The various types of grafting of the vine
The graft consists in fixing a part of the plant on the rootstock, called scion (if it is a part of a branch) or shield (if it is a bud), to obtain a single plant composed, however, of two different sections . For this reason, the grafts are divided into scion and bud (or shield) grafts. In the first category, the most common grafting of the vine is the simple or total split graft (with wood scion, it is performed on the field in the winter); the double split English graft (with wood scion, is performed at the table in winter); grafting by approximation (to replace dead plants). Among those with bud, the grafting of the vine is with dormant bud and with vegetative bud. In the first case, we find the Majorcan graft and the herbaceous wood graft; in the second, on the other hand, the T-joint and the socket-like graft are suitable for the screw.
The double split, interlocking and omega couplings
The most common screw grafts are those with a double English split. The material execution technique involves the use of two sections, the scion and the rootstock, of equal diameter, cut at an angle of 45 degrees near a clarinet-bored knot. Since it requires specialized and expensive labor, the machine coupling technique has been introduced (simple interlocking, omega, double split), which entails greater speed of work without affecting the percentage of engraftment. Other graftings of the vine that are particularly used are the interlocking and omega ones, as they allow to stabilize the escape of the lymph and, consequently, a good scarring. In the southern Italian regions the graft to the Majorcan is widespread, which is typical of the temperate-hot or warm areas. After the graft (which takes place in August) the two sections are joined with raffia.