Bud extension in plants is the process of producing new shoots or branches from buds. Buds are small structures that contain the immature parts of a plant, such as leaves, flowers, or stems. Buds can be found at the tips of stems (terminal bud), in the angles between leaves and stems (axillary bud), or on other parts of the plant (adventitious bud). Buds can be dormant or active, depending on the season and the plant's needs. When a bud becomes active, it starts to grow and extend into a new shoot or branch. This can result in more leaves, flowers, or fruits for the plant. Bud extension is influenced by many factors, such as light, temperature, hormones, pruning, and environmental stress.
A bud extension is also a technique of propagating a new plant from a single bud of a desirable variety. It involves inserting the bud into an opening in the bark of a compatible rootstock, which provides the support and nutrients for the new plant. This method is commonly used for fruit trees, such as apples, pears, and peaches, as well as some ornamental plants. The advantages of bud extension are that it can produce more plants in less time and space than other methods, and it can preserve the characteristics of the original plant.
Some examples of bud extension techniques are T-budding and chip budding. T-budding involves making a T-shaped cut in the bark of the rootstock and slipping the bud under the flaps of the bark. Chip budding involves cutting a small chip of bark with a bud from the scion and fitting it into a matching cut in the rootstock. Both techniques require wrapping the graft with tape or rubber bands to keep it in place and prevent drying out. The wrapping is removed after the bud has healed and started to grow.