Phenolic maturity of tempranillo grapevine trained as goblet, under different soil and climate conditions in the Duero valley area

A study has been carried out during the 2001 ripening period with Tempranillo variety grafted onto 110R, in order to know the productive and qualitative differences provoked by different geographic locations in the region of Castilla y León (Spain), through experimental plots located on the West side of the Duero river valley, in the Apellation of Origin (A.O.C.) Ribera del duero, and on the East side, in the Cigales A.O.C. The vines were head trained and 2-bud spur pruned, with a radial distribution of the spurs and 10 buds per vine. The Ribera del Duero vineyard was planted in 1987. The annual rainfall along the last 10 years has been 421 mm 3 layers can be distinguished on the soil of the trial with the following kind of textures: the first one is a loamclay- sandy soil, the second is clayey and the third one, deepest, is clayey-loam. The Cigales vineyard was planted in 1993. The annual rainfall along the last 10 years has been 399 mm 3 layers can be distinguished on the soil of the trial with the following kind of textures: the first and second layers are sandy-loam soil and the third one, deepest, is sandy-clay. The average temperature during the vegetative cycle in Cigales A.O.C. is higher than in Ribera del Duero A.O.C. On the other hand, at the beginning of the ripening period the temperatures are lower in Cigales, which together with the soil conditions have provoked a lower vegetative development and the variations on the vegetative-reproductive balance. The soil and climate conditions in the Ribera del Duero experimental plot have provoked a higher vegetative development of the vines and different characteristics of the berries with respect to the Cigales plot, probably due to a lower water stress along the vegetative cycle. The berry weight in the Cigales A.O.C. has been 25% lower than in Ribera del Duero A.O.C. The differences in berry weight were maintained along the ripening period. The vineyard conditions of the Ribera del Duero A.O.C. have allowed to obtain, for a similar yield per vine to the Cigales A.O.C., berries with higher sugar concentration and lower pH. However, the total acidity has shown statistical differences only in the first sample, becoming the results similar over the ripening period. The differences in pH are not correlated with the total acidity evolution, which could be due to the higher potassium concentration in the Cigales A.O.C, being in this case lower the total acidity of the berries. The phenolic maturity has also been affected by the soil and climate conditions, so the Ribera del Duero plot has shown a higher total polyphenols index along the ripening period than the Cigales plot. The total anthocyanins concentration maintained similar values in both plots, although the final concentration at harvest was lower in the Cigales A.O.C. The extractable anthocyanins concentration, measured by Glories method, has followed a similar evolution than the total anthocyanins in both areas of study.