When will the walnut tree, the king of nuts, be grafted? Which trees can be grafted? How is it grafted?

Walnut, also known as walnut and Qiang peach, is a common walnut plant in China, but if we want walnut to produce high yield, in addition to the basic management work, we should also do a good job of grafting and transplanting. When will the walnut tree be grafted? Which trees can be grafted? How is it grafted?

Grafting time:

The main results are as follows: 1. The suitable time for branch grafting is from early April to early May. Because this technique is not easy to master and the survival rate is not high, the application of this method is not recommended.

2. The best time for bud grafting is from mid-May to late June. At this time, the temperature and humidity conditions are suitable, the rootstock and ear grow vigorously, and then the callus is easy to form, the bud germinates quickly, and the Lignification degree is high, which is conducive to safe winter.

3. The grafting of walnut trees was carried out from late March to early April. Firstly, the scion was collected. In the middle of March, when the bud was about to germinate, the one-year-old branches with strong growth and free of diseases and insect pests were collected as scions, and the varieties were stored in wet sand after harvest, and the buds of walnut rootstocks began to be grafted in early April. The rootstock requires that the thickness of the rootstock is about 1.5cm and grafted at 10cm from the ground.

Walnut grafting has bleeding and is not easy to survive. Within 12 hours before grafting, the xylem must be cut to "release water" at the root, then split grafting or skin grafting, the wound is tied up with plastic strips, and the upper end of the scion is smeared with paint to prevent water evaporation. After survival, sprouting and loosening should be removed in time, and the loosening time should be carried out when the new growth is above 20cm. When the grafted seedlings grow to about 40cm, they should be fixed with small bamboo poles or wooden sticks to prevent wind break.

Seedlings that can be grafted:

Generally speaking, the effect of mutual grafting is good only for plants of the same family and genus. The best thing about grafted walnut trees is:

1. Seedling grafting of walnut (seedlings sown from walnut seeds).

2. Juglans mandshurica in walnut family can be grafted, such as Juglans mandshurica (Juglans mandshurica), but it is easy to show small feet (thin rootstock, thick above the grafting interface).

3. Maple poplar of walnut family (south), which can also be grafted walnut.

Grafting method:

1. Split grafting: split on the rootstock and insert the scion, so it is called split grafting. Split grafting is a main method of branch grafting in spring.

① rootstock cutting. Cut the rootstock at a straight scar-free place on the bark, flatten the wound with a knife, and then split a vertical split with a depth of 4-5 cm in the middle of the rootstock.

② scion cutting. There are 2-3 buds left in the scion, and one knife is cut on each side of the scion to form a wedge. Connect the outer wedge of the lower part of the scion with the cambium of the rootstock. The inside doesn't meet. The cutting length of scion is 4-5 cm. The cutting surface should be flat and the angle should be appropriate so that the rootstock at the interface can join with the scion.

③ joint. The key is to align the cambium of both sides, and it is best to make the cambium of the two sides of the scion opposite each other. If you cannot align both sides, keep one side of the cambium aligned. Be careful not to insert the scion wound into the split, to expose more than 0.5 cm, in order to facilitate wound healing.

④ bandage. For medium or thin rootstocks, insert a scion at the split (preferably wax sealed), and then tie up the interface with a plastic strip with a width of 4 cm and a length of 30-40 cm. When binding, all the split, wound and exposed areas should be tightly wrapped and tied.

2. Double open door bud grafting and single open door bud grafting: when grafting, pry open the bark on both sides of the rootstock cut, just like opening two doors, so it is called double open door bud grafting; single open door bud grafting, just pry open the bark on one side of the incision. The other grafting methods of the two are the same. It is suitable for the varieties which are difficult to live by grafting. After the grafting survives, it can germinate in the same year.

① rootstock cutting. Make the length of the bud equal to the cut length of the rootstock. Cut the rootstock up and down where the bark is smooth, so that the width exceeds the width of the bud properly. Then cut the knife longitudinally in the center to make the incision in the shape of "work". If it is a single door, cut 1 knife longitudinally on one side, down to the xylem. Then pry open the bark to form a double door or a single door.

② scion cutting. Cut a knife around the scion bud and take out the square-shaped bud.

③ joint. Put the scion into the cut of the rootstock and carry out double-open bud grafting, that is, cover the scion bud piece on the left and right sides; in the single-door bud grafting, pry open the rootstock bark and cover the scion bud piece, and the bud piece should be close to the pried side.

④ bandage. Use plastic strips with a width of 1-1.5 cm and a length of 30-40 cm to bind the buds together to expose the buds and petioles.

3. Square grafting: the buds taken during grafting are square-shaped, and a square of bark is also taken on the rootstock, so it is called square bud grafting. Square bud grafting has a large contact surface, which is suitable for walnut which is not easy to survive by bud grafting, and it is easy to germinate after grafting.

① rootstock cutting. When grafting, compare the cut length of the rootstock and scion, and carve the mark with a knife. Then cut up, down, left and right, deep into the xylem, then pick out and remove the rootstock bark with the tip of the knife.

② joint. Put the bud into the incision of the rootstock so that it closes right up and down with the incision of the rootstock. If the scion bud is smaller, it doesn't matter: if the scion bud is too large to fit, it must be cut down to make it the right size.

③ bandage. The interface was tied up with plastic strips 1-1.5 cm wide and 30-40 cm long to expose buds and petioles.

Management techniques after grafting:

1. After that: check the survival in about 10 days. The sign of survival is the shedding of petiole or sprouting of buds, and timely replacement if it does not survive.

2. De-sprouting: remove the sprouts on the rootstock to promote budding, except once in about 10 days.

3. Cutting rootstock: after the survival of bud grafting, the rootstock can be cut off around the 2cm above the bud grafting to stimulate the growth of bud grafting.

4. Unbinding: when the grafting shoot grows above 5cm, it can be untied and bandaged. Unbinding too early or too late can affect growth.

5. Heart-picking: when the new shoot of the graft is about 30cm, it is easy to survive the winter safely.

6. Disinfestation: if insect pests such as wood-lifting inchworm and diamondback moth occur, it can be treated with 2000-fold solution.

7. Cold protection: walnut field grafting needs to survive the winter and prevent cold in the same year. Before the soil is frozen, it is possible to bury the soil to prevent cold, and the plastic film that cannot be buried to prevent cold can be used to wrap it, and the next spring sprouting period is timely unearthed or unwrapped.