GRAFTING
Grafting involves unifying two living organisms, it consists in matching the cambium tissues of the scion (the aerial, fruit-bearing part) on to the rootstock (the root system) in order to obtain a biological bonding that unites them into a single individual.
In viticulture, it is usually a graft of Vitis vinifera which gives the aerial and fruit-bearing part of the new plant, and is implanted on an individual naturally resistant to Phylloxera, which supplies the root part of the new plant.
Many ancestral techniques were rehabilitated at the end of the 19th century.
Although the grafting of the vineyard has been known for several millennia, it has remained historically confidential, because the vine multiplies vegetatively wonderfully, by means of cuttings, marcottage or provignage.
The phylloxeric crisis and the Reconstitution were the universal promoters.
Various techniques have been known since Antiquity, such as grafts in full slot, lateral, patch, approach, Jupiter line, crown, inlay etc ... Simple or complicated English slot techniques date from the 17th century.
From the beginning of the Reconstitution, many machines were developed, which witnessed the cutting of the graft and sometimes the rootstock. The assembly is done by hand.
In the 1980s, new machines made it possible to completely mechanize grafting and produce what are called "grafted-welded" grafts.
Today, vine plants from the wine nursery are almost exclusively made from clonal plant material and assembled mechanically.
IMPACTS OF GRAFTING
Whatever the grafting technique used, it generates the formation of a seam of welding which necessarily changes the physiology and consequently the nutrition of the new plant.
The eminent biologist, Danielle Scheidecker, who specializes in plant grafting, explained the phenomenon in 1961 as follows: « The surgical intervention of grafting results in the formation of the scar seam. The anatomical structure of this bulge, which will largely determine its physiological role, varies considerably from graft to graft. »
It depends on the nature of the plants involved, but also on their age and stage of development at the time of the operation, as well as the grafting technique chosen» (“The transplant, its anatomical conditions, physiological consequences and possible genetic results”).
Thus, if the ancient vines could live multicentenarians (v. Bosc), with grafting, they saw their average life expectancy reduced to the simple century - our old vines testify to this.
With the creation and generalization of industrial and mechanized vine plants, in the 1980s, grafted-welded plants became real "consumables" whose average life expectancy is about thirty years.
