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Defoliation is a commonly used viticultural technique to balance the ratio between grapevine vegetation and fruit. Defoliation is conducted around the fruit zone to reduce the leaf photosynthetic area, and to increase sunlight exposure of grape bunches. Apical leaf removal is not commonly practiced, and therefore its influence on canopy structure and resultant wine aroma is not well-studied. This study quantified the influences of apical and basal defoliation on canopy structure parameters using canopy cover photography and computer vision algorithms. The influence of canopy structure changes on the chemical compositions of grapes and wines was investigated over two vintages (2010–2011 and 2015–2016) in Yarra Valley, Australia. The Shiraz grapevines were subjected to five different treatments: no leaf removal (Ctrl); basal (TB) and apical (TD) leaf removal at veraison and intermediate ripeness, respectively. Basal leaf removal significantly reduced the leaf area index and foliage cover and increased canopy porosity, while apical leaf removal had limited influences on canopy parameters. However, the latter tended to result in lower alcohol level in the finished wine. Statistically significant increases in pH and decreases in TA was observed in shaded grapes, while no significant changes in the color profile and volatile compounds of the resultant wine were found. These results suggest that apical leaf removal is an effective method to reduce wine alcohol concentration with minimal influences on wine composition.

Learning to objectively evaluate wine sensory properties (such as appearance, aroma, flavour, taste and mouthfeel attributes) features prominently in wine education programs. Formal, structured sensory classes that involve recording detailed observations and perceptions is the traditional approach to build perceptual and linguistic learning. This research explored students’ behaviour in maintaining wine tasting notes and their perceptions of wine sensory classes by survey across four Australian institutions (n=109) and by focus groups (n=24). International students were not as confident in class room discussions or describing wine, and did not perform as well in sensory exams, suggesting that language ability and/or cultural/life experience is important for technical wine assessment. Given that 98% of students surveyed owned a smartphone, mobile learning may provide an opportunity to enhance and facilitate learning of wine sensory analysis outside of the classroom. The My Wine WorldTM App (developed for smartphones) was evaluated by academic staff and students as a potentially valuable e-learning tool for the development of perceptual and linguistic memory of sensory attributes.

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