How can the survival rate of jujube grafting be higher?

Tracing back to the history of jujube cultivation in China, it has been more than 8000 years. After continuous cultivation and cultivation, there are more and more varieties of jujube trees. In the Atlas of China Jujube Variety Resources, there are 57 fresh jujube varieties, 80 dried jujube varieties, 82 dried jujube and fresh jujube varieties, 7 candied jujube varieties 17 and 4 ornamental jujube varieties 14 in China. So many jujube varieties always attract the attention of jujube farmers and stimulate their grafting desire, hoping to have better, more novel and better jujube varieties and obtain better cultivation benefits accordingly.

Because the skin at the bud eye of jujube tree is thin and curved, the survival rate of grafting will be very low if it is not grasped well during grafting or grafting. So some people say that jujube grafting is difficult to survive. In fact, in the eyes of experienced jujube farmers, solving and improving the survival rate of jujube grafting is not a problem at all. If amateurs complain that jujube grafting is difficult, people will only laugh at you and say that you don't understand the secret of jujube grafting. Novices can easily improve the survival rate of grafting by correctly understanding and mastering the key links of various grafting methods in different periods of jujube. It is not out of reach to create one jujube tree grafting achievement after another.

First, the suitable period of jujube grafting

The most suitable time for grafting jujube trees in northern China is from spring to 3-4 weeks after germination. Outdoor temperature 15-20℃ is suitable for jujube grafting. If you want to graft jujube trees in July and August, especially after early and middle August, you need to avoid the rainy season and the period of high soil moisture. In addition, the rootstock is not cut off after the grafting survives in the same year, so as to avoid that the grafted bud grows less than 30-60 cm and cannot be fully matured, which is not conducive to the overwintering of grafted seedlings or grafted branches.

Second, the collection and standby of scions.

1, scion collection. The grafting scion of jujube tree should choose jujube head 1 secondary branch or permanent backbone branch with full growth, good maturity and thickness greater than 0.5 cm outside the crown of fine varieties. If it is early spring grafting, the scion should be collected 15-20 days before the jujube tree germinates. Whether in early spring or growing season, when scions are used for grafting, they need to be cut into single or double buds of about 4-5 cm immediately after collection and sealed with wax.

2. Scion wax sealing. Put high-quality paraffin into an iron pan and melt it with high fire. The wax temperature is controlled at about 65438 000℃. In order to control the temperature easily, you can also put the paraffin container in a basin that is always open. Soak the jujube scion in wax solution quickly, so that a layer of wax film is attached to the surface of the cut branch, immediately put it in cold water, and then take it out and dry it in the shade. At room temperature, wax-sealed jujube scions can generally be preserved for about 65438 0 weeks. The optimum storage environment temperature of scion is 0-5℃ and humidity is 90%. If the incision is white, the temperature of the wax is too low. Suitable wax should be bright green after closing the incision.

Three, skin grafting operation and matters needing attention

Skin grafting is a kind of branch grafting, which is suitable for high grafting or seedling grafting with thick rootstock and thin scion. Suitable for germination or when the rhizome cortex is easy to peel off after germination. Has the advantages of simple operation, high survival rate and the like. When grafting, first cut the rootstock horizontally, select the smooth part of the epidermis, cut it vertically from bottom to top with a knife or pruning shears, go deep into the xylem, peel off the cortex, and form triangular cracks. Then, at the lower end of the scion 2-3 cm upward, the scion is obliquely cut downward, and the section is 2-3 cm long, showing a horse ear shape, and the section at the base of the section is close to "I". After inserting the scion, the upper end of the cutting surface should be slightly exposed, and then covered with plastic strips.

It should be noted that the seedlings planted in that year were grafted as rootstocks, and the rootstocks cannot be cut after grafting. Otherwise, the rhizome will "suffocate" because of insufficient nutrition in its own storage.

Four, abdominal surgery and matters needing attention

Abdominal grafting is also a kind of branch grafting, and grafting can begin about 30 days before jujube germination. Abdominal grafting can be used to graft thick rootstocks or mature trees. When grafting, the rootstock is first cut into inclined planes, and the high side is cut down to reach the xylem, and the horizontal depth does not exceed 1/3 of the branch thickness. Cut the scion into the shape of a horse's ear, with a face length of 2-3 cm, a thin side and a thick side, a slightly longer side and a slightly shorter side. When grafting, the long section faces inward and the short section faces outward, and then they are bound with plastic strips of plastic film, and the bud eyes of the scion are also wrapped with a single layer of plastic film. Bud eyes can break the membrane by themselves after survival.

If it is grafted in the rainy season or after mid-August, it is advisable to cut the abdomen and not cut the rootstock in the same year after grafting, which will help reduce the bleeding of jujube trees due to excessive soil moisture.

Five, green branch grafting operation and matters needing attention

Green branch grafting is also a kind of branch grafting, which is a method of grafting with semi-lignified branches in the growing season of jujube trees. Grafting of green branches of jujube trees can start from the end of June, avoiding the rainy season, picking the semi-lignified jujube heads of the current year, cutting off the leaves immediately after harvesting, keeping the petiole, selecting well-developed middle branch buds to cut off the scions, and cutting the upper opening 0.3 cm away from the buds, and sealing them with wax immediately after cutting. Then transplant through skin transplantation or abdominal transplantation. Germination began in the next 7 days.

In winter, appropriate protective measures should be taken for the new shoots of jujube trees grafted with green branches to avoid overwintering death.

Six, bud grafting operation and matters needing attention

Bud grafting of jujube trees can be carried out 3-4 weeks after germination in spring and during peeling in June-August. It should be noted that the epidermis of 1 year-old branches on jujube trees is thin, and the lateral buds are cut off at the bending parts of the branches. Cutting off the intact flat buds with thick woody tissue is the key to the survival of grafting. When cutting the bud, first cut a knife at the position 1.2 mm above the bud, with a depth of 2-3 mm, and then obliquely cut it from the position 1.5 cm below the bud to a horizontal knife edge, and then remove the bud with a wooden strip. When the rootstock leaves the ground 10-20 cm, it can be grafted by the usual T-bud grafting method.

If the scion is cut from a developing branch, the scion should be above one side of the bud. Cut the scion from the secondary branch, and the scion should be directly above the bud.

Seven, post-grafting management

After the jujube tree is grafted, on the one hand, the new buds must be pulled out 3-4 times in time. On the other hand, it is necessary to help trees in time. After abdominal cutting or bud grafting, the anvil tip can be cut at 15cm above the joint, so that the film support will be broken when the scion tip reaches 20cm, and then the anvil pile will be cut when the base reaches 50cm, so as to promote healing. On the other hand, we should pay attention to the occurrence of pests and diseases in time and use drugs rationally to prevent them.

Finally, when the scion and rootstock used for jujube tree grafting are relatively thin, tongue grafting can be used. In summer and autumn, the tongue grafting of jujube trees should adopt high anvil piles and leaves to increase nutrient storage and promote overwintering.