Detailed Explanation of Grafting Methods for Chestnut Propagation by Grafting (Part 2)
Grafting Methods for Chestnut Propagation by Grafting (Part 2)
4. Bark-flap tongue grafting
This method is used when both the rootstock and scion are slipping (bark separates easily). When the grafting site on the rootstock is more than 2 cm in diameter, cut off the rootstock at a relatively straight and even spot and smooth the cut surface. On the smooth side of the bark, use a sharp knife to shave away the old bark to expose the green tissue. The remaining bark is thick at the lower part and thin at the upper part. The cut surface should be slightly larger than the horse-ear-shaped cut surface of the scion. Cut the lower part of the scion into a horse-ear-shaped cut surface 3 cm to 5 cm long, and at the same time pinch open the bark on the cut surface, then immediately insert the xylem into the bark of the rootstock, with the rootstock bark inserted between the bark and xylem of the scion, so that the two clasp each other and fit closely. Bind the grafting site tightly. The survival rate of this method is even higher than that of bark grafting, but the grafting speed is slow, making it suitable for beginners. The seedlings grow vigorously, but their wind resistance is poor.
5. Double tongue grafting
Used when the scion and rootstock are basically the same thickness. Cut off the rootstock 8 cm to 10 cm above the ground, cut a horse-ear-shaped surface from bottom to top 4 cm from the cut surface, and also cut the lower part of the scion into a 4 cm horse-ear-shaped surface, and respectively make a vertical cut 1.5 cm to 2 cm long at 1/3 of the upper part of the horse-ear-shaped surface, and insert the cut surfaces of the scion and rootstock together, align the cambium, and interlock them. If the scion and rootstock are not the same thickness, then align the cambium on one side. Then bind the grafting site tightly with plastic strips. This method has a high survival rate, the seedlings grow vigorously, and it has strong wind resistance, making it suitable for beginners, but the grafting speed is slow.
6. Single-bud side grafting
Used when scions are in short supply. Generally, one bud can graft one plant. Cut the scion into a wedge shape, but the two cut surfaces are not the same length: the long cut surface is 1.5 cm, and the short cut surface is 1 cm. Cut off the rootstock 7 cm to 8 cm above the ground, and use scissors to make an oblique cut 1.5 cm long from one side of the cut surface toward the other side of the rootstock stem; the lower part of the cut should be located in the middle of the rootstock stem and must not exceed 2/3. Insert the long cut surface of the scion facing inward into the cut, align the cambium on one side, and then bind tightly. The purpose of the oblique cut is to prevent the rootstock stem from splitting, making it easy to bind and survive. This method is used by skilled grafters, and is not suitable for beginners.
7. Chip budding
This is a method of budding with wood. Because the xylem of chestnut has grooves, the bud piece of T-shaped budding does not sit firmly and is not easy to survive, so chip budding is used. This method saves scions and is used when scions are in short supply. It is used more in spring. The method is to make a downward oblique cut 0.8 cm to 1.0 cm above the bud to be grafted, then make an oblique cut at about 0.8 cm below the bud at a 30° angle to the bottom of the first cut, and remove a bud piece with wood about 1.6 cm to 2.0 cm long. Then, according to the size of the bud piece, cut a corresponding incision on the rootstock. Insert the bud piece into the incision on the rootstock so that the cambium layers on both sides align. If the rootstock is thick and the scion is thin, then align the cambium on one side. Then bind tightly and securely with plastic strips. This method is highly technical, and only skilled grafters can achieve a relatively ideal survival rate.
This method is used when both the rootstock and scion are slipping (bark separates easily). When the grafting site on the rootstock is more than 2 cm in diameter, cut off the rootstock at a relatively straight and even spot and smooth the cut surface. On the smooth side of the bark, use a sharp knife to shave away the old bark to expose the green tissue. The remaining bark is thick at the lower part and thin at the upper part. The cut surface should be slightly larger than the horse-ear-shaped cut surface of the scion. Cut the lower part of the scion into a horse-ear-shaped cut surface 3 cm to 5 cm long, and at the same time pinch open the bark on the cut surface, then immediately insert the xylem into the bark of the rootstock, with the rootstock bark inserted between the bark and xylem of the scion, so that the two clasp each other and fit closely. Bind the grafting site tightly. The survival rate of this method is even higher than that of bark grafting, but the grafting speed is slow, making it suitable for beginners. The seedlings grow vigorously, but their wind resistance is poor.
5. Double tongue grafting
Used when the scion and rootstock are basically the same thickness. Cut off the rootstock 8 cm to 10 cm above the ground, cut a horse-ear-shaped surface from bottom to top 4 cm from the cut surface, and also cut the lower part of the scion into a 4 cm horse-ear-shaped surface, and respectively make a vertical cut 1.5 cm to 2 cm long at 1/3 of the upper part of the horse-ear-shaped surface, and insert the cut surfaces of the scion and rootstock together, align the cambium, and interlock them. If the scion and rootstock are not the same thickness, then align the cambium on one side. Then bind the grafting site tightly with plastic strips. This method has a high survival rate, the seedlings grow vigorously, and it has strong wind resistance, making it suitable for beginners, but the grafting speed is slow.
6. Single-bud side grafting
Used when scions are in short supply. Generally, one bud can graft one plant. Cut the scion into a wedge shape, but the two cut surfaces are not the same length: the long cut surface is 1.5 cm, and the short cut surface is 1 cm. Cut off the rootstock 7 cm to 8 cm above the ground, and use scissors to make an oblique cut 1.5 cm long from one side of the cut surface toward the other side of the rootstock stem; the lower part of the cut should be located in the middle of the rootstock stem and must not exceed 2/3. Insert the long cut surface of the scion facing inward into the cut, align the cambium on one side, and then bind tightly. The purpose of the oblique cut is to prevent the rootstock stem from splitting, making it easy to bind and survive. This method is used by skilled grafters, and is not suitable for beginners.
7. Chip budding
This is a method of budding with wood. Because the xylem of chestnut has grooves, the bud piece of T-shaped budding does not sit firmly and is not easy to survive, so chip budding is used. This method saves scions and is used when scions are in short supply. It is used more in spring. The method is to make a downward oblique cut 0.8 cm to 1.0 cm above the bud to be grafted, then make an oblique cut at about 0.8 cm below the bud at a 30° angle to the bottom of the first cut, and remove a bud piece with wood about 1.6 cm to 2.0 cm long. Then, according to the size of the bud piece, cut a corresponding incision on the rootstock. Insert the bud piece into the incision on the rootstock so that the cambium layers on both sides align. If the rootstock is thick and the scion is thin, then align the cambium on one side. Then bind tightly and securely with plastic strips. This method is highly technical, and only skilled grafters can achieve a relatively ideal survival rate.