How to select grapefruit seeds? What are the methods of raising seedlings?

Grapefruit is a kind of fruit with high vitamin C content, which is rich in nutritional value. At present, grapefruit is cultivated in many areas of our country, and the difference is the variety. So how to choose grapefruit in the end? What are the methods of raising seedlings?

First, how to select grapefruit?

1. Wen Dan

The fruit is flat and round, the top is slightly concave, the base is slightly narrow, the pedicel has a raised ridge, the pericarp is thin and smooth, the oil cell is small and dense, and the pulp flavor is slightly sour. Mainly produces Fujian (Zhangzhou area), Taiwan, Zhejiang and so on.

two。 Shatian pomelo

The fruit is pear-shaped or gourd-shaped, the top of the fruit is slightly flat, there are obvious rings and radial grooves, the pedicel is narrow and extended in neck shape, the pulp is crisp, the taste is thick and sweet, but there is less moisture and a lot of seeds. After the last ten days of October, it is a medium-ripe variety. Mainly produces Guangdong (Meizhou), Guangxi (, Rong County, Guilin, Liuzhou and other places). Rich in soluble solids and vitamin C, pomelo is the best.

3. Orange red

Also known as Huazhou Juhong, Huazhou Xianju. The fruit is pilose, the pericarp is thicker than other varieties of pomelo, the flesh is light yellow and white, the taste is sour and bitter, and can not bear raw food. The fruit period is from October to November. Mainly produces Guangdong (Huazhou, Maoming). There are also in Guangxi (Bobai, Lu Chuan, etc.) and Hunan (Qianyang).

4. Red heart honey pomelo

Hongxin honey pomelo, also known as red flesh honey pomelo, red meat pomelo, red meat pomelo, blood pomelo.

Second, the method of raising grapefruit seedlings

1. Propagation method: grafted pomelo is usually propagated.

1.1 selection of rootstocks

The commonly used grapefruit rootstocks are sour grapefruit and Fructus Aurantii.

(1) sour pomelo

The grapefruit tree with sour pomelo rootstock has developed root system, strong main root, strong affinity, high survival rate, vigorous growth, tall crown and strong adaptability. In the full fruit period, the yield is high and the fruit quality is good. However, it is easy to be infected with gum disease because it is put into production late.

(2) Fructus Aurantii

The grapefruit tree with Fructus Aurantii rootstock has good affinity, dwarfing tree potential, strong growth, early production and good quality. But in the later stage, it is easy to senescence early and the yield is low.

1.2 cultivation of rootstock seedlings

The fruit used for seed collection (sour pomelo or Fructus Aurantii) is harvested when it is fully ripe, cut open and rinse the seeds, then spread them out in a cool, ventilated place and dry until the seed coat turns white.

The seeds were sown immediately after harvest, and the germination rate was high. If you do not sow immediately, you can use 3-4 times of clean wet river sand (humidity pinched by hand into a ball, spread out into several pieces is better) and seeds, stacked in a cool leeward place indoors, 35-45 cm high, the bottom two layers of sand thickness about 5 cm, the upper cover of plastic film moisturizing, and then pressed with film around to prevent rodent damage.

In February-March or September-October, soil preparation and sowing in fertile plots with easy drainage and irrigation were selected, and the sowing rate was determined according to rootstock varieties, sowing methods and seed quality, such as 50-75kg per mu of sour pomelo seeds and 70-90kg seeds of Fructus Aurantii. After sowing, gently press the border surface such as wood to make the seeds into the soil, cover the river sand, burn the soil or fine soil until you can't see the seeds, then cover the straw 3-4 cm, fix the straw with a straw rope and fully water it. After sowing, keep the soil moderately moist, remove the straw after emergence, make the seedlings accept the sun and prevent bending. The principle of applying thin fertilizer frequently should be grasped in the management of fertilization at seedling stage, watering should be reduced and fertilization should be stopped before the occurrence of 3-4 true leaves, seedlings are prone to bacterial blight, and attention should be paid to the prevention and control of diseases and insect pests such as blight, butterfly, leaf moth and so on.

1.3 Transplantation of rootstock seedlings

The seedlings can be transplanted when they have 10-14 true leaves and are more than 10 cm high. If newly planted seedlings are cultivated, they will be transplanted in May-June of the same year after sowing. Grafting in winter or the following spring will take two years for the whole seedling period. If the old seedlings are cultivated, the spring shoots are transplanted in the autumn of the same year or April-May of the following year after sowing, and grafted in the winter of the second year or in the spring of the third year. The whole seedling raising period takes 3 years.

1.4 grafting

(1) Collection of scion

Scions should be collected from strong mother trees with high yield, stable yield, high quality and free from quarantine venereal diseases and insect pests, or from young trees or seedlings in ear nurseries directly propagated by these excellent mother trees. Choose autumn or spring shoots with full growth, full bud eyes, moderate thickness, complete leaves and glossy autumn or spring shoots as scions. Scions should be picked on windless sunny days after dew drying in the morning and weak sunshine in the afternoon, but not in rainy days. Remove the leaves immediately after the scion is cut off.

(2) Storage

The survival rate of grafting was higher when the scion was picked. If the quantity is large or long-distance transportation, must store, can use clean wet river sand (insert into the sand by hand, hands stick sand but nails do not stick sand for degrees) layered stacking. During storage, the humidity of sand should be checked and adjusted frequently, and rotten branches and ears should be removed to prevent spread. It can be stored for 50-60 days in winter and spring.

(3) grafting method

It is mainly cut in spring and abdominal in autumn.

① single bud splicing method

When cutting the scion, the prismatic side of the scion is upward, and the flat side is pressed down against the index finger, and the oblique face is cut forward at an angle of 45 °about 1 cm below the bud point; then the flat side of the scion is turned upward, and the skin is cut forward from near the bud point, which requires that the cutting surface is smooth, just to the cambium, and it is appropriate to expose the white part of the xylem; then turn the scion to the side, and the bud point upward. Cut off about 0.2 cm above the bud point and put it in a basin filled with water.

Cut the rootstock 6-8 cm from the ground, choose the smooth side, obliquely cut off the upper part of the rootstock, the cutting surface is 45 °angle. Then at the bottom of the slope, cut longitudinally along the junction of the cortex and xylem, preferably the white xylem you just saw. The section length depends on the scion length.

Bud embedding and bandaging should try to select buds that are similar in size and length to the cutting surface of the rootstock, and insert them into the cutting surface of the rootstock, so that the base of the bud is close to the bottom of the cut of the rootstock, and the cambium of the cutting surface of the rootstock is closely connected with the cambium of the scion; if the rootstock is thicker than the scion, it should be aligned with one side of the cambium, which is easier to live. Finally, it is wrapped with plastic film tape and sealed with wax.

② abdominal grafting with small buds

Cut the bud point of the scion upward, cut it obliquely at an angle of 45 °at about 1 cm below the bud, then cut forward about 0.5 cm above the bud, cut off the bud slightly with xylem and put it in a basin filled with water. The buds of long buds are thinner, 1.2-1.5 cm long, which are longer than those of general buds.

The upper part of the cutting rootstock is not cut off, and the smooth side of the main trunk 10-20 cm from the ground is required to be smooth, deep enough to the cambium, the cutting surface length to be able to put down the buds, and then cut off the cut layer 1 to 3 to facilitate bandaging and bud germination.

Insert buds and bandage the cut buds into the incision of the rootstock, so that the base of the rootstock and ear are close to each other, and the cutting surface is aligned, and the bud eyes are exposed by bandaging with plastic film.

③ single bud ventral grafting

Cutting scion is the same as single bud splicing method.

The method of cutting rootstock, embedding buds and bandaging the abdomen of small buds.

(4) Management of grafted seedlings

① check survival and patch

Where the bud is fresh and the petiole falls immediately after 15 days of grafting, it indicates that it has survived. The rootstock that did not survive should be repaired in time, and the rootstock could not be removed from the skin too late, which would affect the survival.

② cutting anvil and patching

If the grafted buds have survived, in addition to the grafted ones, the ventral grafted ones should be cut off, and the rootstocks above the grafted stocks should be cut off before germination to concentrate nutrients for budding and growth. However, the cutting anvil should not be too early, so as not to be easily air-dried and frozen. The rootstocks that did not survive after overwintering can be repaired by grafting in spring.

③ detoxification

After cutting the rootstock, it is easy to sprout a large number of tillers from the base of the rootstock, which should be removed in time to avoid easy air-drying and freezing.

④ fixed dry shaping

Pomelo seedlings the Beginning of Autumn before and after cutting the top, leaving a dry height of 30-40 cm, generally in the first summer shoot top 2-3 internodes are the most suitable. The height of the cultivated seedlings is about 50 cm, and there are 2-3 robust seedlings with evenly distributed branches.

⑤ fertilizer and water management

The principle of fertilization is to apply thin fertilizer frequently. In case of drought, drench water once in 3-4 days. It is rainy in summer, so drainage should be done well.

⑥ pest control

Timely control of anthracnose, canker and leaf moths, red spiders, yellow spiders, aphids, butterfly larvae and so on.

To sum up, you can refer to and learn. If you still want to learn the cultivation and management techniques of different varieties of grapefruit, you can come to Nongxun to continue to study.

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