Plant Propogation and Nursery Management

Methods of Budding

Chip Budding: Chip budding is done in early spring, summer or autumn. In chip budding, a chip of bark and wood is removed from the smooth surface between the nodes of the stock. The various steps involved are shown in Plate 8.1. A chip of similar size and shape is also removed from the bud wood of the desired cultivar. For which, a 2-3cm long downward cut is made through the bark and slightly into the wood of the stock. Then a second cut of about 2.5cm is made so that it bisects the first cut at an angle of 30-45O and the chip is removed from the stock. Similarly, a chip of bud is removed from the budwood, ensuring that the bud is in the middle of chip. The bud chip inserted in the stock in such a way that cambium of the bud chip should have direct contact with the cambium of the stock. It is then tightly wrapped with polythene strip, leaving the bud uncovered. The bud may sprout after 3-4 weeks and afterwards the wrapping material should be removed. When the bud starts growing, the stock may be cut above the bud union.



Plate 8.1: Chip budding in walnut Plate 8.2: Chip budding in apple

Shield or T-budding: As the name indicates, shield is the shape of the bud and ‘T’ is the shape of cut given on the rootstock. It is the most common method of budding used by nurserymen worldwide. The various steps involved are shown in Fig.8.1. For shield budding, one year old rootstock seedlings of 25-35 cm height and 2-2.5 cm thickness is selected. The bark of seedlings should slip easily. The selected bud of desired cultivar is inserted 15-20cm above the ground level and is tied with a polythene strip.



Fig.8.1: T- budding (Hartman et.al 1997)

For performing budding operation, a “T” shaped cut is made on the selected portion of the stock with the help of a sharp budding knife. The incision should be given through the bark not the wood. The two flaps of bark are loosened with the help of budding knife. The healthy bud is removed from the bud wood by cutting shallowly about 5-6 mm below and 2-3cm above the bud. This shield piece containing a bud is inserted in the “T” cut made on the rootstock. The shield should be covered by two flaps of the bark, but bud should be exposed. The buds are pressed firmly, fitted into the “T” cut and finally tied with polythene strip. When bud healing process is over, the bud may attain a height of 15-20cm, the remaining portion of the stock is cut to about 10-15cm above the bud. Plants with thin bark, with sufficient flow of the sap like apple, pear, peach, plum, apricot, cherry, rose and citrus are propagated by this method.
Patch budding: In case of patch budding, a rectangular patch of bark is removed completely from the rootstock and replaced with a patch of bark of the same size containing a bud of the cultivar to be propagated. It is a slower and difficult to perform method than T-budding. It is widely used in thick-barked species, such as walnuts, pecans and rubber tree, where T-budding gives poor results due to poor fit around the margins of the bud-particularly the top and bottom. It is usually done in late summer or early fall, but can be done in spring also.
In patch budding, the stock and scion should preferably be of same thickness (20-25mm). The various steps involved are shown in Plate 8.3. First, a rectangular piece of bark (25mm long and 10-15cm wide) is removed from the stock and a similar patch, containing a bud is removed from the scion by making two horizontal cuts above and below the bud and then two vertical cuts connecting the horizontal cut.



Plate 8.3: Patch budding in walnut

After removing the patch, the bud should fit tightly at the top and bottom. It is then wrapped with polythene strip, keeping the bud uncovered. The wrapping material should hold the bark tightly and cover all the cut surfaces to prevent free entry of air or water or pathogens. After the bud starts sprouting, the stock above the bud union may be cut off step-by-step. In addition to pecan nut and walnut, mango, rubber plant, aonla, jackfruit and jamun are also propagated by this method.
Ring or annular budding: In this type of budding, a complete ring of bark is removed from the stock and it is completely girdled. A similar ring of bark containing a bud is removed from the bud stick and is inserted on to the rootstock. The various steps involved are shown in Fig.8.2. The thickness of stock and scion should be of same size. It has been utilized in ber, peach and mulberry because the newly emerged shoots from the heavily pruned plants are capable of giving such buds for budding, which can be easily separated. In this method since the stock is completely girdled and if the bud fails to heal in, the stock above the ring may eventually die.



Fig.8.2: Annular budding in walnut

Forkert budding: In forkert budding, the stock is prepared by giving two vertical cuts and a transverse cut above the vertical cuts to join them. The bark is removed carefully along the cuts, so the flap of bark hangs down. The scion is prepared in a fashion similar to patch budding, having the size similar to cuts made on the stock. The scion is then slipped into the exposed portion of the stock and the flap is drawn over the inserted bud patch. It is then tied with a suitable wrapping material. After successful growth of bud, the portion of stock above the union is removed carefully.
Flute budding: In flute budding, the patch of bark is removed from the stock in such a way that it almost completely encircles the stock except with a narrow bark connection between the upper and lower cuts on the stock. A similar patch of bark is removed from the bud stick containing a healthy bud. The shield containing the bud is then inserted in the vacant area of the stock and the shield should fit tightly on the stock. It is then wrapped with suitable wrapping material, leaving the bud uncovered. The other procedure is same as in patch budding. Because of the presence of a narrow connecting strip of bark on the stock, it remains alive even if the bud fails to sprout.
I-budding: In I-budding, the bud patch is cut in the form of a rectangle or square like patch budding. With the same parallel–bladed knife, two transverse cuts are made through the bark of the rootstock. These are joined at their centre by a single vertical cut to produce the shape of letter-I. The two flaps of the bark can then be raised to insert the bud patch beneath them. A better fit may occur if the side edges of the bud patch are slanted. While tying the I-bud, one should ensure that the bud patch does not buckle outward and leave a space between the rootstock. I-budding is the most appropriate method of propagation when the bark of the rootstock is much thicker than that of the bud stick. In such cases, if the patch buds are used, considerable paring down of the bark of the rootstock around the patch would be necessary.
Micro-budding: Micro-budding is used successfully for propagating citrus particularly in Australia. It is similar to “T” budding except that the shield (bud piece) utilized is thin and tiny like “T-budding”; the micro-budding is also not done under aseptic conditions. The petiole is cut off just above the bud and then bud is removed from the bud stick by a flap cut just underneath the bud. Thus, only the buds are utilized in micro-budding. In stock an inverted “T” cut is made and the tiny shield containing the bud is inserted in it and later tied with a thin plastic tape. The tape may be removed soon (15-20 days) after the healing has taken place.