Global warming allows two grape crops a year, with about two months apart in ripening dates and with very different grape composition - The forcing vine regrowth to obtain two crops a year

Abstract

With the aim of delaying the ripening of grapes by around two months, a technique has been proposed based on forcing vine regrowth (Gu et al. 2012, Martinez de Toda et al. 2019). It is a bold method to fight against climate warming that could be only developed in really warm viticultural regions. It consists in shortening the growing shoots to several nodes with the aim of forcing vine regrowth; in order to force budbreak, shoot regrowth, and cropping, the source of inhibition needs to be eliminated and to this end, lateral shoots, leaves, and primary clusters, if they exist, are removed.But the main drawback of the forcing vine regrowth technique is loss of yield. In order to avoid this loss of yield and not to eliminate the primary clusters already formed in the main shoots, it is possible to force the development of buds of the fifth and sixth nodes, but maintaining the clusters of the main shoots. In this way, the yield of the forced buds would be added to the normal or primary yield of the shoots. The experiences carried out with 'Grenache', 'Tempranillo' and 'Maturana Tinta' varieties in La Rioja (Spain) are presented.