IRRIGATION EFFECTS ON THE PERFORMANCE OF GRAPEVINE (VITIS VINIFERA L.) CV. 'ALBARINO' UNDER THE HUMID CLIMATE OF GALICIA

Aims: Vine-growers worldwide are concerned about climate change effects on grape yield and quality. Drip irrigation systems are increasingly being installed even in humid regions such as Galicia (NW Spain). In this context, a field experiment was carried out over three seasons (2012-2014) on white Vitis vinifera L. cv. 'Albarino' to assess the effects of deficit irrigation on vine physiology, yield and must and wine composition. Methods and results: Rain-fed vines were compared with a treatment irrigated to 50% of the estimated crop evapotranspiration (ETc) from bloom to two weeks before harvest. Irrigated vines showed more positive stem water potentials than those rain-fed. Yield was unaffected by irrigation except in 2014 (19% increase). Pruning weight was increased by irrigation. Must soluble solids tended to decrease and total acidity to increase with irrigation; however, wines were similar between treatments. Water productivity was slightly higher under rain-fed conditions. Conclusion: Under the conditions of this experiment, irrigation was of no interest either in terms of grape and wine quality or in terms of net income. Significance and impact of the study: These results may be useful for managing water resources in vineyards under similar climatic conditions.