Darrah, L.LPenny, L.H2015-06-292015-06-291974East African Agricultural And Forestry Journal, 40 (No 1), pp. 77-880012-8325http://localhost:8080/dspace/handle/0/1196Several countries in Eastern Africa now have established maize (Zea mays L.) research programmes, which are producing improved breeding populations and commercial varieties and hybrids. Regional trials have been used to evaluate nationally developed maize varieties in different environments. Ranges of wide adaptation have been found for Kenya's Hybrid 632 and the Rhodesian hybrid SR52, now produced commercially in Zambia [5].Eberhart, Penny, and Harrison [2] found current commercial varieties were adapted, in the appropriate altitude zone, throughout Eastern Africa. Harrison [5] gives length of the growing season, disease prevalence, and altitude as the primary factors determining the potential of an environment for a particular variety.enhttp://creativecommons.org/licenses/by/3.0/Journal ContributionZea maysMaize