Effects of deficit irrigation with saline water on wine color and polyphenolic composition of Vitis vinifera L. cv. Monastrell

Abstract

The Mediterranean climate is characterized by rain scarcity resulting in the frequent use of low quality water for irrigation often containing high concentrations of sulfates and chlorides. This work was undertaken to study the influence of drought and saline irrigation water on the composition of Monastrell wines. The experiment was carried out during three years in a commercial vineyard sited in D.O. Jumilla (SE Spain). Six watering regimes were performed: Rainfed (no irrigation); Control, irrigated throughout the season with good quality water and other four treatments with a combination of two moments of initiation of irrigation (pre- and post-veraison) with two types of salinity water (sulfates and chlorides). The watering regime had more effect on the wine composition than the application of saline irrigation. In general, wines made with grapes from the Rainfed treatment had the highest polyphenols concentration and color intensity. Treatments with post-veraison saline water application improved wine quality with respect to the treatments irrigated during the entire season. Indeed, saline irrigation itself did not influence wine composition, while the watering regime modified wine quality, improving the wine phenolic composition particularly when water is restricted during pre-veraison. In any case, the best wine phenolic and chromatic composition was obtained from the Rainfed vines being the preferred watering management for optimizing wine quality. If saline irrigation has to be applied to improve vine performance, it is preferred to concentrate its application during the post-veraison period.