(a) Garden selection and preparation:
Shatian pomelo is an evergreen fruit tree with tall tree shape and developed root system, which grows well in loose, fertile, moist and well-ventilated soil. Therefore, red loam and sandy soil with deep soil layer, fertile soil and good air permeability should be selected for planting Shatian sleeves. Generally, the hillside below 30 degrees should be selected in mountainous areas, and terraces should be planted on the south or southeast hillside. The alluvial soil in the mountain nest is ideal, and the garden is most suitable in the place where irrigation and drainage are convenient, such as the alluvial zone next to rivers and streams.
Before planting, it is necessary to make a good plan, use trenches or large holes, and apply sufficient base fertilizer to make it grow early and quickly. Generally, holes are planted in the flat land, with the length × width× depth1×1× lm; In mountainous areas, trenches with a width of1-1.5m and a depth of 1m should be adopted along the contour line. Fill the ditch and hole after one week of exposure to the sun, and laminate forage and decomposed soil mixed fertilizer when the soil recovers. That is, the bottom layer is covered with green manure, the middle layer with decomposed pig manure, and the surface layer with fine fertile soil. After the trench filling is completed, the planting pier with a fixed width of 1m and a height of 0.3m will be planted.
(2) Planting:
Choose seedlings when planting. It is appropriate to select grafted seedlings of Shatian pomelo varieties with more fruits, good quality, high and stable yield and no pests and diseases. The interface should be exposed on the soil plane. The planting time should be carried out when the branches are fully mature, and it is generally better to plant in February-April in spring. The planting distance should vary according to the topography and soil quality. The mountainous area is barren, but it has good ventilation and light transmission, so it can be planted closely. 30-40 plants per mu, fertile and flat soil, suitable for sparse planting, about 20 plants per mu.
Because self-pollination of Shatian pomelo is not as good as cross-pollination In order to improve the fruit setting rate and increase the yield of pomelo, it is necessary to plan to interplant sour pomelo or crystal sleeve with about 10% as pollination trees. When planting, we should pay attention to the fact that the root system can't contact with fertilizer, the composite soil should be slightly compacted, the tree tray should be covered with grass, and the root water should be poured thoroughly to prevent drought and keep moisture.
operate
(1) Young tree management:
The infancy of Shatian pomelo is the period from designated planting to first fruiting.
1. Water spraying fertilization: After planting Shatian pomelo, in case of drought, water should be sprayed every day to keep the soil moist and promote its survival. Pay attention to remove accumulated water in rainy days to prevent root rot. When new roots begin to sprout/0/5-20 days after planting, decomposed human feces should be applied, and 3-4 kg of human feces should be added for each load of water, once a month/0/-2 times. The concentration of fertilizer increases gradually with the increase of trees. The method of one branch and two fertilizers should be adopted in the new shoot stage, that is, 10 ~ 15 should be applied with one fertilizer before shoot shooting and one fertilizer at leaf spreading stage after shoot shooting. Fertilization should be shallow in spring, summer and autumn, such as plate application or shallow furrow application. Winter fertilizer and heavy fertilizer should be applied deeply and in layers. In short, small trees have weak root absorption. Fertilization should be based on the principle of "diligent application and irrigation", so as to ensure that there is 1-2 times of heavy fertilizer (mainly available water and fertilizer) before each shoot, so as to promote the strong and plump shoot and form a high-yield crown as soon as possible.
2. Wipe and control shoots to cultivate high-yield crown. After planting survives, we must first do a good job of fixing the stem. When the trunk of the pomelo tree is 40-45 cm above the ground, the top will be cut off to promote the development of new shoots. Leave 2-3 new shoots with different directions and uniform distribution at the top as main branches. For the second time, three secondary branches were cultivated on the main branch, and for the third time, a group of lateral branches were cultivated on the secondary branch, each branch was 15-20 cm long, and the angle was not enough, so it could be shaped by pulling wires. Young trees can be picked 3-4 times a year, that is, spring shoots (before and after rain), summer shoots (before and after harvest), autumn shoots (after bumper harvest) and late autumn shoots (Millennium and autumn equinox). In addition to applying sufficient base fertilizer before each shoot, we should also pay attention to bud control, zero cutting and whole retention to promote more, orderly and robust new shoots. During bamboo shoot release, we should do a good job in pest control to lay a good foundation for early fruiting and high yield.
3. Dig deep into the soil and expand the planting holes year by year. It is generally required to complete deep ploughing in the whole garden within 3-4 years after planting. Green manure or decomposed organic manure should be pressed every time deep ploughing, so as to achieve the purpose of increasing fertilizer and improving soil, create good conditions for root growth, and make pomelo trees live long and yield. Digging time should be carried out after each new shoot matures, and there should be an outlet for digging ditches (holes) to prevent the roots from rotting due to long-term rain.
4, intertillage weeding and mulching. Through intertillage, loosen soil, adjust soil moisture and air, and promote fertilizer decomposition. Spring and summer intertillage is mainly weeding, and shallow tillage is needed. Tillage after rain in autumn and winter can reduce water evaporation and improve drought resistance. Where there are many weeds, grass can be covered all year round to protect water, drought and erosion.
(2) the management of the result tree:
Shatian pomelo can generally blossom and bear fruit in 2-3 years after planting, but to achieve high and stable yield, we must focus on the following aspects.
First, rational fertilization and irrigation.
After the Shatian pomelo tree bears fruit, the plant changes from simple vegetative growth to reproductive growth and vegetative growth, and the demand for fertilizer and water is greatly increased. Reasonable water and fertilizer management is the key to high and stable yield of Shatian pomelo. Fertilizer should be mainly organic fertilizer, so that organic fertilizer and inorganic fertilizer (nitrogen, phosphorus and potassium) can be reasonably matched. The specific amount of fertilizer applied per plant depends on the age of the tree and the amount of fruit. The principle of fertilization is to apply fertilizer before flowering and after fruiting, to apply fertilizer skillfully to stabilize and strengthen fruits, supplemented by topdressing outside roots.
Fertilizer before flowering: Spring shoots are the main fruiting branches of Shatian pomelo. Paying attention to applying fertilizer before flowering is beneficial to the development of pomelo flowers and the appearance of spring shoots. Pre-flowering fertilizer is mainly composed of decomposed organic fertilizer and phosphate fertilizer, combined with nitrogen fertilizer, and applied to the crown and shallow ditch of drip irrigation line at the front end of flower bud. Fertilization amount: Generally, 0.5- 1 kg of potassium dihydrogen phosphate, 0.5 kg of urea and 0.5-25 kg of decomposed human livestock and poultry manure are applied to fruit trees over five years old. Irrigation should be done in time in case of drought after application.
Fertilization before and after fruit picking: Normal fruit trees are generally planted after fruit picking. High-yield trees and weak trees should be planted about 0/5 days before fruit picking. Before and after fruit picking, the fertilizer should be mainly decomposed organic fertilizer and available nitrogen fertilizer. Five-year-old fruit trees, each with 0.5 kg of compound fertilizer, 0.5 kg of urea and 30 kg of decomposed human and animal manure. After fruit picking, add 0.3 kg urea and 50% pure light fertilizer to restore tree vigor.
Fruit-stabilizing fertilizer: applied after flowers wither. Five-year-old fruit trees, which are mainly phosphorus and potassium fertilizers, should be applied with 30-50 kg of decomposed manure, 0.5- 1 kg of compound fertilizer or 2.5 kg of peanut bran (which should be used after fermentation with manure).
Strengthening fruit and promoting branch fertilizer: Autumn shoot is an important fruiting mother branch of Shatian pomelo. Fertilizing in autumn to strengthen fruit and promote shoot growth can achieve the effect of strengthening fruit and promoting shoot growth in autumn. This kind of fertilizer should use full fertilizer. It can be applied in two times: the first time, before autumn shoots 10 day, 0.5 kg urea, 0.3 kg potassium fertilizer and 50- 100 kg decomposed chaff water are generally applied to fruit trees over five years old, and the second time, after autumn shoots are self-sheared, 50- 100 kg decomposed manure water is applied.
Water management: The principle is wet in spring, drained in summer, irrigated in autumn and controlled in winter. Wet all year round, no waterlogging, no shortage of scientific water for drying.
Second, do a good job in thinning flowers, pollination and fruiting.
Sparse flowers: it can be divided into three steps: ① Sparse the ear of flowers, at this time, the bud is as big as mung bean. That is to say, for the flower spike (sequence) on the fruit-bearing branch, the head is cut off and the tail is removed, leaving 2-3 bundles of well-developed inflorescences in the middle. (2) Sparse flower buds: When the flower buds are white, the head and tail pests and weak flower buds are stripped from each flower spike, and 4-5 robust and full flower buds are left in the middle. (3) Sparse flowers, that is, pick off weak flowers, diseased flowers and abnormal flowers when flowering, and leave 3-4 robust flowers per ear for pollination. Generally, the ratio of flowers to fruits is 5: 1.
Pollination: Shatian pomelo has small self-pollinated fruit and low fruit setting rate, so artificial cross-pollination must be used to increase yield. Pollination method: ① Put bees in the orchard and pollinate by bees. ② Artificial cross pollination. On sunny days, at 8- 10 a.m. and 3-4 p.m., miscellaneous pollen is lightly smeared on the stigma of female flower of Shatian pomelo. Artificial pollination should be carried out after flower thinning.
Fruit thinning: when the grapefruit fruit grows to the size of thumb, it begins to be thinned for the first time and the weak leaves are removed. In winter, organic fertilizer should be buried in combination with clearing the garden to improve soil fertility. For fruit trees over five years old, each tree can be buried with decomposed pig cow dung or soil miscellaneous fertilizer 100kg, phosphate fertilizer or compound fertilizer10.5 kg, lime 1kg, and can be applied together with winter fertilizer.
Seven, do a good job in pest control.
Timely prevention and control of pests and diseases is an important link to win a bumper harvest and improve the commodity value of Shatian pomelo. The main pests and diseases of Shatian pomelo are canker, scab, Fusarium wilt, Huanglongbing, Cerambycidae, liriomyza sativae and mites.
Canker disease and scab disease: mainly harm branches, leaves and fruits. The prevention and control methods are as follows: ① clearing the garden in winter; ② Spraying 0.5- 1% Bordeaux solution or 500 times of copper ammonium chloride at the new shoot stage and after typhoon rain.
Gummosis: It mainly harms trunks and branches. The prevention and treatment method is to scrape the affected area and apply 50% Tobuzin solution or 100 times carbendazim solution.
Epidemic disease: the main damage to sleeve fruit. Wet orchards often appear. The prevention and control should start from the young fruit to the fruit expansion stage, spraying 800 times of thiophanate or 500 times of copper-ammonia mixture on the fruit surface, and cleaning the garden in winter.
Huanglongbing: It is a dangerous infectious disease. Once found, it should be uprooted and burned, and lime should be sprinkled on the planting hole. At the same time, pay attention to the prevention and control of aphids and psyllids.
Anoplophora longicorn: Harm tree trunks and branches. The control methods are as follows: ① scraping eggs and hatching larvae; (2) Kill the larvae with a wire hook or put a cotton ball filled with pesticides in the hole and seal the hole with soil.
Scale insects: harm branches, leaves and fruits. The control method can be sprayed with turpentine mixture 10- 15 times or 40% quick kill EC 800 times.
Liriomyza huidobrensis: it mainly harms new shoots. The control methods are as follows: (1) bud control, placing branches around; ② Spraying 25% dimehypo 500-800 times or chlordimeform 8000- 10000 times in the bud stage.
Mites: There are red spiders and rust spiders, which mainly harm leaves and peels. Control method: 5% Nisolone emulsion can be sprayed 3000 times, isocarbophos 800- 1000 times, sulfur mixture 0.2- 1 degree (according to seasonal use concentration) or dimethyl phosphate 1000-2000 times.