Remote sensing of vineyard management zones: Implications for wine quality

High-spatial resolution multispectral imagery, was acquired at mid-season 1997 by, an airborne digital camera system and used to establish management zones within a 3-ha commercial wine vineyard in California Napa Valley. Image processing included off-axis brightness correction, band-to-band alignment, ground registration and conversion to a Vegetation Index to enhance sensitivity to canopy density. The image was then stratified by Vegetation Index and color-coded for visual discrimination. An output image was generated in TIFF-World format for input to mapping software on the grower's laptop computer The imagery was used to delineate low-, moderate-, and high-vigor zones within the study block. Supporting field measurements per zone then included canopy structure (woody biomass, canopy transmittance), vine physiology (leaf water potential, chlorophyll content), and fruit biochemistry. Grapes from each zone were fermented separately and the resulting wines were formally evaluated for difference and quality. The low- and high-vigor zones were clearly distinct from one another with respect to most measurements. Block subdivision enabled the production of a "reserve" (highest) quality, wine for the first time ever from this particular block.