Grafting preparation of conventional Seedling techniques of Walnut

   1. The superior varieties were selected as the mother tree of ear harvesting, and the nursery was established. Cutting from the harvest nursery can ensure the purity of the variety. The mother tree should have pure varieties, strong growth and no diseases and insect pests. After collecting, it is necessary to make a good mark to prevent mixing, because it is difficult to distinguish walnut varieties from branches and trees, and once mixed, it will bring great trouble to the future production. Sometimes cutting scions from the production garden, we should also pay attention to the purity of varieties, while collecting less, so as not to weaken the tree or reduce the yield. It is best to cut the cuttings from the trees where the fruit has been hung, so as to distinguish the varieties. However, due to the large demand for seedlings in production, the phenomenon of cutting scions on young trees is more common, which often brings hidden dangers to the mix of varieties and is not conducive to the growth of young trees.

   professional harvest nursery requires a clear source of varieties, it is best to have results, no major diseases and insect pests. According to the need, the mother tree can be picked up three times a year. When the grafted shoots are picked before sprouting in spring, all the annual branches can be truncated with 3-5 buds to promote the emergence of new branches. After cutting the cuttings, we should pay attention to apply paint on the cut mouth in time to protect the mother plant and prevent the tree from being weakened by too much injury. The second time was collected at the end of May and the middle of June, and the harvest was 60% of that of the new shoots of the same year, and the remaining branches should be reserved for branch grafting in the next spring. It was collected for the third time in late July, and it was collected from the new shoots germinated after the second harvest. The management of fertilizer and water should be strengthened in the harvest nursery, the growth and enrichment of branches should be promoted and the quality of grafting should be improved.

   2, the collection of branch grafting should choose the annual branch with a length of about 1m and a thickness of 1cm to 1.5cm, which requires full development, small pith, leaving 3 buds at the base to be cut off, and then according to thickness and length classification, 50 bundles are bandaged, variety labels are hung, and registration work is done. Winter harvest should be put in the cellar and buried with wet sand, and the scion should be scattered and placed, so that the wet sand can fully contact the scion. Early grafting of ear harvesting in spring.

   3. Collection of buds and scions from the end of May to the middle of June, the developing branches of Lignification in the current year should be selected, the buds should be high mature, fat and full, and should be used whenever they are picked. Immediately after cutting off the blade, leave a petiole of about 2 centimeters, not too short, otherwise the wound is too big. The cut grafts are bundled (20 or 30 each), wrapped in wet cloth, marked with varieties, and grafted as soon as possible.

   4. The grafting of storage and transportation branches can be transported in early spring or autumn, when the temperature is low but it will not be frozen, so pay attention to moisturizing during transportation. It can be stored in the wet sand of local guests, and the effect is better. Methods with reference to the stratification treatment of seeds, it is necessary to pay attention to the contact with wet sand, so the bundles stored should not be too large, and it is best to spread and bury them and make full contact with wet sand.

   bud grafting is best used locally to avoid long-distance transportation. Transport should be wrapped in plastic film, put some wet sawdust inside, can not be airtight, should be properly ventilated. Short-term storage can be suspended in a well, 10 cm from the water surface, can also be placed in a cold storage, keep more than 0 °C, do not freeze. The survival rate of bud grafting will decrease with the extension of storage time, and the general storage period should not exceed 5 days. When grafting in the field, wrap the graft in a cool place with a wet cloth to avoid exposure to the sun.

   5. Generally, wax seal should be used for grafting treatment, which can prevent water loss and improve the survival rate of grafting. 3-5 days before grafting, take out the grafts stored in winter and cut them into branches that are 15-20 cm long, with 3-4 full buds and 1-2 cm from the first bud. The first bud will grow into the best branch in the future, so we should pay special attention to the quality of the first bud. The method of wax sealing is to put the paraffin wax sold in the market (adding a small amount of beeswax for better effect) into a container (either aluminum pot or iron pot), heat the wax to open it, insert a thermometer into the wax liquid, and control the temperature of the wax liquid to 120-140 ℃. After the wax is melted, the scion is quickly dipped into the wax to get rid of the excess wax on the surface, so that the whole surface of the scion is covered with a thin, uniform and transparent wax film. A small number of joints can be dipped one by one with clips or chopsticks, and a large number of hedges can be used to handle 10-20 joints at a time, not too many, so as to prevent the wax temperature from falling. The specific method of operation is as follows: put 1020 joints in the hedge, quickly submerge the wax, instantly take out the hedge, fix it and make part of the wax fall back into the pot, and then throw some of the wax back on the floor covered with plastic sheeting, so that the joints are scattered everywhere instead of stacked in one place, in order to dissipate heat, and the joints will not stick together. Note that the temperature of the wax should not be too high or too low. If the temperature is too high, it is easy to burn to death. At this time, the container can be removed from the heat source to cool down. If the temperature is too low, the wax layer on the scion is too thick, which is easy to crack and fall off. when the wax temperature decreases, it needs to be reheated. Now the temperature can be easily controlled by heating with an electric magnet furnace. A small amount of water can also be added to the container, which can be heated indirectly by using water to control the temperature of the wax in the range of 90 ~ 100 °C, which can protect the contact from being scalded, but because of the low temperature, the effect of wax sealing is not as good as direct heating with fire. The newly sealed joints should not be piled together, but should be released to promote the rapid loss of heat to protect the joints from being scalded. If the grafting is not carried out immediately after the wax seal, the bag can be wrapped with a wet cloth and put in the refrigerator or buried in the cellar wet soil for temporary preservation.

After the collection of    bud grafting, it is also necessary to seal the cut with wax during long-distance transportation to reduce the loss of moisture. Those that can be used as you like can not be sealed with wax, but can be wrapped in wet cloth.