Achievements and impact of NERICA on sustainable rice production in sub - Saharan Africa.

Abstract

In terms of production, rice is the fourth most important cereal (after sorghum, maize and millet) in sub-Saharan Africa (SSA). It occupies 10 percent of the total land under cereal production and accounts for 15 percent of total cereal production (FAOSTAT, 2006). Approximately 20 million farmers in SSA grow rice and about 100 million people depend on it for their livelihoods (Nwanze et al., 2006). Rice is the staple food of a growing number of people in SSA: from 1961 to 2003 consumption increased at a rate of 4.4 percent per year (Kormawa, Keya and Touré, 2004). Among the major cereals cultivated, rice is the most rapidly growing food source in Africa: between 1985 and 2003, the annual increase in rice production was 4 percent, while production growth for maize and sorghum was only about 2.4 and 2.5 percent, respectively (Kormawa, Keya and Touré, 2004). The most widely grown rice species, Oryza sativa, is originally from Asia and was introduced into Africa only about 450 years ago. Another less well-known rice species, O. glaberrima (Steud), is originally from Africa and was domesticated in the Niger River Delta over 3 500 years ago (Viguier, 1939; Carpenter, 1978). As a result of their evolution, domestication and breeding history, both species have distinct and complementary advantages and disadvantages for use in African farming systems. The Asian rice (O. sativa) is characterized by good yields, absence of lodging and grain shattering, and high fertilizer returns – unlike its African counterpart (O. glaberrima). However, in contrast to Asian rice types, landraces of O. glaberrima often have good weed competitiveness and resilience against major African biotic and abiotic stresses (Koffi, 1980; Jones et al., 1997a). Dalton and Guei (2003) concluded that research into genetic enhancement of rice generated approximately US$360 million in 1998, compared with a total investment of just US$5.6 million. This is evidence that rice variety improvement has a potentially enormous impact on the economic development of SSA. Numerous conventional breeding efforts have been made to improve the performance of upland rice (O. sativa) for use in African farming systems. These efforts have had only limited success, partly because the Asian rice, O. sativa, lacks resistance or tolerance to many of the typical African stresses (Jones et al., 1997a).