Effects of surface and subsurface drip irrigation on physiology and yield of ‘Godello’ grapevines grown in Galicia, NW Spain

Abstract

Irrigation has been considered a controversial practice in European traditional viticulture due to potential alterations in the balance between vegetative growth and yield. In this regard, the influence of surface (DI) and subsurface (SDI) drip irrigation on physiological performance of the ‘Godello’ grapevine (Vitis vinifera L.) cultivar was compared with a non-irrigated control (R) over three consecutive growing seasons (2012- 2014) in NW Spain. Irrigation improved vine water status; R plants reached a minimum of midday leaf water potential of –1.5 MPa, whereas DI and SDI plants reached –1.3 MPa. Stomatal conductance was unaffected by irrigation as well as chlorophyll a fluorescence. However, photosynthetic pigments were present at higher concentrations in leaves from irrigated plants than in those from R plants in 2013. In addition, R plants showed higher values for the indicators of oxidative damage. No significant yield improvements were observed for irrigated plants, although the trend was to obtain slightly higher yields under irrigation in years with low rainfall amounts. This may not encourage growers to establish irrigation systems on their vineyards. However, these results may be important with the objectives of stabilizing yield from year to year.