate is low, and there are many and serious pests and diseases; at altitudes above 2,600 meters , the annual average temperature is below 9℃, and the annual accumulated temperature and the temperature during the growing period are insufficient, the trees become dwarfed, the internodes become shorter, the number of fruit cell divisions is small, and the expansion coefficient is small, resulting in small fruits, thick skin, hard flesh, and low sugar. All are unsuitable areas for apples. Therefore, when developing apples, we should choose the most suitable and appropriate areas to build orchards, so that we can give full play to the local natural advantages and the excellent traits of the varieties, obtain high-yield and high-quality fruits, and receive the best economic benefits. 2. Rainfall: Although apples are native to inland climate areas with dry summers and prefer a drier environment, they still need sufficient water and suitable air humidity during the growth period for normal growth and development; however, excessive rainfall and excessive humidity will It will also lead to dense branches and leaves, serious diseases and insect pests, poor color of fruits, low sugar and high acidity. Generally, the annual rainfall is 500-1000 mm and the air humidity is 60%-70%. Since the spatial and temporal distribution of rain in Yunnan is uneven and the dry and rainy seasons are distinct, in the dry season from February to May, top dressing should be combined with irrigation once a month to meet the water requirements for leaf growth and flowering and fruiting; drainage must be done during the rainy season. Reduce soil moisture content and air humidity to reduce the occurrence of diseases and insect pests and improve fruit quality. 3. Light: Apple is a light-loving fruit tree. According to measurements, the light compensation point of most varieties is 600-940 lux, and the saturation point is 24000-75000 lux. Insufficient light directly reduces photosynthesis and tree nutrition levels, and affects fruit coloring and sugar conversion; too much strong direct light and too long exposure time can easily cause branches and fruits to be burned. Therefore, it is necessary to select a good garden site and perform pruning, improve ventilation and light transmission, and have a reasonable leaf curtain layer to avoid the aforementioned disadvantages. 4. Terrain: Planting can be done on flat land, mountains, beaches, and river flats, but it is best to plant on sunny, open, leeward, gently sloping land with good surrounding vegetation, good lighting, and convenient irrigation and drainage; although depressions and ditches, The soil layer is deep, but the light is poor, water easily accumulates in the rainy season, and the air humidity is too high; the soil layer is shallow, the soil is thin, the soil is thin, and water and soil erosion are heavy, all of which are not conducive to the growth of fruit trees.

5. Soil: Apples do not have strict soil requirements. Clay, sandy soil, and loam are all acceptable, but sandy loam with deep soil, loose and fertile soil is best. Heavy clay soil with shallow soil layer and excessive gravel must be improved before planting. The range of adaptable pH value is 5.3-8.2, and the optimum range is 5.4-6.8. If it is lower than 5.4, it is too acidic, and it is prone to fruit shrinkage and bitter pox disease caused by boron and calcium deficiency; if it is higher than 7.8, it is too alkaline, and it is prone to iron deficiency, causing leaf chlorosis. Garden use: It can be viewed during the flowering season; during the fruit ripening season, the fruits are abundant and colorful, which is attractive.