Change in variety is achieved through CROWN-grafting. It is a low-impact graft for the conductive tissue and no vertical cuts are performed on the stem. The scion is inserted at the side of the trunk instead. This way, the plant easily overcomes the delicate operation of grafting. This method grants higher engraftment chances. The right moment is from April to May. Under optimal conditions, by the end of the vegetative season, it will have developed a stem of about 2 meters.
This technique uses a high pre-topping in winter (the chainsaw cuts the plant’s trunk 50 cm above the spot where grafting will be performed). In late April/May the trunk is re-topped at the graft height, at approximately 80 cm from the ground. Two vertical cuts are performed at that same height, then the phloem is removed from the wood in a tongue-like shape. The 3-4 buds-scion is inserted in between this tongue and the wood. Resulting from this is a callus of great importance and with excellent mechanical resistance.
Post-grafting maintenance is just as important as grafting itself. During the season the stem has to grow and form the actual trunk, forcing developing branches and a structure for the plant, thus avoiding growing one, single stem.
At the end of the vegetative season, grafts are performed in the nursery using dormant buds. In the same period it can also be done in the field.