The walnut is a fairly large tree with a lifespan of up to 500 years. To improve the fruiting of the nut, grafting is used.
- When is nut grafting done?
- How to choose the right stock and graft?
- Basic rules for grafting a nut
- Inoculation of the nut into the split and budding of the nut
- Necessary tools for vaccination
When is nut grafting done?
The most optimal time for grafting a nut is the beginning of summer. During this period, cuttings have the highest survival rate. To increase this degree, you can graft two cuttings at once. Young two-year-old trees with a thickness of 25mm are used as cuttings.
The smoothest branches with a large number of developed buds are selected for inoculation. Sometimes inoculation can be carried out in the winter.
In this case, the cuttings should be with the most developed buds. Cuttings need to be harvested in the fall even before frosts come. Annual seedlings are used as rootstocks.
In the spring season, walnuts are practically not grafted. This is due to the fact that the germination of grafts should take place at a temperature of 10 degrees, so the grafted cuttings may not have time to take root and die. To prevent the death of cuttings, they should be harvested in the fall.
How to choose the right stock and graft?
In order for the scion to take root quickly and well, it must meet the following criteria:
- High winter hardiness
- Resistance to pests and diseases
- Rapid environmental adaptability
- Moderate growth
- Maximum compatibility with rootstock
The most commonly used rootstocks are:
- Seedlings of cultivated walnut varieties. These varieties include Pyatiletka, Zarya Vostoka and Urozhainy. In the process of grafting, such varieties quickly take root and can withstand severe frosts. In addition, these seedling varieties are the most compatible rootstocks.
- Rocky nut seedlings. Only vigorous seedlings are selected for grafting. They have good winter hardiness and begin to bear fruit as early as the fourth year after vaccination. The only drawback of these seedlings is that they are very demanding on the soil.
- Hinji nut seedlings. These are strong and fast-growing scions that bear fruit as early as the third year after planting. Such trees can very easily tolerate drought, but can also suffer from cold winters.
As for the grafts, they should be chosen only from the most productive varieties. Most often, the selected scions have large enough fruits and high resistance to frost and various diseases.
Basic rules for grafting a nut
The transverse incision on the stem should be made so that the bud is in the middle. Next, you need to make two more longitudinal cuts and separate the bark. On the rootstock wood, you need to perform the same actions, with the removal of the tube from the root collar.
The section of the branch from which the wood was removed must be moved so that small longitudinal slots can form on it. The joint should be sealed with plastic wrap. After two weeks, you need to open the film and grease the grafted area with garden varnish. After that, the vaccination site is reinforced with polyethylene again.
Nut grafting video:
All grafting operations must be carried out very carefully and quickly in order to prevent oxidation of the juice on the scions and rootstocks. In this case, the tools used must be well sharpened.
Inoculation of the nut into the split and budding of the nut
This method of inoculation is carried out during the period of active circulation of the juice. Initially, you need to choose a place for vaccination. Then, in the chosen place, a split should be made, the depth of which should be about five centimeters. A handle is inserted into the finished slot so that it is tightly compressed.
If there is a need to vaccinate on an old tree, then it is advisable to first cut off its crown and wait for the young branches to germinate. After all, it is necessary to vaccinate exclusively on young branches.
Budding is considered the best way to propagate walnuts. All budding work should be carried out with a special double knife, with the help of which two identical transverse cuts are made on the scion. After that, one longitudinal incision is made, which will connect the ends of the two transverse incisions.
Using the budding knife, you need to separate the bark from the wood on the scion handle. Further, a ring of bark with an eye is removed from the handle. In turn, on the rootstock, transverse cuts are also made at a distance of ten centimeters from the soil level. The cut rootstock bark must be removed using the bone of the budding knife.
A scion should be applied to the area with the bark removed, along with the eye. If the length of the flap is too long, then it is slightly shortened. The scion shield and rootstock bark should be connected in such a way that a gap remains between them, with a diameter of about one millimeter. It is best to peel the nut from May to August.
Necessary tools for vaccination
The most basic tool is the grafting knife. It should be sharp, since the quality of the vaccine depends on the sharpness. Also, the knife should have an elongated blade and straight blades. To sharpen the grafting knives, you need to stock up on a file and granular bars. Even in the process of grafting, garden shears are often used, with which old branches are cut and the bark is corrected.
Also, in the process of grafting, garden var and various strapping materials are used. As a binding material, use electrical tape, which can be cut lengthwise into strips eight millimeters wide. In the absence of electrical tape, plastic bags are used, which can also be cut into strips. Some gardeners use a washcloth when tying.