Crop yield response to water - Cra

Figure 10Negative associations between berry traits related to wine quality and yield. (a) Totalred pigments in berry skins of Pinot Noir grown in a cool climate. (b) Correlationcoefficients of the regressions between the rate of anthocyanins or soluble solidaccumulation in berries and yield related variables in Cabernet Sauvignon grown in awarm environment. Sources of variation were (a) source: sink manipulation throughbunch thinning and pruning, and (b) season, water supply and fruit load. Asterisksindicate P < 0.05 (*), P < 0.01 (**) and P < 0.0001 (***). Adapted from (a) Dunn et al.(2005) and (b) Sadras et al. (2007).14aTotal red pigment (au)1210r = - 0.96***80 1 2 3 4Yield (kg/vine)0.0bCorrelation coefficient-0.2-0.4-0.6-0.8************-1.0***Bunch massBerries per bunchBerry massYieldWhite varietiesCompared to red varieties, white varieties are generally more sensitive to stress periods andcan show negative compositional changes (Christoph et al., 1998 and Peyrot des Gachonset al., 2005). Phenolic compounds are judged less desirable in white grapes, since sensoryattributes such as astringency or bitterness, associated with both flavonoid, i.e. flavan-3-ols and proanthocyanidins (Singleton and Noble, 1976 and Brossaud et al., 2001) andnonflavonoid phenols, i.e. hydroxycinnamic acids or their esters (Arnold et al., 1980 andHufnagel and Hofmann, 2008) are incompatible with the current type of white wine populargrapevine 473