Yield, Must Composition, and Wine Quality Responses to Preveraison Water Deficits in Sparkling Base Wines of Chardonnay

Abstract

A field experiment was carried out over three consecutive seasons on Vitis vinifera cv. Chardonnay destined for sparkling base wine Cava. Four different irrigation treatments were applied: (i) control (C), fully irrigated, in which irrigation was scheduled according to a water balance approach; (ii) RDI_m, irrigated during stage II (from berry set to the onset of veraison) when Ψ_stem was less than −1.0 MPa and as C during other phenological stages; (iii) RDI_s, irrigated during stage II when Ψ_stem was less than −1.2 MPa and as C during other phenological stages; and (iv) DI, irrigated when Ψ_stem was less than -1.2 MPa from flowering to harvest. Differences in yield and base wine composition were observed among years. Over the three years, reducing the quantity of water applied by 20% below that of C in the RDI_m treatment was associated with an average reduction in grape yield of 19%. The reductions in grape yield observed in the RDI_s and DI treatments were even greater at 35 and 48%, respectively. Water stress negatively affected aroma quality, titratable acidity, and malic acid and increased polyphenol concentration, which is unfavorable for oxidation issues. Therefore, C was the best irrigation strategy to maximize quality variables for sparkling base wines. However, to facilitate crop management by controlling excessive vegetative growth, it could be interesting to use the RDI_m strategy at the cost of slightly reducing some sensory attributes such as floral and tree fruit aromas and wine structure. The adoption of RDI_s or DI strategies are not recommended due to their negative effect on acidity and desirable aromas in sparkling base wines.