Effects of mesoclimate on the yield, quality and phenolic maturity of Grenache

The potential climate change, due to global change, will increase temperature general and could increase at local level. These changes are not going to be the same in different parts of the world, being especially important in the Mediterranean Basin. Thus, according to the most pessimistic predictions temperature can rise until 4ºC and precipitation can be reduced close to 20% but this would be different according local conditions, being also changes in the distribution. In order to study the differences promoted by these climate differences we compared the phenology, yield and quality parameters of Grenache, grafted onto 110-R in two mesoclimatic areas in Catalonia (Spain), Batea (TA: Terra Alta Appellation) and Caldes de Montbui (CAT: Catalunya Appellation) during two consecutive years 2007 and 2008.
In TA rainfall and potential evapotranspiration (ET0) were higher than in CAT, but accumulated growing degree days (∑GDD) were lower, due to lower maximum temperatures and higher minimum temperatures in winter in CAT. The year 2007 was drier and warmer in both locations. Yield was significantly lower only in CAT2007, being no differences in leaf area, nor pruning weight. Veraison and harvest were advanced in 2007 in both locations. Phenological stages were longer in CAT both years. The length of the period between flowering to veraison, and from veraison to harvest is longer when accumulated rainfall during each period is higher. On the other hand, the higher the average of GDD during the period, the shorter the period was. Probable alcohol degree (PAD), Total Phenol Index (TPI), Color Index (CI), Anthocyanin Content (ANTT and ANTE), were higher and Flavan-3-ols content (DMACH) and Seed Maturity (SM) were lower in 2008, in both locations than in 2007, which could indicate that these parameters are very affected by drought, that in 2007 was one of the most dry ripening periods of last century in Catalonia.