Cultivation techniques of pomelo

Pomelo, also known as Wendan, Xiangqi, Zhu Ji, Nei Zi, Tiao, Lei pomelo, pomelo, mandarin, smelly orange, stinky pomelo, throw, bud, pomelo, grapefruit is the mature fruit of Rutaceae plant pomelo, produced in Fujian, Jiangxi, Guangdong, Guangxi and other southern regions of China. Grapefruit is fragrant, sweet and sour, cool and moist, rich in nutrition and high in medicinal value. it is one of the fruits that people like to eat, and it is also recognized as the most therapeutic fruit in the medical field. Grapefruit tea and grapefruit peel also have practical value.

Biological characteristics

1. Division of varieties

① grapefruit variety can be pregnant by pollination and produce multi-seed fruit. Such as white sour pomelo, red sour pomelo and so on.

The pollination of ② grapefruit variety is incompatible, the pregnancy rate is very low, and it can produce a small number of fruits with fewer seeds. The fruit setting rate of different varieties (strains) is high, but there are more fruit seeds. Such as Shatian pomelo (white meat system), Zaohe pomelo, mulberry pomelo, golden orchid pomelo, Zhaipo pomelo, village sleeve, Cai Jia pomelo, Shitou pomelo, Jincun pomelo, longevity Shatian pomelo Duan pomelo, ancient money Shatian pomelo, silk pomelo and so on.

③ pomelo variety pollination sterility, parthenocarpy ability is strong, can bear seedless fruit, but the fruit setting rate is low, easy to crack fruit, pollination fruit setting rate of different varieties is significantly increased, fruit cracking is reduced, but more fruit seeds. Such as Yuhuan flat cone round Wendan pomelo, Guanxi honey pomelo, Dukou pomelo, Duwei Wendan pomelo, Liangping pomelo, Yue pomelo No. 5, grapefruit and so on.

④ has degenerated stamens and lacks pollen (male sterility), but it has strong parthenocarpy strength and can bear seedless fruits. The fruit setting rate of pollination with different varieties is significantly increased, but there are more fruit seeds. Such as hairy orange, red pomelo, etc.

2. Growth habits

Grapefruit is an evergreen tree, the leaves of pomelo are like oranges and oranges are long oval or long oval, and the winged leaves are heart-shaped; most of the fruits are gourd-shaped, pear-shaped or spherical, with yellow and orange surface, and the fruit is glossy with concave spots and generally has an irritating odor. the pericarp is relatively thick and can be peeled off by hand. The fruit is larger than citrus, with a single weight of more than 1 kg and a diameter of 15 mi 25 cm. There is a white sponge layer between the skin and pulp. The flesh is red or yellowish white, white is more common, rich in juice with a strong flavor, sweet or sour, sometimes bitter, which mainly comes from its biological glycosides. Grapefruit can be placed in the natural environment for months without going bad. The petal is 12 Mel 15 petals. Artificial cultivation is often bagged to make it seedless. In the natural state, there are more than 100 seeds per fruit. Grapefruit usually matures from October to November, while early-maturing varieties can be on the market in September, and late-maturing varieties can be as late as January-February of the following year. The root system is relatively shallow, mostly concentrated in about 1 to 3 meters.

① root system. Root distribution: the crown of the real tree is tall, the main root is well developed, and the lateral root of the grafted tree is well developed. The growth of new roots and shoots take place alternately, so there are several rooting peaks in a year. The first peak of rooting was after the spring shoot stopped, and before the summer shoot was sprouted, it was the highest in the whole year, and the upper temperature of root growth was 37 ℃. If the temperature is too high, the root growth is inhibited.

② shoots. The young trees of pomelo grow vigorously and can shoot four times a year in spring, summer, autumn and late autumn, with large branches and rapid crown expansion. When the 4-5-year-old grapefruit enters the fruiting stage, the crown has a large number of fruiting parts, which is an important reason for the high early yield of pomelo. After entering the full fruiting period, they generally only smoke spring shoots, not summer shoots. The new shoots drawn from the Beginning of Spring to the Beginning of Summer are called spring shoots. Spring shoots are neat and concentrated, with a large number of branches, short and full, with a length of 10-20 cm. They are the main new shoots that bear fruit and create and accumulate nutrients in the same year. The strong spring shoot can become the base branch of the summer and autumn shoot, the medium growth branch can develop into the fruiting mother branch of the following year, and the spring shoot developed from the mixed bud can develop into the fruiting branch of the same year. The quantity and quality of spring shoots depend on the nutritional status of the tree. If the nutrient accumulation of the tree was sufficient last year, the quantity and quality of spring shoots would be large and good, and the quantity and quality of spring shoots would determine the quantity and quality of fruiting branches in the current year and the mother branches in the coming year. Cultivating spring shoots with large quantity and good quality is a prerequisite for high and stable yield.

3. Flowering and fruiting habits

Grapefruit trees generally begin to bear fruit in 8-10 years, grafted trees bear fruit in 4-5 years, and enter the full fruit stage 1-2 years after the first fruit grafting. The yield of grafted trees with 5-7-year-old Fructus Aurantii stock is 15-50 kg, and that of 8-10 years can reach 50-100 kg.

① fruiting mother branch. The spring shoot of grapefruit is the main fruiting mother branch. Results the leaf axils of each node of the mother branch could differentiate flower buds and sprout fruiting branches, and there were more fruiting branches in the top nodes. According to the survey, the fruit branches extracted in section 1 accounted for 23.7%, and those in sections 1-4 accounted for 72.7%. The fruiting branches produced at the top nodes have a large number of buds and high fruit setting rate. Therefore, the fruit is mostly concentrated on the fruiting branches at the first nodes of the fruiting mother branch, and the cutting of the fruiting mother branch should be avoided when pruning. The investigation on the fruiting ability of fruiting mother branches of different length shows that the fruiting ability of 10-20 cm long fruiting mother branches is the strongest, accounting for 56.9% of the total fruit.

② fruiting branch. The flower bud of grapefruit is a mixed bud, which blossoms after sprouting in spring. Fruiting branches can be divided into four types according to their morphology: inflorescence branch, leafless inflorescence branch, leafless single flower branch and leafless single flower branch. A single flowering branch with leaves, that is, a fruiting branch with a flower bud at the top of the spring shoot with leaves, blossoms later, has a high fruit setting rate, and has good fruit quality, but a small number. The fruit setting rate of leafy fruiting branches was higher than that of leafless fruiting branches. The number of leafless fruiting branches is large and the fruit setting rate is low. There are more leafy inflorescence branches and flowering branches in strong trees, and more leafless inflorescence branches in weak trees. Therefore, cultivating strong bond tree potential and good fruiting mother branches, striving for more leafy fruiting branches, especially leafy single flower branches, reducing flower bud quantity and nutrient consumption and increasing fruit setting rate are of great significance for achieving high and stable yield. The internal branches of grapefruit with strong fruiting ability and weak light intensity can differentiate and develop normal flower buds and blossom and bear fruit. This is also one of the important factors for the high yield of grapefruit.

③ blossoms and bears fruit. Pomelo flowers solitary or in racemes. It began to blossom in late April and bloomed in early May. Normally developed pistils and stamens produce seeded fruits after pollination and fertilization, pomelo also has the ability of parthenocarpy, and unpollinated ovaries can also expand and develop into seedless fruits. Physiological fruit drop: the physiological fruit drop of pomelo is basically over from the middle of May to the end of June. Fruit drop accounts for 17.8% of the total fruit drop in mid-May and 40.6% in late May, which is the peak of physiological fruit drop. Fruit drop accounts for about 90% of the total number of flowers and fruits from mid-May to mid-June, and the basic results of physiological fruit drop in early July. Grapefruit ripens before and after the Beginning of Winter.