Dolichos lablab: A Legume that Feeds People, Animals and the Soil

The lablab bean Lablab purpureus (or Dolichos lablab) is a versatile subtropical and tropical nitrogen-fixing legume. The many agricultural and nutritional uses of this bean are worth noting. Depending on the variety and regional practices, lablab can potentially be used for human consumption, animal fodder and forage. It is a multipurpose legume that can be used as a cover crop, providing green manure, erosion control and weed suppression. Lablabs are most widely cultivated in sub-tropical areas of Africa, Central and South America, the West Indies, Southeast Asia and Indonesia.

Lablabs are drought-tolerant, but do need adequate moisture for establishment. In drier areas they tend to do better than velvet bean, Mucuna pruriens. The ideal temperature range for lablabs is between 18 and 30˚C (64 - 86˚F) but they can withstand temperatures as low as 3˚C (37˚F). Depending on whether frosts occur in your area, the bean can be grown as an annual or as a short-lived perennial. Most lablabs can be used for human consumption in some form. Most ‘red’ varieties are considered entirely edible. Young pods are eaten as vegetables, while leaves and flowers can be eaten raw or cooked and eaten like spinach. Leaves are a high source of iron and contain up to 28% protein on a dry weight basis. Seeds can be eaten as sprouts; in such a form they are comparable to soy or mung beans. Seeds of any variety can be eaten as a cooked pulse or can be processed further into tofu or fermented into tempeh. Like most other legumes, when eaten as a pulse the dried seeds need to be soaked and boiled to break down a trypsin inhibitor. Lablabs’ hard seed coat necessitates a longer cooking time than common beans.

Lablabs also have a huge potential as forage/fodder material for livestock. Cattle, sheep, goats and pigs graze on the bean. Palatable hay and silage can also be made from the leaves. Lablabs are often intercropped with corn and sorghum or used as a ground cover between bananas or other taller plants.

Lablabs come in two main botanical types (although like many classifications in science, the lines can get blurry here, even within the same variety depending on when the planting occurs). The “garden-type” varieties are generally twining and like support.

They are most often used as green vegetables and typically mature later. ECHO carries one variety of garden-type lablab. The “field-type” varieties are more erect and bushy. The pods are often more fibrous and not used as vegetables. These generally mature earlier and are used as a forage or groundcover.

A caution worth noting is lablab’s slow early growth, which necessitates weeding during establishment. Lablabs are also susceptible to root knot nematodes.

The varieties ECHO currently offers from our Seedbank are as follows:

Highworth: This field-type variety originated in South India. It was originally intended for use where early frosts prevented the use of Rongai. It is known for early flowering and can produce high yields. Highworth is a black-seeded variety with purple flowers and is specifically for pulse (i.e. dried seed) production and forage use. Pod maturity is more uniform than on Rongai. Pods are borne well above the foliage, which simplifies seed harvesting; this variety could be suitable for mechanical harvesting and production. Highworth has performed well on the ECHO farm in Florida.

Rongai: The Rongai variety, also a field-type, was first introduced from the Rongai region in Kenya and was further developed in Australia. It is a white flowering, brown-seeded variety known for vigorous production. It matures later than Highworth, but in some places will out produce Highworth. Rongai has also performed very well in Florida. It can be used for pulse production and forage.

White: This white-seeded field-type variety is good for a cover crop and forage. It can also be used for pulse production. Historically, we have found white lablab to produce less than other varieties.

Red: This garden-type variety is completely edible. Young pods can be eaten raw or cooked like vegetables, and seeds in older pods can be eaten as a pulse. Young leaves can be eaten raw in salads and older leaves can be cooked like spinach. Flowers can be eaten raw or cooked. The large starchy root is also edible.

Lablab is a versatile legume; its multiple uses and highly nutritious quality for humans, animals and for the soil make it an important underutilized crop. It is easy to collect seed from lablab plants. Like most legumes, the seeds can be stored for a long time under dry, cool conditions. Those working in agricultural development in a developing country may request free sample packets of the above varieties of lablabs or a packet of mixed lablab varieties (save seed from whichever plants do best).