When can apple trees start grafting in spring?
2. The scion used to select the high-grafting and head-changing scion must be taken from a well-managed, robust and pest-free tree. The standard of excellent scion is that the diameter of base is 0. 8 ~ 1.2 cm, and the length is greater than 1. 2 m, with more than 20 full buds, 1 year-old robust spring shoots are free from pests and diseases.
3. The fruit trees with high grafting in the orchard must be 4- 10-year-old young trees, which are robust, neat and consistent, and free from virus diseases; The soil must be deep, fertile, loose and breathable, and can keep moisture and fertilizer, with a p H value of 6. Number five and number seven. 0 and away from pollution sources.
Generally speaking, the best time for high connection is in the middle of April. When the apple inflorescence is separated and exposed, the temperature of premature grafting is low, the juice does not flow or flows slowly, the bark is not easy to separate, the operation is difficult, the wound healing is slow, and the grafting survival rate is low; Grafting is too late, a large number of flowers and trees flourish, which consumes a lot of nutrients stored by trees, and the nutrient supply of scions is insufficient, which seriously affects growth and survival rate.
5. Preparation before grafting ① Listen to the weather forecast 10 d (days) in advance. In case of rainy weather or sandstorm, the grafting time should be properly adjusted to make the whole orchard graft at the same time, so that the grafted garden looks neat and consistent; ② Top dressing and irrigation before high grafting 1 week; (3) Prepare binding strips 3 days in advance, grind fruit tree shears and grafting knives, and disinfect to prevent the spread of virus diseases; ④ Take out the scion 2 d (days) in advance, clean it, cut off the base of the scion 5 cm, insert it into clean water, and fully absorb water for 24 h (hours); ⑤ Before grafting, in the evening of 1 d (day), cut the fully absorbent branches into scions of about 15 ~ 20 cm, and order them according to the bud shrinkage at the base of autumn shoots, full bud at the middle and full bud at the top. When grafting, use a full bud scion first, and then consider using the other two when the scion is insufficient; ⑥ Put the paraffin wax into an open pot and heat it to melt, then soak the upward 2/ 3 part of the scion bud eye (base 1/ 3 is used for cutting plane) in paraffin wax for 2 s (seconds) and take it out. After the paraffin is solidified, bind 30 pieces into 1 bundle for standby (to prevent the scion from losing water).
6. High grafting and head changing method ① Multi-head high grafting is adopted, and 3-4 young flourishing trees of 4-6 years old are generally left; 6 ~ 10 years old is generally divided into 2 floors, and 5 ~ 6 floors are reserved. (2) All the high grafting in spring adopts branch grafting, and the high grafting in autumn adopts bud grafting with wood. (3) Transplantation generally includes split transplantation, skin grafting, abdominal transplantation and subcutaneous transplantation, mainly split transplantation and skin grafting. Butt joint diameter is less than 1 cm, and splicing joint should be adopted; The diameter above 1 cm is suitable for skin grafting and is beneficial to wound healing.
7. Operation flow of high-joint head-changing ① Saw the reserved head-changing main branch from the glossy surface 20cm away from the base and 40 cm away from the top main branch. All saws must be smooth and flush, and sawdust should be removed; Other main branches and auxiliary branches are sparse. ② The grafting sequence is from top to bottom and from inside to outside. And is connected with the saw to prevent the saw mouth from losing water. ③ Splitting: firstly, cut the scion from the center of the joint with a sharp knife, with a depth of 5-6 cm. The cutting surface of the scion is arrow-shaped, and the cutting surfaces on both sides should be cut evenly and smooth. After insertion, the cambium on both sides should be aligned (it is best to choose scions with thickness greater than 0. 2 cm, so that after the cutting is inserted, the cambium on both sides of the cutting surface can be completely consistent with the cambium on the interface, and the survival rate can be greatly improved. If the thickness is inconsistent, try to align the cambium to one side.) No matter how thick the scion is, only cut a smooth section at the base of the scion, and then scrape off part of the epidermis at the back to expose the cambium. The switch of the main branch is directly above the interface (if the azimuth angle of the main branch needs to be adjusted, it can be on the side or directly below the interface as needed), and the switch of the middle branch is vertically cut in the north of the interface, cutting off the cortex, and the incision is 5 ~ 6 cm long, then inserting the scion from the incision, wrapping the scion tightly with the cortex, and finally tying the interface tightly with a bandage. (4) Individual plants can't be grafted in the normal position due to rot, mechanical damage or trunk deformity, so they can be sawed off at one time, and then directly grafted on the root cortex, and the wound should be tightly bandaged. Finally, we should carefully bury it with wet soil, only exposing the eye of the scion bud, and mark the ground at the same time. The survival rate of grafting in this way is extremely high. ⑤ After the trees are grafted, obvious protection signs must be set to prevent the scion from being knocked down or smashed when sawing the branches.
8. After management ① After the whole park is changed, it is filled with water to ensure water supply. ② Erase the trunk, main branches and interface buds at any time. (3) Check the survival rate after 3)20 ~ 30d days (days) and repair it in time. If a few scions are still not alive, we should choose the scion with the best top growth, position and angle to protect the wound and woody bud grafting in autumn. ④ Spraying 10% imidacloprid to control the apple aphid according to the insect situation after harvesting. ⑤ The interface is completely healed. When the scion begins to thicken, untie the tie in time, but don't take it off immediately to avoid lignification of the joint. In the hot season, straw is used to protect the bare trunk from sunburn. ⑥ Apply 0. Apply 1 kg urea or ternary compound fertilizer every 15 d (day) from June to August. After fertilization, irrigate according to the weather and soil moisture, and spray 0. 3% urea and 0. 3% potassium dihydrogen phosphate foliar spraying combined with pest control. ⑦ When the new shoots grow to more than 30cm, erect the upright posts with wooden sticks or bamboo poles in time to prevent them from being split by the wind. ⑧ In September, moderately remove the dense branches and sparse branches, gently knead and soften the main branches in a reasonable direction, and then pull the branches to 90 degrees, so as to restore and expand the crown as soon as possible, blossom and bear fruit.