Supporting the plants with poles and stakes is indispensable both in vineyards and fruit orchards, especially when the rootstocks are not well anchored. Poles that are strong enough can also be used to support the hail netting, shade netting and overhead sprinkler and drip irrigation lines.
The main elements of the support system are:
poles
wires and wire tensioners
anchors, collars, pole-rests and pole caps.
The most frequently used concrete poles are made of vibrated and pre-compressed reinforced concrete. These are stronger, longer-lasting and cheaper than wooden poles, but heavier.
The most commonly used wire is made of galvanized iron with a tensile strength of 40 kg/mm. Plastic coated wire is also used. The plastic coating protects the wire from rust, increases its life and doesn't dirty the fruit it comes into contact with. Plastic coated wire is 10-20% more expensive than galvanized wire of the same gauge, but lasts longer. Stainless steel wire of diameter 1.2-3.5 mm is used for the trellis because of its longer life, even though it costs 20-30 % more than galvanized wire. The different types of wire last the following number of years:
- galvanized iron wire 15 years.
- plastic coated iron wire 20 years.
- stainless steel wire over 25 years.
The other support system components are:
- the pole bases, that stop the poles sinking into the ground
- the anchors, made of concrete or iron, to anchor the support system firmly to the ground and stop it blowing over in storms.