Three methods of fruit tree grafting in spring;
1. Cutting: Suitable for ground grafting of rootstocks with root neck 1-2 cm thick. The method is as follows:
(1) Cutting the scion: Cut the scion into 5-8 cm long with 3-4 buds, cut the scion into two sections, one is long and the other is short, and the long inclined plane is 2-3 cm long. Cut the back of the scion into a small inclined plane less than 1 cm to form a flat wedge below the scion.
(2) rootstock treatment: cutting the rootstock off the ground by 4-6 cm. Select a rootstock with thick skin and smooth texture, and cut it vertically with a knife at the place with slight xylem in the section cortex, the depth is slightly shorter than the long inclined plane of the scion, and the width is equal to the diameter of the scion.
③ scion: insert the scion with large section into the incision of the rootstock inward to ensure that the scion is aligned with the cambium of the rootstock. If both sides cannot be aligned, you can align one side.
(4) Binding: Tie it tightly with hemp skin or plastic strips, wax it, and cover it with moist loose soil from bottom to top, which is 3-4 cm higher than the scion without heavy pressure.
Second, skin grafting: skin grafting is a common method in branch transplantation, which is mostly used for high-level transplantation and head replacement. This method is simple and fast, and can only be used when the rootstock buds germinate and fall off.
(1) Cutting the scion: cutting the scion into 3-5 cm long sections. If the scion is thick, the section should be longer. Cut the back of the long section into small sections of about 1 cm, and sharpen the lower end into a wedge shape. The scion should have 2-3 buds, and the top buds should be kept face to face. The thickness of scion is generally 0.3-0.5 cm, depending on the thickness of scion and tree species.
(2) rootstock treatment: rootstocks with a diameter greater than 10 cm can be grafted. Choose a suitable height on the rootstock, choose a smooth part to saw or cut, the section should be perpendicular to the branches, and the incision should be smoothed with a knife to facilitate healing.
③ Grafting: select a smooth and radian part on the flattened rootstock mouth, cut a longitudinal incision slightly shorter than the section of the scion through the cortex to reach the xylem, gently lift the bark to both sides of the incision with a knife, align the scion with the middle of the interface of the cortex, and insert the long incision into the xylem 0.5cm between the xylem and the cortex of the rootstock.
④ Binding: Tie the interface firmly with plastic strips.
Third, tongue grafting: this grafting is very suitable for the situation that the diameter of scion and rootstock is very small (6- 12 mm in diameter) and the thickness is equivalent. This method has large contact area with the cambium of rootstock, fast healing and is beneficial to survival.
(1) scion cutting: cut a long section with a length of about 2.5 cm at the internode below the basal bud of the scion. The cutting surface should be smooth and flat, and then a vertical cut with a length of about 1 cm should be made at the top of the cutting surface13, thus forming a scion with a tongue-shaped mouth downward.
② rootstock treatment: the method is the same as scion cutting.
③ Connection: Butt the scion with the tongue-shaped mouth of the rootstock and align it with the cambium. If the two sides can't be aligned, align one side to maximize the contact between the layers.
④ Binding: Tie the interface firmly with plastic strips.
After grafting, it is necessary to check the survival situation in time and unbind it. Generally, it takes 20-30 days for grafting to see whether it is alive or not. After survival, the direction and position are better, the upper branches with vigorous growth should be prolonged, and the rest should be removed. Those that don't survive should choose strong branches from roots and tillers to keep, and the rest should be cut off to make them grow healthily and keep them for next spring.
The grafted fruit trees become semi-mature seedlings, the branches are grafted in spring, and they leave the nursery in autumn that year. In order to make grafted seedlings grow and develop normally, a series of management measures are needed. Topdressing 1-2 times in June and July, topdressing 10- 15 kg urea per mu, watering and spraying seedlings, digging ditches and burying them in soil 2 inches away from the original seedlings, watering them in time after topdressing, or spraying 0.3%-0.5% urea solution on the leaves.