Tropical legumes: resources for the future.
This report describes underexploited leguminous spp. Some have only a very limited distribution, others are almost unknown, but many have attributes suggesting that they could become major crops. Almost 200 of 600 neglected spp. are included in 31 chapters, but most plants are presented in separate chapters with descriptions, limitations and research needs outlined and selected readings and research contacts listed. Promising root crops include the 3 climbers Pachyrhizus erosus, P. tuberosus from Mexico and Apios americana from New England, Psophocarpus tetragonolobus, 5 Vigna, 2 Psoralea, 3 Phaseolus and 3 Pueraria spp. Tuber protein contents are higher, except in Psoralea spp., than in other tuber-bearing plants. Among the pulses, Voandzeia subterranea will grow in arid regions on worn-out soils and is almost unknown outside Africa, the climbers Canavalia ensiformis and C. gladiata are exceptionally adaptable and can yield highly, but leaves and pods must be cooked to destroy growth-inhibiting compounds, and Lablab purpureus is similarly adaptable and will grow in an annual rainfall range of 200-2500 mm. Tylosema esculentum is native to the Kalahari and nearby sandy regions and yields edible tubers and seeds higher in protein but lower in oil content than groundnuts. Vigna aconitifolia is the most drought-tolerant Indian crop and Phaseolus acutifolius, cultivated in Mexico for 5000 yr, matures quickly and survives after germination in flood water with a minimal subsequent water supply. Cordeauxia edulis, a small bush, can provide the only food left for destitute Somali nomads. The fibre plant Crotalaria juncea (sunn hemp) will grow on poor soils, needs little or no added N, and some strains are resistant to root knot nematodes, in common with most other legumes described in this book. It has been the subject of very little study and selection.<new para>ADDITIONAL ABSTRACT:<new para>This report describes underexploited leguminous spp. Some have only a very limited distribution, others are almost unknown, but many have attributes suggesting that they could become of major importance. Almost 200 of 600 neglected spp. are included in 31 chapters, but most plants are presented in separate chapters with descriptions, limitations and research needs outlined and selected readings and research contacts listed. Woody plants are in general ignored in plans for improving tropical forages although livestock have been fed for several thousand yr in the Mediterranean region on carob (Ceratonia siliqua) pods. Cassia sturtii is grown as a browse plant in the Negev; Desmanthus virgatus tolerates very heavy grazing, suggesting that other Desmanthus spp. deserve investigation, as do Desmodium discolor, D. distortum, D. gyroides and D. nicaraguense as all are highly palatable and nutritious forage crops. Acacia tortilis is very drought resistant and it and 4 other Acacia spp. are useful for pod and browse production, as are 6 non-invasive Prosopis spp. Sesbania grandiflora is a very fast-growing Asian tree which can be topped for forage, yields green manure and whose prolific nodulation suggests high capacity for soil improvement. Many spp., of which Pueraria phaseoloides and Mucuna pruriens are only examples, will survive, grow and dominate other vegetation on sites subject to erosion and will stabilize bare ground and can be used to reclaim mine spoil heaps.