Background and Aims Available soil water is an important factor determining grapevine yield and grape composition. The aim of this study was to determine the impact of water availability on the yield components and the composition of must and wine of Vitis vinifera L. cv. Verdejo. Methods and Results The irrigation strategies [rainfed (R0), drip irrigated at 25% ETo (R25) and 50% ETo (R50) applied weekly from the end of the vegetative main shoot growth until harvest] were imposed on white Verdejo grapevines over three consecutive seasons (2012–2014). The 50% ETo treatment resulted in the highest yield. Increasing water availability also reduced the concentration of volatile phenols in all seasons, and of the C6 compounds in 2014 alone. The highest concentration of five individual volatile compounds was associated with the lowest water availability (R0). Conclusions High water availability increased yield and its components, mainly in the wettest season. Volatile compounds in wine were modified by water regime, with their concentration increased by the most severe deficit irrigation regime (R0). The effect of the year on must and wine composition was greater than the in-season effects of water availability treatment. Significance of the Study This study has described the effect of soil water availability on yield and its components and the composition of must and wine of Verdejo.

This research was supported by FEDER and INIA funds through Project RTA2011-00100-C05 and help of Project RTA2014-00049-C05. We thank Dr Manuel Marcos for the GC/MS service from Scientific and Technological Research Assistance Centre (CACTI, Vigo University, Northwest Spain).

Peer reviewed