In California's Central Valley, where most processing tomatoes are grown, ozone caused slight damage in one year, none in the next.

This work was conducted under cooperative agreement with the U.S. Environmental Protection Agency and the California Energy Commission. Although this research was funded in part by USEPA through Inter agency Agreement EPA-82-D-X0533 with G.E. Bingham, this article has not been subjected to agency review and therefore does not necessarily reflect the view of the agency. No official endorsement should be inferred. The cooperation of the grower, John Paulsen, is gratefully acknowledged.