TRELLIS POSTS FOR VINEYARDS: WHERE METAL IS UNBEATABLE
The trellising systems now being used in state-of-the-art winemaking are at last being deployed with confidence, after many troubled years of uncertainty.
The process of updating the vine-training systems utilised by winemakers, ongoing since the late 1980s, has taken more than 20 years to arrive at what is the ideal material from which to make trellis posts for a modern vineyard.
A wide array of different experiments conducted over the years – encompassing pre-stressed concrete, treated wood and various types of plastics – have highlighted the pros and cons of the materials in question.
Today, in an awareness that the ideal stake must be elastic, resistant and durable, the choice faced by winemakers is a proverbial “no brainer”, since these are the properties of metal trellis posts– steel trellis post, to be precise.
The consolidation of the latest solutions used for vineyard-post systems has, in turn, conditioned the selection of the type of wire, with a view to meeting, first and foremost, the requirement for practicality of installation, but also to achieving the correct tension.
METAL TRELLIS POST: WHAT AND HOW TO CHOOSE?
For many winemakers, the most popular vineyard trellising systems – which have been in use for more than 15 years and, as such, have been widely tested – are those based on metal poles.
These vineyard trellis posts may be of various shapes, sizes and thicknesses, using different types of steel and featuring different cut-outs.
The popularity of metal vineposts due to their specific features (see here) has simplified to a great extent the choice faced by winemakers – indeed, today, metal is practically taken for granted as the only viable option.
Nevertheless, appropriate evaluations should still be made in relation to the type of steel (whether certified or uncertified), as well as to the shape of the stake and its thickness.
Farming systems are numerous and can be classified according to 3 factors:
The height of the trunk
The height of the fruiting canes
The development of the shoots
Based on these differences, there are different types of system. The most common are the following:
Espalier system (or Guyot in honour of the winemaker who first formalised it): the vegetative surface is perpendicular to the ground using posts and the shoots are supported by wires or twines parallel to the ground with a 30-40 cm space between them.
Pergola system: the vegetative surface extends horizontally or obliquely from the ground. Difficult to mechanise, it is also the most expensive from an economic point of view.
