Fruit trees generally do not need chemical fertilizers, especially chlorine-containing chemical fertilizers. The first fruit-bearing tree (3-4 years) is mainly fertilized three times after fruit picking, before spring germination and during the strong fruit period. Apply base fertilizer once in August-September after fruit picking, mainly farm manure, compound fertilizer and withered fertilizer; In February, apply quick-acting nitrogen fertilizer once before spring shoots germinate to promote the growth of spring shoots; At the beginning of June, a strong fruit fertilizer, mainly phosphorus and potassium fertilizer, was applied to promote fruit expansion and new shoot growth.
Germination-accelerating fertilizer was applied 10- 15 days before germination in early March, with quick-acting nitrogen fertilizer as the main fertilizer and appropriate amount of phosphorus and potassium fertilizer, accounting for 30% of the whole year;
Strong fruit fertilizer, applied in the fruit expansion period from June to August, is mainly nitrogen fertilizer, supplemented by phosphorus and potassium, accounting for 30% of the whole year;
Fruit picking fertilizer,165438+1early October, the combination of quick-acting fertilizer and organic fertilizer, and the combination of nitrogen fertilizer and phosphorus and potassium fertilizer accounted for about 40% of the whole year.
Fertilization principle: we should fully meet the demand of blood orange for various nutrients, advocate applying more organic fertilizers, and rationally apply inorganic fertilizers and formula fertilizers. According to the results of leaf analysis, orchard soil analysis and blood orange phenology, fertilization is guided.
Fertilization method: mainly soil fertilization combined with foliar fertilization. The methods of annular furrow application, strip furrow application, hole application and soil surface fertilization were adopted.
Fertilization for young trees: apply fertilizer frequently and thinly, with nitrogen fertilizer as the main fertilizer and phosphorus and potassium fertilizer as the auxiliary fertilizer. Apply fertilizer 5-6 times in the bud germination period (March, May, June, July, September, 65438+February) in spring, summer and autumn, and apply 0.4 kg of ammonium carbonate or 0.2 kg of urea to each plant each time. 1-3 young trees should be applied with pure nitrogen 100-400g every year, and the ratio of nitrogen, phosphorus and potassium is1.0: (0.4-0.5):1.0. Adult trees should be fertilized four times, that is, germination accelerating fertilizer, fruit protection fertilizer, fruit strengthening fertilizer and fruit picking fertilizer. Generally, the amount of fertilizer applied is 2-3 kg of chemical fertilizer and one load of manure. Fruit-keeping fertilizer 1-2 kg phosphorus and potassium fertilizer+1 kg chemical fertilizer; Strong fruit fertilizer 1-2 kg chemical fertilizer+1-2 kg phosphorus and potassium fertilizer; The fruit picking fertilizer (base fertilizer) is mainly organic fertilizer, and each plant is applied with 50- 100 kg organic fertilizer+1-2 kg chemical fertilizer.
cultivation techniques
Moisture: Irrigation when soil is dry, and drainage when water accumulates. Plastic trimming 1, principle. Adjust measures to local conditions, prune trees, properly raise and lower them, and ventilate and transmit light to achieve three-dimensional effect. 2, plastic surgery (natural and happy appearance). The trunk is 20-40cm high, and the trunk branches (3-4 branches) are scattered on the trunk. The branching angle of the main branch is 30-50 degrees, and 2-3 auxiliary main branches are left on each main branch. Generally, after the third main branch is formed, the central trunk of this kind is cut off and twisted to one side to form a fruiting branch group.
Seedling raising: rootstock is the best, which grows fast after grafting, bears early fruit, has high yield and good fruit quality. Sowing is generally carried out in the field, and a small plastic arch shed should be built to keep warm. Emerge in the same year, and germinate in the next autumn, which can be as early as 1 year. Grafting is usually carried out from early March to early April, and the autumn shoot or spring shoot scion is about15-25 cm; In August -65438+ 10, T-type bud grafting is commonly used. In the first ten days of March of the following year, after the bud grafting survives, it is cut off 3-5 cm away from the bud. When the spring shoots stop growing, all the grafting piles are cut off.
Garden construction: after soil preparation, ditch shall be drawn, with a width of 100cm and a depth of 60-80 cm. Base fertilizer, namely garbage, straw, branches and leaves, turf, etc. Layered application, 5000- 1 10,000 kg per mu, fence fertilizer, compost, cake fertilizer, etc. Apply to the upper layer, 250 kg per mu.
Planting: Planting density, grapefruit grows vigorously and has a large crown. Grafted trees enter the full fruit stage after 6-7 years, and the planting density should not be too close. Planting 45 plants per mu on slopes above 20 degrees; 40 plants per mu 10-20 degrees; On the gentle slope below 10 degree, about 35 plants are planted per mu.
Blending pollination trees: Grapefruit has strong fruiting ability, but cross pollination can improve fruit setting rate and increase fruit, so it is suitable for single-row mixed planting.
Planting time: pomelo can be planted in spring (March) and autumn (165438+1October), and the first half of March is the best. Planting should be carried out in cloudy or sunny evening, not in rainy days or when the soil is too wet.
Extended data
Pomelo trees are cultivated in China, Guangxi, Fujian, Zhejiang, Guangdong, Sichuan, Chongqing and Hunan, as well as in Xinyang and Nanyang, south of the Yangtze River. Southeast Asian countries have planted it. ?
1, function indication
Pericarp: regulating qi, resolving phlegm and relieving cough. Used for qi stagnation, abdominal distension, stomachache, cough and asthma, and hernia pain.
Leaf: detoxify and reduce swelling. Used for mastitis and tonsillitis.
Xiaoshi; Wake up. Stagnation of main diet; Loss of appetite; I'm loaded.
Naringin is similar to other flavonoids and has anti-inflammatory effect. Intraperitoneal injection of 100mg/kg in mice can alleviate the edema of ankle caused by formaldehyde. It has no effect on inflammation caused by serotonin. Subcutaneous injection of 100mg/kg in rats also has significant anti-inflammatory effect (granulation sac method), and naringin complex has stronger effect than pure product. It has also been reported that oral naringin (or hesperidin) has no anti-inflammatory effect on joint swelling (Arthus reaction) in guinea pigs, but another unknown component in orange and pomelo peel has anti-inflammatory effect. It is generally believed that the anti-inflammatory effect of flavonoids is related to the change of capillary permeability (inhibiting the conversion of ADP to ATP, thus preventing the relaxation of anterior sphincter of capillary).
2. Other functions
Naringin can protect mice from virus infection (anemia). The activity of succinate dehydrogenase in the supernatant of spleen homogenate of mice with this disease is higher than that of normal mice, and naringin has no effect on this increase. But it can reduce the activity of this enzyme in the spleen of normal mice in vitro. Mice were fed with a diet containing 2-4% naringin for 6 rounds, and then were irradiated with X-ray (600r/ week, total amount 1200r). The survival time of mice in the administration group is significantly longer than that in the control group, so it has protective effect.
Naringin has no obvious effect on the respiratory function of Ehrlich ascites cancer cells. Naringin has spasmolytic effect. Naringin has little toxicity. Rats were fed with drugs containing 1% in food for 200 days, and their weight gain, blood sugar and histological examination were the same as those of the control group. In fresh fruit juice, it is reported that it contains insulin-like components, which can lower blood sugar.
3. Other values
The leaves, flowers and skins of grapefruit contain almost the same aromatic oil as citron and lemon, and the pulp contains higher vitamin C.
References:
Grapefruit Tree-Baidu Encyclopedia