graftage is the art of inserting a part of one plant into another plant in such a way that the two will unite an continue their growth. It differs from cuttage, layer age, and bulb propagation in that the plant part expected to produce the top of the new plant is deprived of its own root system and unites with another plant that supplies this part. The art of graft age is not new. Country to popular opinion, it is no recent innovation in the arts op plants craft. Pliny, writing before the birth of Christ, Recognized graftage as horticultural practices, and it known that is was practiced before his time. Columella, who died shortly after the birth of Christ, mentioned certain kinds of graftage, praticularly the bark graft, cleft graft, and patch bud, which he said had been practiced by the ancients. It is a significant fact that at those early periods in agricultural history the unreliability of seeds and the important of graftage were appreciated in the reproduction of varieties. At various times have actually been rediscovered by worders who were not familiar with their previous use.
The field of graftage includes scion grafting and bud grafting, commonly referred to as grafting and budding. The two, however, are so different that a discussion of each will be reserved for separate chapters. Some of the operations and terms that are common in all types of graftage will be considered in the following sections.
Top- Working :
The series of operation whereby the top of a plant is replaced with a top a different variety is known as top-working. In some cases a large plant of the old top is cut away and a new one started ; after which the old one is cut away by degrees until the top consists largly of a differnt variety. Trees may be top-worked successfully by either budding or grfting or by a combination of the two. The process may be completed within on season of it may extend over several years, depending upon the size and conformation of trees to be top-worked. In reality, bud-ding or grafting of small nursery tree is top-working ; the term, however is generally use with regard to changing the tops of larger trees.
The practice of cutting the main limbs and trunk of a tree back to stubs is known as dehorning. The extent to which trees can be safely cut back varies with the species, some can be cut back much more severely than others. In practice, trees are cut back so that the stubs that remain range in length from 1 to 4 feet and diameter from 1to 6 inches. when a tree is dehorned, the limbs should, if possible, be cut at points that will result in the new top having a symmetrical shape. It is not advisable to cut limbs at different heights so that the new growth of some will obstruct sunlight and create shade for others. In order to facilitate healing of the wound , a limb to be dehorned should be cut a t point where a side limb or a lateral bud occurs on the upper side. This virtually assures growth from very near the terminal part of the stub, and this encourages over waling of the wound . If no shoot grows within 1 inch of the end of the stub, it usually becomes advisable tore cut it during the first year at a point whee a lateral limb has developed in the meantime, preferable on the upper side of the stub. Considerable application in renovation pruning and is use in many cases as a preliminary step in the top-working of large trees.
Any treatment that encourages and hastens growth of a bud or graft is referred to as forcing, It is known that the terminal growing point creates hormones which restrain the growth lateral buds below.Essentially, forcing consists of elimination of this influence and creating for the bud or graft a terminal position from a physiological standpoint. In practice, of a tree are different from the budded or grafted top. The body stock may be the same as the root system, bud in many cases it is of different king, as consequence of double-working.
The matrix is a place on the rootstock that is prepared for the insertion of a bud or graft.
The limbs that are cut from any plant to be sued in graft age are known as scions those which are to be used for grafting are known as grafts, or graft wood; and the ones that are to be sued as a source of buds for budding are called bud wood scins reproduce the kind of tree or plant from which they are taken and hence are obtained from they variety to be propagated. Healthy parent plants should be selected in order to prevent the spreading of disease in propagation.
The success of budding and grafting by the different methods depends, among other things, upon the use of the appropriate kind or type of scions, and also upon methods of handling them from the time they are cult from the parent tree until they are finally sued. The time that intervenes may be a few hours or several months.
d Scions for grafting are usually obtained from one year-old wood, sometimes older wood is used. They should be straight, smooth, have normal, plump buds, and few or no side branches. The size range for graft wood amy vary considerably for different methods.
--> Scions for grafting should be thoroughly dormant at the time they are used. Dormant scions normally contain reserve stored food to provide energy for respiration callus formation, and early growth of the scion. They should be secured before the plant from which they are to be taken shows any signs of growth .Those cut in midwinter tend to remain dormant longer after they are inserted in to a stock than those that are cut a later date, scions that make premature top growth before union is established usually wither and die within a few days. In practice it is customary to cut scions any time from midwinter until 2 or 3 weeks before the parent tree, with no more than a day day or two intervening.
Scions that are to used relatively late in the grafting season may be cut and held in cold storage in order to keep them dormant. At a temperature of from 32 to 36˚ f. graft wood can be stored successfully for 4 months or longer, though there is seldom any occasion for storing it this long. Prior to storage, the scions should be packed in moist insulating material .Sphagnum moss and coarse sawdust are commonly used for this purpose, both are light and easy to handle, absorb be moist, scions show that from 3 to 5 pounds of water for each pound of sphagnum moss is sufficient. It is desirable to add the water and soak it uniformly in to the insulating material before packing if around
A solution grafting wax can be made by mixing, by weight, 10 10 parts of pine resin, 2 parts beeswax, and 1 part talc. These are mixed by heating and are applied in a melted condition with a ⅓ -inch brush. The melting point of this mixture is a about 165˚ F , and the mixture should be used when it is at about this temperature or only slightly higher.
Melted paraffin is suitable as waxing material and is used quite commonly for earl spring budding and grafting. It is not suitable for budding or grafting when the temperature is above 85 or 90˚ because of its tendency to melt and to cause scalding of the bud or graft. A pint Thermos bottle shown in Fin 102, with a brush handle inserted through a cork stopper, is a very convenient type of dispenser for melted paraffin.