Using Sophora japonica as rootstock, bud grafting or split grafting is adopted before spring germination, and serrated bud grafting, bag grafting or skin grafting is adopted after germination. It took 10 days before and after Xiaoman in early summer (Jinan area). If the grafting technology is skilled, the survival rate of the above methods can reach about 90%. The root segments of Sophora japonica can be propagated by cutting roots.
method of grafting
I. Selection of rootstock and grafting method Rootstock can be an annual seedling with root neck diameter of 0.5 ~ 1cm or a perennial seedling with DBH of 3 ~ 5cm. But for different rootstocks, different grafting methods should be adopted.
The growth rate of Sophora japonica is faster than that of Sophora japonica, and the phenomenon of "small head and big feet" is easy to form at the grafting place. Using perennial seedlings as rootstock and adopting high-level grafting method, the formation is fast and the nursery is short. However, many scions are spliced together in the same section, and the branch opening angle is small, which is easy to cause necking, weak joints and vulnerable to wind damage. In addition, the shaping, regeneration and rejuvenation of such seedlings are limited, and the colors of trunk and upper branches are not uniform. One-year-old seedlings were used as rootstocks, and bud grafting was carried out at 10 cm above the root neck. Although it takes a long time to form, it also has some shortcomings such as "small head and big feet", but before the trunk epidermis is completely cork, the whole plant has the same color and good ornamental value. Moreover, it has strong wind resistance and great flexibility in shaping, renewal and rejuvenation. If the rootstock neck and the grafted part are buried in the ground together during transplanting, it is not only beautiful, but also plays a role in fixing the seedlings. Therefore, in the long run, the method of grafting the bottom bud with annual rootstock has more advantages.
Second, the grafting time of Sophora japonica mainly considers the following factors:
1. seedling size requirements and production batch arrangement;
2. Phenological period of local rootstocks and scions;
3. Avoid catastrophic climate;
4. Grafting methods are different.
Take the middle and lower reaches of the Yellow River as an example. In March and April every year, when the scion is full of buds and is about to germinate but not germinate, the annual rootstock can be used for bottom bud. The scion is used when it is picked, and the bud grafting is carried out with the bud eye with xylem. Unused scions should be stored in a cool and ventilated place in time and covered with wet sand for later use. From late May to June and July, the sap flows vigorously and is easy to peel, so it is appropriate to adopt T-shaped method for bud grafting, that is, "hot bonding" method. After the survival of bud grafting in August, due to the short growth period, it can "suffocate the bud" and overwinter until the next year. In the second year, before bud germination, the upper rootstock is cut off for normal management. Grafting can be carried out from mid-late March to early May, and the key is to harvest and store scions in advance. However, if the storage time is too long, the vigor of the scion will become weak, so the branch grafting should be done sooner rather than later. No matter which method is adopted, it is required that the scion branches are robust and free from pests and diseases, and the grafting operation should avoid rainy days to prevent rainwater from infiltrating and affecting survival.