A New Method of Grafting Jujube Trees: A Detailed Guide to the Chip Budding Technique

Chip budding jujube trees is a good method for developing fine jujube varieties. It is introduced as follows:

1. Tools: pruning shears, grafting knife, plastic strips.

2. Collection and storage of scions. ① Spring-summer grafting: (late April to late June), before the end of March, collect well-developed, pest-free one-year-old jujube head branches from a mother tree orchard of fine varieties, cut off the secondary branches (leaving 2 cm), store them in a cool, moist place, bury them well in moist sand, or store them in a cellar less than 4 m deep or suspend them down a well (below 7°C). In this way the scions can be stored until late June to early July. ② Autumn grafting: (early August to mid-to-late September) collect current-year lignified branches, immediately remove the secondary branches and leaves, and use them as soon as they are collected. If they need to be stored for a short time, they can be placed in a container holding 10 cm of clean water and suspended down a well 0.5-1 m above the water surface or placed in a cellar.

3. Grafting method

① Cutting the bud chip with wood: use pruning shears to cut off the remaining stub of the secondary branch previously retained 1-2 mm above the lateral bud, and at the same time remove the thorns. When cutting the bud, hold the branch above the main bud to be taken with one hand, hold the knife with the other hand, and at the junction of the secondary branch and the primary branch, push the first cut flat from top to bottom, about 3.5-4 cm long; this is the long cut surface. Then 0.5 cm above the end of the first cut, make a second cut diagonally downward horizontally until it meets the first cut, with an angle of 30 degrees; this is the short cut surface. If the scion is too thick, longitudinal stripe-like protrusions may sometimes appear on the long cut surface; it can be turned over and the protruding part carefully shaved off so that the long cut surface becomes smooth.

② Rootstock treatment: for spring-summer grafting, cut the rootstock at 20 cm above the ground and remove the secondary branches and thorns above it. For autumn grafting, do not cut the rootstock in the same year; remove the secondary branches and thorns below 20-50 cm on the lower part of the seedling. At 10 cm above the ground, choose a flat, smooth surface, hold the rootstock with one hand and push the first cut diagonally downward with the other hand, slightly longer than the long cut surface of the graft bud and the same width as the graft bud, then make a second cut diagonally horizontally 0.5 cm above the end point of the cut, the same as the short cut surface of the scion. Remove the rootstock chip.

③ Grafting: quickly insert the removed bud chip into the rootstock cut so that the lower diagonal opening and the cambium on the left and right sides align. Use a plastic film band with good elasticity, high tensile strength and good softness to wrap tightly from bottom to top, leaving the bud body exposed.

4. Management of grafted seedlings. For spring-grafted seedlings, when the jujube head branch or jujube hanging branch grows to 3-10 cm, perform a second cutting of the rootstock 1 cm above the graft bud, and apply paint or grafting wax to protect the wound. For autumn-grafted jujube seedlings, cut the rootstock in the spring of the following year. Other management techniques are the same as for ordinary jujube seedlings. This method is suitable for nursery fields, top grafting to change the head, and changing wild sour jujube to improved large jujube varieties, etc.