Effects of restricted irrigation at different stages of development of Cabernet Sauvignon grapes on production and wine quality

Raúl Ferreyra E.1, Gabriel Selles V.1, Jose Peralta A.1, Loreto Burgos R.1, y Jorge Valenzuela B.1

Different water stress treatments were applied to Cabernet Sauvignon vines (Vitis vinifera L.) during the 1994/95 and 1995/96 seasons at La Platina Research Center, Santiago (33º34’ S. lat; 70º38’ W. long). Treatments T1 and T2 were 100% and 40% of the crop evapotranspiration (ETc) during the whole season; T3 had no irrigation from budburst to veraison followed by 100% ETc until harvest; and T4 100% ETc from budburst to veraison and no irrigation until harvest. Stressed treatments (T2, T3 and T4) significantly reduced weight and size of berries. Yield was also reduced, mainly when no water was applied between budburst and veraison (T3). In addition, in the following season, floral induction was affected by water stress. Wine color intensity, phenols and anthocyanin concentration were higher in the stressed treatments, while acidity was increased when water stress was applied between veraison and harvest. The attributes and global quality of the wine were favored by water stress, especially after veraison. The stem water potential (SWP) and plant water stress index (PWSI) were adequate indicators of plant water status.

Keywords: water stress, grapevine.
1 Instituto de Investigaciones Agropecuarias, Centro Regional de Investigación La Platina, Casilla 439, Correo 3, Código postal 7083150, Santiago, Chile. E-mail: rferreyr@inia.cl