Manual of techniques for sustainable mountain viticulture Josep Lluís Pérez Verdú

Experience must be accumulated and a learning curve followed on the use of the model in order to

enter the appropriate data at all times and to interpret the results. If this is achieved, however, the

model is extremely effective and avoids many different unnecessary applications in relation to the other

two strategies, with the consequent financial and environmental savings. It can be said that the spe-

cific model and experience may become true risk management. For example, the results from Mas

Martinet in the Priorat region for 2006 were as follows:

•

Systematic treatment of oidium: 6 applications (preventative and curative); Mas Martinet: 2 preven-

tative applications.

•

Systematic treatment of Mildew: 5 applications; Mas Martinet: none.

•

Systematic treatment of Botrytis: 3 applications; Mas Martinet: none.

The collective model for the district gave intermediate results. 

Minimisation of the use of fungicides by using the specific model can be considered sufficiently expe-

rimented, with good results.

In the Priorat region, wineries often follow the collective model whereas farmers selling the grapes pre-

fer systematic treatments to avoid any risks, except where their customers indicate another form of

procedure.

Among other controlled diseases and blight that are not included within the model, the following are

of note:

•

Grape moths: This is blight, the damage of which is caused by the first-generation larva that des-

troys the floral buds, flowers and even recently-appearing fruit. The second and third-generation

larva produce more severe damage and even loss of the entire crop. The trap system is used to

count moths and to decide when an insecticide is necessary. 

•

Root rot: This disease is caused by the fungus Armillaria mellea that takes hold of the stock roots

and causes them to rot. It affects specific stock and only spreads through contact among roots. It

has no treatment. The affected stock must be pulled up, the hole cleaned and covered and irriga-

tion removed. Before planting the vine, all roots must be removed and the land turned over so that

it is aired and dried, thus causing fungus inactivation.

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The integration of terracing techniques into those of vigour control allow for sustainable mountain viti-

culture to be developed from an environment, economic and social viewpoint based on two mainstays:

•

In eco-designed terraces, the two types of new vine training are used for optimum soil use, which

is essential for increasing the productivity of the remaining production factors. Depending on the

topographic profile of the natural land, planting takes place on both slopes and on the terraces

themselves to obtain the best results. 

•

Once planting is complete, all the necessary information is obtained and prepared regarding the

condition of the soil, the plant and the environment for easier decision-making as to the applica-

tion of the remaining vigour control techniques.

With this in mind, comprehensive vineyard control is implemented. One of the main characteristics of

this viticulture is controlling the even ripeness of the grape berries with very low dependence on the

weather.

4.1. Soil productivity: planting on terraces or on slopes

As indicated in Section 2.2.1, one of the basic design conditions of terraces is to limit the slope height

to ensure it blends in with the surroundings. Once fixed, this height must be constantly maintained

along the entire length of the terraces. This ensures that the terraces have a uniform gradient of 3% in

order to control the runoff of rainwater to avoid erosion. 

Moreover, the gradient of the slope on terraces cannot exceed a maximum as of which the risk of ins-

tability is significant. This theoretic maximum, which can be estimated using sufficiently representati-

ve soil cutting tests, must also involve a safety factor. As already said, the extensive experience of Mas

Martinet in the building of terraces in the Priorat region proves that slopes with a gradient of up to 65º

are safe

1

, provided that the construction technique described in Section 2.2.3 is applied. 

4. Comprehensive sustainable mountain viticulture management

1

In some vineyard, 70º has been used with good results

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Given that terraces must have a constant, minimum width for machinery to pass (1.3 m), the greatest

difficulty in maintaining the height of the slope below 1.5 m without its gradient being over 65º arises

in the area of the estate where the natural gradient is at its maximum. If, in other areas of the estate,

the natural gradient decreases, the height of the slope can be maintained by reducing its gradient. 

Therefore, the construction of terraces must begin in the area of the estate where the natural gradient

is at a maximum. At this point, a decision must be made as to whether the vineyard is to be planted

on the terrace or on the slope, as this decision will determine the height of the slope and, given that

this height must remain constant, it will also determine planting on terraces or slopes if the natural gra-

dient drops along the terraces. 

To make this basic decision, the design conditions of the terrace must initially be established. As

explained in Section 2.2, Mas Martinet applies the following design conditions at the current stage of

the experiments: 

•

Maximum slope height: 1.5 m (2 m if planting on the slope).

•

Terrace width: 1.3 m.

•

Maximum slope gradient: 65º.

•

Maximum slope length for gentle gradients (as a guideline <25%): 11 m.

•

Maximum slope length for gradients > 25%: 6 m.

•

Vine training type: double vine training when planting on the slope and circular training when plan-

ting on the terrace (double vine training can also be used, particularly if the terraces have a relati-

vely straight layout).

Once these conditions have been established, two causes can be presented in relation to the natural

gradient of the land: 

•

The natural gradient remains significantly constant along the entire length of the terrace (although

it may vary sideways in peak-valley direction). 

•

The natural gradient decreases significantly along the terraces.  

In the first case, the best solution is to plant on the terrace, whatever the natural gradient (Chart 4.1).

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