What are the common grafting methods?

At present, there are many grafting methods used in production, and different methods have their specific conditions and application scope. Therefore, it is necessary to choose the appropriate grafting method according to the local specific conditions, the nature of the scion, the grafting period and purpose.

1. Cutting method:

It is a common grafting method in branch grafting. Generally, it is suitable for thin rootstocks, and ground grafting is carried out when the rootstock juice begins to flow in spring. Selecting 1 ~ 2cm thick seedlings as rootstocks, cutting them about 5cm from the ground, and then vertically cutting them to a depth of 2 ~ 3cm on one side of the rootstocks (slightly xylem, with a cross section of about 1/5 ~ 1/4); One side of the scion is cut, showing a parallel section of 2 ~ 3 cm, and a small inclined plane is cut at the opposite base. Keep 2 ~ 3 complete and full buds on the scion. Insert the cut scion into the incision of the rootstock, align the cambium, closely combine the cut surfaces of the rootstock, and then bind it with binding materials such as plastic strips. If necessary, the joints can be coated with wax or soil to reduce water evaporation. After grafting, the method of burying soil is generally used to moisturize.

incision

1. Scion 2. Rhizome 3. Insert scion 4. Bonding and burying soil. Arrangement of cambium in scion and rootstock

2. Split method:

Grafting is similar to cutting and is suitable for most deciduous trees. The thickness of the selected rootstock is required to be 2 ~ 5 times that of the scion. After the rootstock is cut off about 5 cm from the ground, the center of its cross section is cut vertically, and the rootstock is split, with a length of 2-3 cm; Cut the scion into wedges on both sides of the lower end, with a cut of 2 ~ 3cm. Insert the scion into the rootstock so that the cambium of the rootstock is aligned. If the rootstock is thick, insert 2 or 4 scions at the same time and tie them tightly with straps. Because the incision is large, we should pay attention to covering the soil to prevent water transpiration from affecting survival.

Wedge grafting

1. The scion cuts the front, back and sides. 2. Split the rhizome. 3. Scion insertion side. 4. Double scions are inserted into the front. 5. Form a combined part.

3. Skin transplantation:

Also called subcutaneous transplantation. Suitable for rootstocks with a diameter of more than 2 ~ 3 cm, when the rootstocks can peel off the bark during the liquid flow period of the growing season. At present, this method is also being used to change heads.

Scion cutting: cut a 2 ~ 3cm long bevel on the back of the bud under the scion at 1 ~ 2cm, gently scrape off the cortex to expose the cambium, and then cut a small bevel of about 0.6cm at the tip behind the bevel. Cut off rootstock seedlings at a distance of 1 ~ 2 cm from the ground, and flatten the section with a sharp knife. In the smooth part of the rhizome epidermis, it is cut vertically from top to bottom, reaching the xylem, about 1.5 cm long. Lift the cortex from left to right along the cutting edge with a knife tip, and insert the scion so that the horse-ear section is close to the cambium at the outer edge of the xylem (so that the section is between the phloem and xylem of the rootstock). After cutting the scion, bind it and bury it with chopping method.

Bark grafting

1. Cut the scion 2. Open rootstock 3. Cut the scion 4. Bind and cover the soil

4. The medullary cambium attachment method:

This method is mainly used for grafting conifers. The advantages are: the contact area between scion pith and rootstock cambium is large, and it is easy to fit closely. There are meristems (cambium) in almost the whole section of rootstock, and the marrow cells and parenchyma of scion also play an active role in healing, thus accelerating the healing of scion and rootstock and improving the survival rate. Even if it can't be grafted, it has little effect on the rootstock, and it can be grafted again. The grafting of medullary cambium is most suitable when the rootstock buds begin to swell, but it can also be done when the annual branches of rootstock and scion are completely lignified in autumn.

Junction of medullary cambium

1. Scion cutting 2. Scion front 3. The fourth side of the scion. Rootstock cutting 5. Bonding 6. Binding.

Cutting scion: Cut 8 ~ 9 cm long branchlets from the scion branches, and remove all needles except 10 bundles of needles or two or three buds near the terminal bud. Then use a sharp knife to cut half of the scion from the terminal bud 1.5 ~ 2 cm through the pith, and the remaining half with terminal buds and needles as scions. Note that it is best to let the removed needles account for 2/5 of the retained needles, not more than half, otherwise the bud grafting will die due to lack of nutrition and it will be difficult to heal.

Cutting the rootstock: in the annual part of the main branch of the rootstock, select a section slightly thicker than the scion, except for the top 15 needle cluster, remove the needles and lateral buds, take the leaves longer than the scion, and then cut the bark from top to bottom with a knife to expose the cambium. When cutting rootstocks, the depth is appropriate, and the water-white slice is appropriate. If it is light green, it is shallow, leaving phloem. If it's white, it's deep and cut to the xylem. The length and width of the cutting surface of the rootstock should be consistent with the cutting surface of the scion, and the cutting surface can also be cut at the smooth part of the rootstock.

Bonding and binding: stick the cutting surface of the scion on the cutting surface of the rootstock, align it up and down, left and right, hold the rootstock with your left hand, press the lower end of the scion and one end of the plastic tape with your thumb, and wrap the other end of the plastic tape with your right hand from bottom to top. When packing, press one ring at a time and tighten it properly. After wrapping the upper end on the incision, wrap it from top to bottom, and then pull out a button to press the end of the plastic belt to prevent it from coming loose.

Management: After more than one month, use scissors to cut off the main branches of the grafted seedlings near the upper end of the interface, so that the scion can grow upward instead of the main branches of the rootstock, and at the same time cut off or cut off some overgrown side branches on the rootstock, especially the big side branches near the scion, so as not to squeeze the scion onto the side branches. In those years, not all the side branches could be cut off to avoid the scion "starving". Later, with the growth of the scion, all the lateral branches of the rootstock were gradually cut off.

(1)T-type bud grafting (cutting scion)

1. Scion cutting leaves 2. Scion cutting process

5.t-shaped budding method:

Suitable for general tree species with thin roots and thin cortex. This is the most commonly used method in bud grafting. Simple operation, high survival rate and long grafting time, which can be carried out in June-September. Generally, in late summer and early autumn, when the branches and buds are fully developed and the bark is easy to peel off, the shield-shaped buds are cut from the selected branches with a bud grafting knife. At the same time, cut the smooth side of the rootstock into a T-shaped joint with the same length as the bud piece at a distance of 5 ~ 10 cm from the ground, and reach the xylem directly, then peel off the cortex with the tail of a knife, unscrew the bud piece from the branch where the bud piece has been cut, and take the bud vascular bundle on the bud piece as a whole. Then insert the incision, so that the upper edge of the bud and the upper edge of the incision are closely connected with the upper edge of the incision, and then wrap the joint tightly with plastic film tape.

1. T-shaped opening of rhizome 2. Add 3. stripe

6. I-shaped budding method:

The bud piece is 3 ~ 4 cm long and 1.5 ~ 2.5 cm wide. When grafting, first select a medium-sized mature bud on the scion, cut one knife on the upper and lower rings of the petiole to reach the xylem, then take the skin 0.3-0.5 cm wide from the back of the scion as a ruler, measure the same length at the appropriate part of the rootstock, cut one knife on the upper and lower parts, the width is about 2/3 of the surrounding stems, and tear off the skin 0.3-0.5 cm wide vertically from the middle. Then peel off the cortex on both sides, peel off the periphery of the scion bud (only the vascular bundle is connected), press one side of the scion bud with your thumb, and push the bud to the left, so that you can take it off with the bud-protecting meat. Embedding the bud into the incision of the rootstock, and tying it tightly with plastic strips from bottom to top.

I-bud grafting

1. Scion 2. Rhizome 3. Add 4. promissory

7. Block budding method:

Square bud grafting is square when taking buds, and the rootstock is also stripped of a layer of square skin, so it is called "square bud grafting". This method is more complicated than T-bud grafting, so it is not needed for general tree species. However, this method has a large contact area and is suitable for T-type budding tree species that are not easy to survive, such as persimmon and walnut.

When grafting, compare the length of the incision between the scion and the rootstock, carve a mark with a knife, or cut it with a double-edged knife. Cut a square piece of bark from the rootstock, and take off buds of the same size from the scion. There are buds and petioles in the center of the buds.

When grafting, the scion buds are placed in the cut place of the rootstock, which generally requires the appropriate size. In the case of poor technology, it is better to have a smaller incision than the rootstock, and some gaps generally do not affect the survival. If the bud piece is larger than the cut of the rootstock, the bud piece is easy to tilt up and cannot contact with the rootstock, which affects the survival. In addition, it should be noted that the cambium in the bud and the cambium outside the xylem of the rootstock should be kept clean, and the buds should not move left and right after being put in, so as not to scratch the cambium. After putting the buds, bind them with plastic strips, and the buds and petioles are exposed.

square budding

1. Take scion bud 2. Cut the roots 3. Add 4. Binding.

8. Germination method:

Also called budding with wood. This method is suitable for trees before peeling in spring or without peeling in autumn. Compared with grafting, it saves scions, has simple operation and high survival rate. Suitable for large-scale seedling raising.

The bud on the scion is cut from top to bottom, the upper part of the bud is cut down flat, and the lower part of the bud is cut horizontally, and the bud piece is removed. Generally, the length of buds is 2 ~ 3 cm, and the width varies according to the thickness of scion. The cutting of rootstock is to cut the selected part from top to bottom in parallel, but don't cut it completely, leaving about 0.3 cm at the lower part. After inserting the bud piece, stick this part on the bud piece and tie it up. When taking buds and cutting rootstocks, make the two incisions as close as possible, so that the cambium can be aligned up and down, left and right, which is beneficial to survival.

Embedding grafting

1. Cut the buds. 2. cut the buds. 3. cut off the joints. 5. Insert the bud. 6. Tie it up.