Corn Belt in the 1930s and 40s (Gerhart 1975). H611 has since served as the basis of many of the hybrids released by the national maize program (Hassan et al. 1998).

Similarly in Zimbabwe, just after independence in 1980, smallholder Africans rapidly adopted the R-200 series of maize hybrids. Originally bred for European settlers, they were suitable for cultivation on sandy soils in low-rainfall areas and performed relatively well for smallholders (Rohrbach 1988). Following independence in 1964, Zambia‘s maize breeders also introduced an impressive array of both hybrids and improved open-pollinated varieties (Howard 1994).

The lack of a large farm sector prior to independence and local consumption preferences delayed Malawi‘s maize revolution. Malawi‘s smallholder farmers preferred flint maize types that processed and stored well on their farms. At that time, regional breeding efforts were focused on dent maize types suited to large-scale milling, and flint breeding materials from outside Malawi were not easy to find. Malawi‘s breakthrough hybrids (MH17 and MH18), not accomplished until 1990, resulted from an innovative top-cross of Malawian lines, including SR52, with flint maize populations. The earlier-maturing of the two, MH18 often escaped dry spells, processed and stored well on-farm, and yielded more than local maize even when both were unfertilized (Heisey and Smale, 1995). According to surveys undertaken by the National Statistical Office in 2006, MH17 and MH18 were still planted to over half of the area of improved maize in this densely-populated, maize-dependent nation (Sauer and Tchale, 2009).

The International Maize and Wheat Improvement Center (CIMMYT) played a key role in the development of the successful hybrids in Malawi. Although CIMMYT had a regional presence in maize breeding from the late 1970s, it only seriously invested from 1985 when it established a research station at Harare in Zimbabwe. It has since maintained a strong presence in the region and many of the more recently released hybrids and OPVs contain CIMMYT parentage.

In West Africa, where there were no settler farmers like those found in Eastern and Southern Africa, maize hybrids were not developed. The scientific breakthrough in West Africa came with the release of the open pollinated varieties, TZB and TZPB, developed by IITA during the 1970s. These varieties combined high yields with resistance to rust and blight (TZPB) and drought tolerance (TZB), spearheading the Nigerian maize revolution in the 1980s (Smith et al., 1997). They have been also widely adopted elsewhere in West Africa. Later varieties focused on streak virus resistance and are the basis for currently grown varieties (Alene et al., 2009). Overall, the number of varieties released in the region jumped from less than one annually in the 1970s to five in the 1980s, to 12 in the late 1990s.

Strong national programs are critical to successful R&D systems. Investment in national R&D programs increased rapidly from the 1970s but then stagnated in the 1990s. Spending on R&D fell in about half of the countries of Sub-Saharan Africa during the 1990s (Beintema and Stads, 2007). Over the whole period staffing increased faster than funding, so that funding per scientist fell to less than half of the levels of 1971. Research capacity has also been affected by staffing discontinuities in the national maize breeding programs, and shifting emphasis between efforts to breed hybrids as compared to improved, open-pollinated varieties. Two of the three maize breeding programs recently reviewed by Lynam et al. (2010), in Ghana and Malawi, have lost all the senior maize breeders that were instrumental in earlier successful maize varietal releases. Lynam et al. (2010) identified only Kenya, with six maize breeding programs and six 7