Calopogonium mucunoides (Photo from Wikimedia)
A vigorous, creeping, twining or trailing, short-lived perennial herb, up to several metres long, forming a tangled mass of foliage 30-50 cm thick, with densely pilose stems with long rust-coloured hairs. Leaves trifoliolate, petiole up to 16 cm long, pilose; leaflets elliptical, ovate or rhomboid ovate, 4-10 cm x 2-5 cm, the laterals oblique, adpressed pilose or pubescent on both surfaces. Inflorescence a slender rust-coloured raceme, up to 20 cm long, covered with short, dense hairs; blue or purple flowers in fascicles of 2-6; bell-shaped calyx with five unequal lobes; corolla with emarginate standard, about 1 cm long. Pod linear-oblongoid, 2-4 cm x 3.5-5 mm, straight or curved, softly pilose with coarse reddish-brown hairs, impressed between the seeds. Seeds 3-8 per pod , compressed squarish, 2-3 mm long, yellowish or reddish-brown. There are 65,000-70,000 seeds/kg.
Calopogonium mucunoides Desv.
Calopogonium brachycarpum (Benth.) Benth. ex Hemsl.
Calopogonium orthocarpum Urb.
Stenolobium brachycarpum Benth.
Family: Fabaceae (alt. Leguminosae) subfamily: Faboideae tribe: Phaseoleae subtribe: Glycininae. Also placed in: Papilionaceae.
calapo, calopo, wild ground nut (English); kacang asu (Indonesia); santing, karaparapak (Philippines); thua karopo (Thailand); bejuco culebra, calopogonio-indico, falso-or¢, jequirana, cama, marmelada-de-boi, mielillo, orelha-de-on‡a.
Native to: Tropical America from the Tropic of Cancer to the Tropic of Capricorn. Now widespread throughout the tropics.
Grazing legume, green manure, pioneer legume and cover crop. Mainly used as cover crop in tropical tree plantations over the past 100 years. Recognised as a valuable pioneer species, reducing erosion and improving soil fertility. Despite generally low palatability, cattle graze calopo during the latter part of the dry season in tropical Asia and Africa. One of very few commercially available legumes in Brazil, but used more as a cover crop rather than as forage.
Soil requirements. Grows on a wide range of soil types, but prefers clay soils with pH 4.5-5.0. In tropical America, grows well on acid soils with high Al saturation. Poor tolerance of salinity.
Moisture. Adapted to the hot, wet tropics with annual rainfall exceeding 1,500 mm where individual plants will persist for 2-3 years. Will grow in drier environments (>1,000 mm) where it behaves as an annual. Poor drought tolerance but plants will regenerate from seed. Good tolerance of inundation
Temperature. Grows best at 32ºC maximum and 24ºC minimum daily temperatures, with outer limits of 36ºC maximum and 18ºC minimum. Prefers humid-tropical, low elevations but will grow up to altitudes of 2,000 m asl .
Light. Productivity is relatively constant at 60-100% light transmission. Will grow productively under mature coconut plantations (60-70% PAR ), but is not tolerant of heavy shade. DM yield, root growth and nodulation decrease markedly as light transmission decreases. Less shade tolerant than C. caeruleum , puero (Pueraria phaseoloides ) and centro (Centrosema molle ), which are slower to establish but more persistent under shade.
Reproductive development. Flowering is initiated by short days (14 hours), depending on accession. Calopo is self-fertile and seeds freely. May act as an annual in seasonally dry environments.
Defoliation. It is not tolerant of frequent severe defoliation but can be cut at intervals of 2-3 months. Recovers slowly from defoliation . In grazing systems, best results are achieved with rotational grazing at 8-12 week intervals.
Fire. Will not tolerate fire. However, can regenerate from seed.
Calopogonium mucunoides (Photo from Tropical Forages)
Guidelines for the establishment and management of sown pastures.
Establishment. Has a high proportion of hard seed that requires scarification by mechanical abrasion, soaking in concentrated sulphuric acid for 30 minutes, or hot water treatment (3 minutes at 75ºC). Normally planted by seed at 1-3 kg/ha, drilled in rows in new plantations or broadcast in open pastures. When broadcast, seed should be spread on the soil surface and then rolled to improve establishment. As a cover crop in plantations, planted at 1-3 kg/ha in species mixtures of 12-15 kg legume seed. Calopo is promiscuous in its rhizobia requirements, but cowpea inoculant can be used in sterile soils. Has been established into pangola grass (Digitaria eriantha ) and Paspalum plicatulum in the Northern Territory, Australia, by thoroughly spraying the grass swards with glyphosate (360 g/litre) at 10 ml/litre and sowing seed on the same day. Can also be established into cultivated strips prepared using disc harrows. Established well when broadcast into upland rice following the final weeding. Mid-season plantings may reduce rice yields.
Fertiliser. On acid soils in the Pantanal, Brazil, productivity was improved by fertilizer application using 20 kg/ha P, 20 kg/ha S, 60 kg/ha K and 1 t/ha dolomitic limestone.
Compatibility. (with other species). Will dominate cover crop mixtures during early growth due to its rapid establishment, but is suppressed by shading as other species develop. Commonly reported as a volunteer legume in humid-tropical native pastures.
Grasses: Excellent compatibility with tall, erect grasses such as Rhodes grass (Chloris gayana ), pangola grass (Digitaria eriantha ) and setaria (Setaria sphacelata ), because it is little eaten. However, its low palatability can lead to calopo dominance. Sometimes oversown into signal grass (Brachiaria decumbens ) pastures in Brazil.
Legumes: As cover crop in tree plantations in southeast Asia, often planted in a species mixture with one or more of the species C. caeruleum , Pueraria phaseoloides , Centrosema molle , and Desmodium ovalifolium .
Pests and diseases. Affected by viruses, including cowpea severe mosaic comovirus geminiviruses, and Centrosema mosaic potexvirus, but these rarely significantly impede growth. Susceptible to the root-knot nematode, Meloidogyne javanica.
Ability to spread. Will spread naturally under favourable conditions.
Weed potential. Can become a localised weed in humid-tropical environments. Has invaded tropical ecosystems in northern Australia and is listed as a weed in the Philippines, Malaysia and Indonesia.
Nutritive value. In vitro digestibility of leaf DM ranges from 58-66% depending on the age of regrowth and level of hairiness. High densities of epidermal hairs (34 hairs/mm²) are associated with lower IVDMD. CP content of top growth ranges from 16-24%, with lower values for older growth. In vivo DMD of leaf and stem DM was 58% and DMD of nitrogen was 85%.
Palatability/acceptability. Generally regarded as being of low-moderate palatability , but considerably more palatable than C. caeruleum . Cattle in confinement have refused to consume freshly cut material, eating the legume only if wilted. In other situations, the legume is consumed after cattle become accustomed to it. However, in the state of Minas Gerais in Brazil, where pastures may naturally contain a significant amount of the legume , grazing cattle have been observed consuming plants without any problems.
A 40% increase in intake was achieved by modifying the taste of calopo with monosodium glutamate (2% DM fed) and molasses (5%), or with sodium hydroxide (4%).
Toxicity. Does not contain toxic factors.
Dry matter. Under regular cutting, annual yields of 4-6 t/ha are achieved when cut every 9-12 weeks. DM yields generally decline over time with repeated cutting or grazing, and yields may be substantially lower in the second and third years after planting.
Wet season yield of 3,300 kg/ha was recorded for a Brachiaria decumbens -C. mucunoides pasture in Brazil, compared with 3,000 kg/ha for a pure B. decumbens pasture . In Planaltina, Central Brazil, DM yields ranged from 2 to 8 t/ha in the first year of growth, and was highest for late-flowering varieties. When used as an improved fallow , C. mucunoides increased maize yield by about 20%, compared with a weed fallow . In association with Brachiaria decumbens in Brazil, calopo contributed 416 kg/ha N over 2 years.
Animal production. In Brazil, cattle grazing signal grass (Brachiaria decumbens ) and B. brizantha pastures at 3.1 head/ha gained 0.35 kg/head/day over a 3 year period, whereas grass pastures oversown with C. mucunoides gained 0.40 kg/head/day over the same period. The legume percentage decreased linearly from the 1st to the 3rd year.
Genetics/breeding. There are no breeding programs for calopo. A large germplasm collection was assessed by Pizarro and Carvalho (1997), who reported significant variation in DM productivity, dry season leaf retention, nutritive value (IVDMD ), seed yield and natural habitat (collection site).
Seed production. Produces high yields of seed. In the Brazilian savannas, pure seed yields ranged from 118-860 kg/ha/year, with early-flowering accessions being higher yielding than late-flowering accessions. Elsewhere, yields of 200-300 kg/ha have been recorded. Seed may sprout in the pod in wet conditions.
Herbicide effects. No information available.
- Wide edaphic adaptation.
- Useful cover crop or pioneer legume.
- Establishes rapidly from seed to provide early ground cover.
- Relatively low palatability to ruminants.
- Intolerant of heavy grazing or regular cutting.
- Poor tolerance of heavy shade.
- Weed potential.
- Carvalho-Okano, R.M. de and Leitão Filho, H. de F. (1985) Revisão taxonômica do gênero Calopogonium Desv. (Leguminosae - Lotoideae) no Brasil. Revista Brasileira de Botânica, 8, 31-45.
- Chen, C.P. and Aminah, A. (1992) Calopogonium mucunoides . In: 't Mannetje, L. and Jones, R.M. (eds) Plant Resources of South-East Asia No. 4. Forages. pp. 72-74. (Pudoc Scientific Publishers, Wageningen, the Netherlands).
- McSweeney, C.S. and Wesley-Smith, R.N. (1986) Factors affecting the intake by sheep of the tropical legume , Calopogonium mucunoides . Australian Journal of Experimental Agriculture, 26, 659-664.
- Pizarro, E.A. and Carvalho, M.A. (1997) Evaluation of a Collection of Calopogonium mucunoides Desv. for the Cerrado Ecosystem, Brazil. Journal of Applied Seed Production, 15, 17-21.
- Seiffert,N.F. and Zimmer, A.H. (1988) ContribuciÓn de Calopogonium mucunoides al contenido de nitrÓgeno en pasturas de Brachiaria decumbens . Pasturas Tropicales, 10, 8-13.
- Veasey, E.A., Werner, J.C., Colozza, M.T., Freitas, J.C.T. de, Lucena, M.A.C. de, Beisman, D.A. and Gerdes, L. (1999) Evaluation of morphological, phenological and agronomic characters of tropical forage legumes in relation to seed production. Boletim de Industria Animal, 56, 109-125.