New Opportunities in Vigna

INTRODUCTION The genus Vigna Fabaceae, formerly Leguminosae, is composed of more than 200 species that are native to the warm regions of both the old world and new world. Vigna is closely related to Phaseolus, which is composed of more than 20 species that are native to warm or tropical regions of the New World. A number of species previously placed in Phaseolus are now placed in Vigna. The genus Vigna contains several species that are of considerable economic importance in many developing countries. Cowpeas [V. unguiculata (L.) Walp.], mung beans [V. radiata (L.) Wilczek], and urd beans [V. mungo (L.) Hepper] are key dietary staples for many millions of people. Additionally, adzuki beans [V. angularis (Willd.) Ohwi & Ohashi], bambara groundnuts [V. subterranea (L.) Verdn.], mat beans [V. aconitifolia (Jacq.) Marechal], and rice beans [V. umbellata (Thunb.) Ohwi & Ohashi] are important in the diets of many societies. Many of these Vigna species are also valued as forage, cover, and green manure crops in many parts of the world. Annual worldwide production of the various Vigna species likely approaches 20 million hectares, and virtually all of this production is in developing countries. The economic Vigna species exhibit a number of attributes that make them particularly valuable for inclusion in many types of cropping systems. They can be grown successfully in extreme environments (e.g., high temperatures, low rain fall, and poor soils) with few economic inputs. Many of these species produce multiple edible products, and these products provide subsistence farmers with a food supply throughout the growing season as well as dry seeds that are easy to store and transport. For example, tender shoot tips and leaves of cowpeas can be consumed as soon as the plants reach the seeding stage and immature pods and immature seeds can be consumed during the fruiting stage. Harvested dry seed of all of the Vigna crops can be consumed directly, and seeds of several of the crops are commonly used to make flour or produce sprouts. Plant residues can be used as fodder for farm animals. Vigna food products exhibit many excellent nutritional attributes and these products provide a needed complement in diets comprised mainly of roots, tubers, or cereals.