This preliminary report summarizes data received from December 16, 1985 to August 15, 1986, for the various trials in CIMMYT's International Maize Testing Program, including the International Progeny Testing Trials (IPTT), the Experimental Variety Trials (EVT), and the Elite Variety Trials (ELVT). Data on population improvement, experimental variety development, locations of the progeny testing trials, and experimental variety trials, as well as on the relationship between gene pool populations and variety trials in CIMMYT's normal and quality protein maize improvement programs, are provided343 pages