Received for publication 25 Mar. 1986. I wish to thank the following persons and organizations for their invaluable help in planting, caring for, and evaluating trials of ‘Winterset’: Keith Mayberry, farm advisor, Imperial County, Calif.; the late Jack Southam, Merrill Farms, Yuma, Arizona; Joe Costamagna, Hansen Farms, Huron, Calif.; and Bart Fisher, Fisher Ranches, Blythe, Calif. The research was financed in part by the California Iceberg Lettuce Research Board. The cost of publishing this paper was defrayed in part by the payment of page charges. Under postal regulations, this paper therefore must be hereby marked advertisement solely to indicate this fact.