Sopinha bean: an ideotype of multiple purpose pulse of high nutritional value

Abstract

The objective of this work was to evaluate the potential of feijão-sopinha, a landrace of cowpea [Vigna unguiculata (L.) Walp.], as a multipurpose plant for use as forage plant, soil cover, and grain production. The identification of multipurpose plants for the diversification of production systems is essential for achieving a sustainable agriculture. Miúdo bean (the common name for cowpea in Portugese) belongs to the genus Vigna and fit this concept because it can be used as soil cover, green manure, and for the production of forage and grain. Embrapa Clima Temperado has a germplasm bank with more than 20 accessions of cowpea collected throughout the temperate region. The studies were carried out at the Estação Terras Baixas, in Capão do Leão, RS, Brazil, in a planosoil of low fertility. The experiments consisted of the agronomic characterization of the plant, and the evaluation of forage and seed productions and their nutritional qualities. In the forage and grains, the following parameters were analyzed: fiber contents, total protein, lignin, and mineral matter. Grains were also analyzed for anthocyanins, carotenoids, polyphenols, and total antioxidant activity. Sopinha bean shows a longer cycle than miúdo bean, and is capable of producing 9,200 kg ha-1 dry mass under a single cut, in the flowering phase of the plants. Sopinha bean fodder shows a good quality of fiber composition and total protein. Sopinha bean has potential for its uses as forage plant, soil cover, and grain production, serving, therefore, as an ideotype for multipurpose plant.