November 1985 - present: Wheat specialist Centro Internacional de Mejoramiento de Maiz y Trigo (CIMMYT) based in Mexico, China.
March 1980 - November 1985: Cropping System Agronomist based in Nepal with IADS/Winrock International.
May 1978 - March 1980: Manager, Sayre's Farms Incorporated, Delta, Colorado.
February 1977 - March 1978. Tropical Forage Legume Breeder, Centro Internacional de Agricultural Tropical (CIAT), based in Cali, Colombia.
March 1974 - February 1977: Head, Department of Plant Physiology, Centro Internacional de la Papa (CIP), based in Lima, Peru.
October 1971 - March 1974: Post-doctoral assignment with the Rockefeller Foundation to the International Potato Program, based in Toluca, Mexico.