Effects of the training system on water productivity and water footprint in Mediterranean vineyards

The training system is a valuable strategy to face water resource limitations under climate changes as its canopy architecture influences evapotranspiration losses and both water productivity (WP) and irrigation water productivity (IWP). Detailed information on them (yield per unit of water) would support the choice of the training system. This study compared the water productivity in 38 irrigated (IRR) and rainfed (RAIN) vineyards trained at tendone (T, n = 30) and vertical shoot positioning (VSP, n = 8). The green, blue and grey volumetric water footprints (WFs) were also employed to characterize T and VSP. At harvest, grape quality traits (pH, sugars and potassium concentrations) were examined too. The mean (+/- SE) IWP in T-IRR reached 45.0 +/- 7.2 kg m-3 being approx. 2.5-fold than that in VSPIRR. Furthermore, T-IRR showed 60% (WFgreen) and 30% (WFblue) lower than VSPIRR. Findings show the attitude of TIRR in valuating water resources with no significant impact on grape quality. This study integrates the set of knowledge to be evaluated for training system choice managing the trade-offs between yield, grape quality and water productivity triggered by climate change.