Manual of techniques for sustainable mountain viticulture Josep Lluís Pérez Verdú

Vine training and production branch 

Vine training is formed by fixed supported upon which the plant architecture is developed so that

the shoots can grow sufficiently ordered and separated to provide aeration and sun exposure of

the grape, pruning, the application of pesticides, collection and, in general, all viticulture work. 

The production branch is the length of woody stock from which the shoots grow. 

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Individual ring training (circle)

Given that terraces follow the level of the natural slope and do not adopt polygonal shapes, the

straight sections of vine training are not generally a good solution. Where vine training cannot grow

lengthways along the terrace, then the solution involves circular vine training. The length of the pro-

duction branch allowing for this type of vine training is over 3 times greater than the linear distan-

ce available between stock (diameter): 

π

x Ø, i.e. 3.14 x Ø.

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Conventional “cordon royat” vine training

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Vine formed by double production line 

Ring vine training

Vine training with double production line 

or double training

Vine formed around rings

1.00 m

Approx. 1.90 m

0.50 m

0.80 m

0.80 m

0.60 m

0.50 m

0.50 m

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In new vine training, the technique consists of leaving an average distance between shoots of 7 cm.

In double vine training, with a distance between stock of 0.5 m, up to 14 shoots per stock may be left,

i.e. 14 shoots per linear metre of production branch. Where vine training in rings of 0.6 m in diameter

is used, stock may house up to 27 shoots, as the production branch measures 1.88 m (once again, 14

shoots per linear metre of branch). 

Therefore, there is more space for a larger number of shoots depending on the vigour of each stock.

For example, in a plantation with a distance between stock of 0.5 m, if the stock has a vigour of 500

g then 10 shoots would be left. If the stock has a vigour of 600 g then 12 shoots would be left. 

Compared with conventional vine training, for a certain plantation framework, new vine training no only

allows for a longer production branch on stock but also increases the effective leaf area (ELA). This

provides a higher ratio between the ELA and the root soil volume (ELA/\RSV), a parameter that, as seen

later on, is essential for controlling the ripeness of the grape in adverse weather conditions.

Furthermore, stock with a higher ELS may increase its production without reducing the concentration

of polyphenols in the grape, as its larger “solar panel” enables it to synthesise larger amounts of sugars

(Figure 3.4).

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Effective leaf area (ELA) 

The effective leaf area (also known as exposed or active) is formed by the leaves of the plant

directly exposed to solar radiation. The greater the ELA, the more solar energy the plant can

attract for synthesis, through the chlorophyll function, of the sugars required for growth and fruit

ripening. 

There is no single universally-accepted way of measuring ELA. A simple method consists of

“scanning” the leaves on the shoot and measuring their area using computer software. However,

not all the leaf area can be considered effective, i.e. directly exposed to solar light, given that in

practice some leaves cover (shade) others, particularly if the shoots tend to intertwine. 

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New vine training offers an orderly layout of shoots so that the ELA is spread continuous and effecti-

vely, thus reducing the shading effect and the overlapping of leaves. Mas Martinet is assessing the ELA

of each of the grape varieties and its relationship to quality production at its Priorat plantations. As a

conservative measure, this Manual adopts an average ELA value of varieties planted of 0.14 m

2

for

each shoot developed. 

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Leaf area in double vine training

Figure 3.4 The effective leaf area may be doubled without increasing the plantation framework and, as a result,

the root soil volume

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3.3. Precise irrigation

3.3.1 Basic functions of water

Thanks to the chlorophyll function of the vine leaves (ELA), the plant photosynthesises sugars, accu-

mulates them in the reserve tissue and uses them as required to carry out its functions. Throughout its

vegetative cycle, the plant must produce the necessary amount of sugar for three purposes: 

•

To grow until all the foreseen shoots are developed and to form the effective leaf area. 

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To reach optimum ripeness of the grape berries. 

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After harvesting, to keep enough reserves to restart growth the following year. 

The availability of water plays a predominant role during these processes of the vegetative cycle. Water

has two basic functions: 

•

Intracellular water takes up the space inside the cells and acts as a universal solvent. All the bio-

chemical reactions that the plant needs for its metabolism (synthesise hormones and proteins,

transform sugar, etc.) are produced in the aqueous medium of the cell. This water is not used up

in its supply and its volume does not vary, in order to maintain a constant osmotic pressure. 

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Extracellular water takes up the interstitial spaces between the cells and is basically taken in

through the roots and released through the leaves after circulating around the wood and bast vessels.

The capacity of the plant to adapt to its surroundings depends on this. When the environmental

temperature increases, the plant evaporates its extracellular water trough leaf transpiration to cool

the plant. Bear in mind that the chlorophyll function stops if the leaves reach a temperature of over

36-37ºC. The leaves must be cooled to be able to continue photosynthesising the sugars. 

If, during the hot months, there is less external water (that collected by the roots and that contained in

air humidity) than that required by transpiration (more demand than supply), the plant uses its intrace-

llular water. This causes a change in its osmotic pressure and, as a result, the plant’s metabolism is

modified: 

•

To transpire less and lose less water, it reduces the leaf area by eliminating the leaves around the

base of the shoot, constricting the sap conducting vessels. These leaves turn yellow and fall off. 

•

It partially or totally dries the grape berries, which wrinkle and turn into raisins before dying off.

These grapes will not longer ripen correctly and will affect the quality of the wine (strong acidity,

green tannins, etc.). 

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