Growing Food: A Guide to Food Production

have very many large root nodules, sometimes more than 1cm in diameter, which fix

large quantities of Nitrogen.

Although winged beans are currently grown mainly as a subsistence or market

garden crop in small areas, they have great potential as a source of protein and soil

Nitrogen. They could be grown in very large areas which are too hot and wet for

soybeans, although they are not a very suitable crop for mechanised agriculture.

All parts of the plant are edible: the seeds, pods, flowers, tubers and leaves can

all be eaten, by both humans and animals. An edible oil is extracted from the seed,

and the tubers have an exceptionally high protein content of 8–25% and up to 30%

starch. Cassava, by contrast, has about 0.7% protein and sweet potatoes 1.2–1.5%.

The available varieties of winged bean are very variable, in shape, size and

colour of flowers, pods and seeds. Some varieties produce both seed and tubers,

others produce only seed.

The seed is about 1 cm long, smooth and shining and either white, yellow, brown

or black in colour. It is a climbing perennial, but is normally treated as an annual.

The stem can grow four metres high if it is supported.

The grain has excellent nutritive and cooking qualities, similar to soybeans,

diet, which is deficient in lysine.

The tubers are also valuable, containing (@ 9% moisture content) 20–25%

protein, 1% fat, 5.4% fibre and 56% carbohydrate.

570 I.U. Vitamin A potency and useful amounts of other nutrients.

Nowadays winged beans are grown throughout the humid tropics, particularly in

Papua New Guinea, southeast Asia and Sri Lanka. In Africa they are widely grown

in Nigeria and Ghana, and they are also grown in the West Indies and southern

Florida.

PLANTING

Propagation: winged bean seed is planted directly into the field. The seed coats are

sometimes nicked with a file or sandpaper to improve germination rates and speed.

Soil: almost any soil which is not too saline or waterlogged, including soils with low

Nitrogen. In clay soils however the tubers are less well developed.

Spacing: very variable. For pods and seed the plants are normally grown up stakes,

while for tubers they are left unstaked, and sometimes treated as perennials.

Two or three seeds are normally planted on hills, at spacings of between 60 × 60 cm

The plants prefer to be in full sunlight.

to provide protein in hot and humid conditions that are unfavourable to other
leguminous crops. The crop also benefits subsequent crops planted since the roots

containing about 33% (29–37%) protein, 15–18% oil, 5% fibre and 32% carbo-

hydrate. It is rich in lysine and is therefore a good supplement to a cereal based

The pods (per 100 mg of edible portion, @ 92% m.c.) contain 42 mg Calcium,

per kg.

Seed rate: about 4–6 kg/ha. 100 seeds weigh about 30–40 g ie 3000–4000 seeds

crops, spacing is about 60 × 10 cm, without supports.

and 4 × 4 m. Average is about 1.3 m × 0.6 m for seed and pod crops. For tuber

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Depth: 2.5–6 cm.

GROWING FOOD – THE FOOD PRODUCTION HANDBOOK