The cultivation of rootstocks and grafting buds

Mothers rootstock plants, made with “basic” material, are grown in dry and healthy environments, perfect for producing and guaranteeing wood with high health characteristics. In Northern Italy, cultivation on supports is practically necessary to make wood mature and produce more wood capable of amortising the high cost of planting and management.

In the scaffolding systems, various green pruning operations are carried out to improve both quality and quantity production.

The cultivation of grafting gems occurs mainly in Trentino, adopting both dual-purpose plants, grapes and gems, and highly specialized plants created for the exclusive production of grafting buds. All the plants from which the gems are taken are subjected to rigorous and repeated checks, both varietal and sanitary. The plants are subjected to treatments against the main diseases of the vine and removed from those that show symptoms of diseases due to viruses.

Particular attention is paid to the golden flavescence and its carrier, the Scafoideus titanus.

The grafts-cutting are then paraffined to protect the joining area of ​​the two bionts, then stratified into boxes with sawdust and finally subjected to forcing. Usually the paraffin used on this occasion is red. The forcing consists in keeping the boxes with the grafts-cutting in greenhouses or premises at controlled temperature and humidity. These conditions favor the development of a cicatrization callus at the grafting point and the radical drafts at the base of the cutting.

After forcing, which lasts from 15 to 25 days, follows a period of greening and acclimatization that strengthens the graft-cutting. 

It is carried out a test for the formation of the callus and at the same time the residues of sawdust on the cuttings grafted with the use of special brushes are eliminated. The second paraffin, usually brown, is used to prevent dehydration of the callus at the grafting point once the grafting of the graft is planted. For the cultivation of rooted cuttings, the choice of the land and the area where it is located is very important. Soils must be loose, fresh and fertile, and must be well leveled in such a way that there are no areas of water stagnation. The nursery can happen to itself at most for a second year. The cuttings can be planted with a mechanical transplanting machine but currently, with the adoption of mulch, they are planted manually using special forklifts.

The nursery management is a complex operation that requires professionalism and experience. Until a few decades ago, the main agronomic operations were almost exclusively done by hand, while currently specialized machines are used for this type of crop.

The nursery management provides pre-implantation fertilizations, any post-implant nutrient inputs even by foliar, several irrigations and numerous phytosanitary treatments. 

These in particular are oriented towards the defense from the downy mildew (about a weekly treatment) and, to a lesser extent, from oidium and botrytis. Acaricidal and insecticide treatments are then carried out, in particular against Scafoideus titanus, a golden flavescence vector. The nursery, moreover, is carefully checked, row by row, several times during the season, to check varietal correspondence and possible diseases. 

To ensure that the vegetation is an upright habit and to prevent it from settling on the ground and to strengthen the growth of the shoots, it is carried out between three and four cuttings.