Untold innovation: Scientific practice and corn improvement in Mexico, 1935--1965

This dissertation examines the scientific activities of plant breeders from Mexico and the United States who worked to improve Mexican corn agriculture during the 1930s through 1960s. My study spans the work of the Instituto Biotecnico (1934--1940), the Mexican Office of Experiment Stations (1941--1946) and Agricultural Research Institute (1947--1960), the Rockefeller Foundation's Office of Special Studies (1943--1960), and the Mexican National Agricultural Research Institute (1960-- ). I focus primarily on the concurrent corn breeding programs in the Agricultural Research Institute (HA) and the Office of Special Studies (OSS), directed by Edmundo Taboada and Edwin Wellhausen (and later R. D. Osler), respectively. Literature on the green revolution written in Mexico and the United States has often asserted that the Mexican IIA focused on open-pollinated corn varieties that had reusable seed and were hence feasible for Mexico's subsistence farmers, while the Rockefeller Foundation's OSS emphasized conventional hybrid corn (as developed in the United States) that benefited only the most wealthy of Mexican corn growers. In contrast to this common account that portrays the goals and activities of these two agencies in opposition, I argue that their scientific activities and strategies for corn improvement resembled one another in important ways.;I demonstrate, first, that the initial relationship between the two programs was the reverse: in the early 1940s, the Mexican agency undertook a conventional hybrid program modeled after programs at U.S. experiment stations, while the OSS program focused on open-pollinated synthetic varieties. Second, I argue that after 1947, the strategies of both programs began to emphasize new types of corn referred to as "stabilized varieties" at the IIA and what I have called "S1 hybrids" at the OSS. Both new kinds of corn were formed using hybridization techniques, yet farmers could propagate them through open pollination. After 1960 when the IIA and OSS merged, both innovative strategies yielded to a more conventional hybrid corn program. I discuss these methodological developments in the context of cutting-edge corn breeding in the United States and theories of hybrid vigor that accompanied hybrid corn development.