Castoro Cellars expands robot vineyard use

Castoro Cellars, a winery in Paso Robles, Calif., has expanded its use of robotic vineyard technology to 600 acres after three years of testing what the company and its partner, Saga Robotics, describe as consistent results in reducing disease pressure and improving farm operations.

The expansion centers on “farming with light,” a system that uses autonomous robots equipped with ultraviolet light to help control powdery mildew in vineyards without relying as heavily on chemical sprays. The technology has been used in wine grapes at Castoro Cellars since the initial rollout, and the winery said the broader deployment reflects confidence built over multiple growing seasons.

The move comes as California growers continue to look for ways to manage labor costs, reduce pesticide use and respond to pressure from regulators and consumers for more sustainable farming practices. In wine regions such as Paso Robles, where warm days and cool nights can create conditions favorable to mildew, disease management is a major part of vineyard work during the season.

Saga Robotics, which developed the autonomous platform, has been expanding its presence in specialty crops and vineyards by marketing the system as a tool that can complement conventional farming rather than replace it. The robots travel through vineyard rows at night or during low-light conditions, when ultraviolet treatment is most effective and less likely to affect workers in the field.

Castoro Cellars said the decision to scale up followed three years of field use that showed the system could be integrated into regular vineyard operations. The winery did not disclose financial terms for the expansion. It also did not say whether the technology would be used across all of its vineyard holdings or only on selected blocks within the 600 acres now covered.

The adoption adds to a broader shift in California winegrowing, where producers are increasingly testing automation, precision agriculture and other tools aimed at lowering input costs while maintaining grape quality. For wineries, those decisions can affect not only farming expenses but also how grapes are grown for wines sold in a market where sustainability claims have become part of brand identity.

Saga Robotics has said its approach is designed to reduce dependence on fungicides by using repeated light treatments through the growing season. In practice, that means vineyard managers still monitor weather, canopy growth and disease risk closely, but they can use the robots as part of a larger integrated pest management plan.

For Castoro Cellars, the expansion signals that a technology once treated as experimental has moved into routine use. The winery’s decision also reflects a wider willingness among growers to adopt automation when it can show measurable results over time, especially in crops like wine grapes where quality and consistency are central to the business.