By Lavernee S. Gueco, Felipe S. dela Cruz, Jr., Marilyn M. Beltran, and Laureano B. Lanosia Jr. (PCARRD, IPB)
Grafting is an asexual propagation technique. This involves the union of two plant parts (scion and rootstock) and continue their growth as one plant. The cambium layer forms the new xylem and phloem, resulting in the permanent union of the scion and rootstock. This is used to perpetuate clones that are hard to propagate using cuttings, layerage, and other asexual methods.
Types of grafting
• Cleft grafting – the most popular grafting method in the Philippines. It is also called ‘wedge grafting’. In it, a scion is inserted into a cleft of the rootstock.
• Side grafting – the base of the scion is inserted into the side of the rootstock. It is usually used when the rootstock diameter is bigger than that of the scion.
• Splice grafting – the rootstock and scion, preferably of equal sizes, are cut diagonally and smoothly, then fitted together.
• Bark grafting – depending on the size of the trunk, one or more scions can be inserted in one rootstock. This is sometimes used to rejuvenate old trees, and it is possible to graft more than one variety on a single stock.
Steps in cleft grafting
1. Choose an appropriate rootstock (a) and scion (b). The scion and rootstock must be compatible. As a general rule, closely related plants (e.g., varieties with the same species) are graft compatible. The scion should come from a tree with desired traits (e.g., good quality, high yield) while the rootstock should possess good root characteristics (e.g., resistance to soil-borne diseases, good anchorage).
2. Remove the leaves of the scion without injuring the buds (c) and cut the rootstock to a height where there is active growth (d).
3. Shape the base of the scion to a short wedge (e). Use a sharp knife when performing this task to ensure a good fit. Gaps will be created between the stock and the scion when the cut is rough, and the union will either take time or not occur at all.
4. Cut the rootstock vertically, about 2-3 cm long (f).
5. Insert the wedge of the scion onto the cleft of the rootstock (g).
6. Bind the graft union and the entire scion with a strip of polyethylene (PE) plastic (h). Make sure to tie them securely to prevent dislocation at the point of union. To test this, hold the scion and lift the whole seedling without affecting the union.
7. Cover with a small PE bag (i). This will prevent water from entering the graft union.
Care of plants
– Water the newly grafted seedling.
– Remove all the lateral growth below the graft union
– Remove the PE bag after a new shoot has appeared.
– Unwind the plastic strips when the graft union is successful (as soon as new shoots come out of the scion).
– Transfer the grafted seedling in a bigger plastic bag whenever necessary.
This originally appeared as “Grafting” in Agriculture Monthly’s February 2014 issue.