Remote sensing as a tool for viticulture research in south-africa with specific reference to terroir studies
The diversity of soil types in the Western Cape of South Africa leads to high levels of within-vineyard variability. Multispectral remote sensing has received a lot of attention recently in the South-African wine industry in an attempt to identify and deal with this variability. The technology is already successfully used by many producers as a tool for harvesting grapes as well as in precision vineyard management, but its potential as a tool in research has not yet been fully utilised. It holds promise as a tool to study the interaction of the grapevine with its environment, especially with regards to differences in vine performance due to soil variability. One of the most important goals of this research is to determine how the information derived from the vegetation indices used in the imaging relates to grapevine performance. Results are presented from a companion study to a terroir study in the Western Cape region, where high resolution multispectral aerial images were used to optimise experimental plot layout in 'Cabernet Sauvignon' and 'Sauvignon blanc' vineyards at different localities according to vineyard characteristics. Additional plots were also selected at each location, where the cause and effect of extremes in vigour were investigated through conventional measurements of vine vigour. Small-scale vinification was also used to investigate the effects of vigour differences on wine style and quality. Preliminary results show that large differences exist in vine vigour within the study vineyards, having effects on most of the parameters measured in viticultural studies, and that remote sensing is a valuable tool to either minimise vigour variability or to improve the researcher's ability to explain variability in statistical results.