Demand-Driven Technologies for Sustainable Maize ... - IITA

17Figure 17. Grain yield/unit land area from 1980 to 2003 in two WECAMANLead Centers for maize breeding.éFigure 18. Grain yield/unit land area from 1980 to 2003 in two WECAMANnon- Lead Centers for maize breeding.Productivity of the maize varieties in the subregion varied amongindividual member countries. Yield/unit land area increased in Lead Centers(Fig. 17) more than in non-lead Centers (Fig. 18) for plant breeding.For example, while grain yield increased annually in Ghana at therate of about 35 kg/ha (r 2 =76%) and in Bénin at about 22 kg/ha(r 2 =76%), (Fig. 17), the trend was less defi nite in Nigeria (r 2