Brent Sams,* Mahyar Aboutalebi, Riley Hibbard, Miriam Villa, Jared Nicholson, Luis Sanchez, and Nick Dokoozlian
*E & J Gallo Winery, 1541 Cummins Dr, Modesto, CA, 95358 (brent.sams@ejgallo.com)

Vineyard spatial variability, the inherent differences found across the physical spaces of vineyards, creates challenges for vineyard and winery management. Vineyard managers are tasked with producing high-quality grapes at the highest yield possible and wineries expect fruit delivered from these vineyards to be of uniform quality, despite differences in spatial variability. In recent years, variable-rate management has been widely discussed, but few options are available for commercial use. While these technologies develop, a more practical approach must be found for efficient management of grapes in vineyards and wineries. In 2022, six Cabernet Sauvignon vineyards in the Lodi area were selected for canopy characterization and fruit compositional analysis. During the 2023 season, 10 Sonoma County and 18 Lodi Cabernet Sauvignon vineyards were selected for maturity tracking and fruit compositional analysis. In both years, plots were distributed based on a targeted histogram analysis of early-season Sentinel-2 NDVI images. This targeted histogram analysis entailed selecting field plots in low-, medium-, and high-vigor categories, and identifying a single, three-pixel transect that best represented high, medium, and low histogram variability, otherwise known as the “Best Fit (BF)”. Results in 2022 showed that fruit zone light interception and fruit composition differed among high, medium, and low vigor zones, with the BF representing variability in most vineyards. The 2023 results confirmed that the BF could be used to monitor vineyard maturity in commercial vineyards. Variability caused by pest or disease pressure, topography, or vineyard management decisions created some limitations for the BF method and must be considered when deploying image-based decision platforms.

Funding Support: NA