Pears are characterized by strong fragrance, thin skin, fine meat, juicy, sweet and crisp, refreshing and delicious.
Pears have a variety of functions, including protecting the heart, reducing fatigue, enhancing myocardial activity, and lowering blood pressure. In addition, the glycosides and tannins contained in pears can expectorant and relieve cough. Reduce heat and heat, nourish yin and nourish people.
Pear morphological characteristics
Pear has a well-developed root system, the vertical root depth can reach more than 2-3m, and the horizontal root distribution is wide, about twice the crown width. It is advisable to choose a gentle slope mountain with deep soil layer and good drainage, especially sandy loam mountainous land is ideal. Strong dryness and obvious layering. The fruit is early and the fruiting period is long. Some varieties begin to bear fruit in 2-3 years, and the fruiting period can be maintained for more than 50 years.
The phenological period of pear trees varies greatly due to their wide distribution. As far as the flowering period is concerned, in Huili, Sichuan, pear trees generally bloom in early and mid-February, and the flowers are white in Yanbian, Jilin, and bloom in mid-May; Yali pears bloom in early March in Changsha, Hunan, and North Liaoning in early May. The flowering period varies by nearly two months from place to place. Pear trees cultivated in the same area have different phenological periods due to different types and varieties. From bud sprouting to flowering, the autumn pears are the earliest, the white pears are later, the sand pears are later than the white pears, and the western pears The variety is the latest, and the range of variation is about 10 days.
A few varieties of flowers and leaves open at the same time or first spread the leaves and then bloom. After the pollen is fertilized, the fruit begins to develop, the receptacle develops into the flesh, the ovary develops into the core, and the ovule develops into the seed.
In the process of fruit growth and development, the early stage is mainly cell division and tissue differentiation, and the later stage is cell expansion and pulp ripening. The fruit volume growth curve is S-shaped. Pear root system growth has two growth peaks each year: the first growth peak occurs when new shoots stop growing; the second peak occurs from September to October. Under suitable conditions, the pear root system can grow annually without a dormant period.
Pear growth habit and growing environment and distribution
Pears are light-loving and temperature-loving, more resistant to high temperatures, and moderate in cold resistance. The annual growth cycle is from the end of March, the beginning of April to November (Table 1). The beginning period of pear bud germination and deciduous leaves is about 10℃, and the period from flowering to fruit maturity is completed within the period when the daily average temperature is ≥15℃. This period lasts for a long time, the temperature is high, sufficient light is beneficial, and low temperature and low light have many disadvantages. The growth period of pears is about 220-230 days, and the accumulated temperature must be higher than 10°C and 3400°C.
Pear efficacy and role
Pears are not only fresh, sweet and delicious, crispy and juicy but also rich in nutrients. Pears have the effects of reducing fire, clearing the heart, moisturizing the lungs, resolving phlegm, relieving cough, reducing fever, detoxifying ulcers, and alcohol poisoning. Regular eating can supplement the body's nutrition. Pears are especially suitable for patients with hepatitis, tuberculosis, constipation, acute and chronic bronchitis, upper respiratory tract infection, high blood pressure, heart disease and esophageal cancer.
Pears contain a variety of vitamins, potassium and calcium, which have the effects of lowering blood pressure, clearing away heat, sedation and diuresis, and have a certain therapeutic effect on hypertension, dizziness and tinnitus accompanied by heart disease. Pears eaten raw can relieve symptoms of yin deficiency caused by upper respiratory tract infections such as dry and itchy throat, dry cough, polydipsia, and hot flashes. Therefore, teachers, announcers and singers often eat pears to protect their throats and prevent laryngeal cancer, lung cancer and nasopharyngeal cancer. When eating pears, it is best to chew them slowly so that they can be absorbed by the stomach.
Pear trees have a strong ability to adapt to the soil, and they can grow and bear fruit regardless of mountains, hills, deserts, depressions, saline soils and red soils. But the quality of the fruit is slightly different. Under general cultivation and management conditions, high yields can be obtained.
Pear trees have a long lifespan and a long economic use period. There are many large trees born between 100 and 150 years old in the pear regions of North and South China, and the branches and leaves are luxuriant, and the fruits are numerous. Some plants can yield more than 1,000 to 1,500 kg. Grafting methods are often used for seedling reproduction. Commonly used rootstocks are du pear, sorbus, bean pear, and sand pear. Dwarf cultivation of pear trees is an important method for the intensive cultivation of fruit trees. For production, the dwarf anvil is better selected from Yunnan quince, which has the characteristics of high cutting survival rate and strong dwarfing effect; Chinese scientific and technological workers are selected and bred The K series rootstocks such as K31.K9.K13.K21.K28 all show dwarfing or semi-dwarfing characteristics, strong compatibility with various pear varieties, good grafting healing, and rooting ability.
Most varieties of pear trees do not bear self-flowering. Even though some varieties have a certain self-pollination ability to bear fruit, cross-pollination can produce better fruit. Therefore, pear orchards must configure good pollination combinations and sufficient pollination numbers.
1. Pear tree sowing and seedling
Spring and winter are the best seasons for planting and raising seedlings of pear trees. The planting and seedling of pear trees are generally carried out using drilling.
2. Cutting seedling technology
Cutting seedlings of pear trees are mainly carried out in summer. In summer, the temperature in southern my country is relatively high. Therefore, cutting seedlings of pear trees should be selected in the cool morning to ensure that the pear seedlings and the water contained in the soil will not be lost due to evaporation. . When cultivating pear seedlings, select branches with better wood and close to maturity, and ensure that the branches are not eroded by pests. When cutting pear seedlings, the distance of each seedling should be kept at about 10 cm, and the moisture of the seedlings and suitable light should be ensured. The cut pear seedlings will take root and sprout in about a month and a half. Before they take root and sprout, they should be watered regularly to ensure their normal growth.
Scientific fertilization and formula fertilization are some of the important measures for pear trees to obtain high and stable yields. The current pear orchard soil is generally deficient in nitrogen, followed by deficient phosphorus and some trace elements. Besides, fertilization management should be carried out according to the different periods of tree age and the different growth characteristics of each period.
The early stage of pear growth is the period of germination, branching, leaf spreading, flowering, and fruit set. During this period, a large amount of nitrogen fertilizer is required, and the application of nitrogen fertilizer should be strengthened at this time. The fruiting period and the fruit-bearing period are important periods of fertilization, and a large amount of fertilizer is required, especially the application of potassium fertilizer during the fruit expansion period. More than 80% of the potassium fertilizer is absorbed during this period.