Issue link: http://winesandvines.uberflip.com/i/137110
GRAPEGROWING grape value positively correlated with SL at harvest for Shiraz from vineyards in hot to cool regions.10 In regional benchmarking studies, SL at véraison positively correlated with wine score for Shiraz4,26 and Pinot Noir.27 All wines with a high score in the Shiraz study had minimum of 40%–60% SL. For Pinot Noir, SL at véraison was correlated with other characteristics such as percent of growing tips and seed maturity. Canopy microclimate Vine characteristics in this category include: leaf layer number in bunch zone, shoot density, bunch density, proportion of exposed bunches and proportion of exposed leaves. Benefits of an open canopy with a low proportion of shaded leaves and bunches are well understood, and this is the basis of modern canopy management.20 However, canopy microclimate indicators are rarely measured in assessment schemes. Canopy density/openness is mainly estimated visually by integration of several of the above characteristics; for example, leafy/dense canopies were negatively correlated with wine grape value.10 Bunch exposure—The proportion of exposed bunches relative to shaded bunches is estimated in some schemes. The influence of bunch exposure on wine quality is well understood.9 However, there is, by necessity, a trade-off between optimal degree of bunch exposure for disease control and quality on one hand and avoidance of berry "chemical damage" and sunburn on the other. This requirement to achieve a balance between over-exposure and under-exposure of bunches is reflected in many assessment schemes and benchmarking studies. Berry Size—Visual assessment of berry size is done many ways. Does it correlate negatively with wine score? Yes—in some studies such as J. Gray et al.,10 P. Iland and R. Ristic.11 No—in many more studies such as G. Roby and M. Matthews,18 K. Bindon et al., S. Poni et al., P. Iland and R. Ristic.1,11,16 The research described in the latter studies has confirmed that environmental and cultural factors may affect skin development independently of pulp and thus can alter fruit and wine composition without any change in berry size.16 For this reason, the use of berry size as a key attribute in assessment schemes must be questioned. Furthermore, some benchmarking studies have shown no correlation between berry weight/size and wine score.22,27 pr actica l win ery & vin eya rd JU LY 20 13 53