GrapeX helps wine growers irrigate efficiently

The USDA Agricultural Research Service’s GrapeX project in Central Valley, California, is using remote sensing equipment to estimate plant water use and stress, as well as wine grape and other crop productivity and yield. ARS scientists are developing techniques to improve estimating actual plant water use so growers and industry can improve irrigation strategies and conserve water where they can.

The mission of GrapeX (Grape Remote Sensing Atmospheric Profile and Evapotranspiration eXperiment) is to refine and apply a multiscale remote sensing evapotranspiration (ET) toolkit for mapping crop water use and crop stress for improved irrigation scheduling and water management in vineyards in the Central Valley of California, a region of endemic periodic drought. While this work primarily focuses on vineyards, the improved tools will also have applications to fruit and nut orchards and other crops with highly structured canopies.

In California, grapes represent nearly 1 million acres of production valued at approximately $6 billion, while fruit and nut orchards represent an additional 2.6 million acres with crops valued in excess of $10 billion. To sustainably continue irrigated agriculture production in this region, better tools for managing water use are needed.

The USDA-Agricultural Research Service is working collaboratively with Utah State University and Ernest & Julio Gallo Wineries for the GrapeX project. During recent growing seasons, micrometeorogical, biophysical and remote sensing data from ground, airborne (including UAVs) and satellite platforms have been collected in adjacent pinot noir vineyards at different levels of maturity near Lodi, California. The aim is to combine in-situ and remotely-sensed data to investigate the effects of canopy structure and row orientation on energy and moisture exchange processes within and above the vine canopy, and to incorporate these effects within the operational ET modeling system.

Results estimating ET at multiple scales are encouraging for these highly structured canopies and studies are underway to assess the utility of very high resolution UAV imagery for identifying important features in the field affecting vine growth and development.