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Few studies have investigated the impact of vine shading on the sensory attributes of the resultant wine. This study examines the effects of canopy exposure levels on phenolic composition plus aroma, flavor, and mouthfeel aspects in wine. Wines were made from Cabernet Sauvignon and Shiraz grapes (Vitis vinifera L.) subjected to different levels of canopy exposure in a commercial vineyard in the Sunraysia region, Victoria, Australia. Canopy exposure treatments included control (standard vineyard practice), exposed (achieved with a foliage wire 600 mm above the top cordon), highly exposed (using a foliage wire with leaf plucking in the fruit zone), and shaded treatment (using 70% shade-cloth). Spectral and descriptive analyses showed that levels of anthocyanins, other phenolics, and perceived astringency were lower in wines made from shaded fruit; however, the reverse was generally not observed in wines of exposed and highly exposed fruit. Descriptive analysis also showed wines from the shaded fruit were different from other treatments for a number of flavor and aroma characters. These findings have implications for vineyard management practices.

Spatial variation in yield and fruit composition has been observed in many vineyards leading to low productivity. In this study, site-specific irrigation was applied in a 6.4 ha commercial vineyard (Vitis vinifera L. cv. Shiraz) block in the Sunraysia region of Australia to improve production in low yielding areas of the block and decrease differences in yield and quality between zones. The block was divided into three irrigation management zones based on normalised difference vegetation index (NDVI). Data collected under uniform irrigation management during seasons prior to site-specific irrigation management showed that spatial variation in canopy cover, yield and fruit composition at the study site was substantial. Water use efficiency and yield improvements were achieved by implementing site-specific irrigation. Fruit composition results were varied; pH and titratable acidity showed increased similarity between zones but other parameters maintained differences between zones. These results lend support to the use of NDVI to determine irrigation management zones.

Basal leaves were removed from Cabernet Sauvignon vines trained to a two-wire vertical trellis at fruit set and at veraison. Leaf removal did not modify total soluble solids and titratable acidity at harvest. Defoliation at fruit set of lower cordon recovered the grape anthocyanin composition gap between upper and lower cordons and that produced a positive effect on anthocyanin synthesis. Hence, control of the upper cordon and defoliation of fruit set of the lower cordon treatments showed comparable values of anthocyanins. Defoliation at veraison did not produce any appreciable effect. This study shows that skin anthocyanin composition in a two-wire vertical trellis can be modified by leaf removal in the fruit zone of the lower cordon, reducing variability in the ripeness between the two cordons.

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