Approaches for estimating the age of old vineyards in Campo de Borja

Abstract

Determining the age of a vineyard is essential for understanding its influence on wine quality and characteristics. Due to the uniqueness, production complexity, and perceived quality enhancement associated with “old vines,” they are increasingly valued by the industry and consumers. Beyond the fact the OIV has recently released a consensus declaration of what an old vineyard is (at least 85% of the plants must be 35 years or older), in many contexts it is relevant to determine or, at least, to estimate, the age of a vineyard. In this context, the appellation Campo de Borja (Aragón, Spain) is developing a valorisation program of old vineyards that includes a scientific approach aimed at developing a probabilistic method that can allow classifying vineyards in age ranges based on objective criteria. To this end, 80 plots were selected and characterized through variables that encompassed the analysis of historical orthophotographs, vine spatial distribution in the field and vine arm structure (measuring the height and distance between pruning cuts, allowing the estimation of the average annual growth in each vineyard), and genetic fingerprinting of rootstocks and varieties.

The study showed that the temporality and quality of orthophotographs in this area are insufficient to precisely identify plots with a planting date prior to 1980. The analysis of the spatial configuration of vines in the field revealed that, since 1997, the predominant training system has been the trellis, whereas the oldest plots are planted using the goblet system, specifically the tresbolillo system, while the estimation of annual arm growth rates is around 1,7 cm in the plots of this study. Regarding genetic fingerprinting, rootstock identification was much more informative than scion’s. Altogether, the combination of all the aforementioned parameters may be suitable to enable a probabilistic estimation of vineyard age.