ISHS Acta Horticulturae 493: I ISHS Workshop on Water Relations of Grapevines
EFFECT OF MODERATE IRRIGATION ON AROMA POTENTIAL AND OTHER MARKERS OF GRAPE QUALITY |
| Authors: | J.M. Escalona, J. Flexas, H.R. Schultz, H. Medrano |
| Keywords: | Vitis vinifera, chemical composition, glycosyl-glucose, water stress |
| Abstract:
The variation of different parameters of grape quality during veraison and over the maturation period was studied in Tempranillo, a common Spanish cultivar and Manto Negro, a local cultivar of Mallorca. Both cultivars were subjected to two different soil water regimes, drought (without irrigation, traditional for this area) and moderate irrigation (0.3 of ETP measured on a weekly basis). Analyses of fresh and dry berry weight, pH, total acidity, soluble solids, total polyphenols and anthocyanins were made in Tempranillo and Manto Negro grapes and must for both treatments. Glucose and fructose as well as organic acids were determined by HPLC. In addition, aroma potential was determined for the last three sampling times (maturation period) using the Glycosyl- glucose (g-g) assay (Williams et al., 1995). Irrigation increased berry fresh weight in Manto Negro but not in Tempranillo. However, sugar content (° Brix) was clearly higher in irrigated Tempranillo. The pH increased from 2.5 to 3.3–3.5, without differences between treatments and cultivars. The major changes in these parameters were during veraison. Under irrigation, Anthocyans content decreased in Manto Negro berries but increased in Tempranillo ones. Total poliphenols showed to be unaffected by irrigation but were clearly higher in Tempranillo. Clear differences between cultivars and treatments were observed in the aroma potential during ripening. Both cultivars showed higher values for the irrigated than for the drought treatment (around 20–30% in Manto Negro and 40–60% in Tempranillo). A contrasting pattern of aroma potential development was observed for both cultivars. Manto Negro showed a maximum at mid maturation, while for Tempranillo this maximum was achieved at the end of ripening (last sampling). | |
Download Adobe Acrobat Reader (free software to read PDF files) | |
