Key Points and Operation Methods of Jujube Tree Grafting Techniques Explained

The jujube tree is a fruit tree with a long history of cultivation in China, and it is grown in many regions. Every year when the jujube trees ripen, knocking down jujubes is also a childhood pleasure. Nowadays many people use grafting techniques when growing jujube trees, and grafted jujube trees have many advantages.

Jujube Tree Grafting Technique Video

Bark grafting. Bark grafting is a type of scion grafting, and it should be used after the jujube tree has budded, when sap flow is vigorous and the bark peels easily. The grafting method is simple, fast, and the survival rate is higher than other grafting methods.

The method is: choose a smooth spot on the rootstock bark and cut off the rootstock, then on one side of the cross-section cut a small slit about 0.5 cm from top to bottom through the bark down to the xylem, and peel back the bark to form a triangular opening. At the lower end of the scion, 2-3 cm from the lower cross-section, use a knife to cut diagonally downward, making the cut surface into a horseshoe shape, with the slant exceeding the pith; on the opposite side of the slant, at the lower end, cut another short small cut surface 2-3 mm long, forming a straight-line sharp point, making it easier to insert into the bark. Insert the long cut surface of the prepared scion along the xylem into the bark through the already cut triangular opening of the rootstock (the long cut surface of the scion should fit tightly against the xylem of the rootstock), leaving a 1 mm cut surface above the cut surface, commonly known as “exposing white,” to promote growth callus tissue, then use plastic film to wrap the rootstock cut and the union with the scion completely tight, so no air can pass through, and grafting is complete. If the scion has not been wax-sealed, use thin plastic film to wrap the scion tightly.

Advantages of Jujube Tree Grafting

1. It can maintain the excellent traits of the scion variety. This is because the scion is taken from branches or buds of excellent mature trees. Its heredity is relatively stable, and variation generally does not occur after grafting. After grafting, the difference between the fruit and root-borne fruit in fruit size and contents is small.

2. It can bear fruit early. Because the rootstock root system is well developed, growth after grafting is vigorous and the branches are robust. This can turn slow growth into rapid growth.

3. It can enhance the stress resistance of the jujube tree. Because the sour jujube used as rootstock for grafting has strong drought resistance and tolerance of barren soil, and broad adaptability to soil, if using local root-sucker seedlings of small jujube or large jujube grown on the same rootstock, or seedlings raised from seeds. It is already fully adapted to the local soil and climate conditions, and this valuable adaptability and stress resistance of the rootstock have a good influence on the grafted jujube tree.

4. Make full use of sour jujube resources. In China's mountainous areas and plains, sour jujube grows everywhere. Using sour jujube to graft large jujube is an effective way to speed up the greening of barren hills, barren beaches, hills, and gully slopes, and to expand the scope of jujube cultivation.

Techniques for Preserving Flowers and Fruits After Jujube Tree Grafting

1. Suppress vegetative growth, regulate the contradiction between growth and fruiting, and promote fruit set. Such measures include root cutting, pinching, bud removal, branch thinning, girdling, ring cutting, scoring, and fertilizer and water management. Taking these measures can regulate the contradiction in nutrient distribution and transport between vegetative growth and flowering and fruiting, improve the tree's nutrient level, and allow more nutrients to be supplied to the needs of flowers and fruits.

2. Spray water during the flowering period to increase air humidity. During the flowering period, air humidity should not be lower than 60-70%, otherwise it will have an effect. Spraying water in the evening or morning has a good effect, generally combined with foliar spraying of 0.3-0.5% urea.

3. Place bees in the jujube orchard to increase pollination agents. Some jujube varieties are self-pollinating and some are cross-pollinating. Pollination within a variety or between varieties can both achieve good fruit set, and increasing pollination agents has a good effect.

4. Spray plant hormones and trace elements, mainly gibberellin, 2,4-D, paclobutrazol, chlormequat, B9, indolebutyric acid, indoleacetic acid, acetic acid, naphthaleneacetic acid, borax, boric acid, etc.

Fertilization Techniques After Jujube Tree Grafting

1. Apply base fertilizer in autumn. It is best to apply base fertilizer before the jujube tree is harvested, which helps accumulate a large amount of stored nutrients and lays the foundation for a high yield the following year. The base fertilizer should be mainly organic fertilizer, and some quick-acting fertilizer can be appropriately added.

2. Topdressing before budding. Generally carried out in early April of the following year. Jujube orchards that did not apply base fertilizer in autumn should pay even more attention to the application of budding fertilizer.

3. Topdressing during the flowering period. Jujube flower bud differentiation has the characteristics of differentiating in the same year, differentiating multiple times, differentiating as it grows, a short differentiation time, and a large number of differentiation. Therefore, jujube has a large number of flowers and a long flowering period, and consumes a large amount of nutrients. If nutrition cannot keep up, it will inevitably lead to serious flower and fruit drop. Topdressing during the flowering period can reduce fruit drop. Topdressing during the flowering period can be applied to the soil or sprayed on the leaves. The effect of increasing the fruit set rate is better.

4. Fruit-promoting fertilizer. Generally topdress in mid-July when young fruits are growing vigorously. This topdressing is directly related to the yield and quality of jujubes. The fruit-promoting fertilizer is best a nitrogen, phosphorus, and potassium compound fertilizer, which can be applied to the soil or sprayed on the leaves. Jujube trees in full fruit period have the highest yield and also the greatest fertilizer requirement. Jujube trees in full fruit period must be applied each year per tree with 100 kg of organic fertilizer, 1 kg of quick-acting nitrogen fertilizer, 2.5 kg of superphosphate, and 2.5 kg of plant ash.

There are many grafting techniques for jujube trees, and different methods are handled in different ways. Grafted jujube trees have the advantages of earlier fruiting and enhanced stress resistance. Field management after grafting is also crucial, and fertilization, irrigation, and branch pruning should be carried out in a timely manner to increase the fruiting rate of jujube trees.