The net present value of benefits from investments in cowpea research-for-development convened by IITA over a 20-year period is estimated at upwards of US$ 1.09 billion with an internal rate of return ranging between 50–103 percent (Kristjanson et al. 2002). Akinola et al. (2009) estimated a return on investment of 81%, generating 53 dollars worth of benefits for the poor for each dollar invested. These benefits captured by the poor represented 54% of the total benefits generated by the work.
In 2010 IITA carried out a survey of national cowpea improvement programs in 16 countries across sub-Saharan Africa that together account for over 95% of total cowpea production in the region (Alene et al. 2012). Improved varieties accounted for an estimated 23% of the total cowpea area in West and Central Africa, versus 16% in Eastern and Southern Africa. In Niger and Cameroon, the yield advantage of improved varieties ranged from 25 to 46% (Sterns and Bernsten 1994; Mazzucato and Ly 1994).
West and Central Africa
A few adoption studies localized to parts of northern Nigeria, and therefore not representative of the entire country, are nevertheless informative about the impacts of project interventions. In a study conducted in 1999 in Kano and Jigawa states, Kristjanson et al. (2002) observed 38% of the cowpea area being sown to improved dual-purpose (grain plus fodder) varieties. In a pilot trial of farmer-to-farmer diffusion of improved cowpea in Kano and Kaduna states, Alene and Manyong (2006) found that more than 70% of the farmers in the project villages adopted improved varieties, viz. an adoption increase from 4,000 to 27,000 farmers over four years (1999-2003). Other local studies reported adoption rates of 56% in Bauchi and Gombe states (Agwu 2004), 40% in Borno state in 2007 (Gadbo and Amaza 2010), and up to 75% in TL II project areas of Kano and Borno States.
Eastern and Southern Africa
Medium adoption (20%-50%) was observed in Tanzania and Zimbabwe. The lowest adoption rates (below 20%) were reported for Malawi, Mozambique, and Zambia. Except for Mozambique these countries have released few improved cowpea varieties. Apart from the former USAID-supported Bean/Cowpea CRSP, no major international research program has been active in Eastern and Southern Africa on cowpea improvement at a level comparable to the activity occurring in West and Central Africa.
Akinola AA, Alene AD, Adeyemo R, Sanogo D. and Olanrewaju AS. 2009. Economic impacts of soil fertility management research in West Africa. AFJARE. 3(2):159-175.
Kristjanson P, Tarawali S, Okike I, Singh BB, Thornton PK, Manyong VM, Kruska RL and Hoogenboom G. 2002. Genetically improved dual-purpose cowpea: Assessment of adoption and impact in the dry savanna region of West Africa. ILRI Impact Assessment Series No. 9. ILRI, Nairobi, Kenya.