There are several ways to obtain grapevines when planting new commercial vineyards. The first prerequisite is to have chosen the variety according to the environmental conditions of the site where the vineyard will be planted, as well as other commercial factors that can influence the choice, such as how fashionable the variety is.
Once the variety has been chosen, the plants need to be obtained, and there are several ways to do this. If the soil is healthy and the area offers good plant health conditions, one option is to plant the chosen variety on its own roots, that is, without grafting.
When soil or climate conditions make it hard to produce quality fruit, rootstocks are used. These are simply other grapevine species, or hybrids between American vines and the European grapevine, that are compatible with the chosen variety and at the same time resistant or tolerant to the unfavorable soil or climate factors.
Commercially available rootstocks are resistant to a range of conditions that are unfavorable to grapevine growth, for example:
- Salinity
- Nematodes
- Phylloxera
Propagating own-rooted vines
This is probably the simplest way to propagate vines for planting a vineyard. Canes of the chosen variety are selected during winter pruning.
These canes must have certain specific characteristics, such as a thickness similar to that of your little finger, roughly 1 to 1.5 cm, and a distance between nodes of about 7 to 10 cm.
Once selected, the canes are kept in cold storage throughout the winter so that their buds accumulate the chill hours they need to break. At the end of winter, the canes are taken out of cold storage and brought to the nursery, where they are planted with rooting hormones that stimulate root growth.
They are left to grow all summer, and at the start of the following winter, once they have roots, they are pruned and lifted from the ground to be planted in their permanent location.
Propagating grafted vines
This process is a little more complicated than the previous one, since in its first stage it involves working with two separate plants. The first is the plant that will be used as the rootstock, which provides the entire root system of the new vine and has already been chosen according to the soil conditions. The second is the chosen variety, which will form almost the entire above-ground part of the new vine and is the one that will produce the fruit.
The first step is to obtain rooted plants of the species or hybrid that will serve as the rootstock. This is done using the same method described above for own-rooted vines, but this time with the rootstock instead of the chosen variety. Once the rootstock has rooted and is dormant, that is, in winter, it is pruned to remove all its above-ground buds.
At the same time, a bud with its surrounding tissue is taken from the chosen variety and inserted into a notch previously cut into the wood of the rootstock. The graft is then closed and tightly secured, and you wait until spring, when growth resumes, to see whether the grafted bud has taken on the rootstock.
The result is a vine grafted onto a rootstock suited to our particular needs that, at the same time, produces grapes of exactly the variety we want.