Jerome Blodgett Jr., age 15, of Erie, Pa., for his question:
HOW MANY WAYS CAN YOU GRAFT A PLANT?
Grafting is the joining of cut surfaces of plants under circumstances that will allow the two parts to grow together. The supporting plant is called the stock and the plant part that is grafted to it is called the scion. There are five popular types of professional grafting: splice grafting; whip or tongue grafting; saddle grafting; cleft grafting.; and side grafting.
In grafting, the scion may be a twig, stem, bud or other part of the plant.
In splice grafting, a simple diagonal cut is made in scion and stock. The cut surfaces are joined, covered with grafting wax or paraffin and bound with grafting tape.
In whip grafting, a sawtooth diagonal is used to provide a larger surface.
Saddle grafting is accomplished by cutting one stem, usually the stock, in the shape of a wedge, and cutting the other stem in the shape of a slot that will fit the wedge tightly.
In cleft grafting, branches of the stock are sawed straight across and the stub of the branch is split to a depth approximating the diameter of the stock. A temporary wedge, sufficient to open the slit, is inserted at the center of the split. Two scions, each having several buds, are inserted at the edges of the split and are adjusted to that the lowest bud is close to the top of the stock and facing outward.
The wedge is removed without displacing the scions and the cut is covered with grafting wax and, if necessary, bound with grafting tape.
Cleft grafting is the most widely used method for grafting scions that produce high quality fruit on mature trees.
Side grafting is used for grafting new branches onto bare spaces of tree trunks. In this method, a longitudinal cut is made through the bark layer. The scion, with its base cut in the shape of a wedge, is inserted beneath the bark, tied and then waxed.
Grafting is frequently used to combine advantageous characteristics of scion and stock. For example, branches or buds of trees known to produce good fruit are grafted to stronger trees that produce fruit of¬poorer quality.
Grafting is also used in propagating seedless fruits, such as seedless oranges and grapes.
Grafts are usually unsuccessful unless plants of the same or closely related kind are used. A seedling or cutting, usually chosen for hardiness and resistance to pests and diseases, or for special characteristics, such as dwarfing, is commonly used as the stock in grafting.
When a seedling is used as a stock, it is first allowed to establish its root system. A graft is then inserted at the base of the stem. As soon as the union of scion and stock has become established, any remaining portions of the shoot of the stock are cut away. All substances absorbed by the root system are thereafter available to the scion for its development.