Crop yield response to water - Cra

Figure 11Wine attributes of Tempranillo in Requena, Spain, as a function of relative evapotranspirationand relative yield. Fitted models are shown when significant (P < 0.05).Source: Intrigliolo and Castel (2008).Total phenolic indexz(Au)908070605040P < 0.005Antocyanins(mg )-1 -1Colour intensity(AU)Tritable acidity(g tartaric acid l )1200900600300211815129687654211815129687654P < 0.005P < 0.02pH4.24.03.83.63.43.2164.24.03.83.63.43.216P < 0.02P < 0.001Ethanol(º vol)1412141210100.4 0.6 0.8 1.00.0 0.2 0.4 0.6 0.8 1.0Relative evapotranspirationRelative yieldwith the consumer. Flavonoids undergo oxidative polymerisation, thus lowering their flavourthreshold during wine ageing (Schneider, 1995) and can negatively affect the volatility offlavour compounds (Aronson and Ebeler, 2004). Depending on the variety, water stress andassociated reduction in nitrogen uptake, have been implicated in alterations of flavour-qualityof various white varieties such as Chasselas, Silvaner, Sauvignon blanc and Riesling (Peyrot desGachons et al., 2005 and Linsenmeier, 2008). In one example, the development of negativelyjudged wine attributes after only a short period of bottle ageing was retarded by irrigation(Table 5). However, there has been at least one report showing an increase in glycosidicallybound monoterpenes contributing to the flavour profile of White Riesling under water deficit474crop yield response to water