The study was carried out in 2006 with Merlot grapes from vines grown using the trellis system, where four treatments were compared with different levels of water stress. These levels were established using irrigation to maintain pre-dawn leaf water potential (ΨPD) values between two different phenological intervals: flowering-veraison and veraison-maturity. Leaf area index (LAI), exposed leaf area (SA) and production were also measured. Conventional grape parameters (weight, ºBaumé, pH and malic acid) and seed and skin phenolic compounds (anthocyanins, procyanidins, tannins and total polyphenols) were also analyzed. The results showed that when grape weight diminished as a result of water stress, the percentage weight of grape skins with respect to total grape weight was maintained, but seed weight increased. When the water stress integral increased, total polyphenol, procyanidin and tannin concentrations in the seeds also increased.
Authors: Juan Luis CHACÓN VOZMEDIANO, Esteban GARCÍA ROMERO, Jesús MARTÍNEZ GASCUEÑA, Raquel ROMERO PECES and Sergio GÓMEZ ALONSO
Servicio de Investigación y Tecnología. Instituto de la Vid y del Vino de Castilla-La Mancha
(IVICAM). Carretera de Albacete, s/n. 13700 Tomelloso, Spain
Keywords: grape, Merlot, phenolic compounds, water stress