Multi-Factor Approach to Identifying Cowpea Genotypes with Superior Symbiotic Traits and Higher Yield for Africa

Cowpea (Vigna unguiculata L. Walp) is an important food crop in Africa and other developing countries. All the parts used as food are nutritious and provide proteins, vitamins (notably vitamin B), and minerals. The cowpea haulm is also a good source of livestock feed. In the last three decades, some efforts have been put into research aimed at improving the yield of cowpea. For example, since 1970, the International Institute of Tropical Agriculture (IITA) has worked on developing and distributing improved cowpea materials. Improved cultivars often with a single trait, such as early pmaturing, pest tolerance, disease tolerance, or high yielding, have been reported (Hall et al., 1997). However, the yields of cowpea at farmer level (240 kg ha⁻¹) are still very low (Quin, 1997) compared with the indicated yield potential of about 3,000 kg ha⁻¹. The aim of this study was to identify cowpea genotypes with superior multiple traits, including N₂-fixation, pest tolerance, and high grain yield.