How to graft ginkgo? A detailed explanation of the key points of green-branch grafting techniques
There are many methods for raising ginkgo seedlings, but these seed-sowing methods are not only costly, but also lead to a long juvenile period of the tree, delaying fruiting, and the survival rate of seedlings raised by cuttings is low. Using hardwood grafting in spring can increase the survival rate to 80%, while using green-branch grafting techniques can raise the survival rate to 95%. Therefore, today the editor will talk about the key points of green-branch grafting techniques, hoping it can be of some help to everyone.
I. Grafting time
The best grafting time for ginkgo is from May to August. Note that grafting cannot be done in hot and dry weather, and grafting should not be done at noon on sunny days or on rainy days.
II. Collecting scions
Collect sun-facing, robustly developed current-year branches from the middle and upper parts of superior mother trees, cut off every leaf on the scion, leaving only the petiole;
Cut the scion into sections every 2-3 buds, then soak the lower end of the scion in water or wrap it in warm cloth for later use. It is best to collect and use them immediately. Scions that cannot be used up on the same day can be placed in a refrigerator or cold storage for later use.
III. Rootstock selection
Select ginkgo seedling trees that are more than 2 years old, grow robustly, have straight trunks and strong resistance as rootstocks.
IV. Grafting position
For street trees, graft at a trunk height of 2.5 m on the rootstock;
For courtyard planting, graft at a trunk height of 1.5-2 m;
For early-maturing dense-planting high-yield forests, graft at a trunk height of 0.6-1 m.
V. Grafting methods
Green-branch grafting of ginkgo mainly includes cleft grafting and cut grafting.
1. Cleft grafting method
Cut the rootstock at the required height, then make a vertical split 2-2.5 cm deep in the center of the cut surface. Then cut a smooth inward-sloping surface on each side of the lowest bud of the scion, with the cut surface about 2.5 cm long, so that the lower end of the scion is wedge-shaped. Then quickly insert it into the split of the rootstock, align the cambium layers of the two, and tie it immediately.
2. Cut grafting method
When cutting the scion, cut a smooth long slope about 2.5 cm long from one side of the lower end of the scion. Cut off the rootstock, and on one side of the cut surface, at a place the same width as the scion interface, cut vertically downward 2-2.5 cm. Insert the scion with the long cut surface facing inward and the short cut surface facing outward into the incision, so that the cambium layers of the rootstock and scion meet or one side is aligned, then bandage.
VI. Management
After half a month, check the survival rate; if the buds are fresh, they have survived;
While checking, loosen the binding, and remove sprouts within 30 cm below the grafting site;
For those that failed to graft successfully, re-graft promptly;
Key management points after grafting: apply thin fertilizer frequently, water in a timely manner, spray medicine in a timely manner, and take good pest and disease control measures.
Ginkgo green-branch grafting techniques
Ginkgo has many seedling-raising methods, but seed sowing is costly, the tree has a long juvenile period, and fruiting is late; cutting propagation has a relatively low survival rate; hardwood grafting must be carried out in spring. The survival rate is about 80%. If green-branch grafting is used during the growing season, the survival rate can be increased to more than 95%. The key points of green-branch grafting techniques are introduced below:I. Grafting time. It can be carried out from late May to late August. However, grafting cannot be done in hot and dry weather, especially at noon on clear days, and rainy days should also be avoided.
II. Collecting scions. From the middle and upper parts of the crown of superior ginkgo mother trees or superior scion orchards, collect sun-facing, robustly developed current-year branches. In a cool place, cut off the leaves on the scion, leaving only the petioles, and cut into sections every 2-3 buds. Then soak the lower end of the scion in water or wrap it in wet cloth for later use. It is best to graft as soon as you collect. Scions that cannot be used up on the same day can be stored in a refrigerator or cold storage.
III. Selection of rootstock. Select seedlings more than 2 years old that grow robustly, have straight trunks and strong resistance as rootstocks.
IV. Grafting position. It depends on the future use of the seedling. For future street trees, graft at a trunk height of 2.5 m on the rootstock; for courtyard planting, graft at a trunk height of 1.5-2 m; for early-maturing dense-planting high-yield forests, graft at a trunk height of 0.6-1 m.
V. Grafting methods. Both cleft grafting and cut grafting are acceptable. (1) Cleft grafting method. First cut the rootstock at the required height, and make a vertical split in the center of the cut surface, 2-2.5 cm deep. On both sides of the lowest bud of the scion, cut a smooth inward-sloping surface, with the cut surface about 2.5 cm long, so that the lower end of the scion is wedge-shaped (the side with the bud is thicker). Then quickly insert it into the split of the rootstock, align the cambium layers of the two, and tie immediately. It is especially required to seal the upper cut of the scion to ensure the survival rate. However, the binding should not be too tight, so as not to break the tender branch. (2) Cut grafting method. When cutting the scion, cut a smooth long slope about 2.5 cm long from one side of the lower end of the scion, and cut a short slope about 1 cm long on the back, so that the lower end is flat wedge-shaped. Cut off the rootstock, and on one side of the cut surface, at a place the same width as the scion interface, cut vertically downward, 2-2.5 cm deep. Insert the scion with the long cut surface facing inward and the short cut surface facing outward into the incision, so that the rootstock and scion meet or one side is aligned, then bandage.
VI. Management. After two weeks, check the survival rate; if the petiole falls off at a touch or the bud is fresh, it has survived. While checking, loosen the binding, and remove sprouts within 30 cm below the grafting site. Re-graft those that have not survived in a timely manner. Apply thin fertilizer frequently, water in a timely manner, spray medicine in a timely manner, and control pests and diseases.
Ginkgo grafting techniques|Ginkgo tender-branch grafting techniques
Ginkgo grafting techniques|Ginkgo tender-branch grafting techniques---Ginkgo tender-branch grafting refers to grafting and cultivating during the growing season using current-year tender branches as scions. This grafting method has a higher survival rate than hardwood grafting, the new shoots grow more than those from bud grafting, and the grafting period is also longer, making it a highly efficient grafting technique. Its key technical points are as follows.
1. Grafting time
It can be done from June to September, but grafting in August gives the best results. At this time the tender branches are thick and plump, rich in nutrients, the interface heals quickly, and the survival rate is relatively high. Grafting should be done on cloudy days and on sunny days at low temperatures. It should not be done on rainy days or at noon in high-temperature weather, otherwise survival will be affected.
2. Scion preparation
Scions should be collected from superior scion orchards or superior mother trees, and new shoots with plump buds should be cut from the middle and upper parts of the outer crown of the mother tree as scion sticks. Remove the leaves from the scion sticks, keep the petioles, align the bases, tie them into small bundles, and keep the bases moist with wet cloth. Scions should be grafted as soon as possible after collection. Those that cannot be grafted on the same day should be placed in a refrigerator or a cool, ventilated place and kept moist for storage.
3. Rootstock selection
Seedlings 2-3 years old, cutting seedlings and root-sucker seedlings can be used as rootstocks. The selected rootstocks are required to grow robustly, have straight stems, strong stress resistance and suitable height. The height of the rootstock seedlings varies according to the cultivation goal: for early-fruiting dense planting, the grafting position is about 1.0 m, and the seedling height is required to be about 1.5 m; for courtyard planting, the grafting position is 1.5—2.0 m, and the seedling height is required to be 2.0-2.5 m; for road greening, the grafting position is about 2.5 m, and the seedling height is required to be about 3 m.
4. Grafting methods
Two methods are commonly used, cleft grafting and cut grafting. The operation methods are as follows:
(1) Cleft grafting. ① Cutting the scion. Cut a section with 2-3 buds from the scion stick as the scion, cut a wedge-shaped surface 2-3 cm long on each side of its lower bud, and cut flat at 0.5 cm above the upper bud of the scion. ② Cutting the rootstock. Cut and smooth the rootstock at the grafting position, and make a vertical split in the middle of its cut surface, with the depth equal to the length of the scion cut surface. ③ Grafting and binding. Insert the cut surface of the scion into the split of the rootstock, and align the cambium layers of the two on at least one side, then tie the interface well with plastic film tape.
(2) Cut grafting. ① Cutting the scion. Cut a section with 2-3 buds from the scion stick as the scion, cut a 2.5 cm long slope on one side of the lower end of the scion, and cut a 1 cm long slope on the opposite side. ② Cutting the rootstock. Cut and smooth the rootstock at the grafting position, and on one side of the cut surface selected to be the same width as the scion cut surface, cut vertically downward, with the cutting depth equal to the length of the scion cut surface. ③ Grafting and binding. Insert the scion with the long cut surface facing inward into the incision of the rootstock, make the two fit together, align the cambium layers, then tie the interface well with plastic film tape.
5. Management after grafting
Half a month after grafting, check whether they have survived. If the petiole falls off at a touch, it has survived. For those that have not survived, re-graft promptly. After the interface has completely healed, remove the binding tape. Frequently remove sprouts from the rootstock, strengthen fertilizer and water management, and control pests and diseases in a timely manner to promote the growth of the grafted plants. When the new shoots of the scion grow to about 25 cm, insert stakes for support and tying to prevent wind breakage.
6. Related matters
Because tender branches have not yet fully lignified, thinner plastic film tape should be used for binding during grafting, and binding should be just firm enough, not too tight, so as not to damage the scion and affect survival. Tender-branch grafting can also be applied to top grafting for variety replacement, and for tender branches with a relatively high degree of lignification, the bark grafting method can also be used.