The technology of storing apples in refrigerated controlled atmospheres began spreading from New York to other states during the early 1950s and was introduced in all the major production areas by 1957. Economic and scientific factors were responsible for regional defferences in diffusion of CA technology. The economic factors included high early-season prices in several short-crop years and low intraseasonal price differentials as U.S. apple production increased during the 1950s. A scientific dispute over the benefits of CA for certain western apple varieties also contributed to the uncertainty of adoption. Robert Smock and his students (Van Doren, Southwick, Dewey, Mattus) at New York's Cornell University pioneered the research, development, and adoption of CA technology during the 1940s and 1950s. Others, chiefly USDA researchers, advocated improved traditional handling practices over adoption of CA technology.