Chapter 17 - Winged bean (Psophocarpus tetragonolobus (L.) DC.)

Abstract

Winged bean (Psophocarpus tetragonolobus (L.) DC.) is a viny, leguminous, vegetable crop of humid regions in Southern Asia and New Guinea. In 1975, a review of 36 underexploited tropical plants by a US National Academy of Sciences select committee highlighted winged bean's promiscuous nodulation and nitrogen fixation across tropical soil types; its high protein content in all plant parts; and favorable amino acid and fatty acid composition in the mature seed. The panel recommended an expanded research effort. This led to a comprehensive assessment of the agronomic potential for production of winged bean's edible components—vegetable pods; seed; tuberous roots, and leafy shoots—in countries across its traditional geographic range and beyond. Research since then has continued to investigate three key limitations to winged bean's expanded use: a relatively high moisture requirement; indeterminate growth habit and delayed maturity, exacerbated by daylength sensitivity; and hard-seededness that constrains germination and food-processing possibilities. Landrace evaluation and conventional breeding, aided by innovative phenotyping and genomic-assisted methods, hold promise of overcoming such constraints. The aim would be to develop winged bean ideotypes suited to a range of cropping scenarios.