Lablab
Lablab purpureus

Summary

  • Tropical climbing or erect annual or short lived perennial legume
  • Used primarily as a vegetable food crop in South-East Asia
  • Also used for fodder, hay, silage, green manure and cover crop
  • Recommended in Hawai`i for green manure on vegetable crops
  • Tolerates acid/low fertility soils
  • Drought resistant once established
  • Adapted to a wide range of soil types
  • Slow early growth: subject to weeds during establishment
  • Short lived
  • Root knot nematode susceptible

Common Name

Its common name is Lablab, hyacinth bean (Bogdan).

Scientific Name

The scientific name is Lablab purpureus (L.) Sweet (Bogdan). Synonyms: Dolichos lablab L. (Shivashankar & Kulkarni).

Cultivars

Lablab cultivar 'Rongai' was introduced from the Rongai area of Kenya to subtropical and tropical Australia. It is a white flowering, vigorous productive cultivar (Bogdan).

Seed Description

Seeds vary in color (white, red, brown, or black with a long white aril around a third of the seed) and in size (Bogdan). There are usually 3-6 ovoid seeds per pod (Shivashankar & Kulkarni).

Seedling Description

No information is available in this database on this topic.

Mature Plant Description

Lablab is a climbing or erect annual or short lived perennial. It grows up to 1 meter (3.2 ft.) high with longer stems in climbing types (up to 6 meters or 20 ft. tall). The leaves are pubescent, trifoliate, 3-15 cm (1-6 in.) long and 1.5-14 cm wide. Flowers are purple or white, 4-20 cm long and 1.2-1.6 cm in diameter, on peduncles that are 2-40 cm long (Bogdan). Pods vary in shape and in color, flat or inflated, 5-20 cm long by 1-5 cm wide (Shivashankar & Kulkarni).

Lablab is a highly variable plant. Some distinguish subspecies, varieties, or cultivar groups: Lablab, Ensiformis, and Bengalensis (Shivashankar & Kulkarni).

Temperature

Lablab requires temperatures from 18°C - 30°C (64.4°F - 86°F) to grow well. The minimum temperature for growth is 3°C (37.4°F). It has low frost tolerance but will survive light frosts which will damage the leaves (Shivashankar & Kulkarni).

Origin and Geographic Distribution

Lablab is thought to be indigenous to India, South East Asia, or Africa. Now it has been cultivated and distributed throughout the tropics and subtropics. It is most popular in India, South East Asia, Egypt and the Sudan (Shivashankar & Kulkarni).

Ecology

No information is available in this database on this topic.

Water

Lablab prefers rainfalls between 750 to 2500 mm/year (about 30-100 in.). Once it is established, it is drought tolerant (due to a deep taproot) and is reported to grow in areas with 200-2500 mm (about 8-100 in.) rainfall/year. It does not tolerate waterlogging (Shivashankar & Kulkarni).

Nutrients

Lablab is not generally fertilized. In poor sandy soils, molybdenized superphosphate at 250-500 kg/ha (223-446 lb/ac) with potash is recommended. Garden cultivars are heavily manured in India (Shivashankar & Kulkarni).

Soil pH

Lablab grows at a pH between 5.0-7.8 (Shivashankar & Kulkarni). pH range from 4.5 - 6.5 (NRCS).

Soil Type

With good drainage, lablab will grow on a wide range of soils from deep sands to heavy clays (Shivashankar & Kulkarni).

Shade Tolerance

No information is available in this database on this topic.

Salinity Tolerance

Lablab is not tolerant of brackish water (Shivashankar & Kulkarni).

Herbicide Sensitivity

No information is available in this database on this topic.

Life Cycle

Germination generally occurs within 5 days. The seeds can remain viable for 2-3 years with an 85-95% germination rate. The growth period ranges between 75 to 300 days. Fruiting on some cultivars begins within 60-65 days of sowing and continues for 90-100 days. Mature seeds are harvested between 150-210 days after sowing (which varies with cultivar). The flowers are cross pollinated (Shivashankar & Kulkarni).

Seeding Rate

  • 7-10 kg/ha (Shivashankar & Kulkarni).
  • 10-18 kg/ha (Bogdan).
  • 5-7 kg/ha drilled, 8-10 kg/ha broadcast (FAO).
  • Minimum seeding rate: 60 lbs. PLS/acre (NRCS).

Seeding Depth

5 cm (about 2 inches) (Shivashankar & Kulkarni).

Seeding Method

  • Broadcast and cover lightly with soil (Shivashankar & Kulkarni).
  • Drill into a well-prepared seedbed (FAO).

Seeding Dates

Year round in Hawai`i at elevations between 0-3000 ft (NRCS).

Inoculation

  • Lablab grows well in the countries of its origin without inoculation. However in Australia the plants do not nodulate naturally and a suitable cowpea-group strain of Rhizobium is used (Bogdan).
  • Inoculant group: lablab specific (NRCS).

Seed Cost

No information is available in this database on this topic.

Seed Availability

Readily available.

Days to Flowering

No information is available in this database on this topic.

Days to Maturity

The growth period ranges between 75 to 300 days. Fruiting on some cultivars begins within 60-65 days of sowing and continues for 90-100 days. Mature seeds are harvested between 150-210 days after sowing (Shivashankar & Kulkarni).

Seed Production

Lablab is generally hand picked as pods ripen. Once the majority of the plants reach full maturity, they are cut down close to the ground with a sickle, left to dry and then threshed (Shivashankar & Kulkarni).

Seed Storage

Dry (reduce moisture content to about 10%), clean, and store. In South East Asia they are stored in earthenware or metallic containers with 5-cm. layer of sand over them as protection (Shivashankar & Kulkarni).

Growth Habit

Lablab is bushy or a climbing branching herbaceous perennial with a taproot (Shivashankar & Kulkarni).

Maximum Height

Some climbing varieties of lablab grows to a maximum height of 6 meters (20 ft.) tall (Shivashankar & Kulkarni).

Root System

Lablab has a well-developed taproot with many laterals and well-developed adventitious roots (Shivashankar & Kulkarni).

Establishment

By seed.

Maintenance

No information is available in this database on this topic

Mowing

Mowing or grazing can begin 7-10 weeks after sowing. It can withstand close severe grazing (Bogdan) if only the leaves are taken (FAO).

Incorporation

No information is available in this database on this topic.

Harvesting

Lablab pods are generally harvested by hand when the seeds are three quarters ripe. For seed production, they are hand picked when ripe until the majority of the plants reach maturity. Then they are cut, dried and threshed (Shivashankar & Kulkarni).

Equipment

No information is available in this database on this topic.

Uses

  • Used primarily as a vegetable food crop in South-East Asia but also used for fodder, hay, silage, green manure and cover crop
  • Grown as a cover crop in rotation with sorghum and cotton
  • Used in orchards for an organic mulch (should be cut frequently)
  • Recommended in Hawai`i for green manure on vegetable crops
  • Intercropped with maize
  • Sown with maize and sorghum in alternate rows for silage (produces good silage especially when mixed with sorghum)

Mixtures / Intercropping

Lablab is grown as a field crop either alone or intercropped with a cereal (maize). In India it is grown with Eleusine coracana (Shivashankar & Kulkarni).

Biomass

Approximate dry matter yield 2.5 tons/acre (NRCS).

N Contribution

  • Approximate N content 50-lbs./T dry matter (NRCS).
  • Estimated 220 kg/ha N (FAO).

Non-N Nutrient Contribution

No information is available in this database on this topic.

Effects on Water

No information is available in this database on this topic.

Effects on Soil

No information is available in this database on this topic.

Effects on Livestock

Lablab is a main fodder crop in Kenya, Rhodesia and the Sudan. Crude protein in herbage is reported to range between 12.7 and 14.1% and reach over 25% in the dry matter. Organic matter digestibility declines over time (61.3% in younger plants to 48.3% in older ones). Milk production from lablab is usually higher than from grasses (Bogdan). A feedy flavor in milk is reported with lablab feed, diminished to acceptable levels with pasteurization (Bogdan, FAO). Bloat may occur if livestock is given a diet solely of lablab (FAO).

Pest Effects, Insects

Pod boring insects such as Adisura atkinsoni are troublesome pests. A. atkinsoni has been controlled experimentally by strain HB-III of Bacterium cereus var. thuringensis. The gram caterpillar (Heliothis armigera), the plume moth (Exelastis atomosa) and the spotted podborer (Maruca testulalis) are of economic importance. Bruchid beetles (Callosobruchus spp.) attack during storage as well as in the field (Shivashankar & Kulkarni).

Pest Effects, Nematodes

FAO reports that Lablab roots are attached by several nematodes: Helicotylenchus dihystera, Meloidogyne hapla and M. incognita.

Pest Effects, Diseases

Anthracnose (caused by Colletotrichum lindemuthianum), Leaf-spot (caused by Cercospora dolichi) and powdery mildew (caused by Leveillula taurica var. macrospora) have been reported (Shivashankar & Kulkarni).

Pest Effects, Weeds

Lablab competes well with weeds once it is established, but early growth is slow and weed control may be needed at that stage (FAO).

Pest Effects, Vertebrates

No information is available in this database on this topic.


Uses in the Pacific Region

No information is available in this database on this topic.

Uses in Hawai`i

The Hawai`i Natural Resources Conservation Service Technical Guide includes Lablab (cv. 'Rongai'). Their specification describes Lablab as follows:

  • Tolerates acid/low fertility soils
  • Minimum seeding rates of 60 lbs. pure live seed/acre;
  • pH range from 4.5-6.5;
  • Inoculant group: lablab specific;
  • Approximate growing time 60 days;
  • Approximate dry matter yield 2.5 tons/acre;
  • Approximate N content 50 lbs./T dry matter;
  • Optimum planting period year round at elevations between 0-3000 ft.

Evans reports that Lablab has potential as a cover crop in Hawai`i.


References

Bogdan, A.V. 1977. Tropical Pasture and Fodder Plants. Longman Inc., New York. pp. 367-369.

Evans, Dale O., Joy, Robert J., & Chia, C.L., 1988. Cover Crops for Orchards in Hawaii. Hawaii Institute of Tropical Agriculture and Human Resources, University of Hawaii at Manoa, Honolulu, Hawaii, United Stated. 16 pp.

FAO Web Site

Shivashankar, G., & Kulkarni, R.S., 1989. Lablab purpureus (L.) Sweet. In: van der Maesen, L.J.G. & Somaatmadja, S. (Editors): Plant Resources of South-East Asia No 1. Pulses. Pudoc/Prosea, Wageningen, the Netherlands. pp. 48-50.

USDA Natural Resources Conservation Service, Hawai`i Field Office Technical Guide, Section IV, Code 340 "Cover and Green Manure Crop" May 1992. Pacific Islands Area Field Office Technical Guide (eFOTG) - East Area

Text last updated on 9/23/02.

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These webpages were originally generated under a grant program from Western SARE entitled "Covering New Ground: Tropical Cover Crops for Improving Soil Quality" EW98-012 (1998-2002).