Assessing the representativeness and repeatability of testing sites for drought-tolerant maize in West Africa. Can. J. Plant Sci. 93: 699–714. The selection of suitable breeding and testing sites is crucial to the success of a maize (Zea mays L.) improvement programme. Twelve early-maturing maize cultivars were evaluated for 3 yr at 16 locations in West Africa to determine the representativeness, discriminating ability, and repeatability of the testing sites and to identify core testing sites.