Much has been said about vine vigour, especially in quality wine-growing regions such as French Burgundy. These wines are produced in very steep slopes where the poor soil facilitates vine vigour control and consequently excellent quality grapes are produced. However, in the plains where the weathering materials from the slopes have been deposited the soil tends to be very fertile. These plains are usually used for hay but not for vine plantations aimed to the elaboration of great wines. This is a fact traditionally confirmed by winemakers of the French region of Burgundy.

It is very difficult to find arguments against this, after so many years of experience. After so many years giving evidence that grapes do not reach full maturity when vine vigour exceeds a given point, it is complicated to deny that in rich soils grapes, generally speaking, are compact and during maturation, humidity breaks the grapes and these are affected by botrytis. It is quite disappointing to consider a pre-existing assumption and bow to its evidence. But we are not going to do it. We did not do it. We try to demonstrate that we do not know everything yet, that we can go further on. We are going to give ourselves the pleasure of doubting these assumptions and long experience. We are going to think, to deduce, and to experiment, just in case there is another truth that could unexpectedly lead us to success.

From the decade of the 90s onwards, when Priorat wines started to be taken into account by the international press, we were faced with the doubt of using the traditional varieties in the new plantations in terraces. Could we then keep the same quality and personality for the wines in those circumstances? We were not completely sure because we had already seen that the new vines produced big, compact grapes, whose maturation was difficult and consequently it was difficult to elaborate wines with a given structure and fragrance range like the ones we had so far got from the old vines. The extensive experience from Burgundy showing that fertile soils were not used in the production of high quality grapes also applied to El Priorat, where the more vigorous varieties were planted on terraces with a richer soil than that of the slopes where fertility had been carried away by rainfall. This was not the right path to follow. We had to find a way to grow those varieties and have high quality wines from young vines. It is unacceptable to think that in a short period of time there will be mutations increasing quality. It is simply impossible!

By observing the young vines during harvest, we could see that from the thin shoots hanged loose grapes with a homogeneous maturation, whereas from bigger shoots hanged big clusters with large, compact berries. We decided to quantify this connection using statistical methods. The result of this short study: the relationship between shoot diameter and grape morphology, was very significant. A new door was opened: “I should find the way to make the vine produce shoots of a reduced diameter”. The first option that crossed our mind was to reduce the distance between vines so that radicular competence could diminish their vigour. We found out that Mr Roberto Voerzio (Piamonte, Italy) was applying this method on the old plantations of 1.2 metres. He planted one vine in between, reducing this way the distance to 0.6 metres. We paid him a visit. We discussed the results he had obtained and decided to plant three hectares. I waited four years and the result was not entirely convincing but this is a different story to be told some other time. The search for the solution went on and we imagined a situation: “In a soil of a given fertility, there are two vines with the same vigour. When pruned, one has two shoots left and the other has fifty left”. Surely in the former the shoots will be very long and thick and the few grape clusters will be big and compact. However, in the latter the shoots will be short and their diameter will be much less than that of the former vine, the grape clusters produced will be small and loose.
This deduction led us to think that vigour is a property of the own plant and that pruning is a way of intervening in it. Proper pruning is then that which leaves the adequate number of shoots, so that vigour can be distributed, and their length does not surpass the trellis in order to prevent bud removal.
Taking this deduction as a base we can claim that no vine has excessive vigour if it is properly pruned.

Josep Lluís Pérez