Throughout the history of grape growing around the world, many grapevine training systems have been used, from those involving no intervention at all, where the vine takes whatever size and shape its environment dictates, to those using support structures of varying sophistication.
The systems most widely used in modern viticulture for winemaking are vertical training systems, which literally form green walls of vines that intercept sunlight. These systems have the advantage of exposing a large leaf area to the light, and they also allow the use of machinery for harvesting and pruning, which means lower operating costs.
Vertical trellis with spur-pruned cordon
This is one of the simplest systems to establish and manage once the vineyard is in place. The vines are planted in the row at a spacing of 1 to 2 meters, depending on soil fertility and the vigor of the variety. Once planted, a single trunk is formed up to a height of 0.5 to 0.8 meters, from which one or two arms are trained (unilateral or bilateral cordon).
Fruiting units called spurs develop along these arms and are pruned back each year to one or two buds. When these buds break, they produce shoots that are trained vertically upward with the help of catch wires. This way, the clusters that grow on the lower third of the shoot are exposed to the light and are easier to harvest and to protect against some vine diseases. The number of spur-pruned cordons (1 or 2) depends on the climate and the vigor of the vine at the particular site, as well as on planting density and irrigation and nutrition management.
This training system is only suitable for grape varieties with good fruitfulness in their basal buds, and in regions with enough sunlight to induce fruitfulness in those buds. For varieties with low basal bud fruitfulness, a vertical trellis with a unilateral or bilateral cane and spur, known as the Guyot system, is recommended.
Vertical trellis with unilateral or bilateral cane
This training system is designed for varieties whose basal buds have low or no fruitfulness, or for regions where sunlight is not enough to induce fruitfulness in the basal buds because the vine’s vigor prevents light from reaching them.
The most widely used system of this type is probably the Guyot, or cane-and-spur, system. At pruning, a cane of at least 8 to 9 buds is left tied to a horizontal wire, with a 2-bud spur close to it. The cane serves as the fruiting structure for that year, and the shoot that grows from the spur during the year becomes the replacement cane for the following season.
The number of canes and spurs (1 or 2) depends on the climate and the vigor of the vine at the particular site, as well as on planting density and irrigation and nutrition management.
Hanging curtain or Sylvoz system
This system is designed for high-vigor climates, soils and varieties in wine grapes. It is attributed to Jackson (1986) and is also known as the Sylvoz system (Smart and Robinson, 1991). It consists of a structure similar to a vertical trellis with spur-pruned cordons or short canes of 5 to 10 buds, but at a greater height, between 120 and 150 cm. The difference from the spur-pruned cordon system is that the fruiting units (spurs or short canes) point downward, so growth is toward the ground.
A modern variant developed in Australia for full mechanization is known as minimal pruning of cordon-trained vines, or MPCT. The vines are trained on a bilateral cordon, and pruning consists of cutting all the shoots that hang down or grow too far into the space between rows, while leaving those on top of the cordon uncut. This leaves an excess of disorderly growth that dilutes the vine’s vigor, which usually causes no problems because not all of the buds manage to break.