Green Manures - Pigeonpea (Cajanus cajan)

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Pigeonpea

Cajanus cajan

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Summary

Tropical erect shrub or short-lived perennial legume
Green manure crop used to add nitrogen and organic matter
Weed control needed during establishment
Be sure to select root knot nematode resistant cultivars

Common Name
Its common name is pigeon pea (van der Maesen).

Scientific Name
The scientific name is Cajanus cajan (L.) Millsp. (van der Maesen).

Pigeonpea at 12 weeks

Photo: USDA NRCS

Cultivars
ICRISAT (India) has conducted extensive research and breeding with pigeon pea. The species is very variable and numerous cultivars are available. In Hawai`i, the low-growing cultivars ‘Norman’ and ‘FL81d’ are recommended by the NRCS for their root knot nematode resistance.

Seed Description
Seeds range in color from white, cream, brown, purplish to almost black, and are plain or mottled. They are globose to ellipsoid or squarish in shape (van der Maesen).

Seedling Description
Pigeon pea seedlings emerge 2 to 3 weeks after sowing. Vegetative growth begins slowly but accelerates at 2-3 months (van der Maesen).

Mature Plant Description
Pigeon pea is an erect shrub or short-lived (1-5 years) perennial legume often grown as an annual crop, 1 to 4 meters high. The leaves have three leaflets. Leaflets are elliptic to lanceolate, green and pubescent above and silvery greyish-green with longer hairs below, 2.5-10 cm long and up to 3.5 cm wide. The flowers are yellow with red/reddish brown lines or a red outside, borne in terminal racemes, and measure 1.2-1.7 cm in diameter. Pods are straight to sickle shaped, 5-10 cm long and 0.5-1.5 cm wide, glabrous and glandular (Bogdan).

Temperature
Pigeon pea’s optimum temperatures range from 18 to 38 °C (van der Maesen). Most cultivars are not frost tolerant (Bogdan).

Origin and Geographic Distribution
Pigeon pea is indigenous to India and spread to South East Asia. It is now grown throughout the tropics, especially in India and East Africa (van der Maesen).

Ecology
No information is available in this database on this topic.

Water
Optimal rainfall for pigeon pea is between 600-1000 mm/year. It does not tolerate waterlogging well (van der Maesen). It does have some drought tolerance (FAO).

Nutrients
Pigeon pea can grow on infertile as well as fertile soils. It has a relatively low (uneconomical) response to fertilizer (van der Maesen). Bogdan reports pigeon pea responding well to P and modestly to K. N applications usually reduce yields.

Soil pH
Pigeon pea grows best at a pH between 5.0-7.0 (van der Maesen).

Soil Type
Pigeon pea will grow on a wide range of soils from coarse to fine textured. It will not do well on waterlogged clays (Bogdan).

Shade Tolerance
No information is available in this database on this topic.

Salinity Tolerance
Pigeon pea has some salt tolerance (electrical conductivity from 0.6-1.2 S/m). (van der Maesen). It is sensitive to salt spray (FAO).

Herbicide Sensitivity
The FAO reports that pigeon pea is fairly tolerant of herbicides.

Life Cycle
Vegetative growth is slow initially. Seedlings emerge 2-3 weeks after sowing. Growth accelerates at about 2-3 months. Half of the plants begin to flower within 56-210 days after sowing. Maturity ranges from 95 to 256 days. Short days will accelerate flowering and reduce length growth. (van der Maesen).

Ten maturity groups have been identified under Indian conditions. They are usually combined into four categories: extra early (120 days), early (145 days), medium (185 days) and late-maturing (200 days) cultivars (van der Maesen).

Seeding Rate
Broadcast: minimum seeding rate of 40-60 lbs. pure live seed per acre (45-67 kg/ha). NRCS

Seeding Depth
2.5 to 10 cm (FAO).

Seeding Method
Broadcast (NRCS)
FAO reports that pigeon pea can be drilled with a maize drill.

Seeding Dates
Year round at elevations between 0-3000 ft. (NRCS)

Inoculation
Bogdan reports that pigeon pea is almost non-specific in its Rhizobium requirement and that inoculation is not usually needed.
Inoculate with a cowpea-group strain of Rhizobium (NRCS).

Seed Cost
No information is available in this database on this topic.

Seed Availability
‘Norman’ cultivar is reported difficult to obtain (Koolau Seed).

Days to Flowering
Flowering of half the plants begins 56 to 210 days after sowing (van der Maesen).

Days to Maturity
Maturity ranges from 95 to 256 days. Ten maturity groups have been identified under Indian conditions. They are usually combined into four categories: extra early (120 days), early (145 days), medium (185 days) and late-maturing (200 days) cultivars (van der Maesen).

Seed Production
No information is available in this database on this topic.

Seed Storage
No information is available in this database on this topic.

Growth Habit
Pigeon pea is a short-term perennial shrub which grows to 4 meters high (usually 1-2 meters). It is woody at the base. (FAO)

Maximum Height
Pigeon pea grows to a maximum height of 4 meters tall (van der Maesen).

Root System
Pigeon pea has an extremely deep-rooting taproot (FAO). Van der Maesen describes pigeon pea roots as thin and up to 2 m deep.

Establishment
By seed.

Maintenance
Weed control is needed during establishment (van der Maesen).

Mowing
No information is available in this database on this topic.

Incorporation
No information is available in this database on this topic.

Harvesting
Pigeon peas are generally hand harvested in the tropics. Ripe pods can be harvested with combine-harvesters for cultivars which mature uniformly with pods at a uniform level above the ground (van der Maesen). Pigeon peas are cut for forage at the preflowering state or when first pods ripen (Bogdan).

Equipment
Ripe pods can be harvested with combine-harvesters for cultivars which mature uniformly with pods at a uniform level above the ground (van der Maesen).

Uses

Used primarily as a vegetable food crop in South-East Asia (both seeds and pods)
Recommended in Hawai`i for green manure for vegetable crops
Intercropped with cereals (sorghum, millets), cotton or groundnut
Can be used as forage or hay (but not grazed)
Branches and stems can be used for baskets and fuel
Also used as a shade crop and wind break (young coffee, forest seedlings), cover crop, or support (vanilla)
Used to improve soil quality
Has traditional medicinal uses

Mixtures / Intercropping
The FAO reports that pigeon pea grows well interplanted with forage grasses rhodes grass, Cynodon dactylon, and molasses grass (in Hawai`i) and with pangola grass (in Brazil).
FAO reports pigeon pea intercropped with sesame or Eleusine coracana (India, Uganda), with maize (Malawi).

Rotations with maize-groundnut-tobacco-pigeon pea are reported in Uganda and Mauritius. In Hawai`i five year rotations of pineapple and pigeon pea (5 years per crop) are reported in 1932 (FAO).

Pigeon pea performs well as an intercrop with 2 rows of cereals (millet, sorghum), cotton or groundnut. After the intercrop is harvested, pigeon pea continues to grow, produce, and protect the soil (van der Maesen).

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

N Contribution
Approximate N content 50 lbs./T dry matter (NRCS).

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
The nutritive value of herbage from pigeon pea is high. Crude protein content ranges between 10 and 18%. Digestibility of crude protein ranges from 60% to 88% (Bogdan).

Pest Effects, Insects
Heliothis borers and Agromyza fruitflies are mentioned by van der Maesen. FAO reports pigeon pea in Hawai`i being attacked by the scale insect (Coccus elongatus), a stem borer, a pod borer (Lycaena boetica) and leaf-eating caterpillars.

Pest Effects, Nematodes
Bogdan reports that root knot nematodes (Meloidogyne spp. and other genera) often attack pigeon pea. The ‘Norman’ and ‘FL81d’ cultivars are root knot nematode resistant (NRCS).

Pest Effects, Diseases
In India, wilt caused by Fusarium udum is common and damaging and crop rotation to control it is recommended (Bogdan, van der Maesen). Root rot from Phaeolus manihotis and stem canker from Physalospora cajanae have been reported (Bodgan).

Pest Effects, Weeds
Weeds must be controlled during pigeon pea’s slow initial growth stage (van der Maesen).

Pest Effects, Vertebrates
No information is available in this database on this topic.

Uses in the Pacific Region
Section to be added later.

Uses in Hawai`i
The Hawai`i Natural Resources Conservation Service Technical Guide includes Pigeon pea (cv. ‘Norman’ and ‘FL81d’). Their specification describes Pigeon pea as follows:

Cv. ‘Norman’ is resistant to root knot nematodes;
Minimum broadcast seeding rates of 40-60 lbs. pure live seed/acre
Increase seeding rate to 60 lbs/A if incorporating early to produce finer stemmed material that is easier to till into the soil or if severe weed competition is expected;
pH range from 5.0-8.3;
Inoculant group: cowpea;
Approximate growing time 90 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.

FOR MORE INFORMATION:
Center for New Crops & Plant Products at Purdue University Website:
http://www.hort.purdue.edu/newcrop/duke_energy/Cajanus_cajun.html

FAO Web Site:
http://www.fao.org/WAICENT/FAOINFO/AGRICULT/AGP/AGPC/doc/GBASE/Mainmenu.htm

REFERENCES
Bogdan, A.V. 1977. Tropical Pasture and Fodder Plants. Longman Inc., New York. pp. 325-328.

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 States. 16 pp.

USDA Natural Resources Conservation Service, Hawai`i Field Office Technical Guide, Section IV, Code 340 "Cover and Green Manure Crop" May 1992.

Van der Maesen, L.J.G., 1989. Cajanus cajan (L.) Millsp. 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. 39-42.

If you have used this plant as a green manure in the Pacific Region, please email us with COMMENTS and FEEDBACK about this plant description so we can continue to refine this educational resource.

Last updated on 9/23/02