Fig. 6. Mean genetic progress of ten bread wheat cultivars, two tall and eight semidwarfs, produced by CIMMYT and released by the Mexican government from 1950 to 1985. Cultivars were planted over 3 yr at four levels of applied N, 0, 75, 150, or 300 kg N per ha at the CIANO (Centro de Investigaciones Agricolas de Noreste) experiment station in Sonora, northwestern Mexico. Cultivar names are listed in Table 3. Reprinted with permission from Ortiz-Monasterio et al. (1997).