Desmodium heterocarpon subsp. heterocarpon


Scientific name

Desmodium heterocarpon (L.) DC. subsp. heterocarpon

Synonyms

Desmodium polycarpon (Poir.) DC.
Hedysarum heterocarpon L.
Hedysarum polycarpon Poir.
Meibomia heterocarpos (L.) Kuntze

Family/tribe

Family: Fabaceae (alt. Leguminosae) subfamily: Faboideae tribe: Desmodieae subtribe: Desmodiinae. Also placed in: Papilionaceae.

Common names

carpon desmodium (English);  buntut meyong sisir, kaci, akar entimor (Indonesian);  rumput kerbau derapah, kacang kayu betina (Malaysian);  mangkit-parang, mani-mani, huyo-huyop (Philippines);  baay dam nnaep (Cambodia);  trang qua di qua (Vietnam).

Morphological description

A perennial (3-5 year) sub-shrub, sometimes a shrub or herb, ascending or often creeping with a woody rootstock.  Stems and branches up to 1 m long, diffuse and ascending or erect, although prostrate under heavy grazing.  Adventitious rooting sometimes occurs from stems lying on the soil surface.  Stems range from nearly glabrous to densely covered with white or yellowish hairs.  Leaves are generally trifoliate , though unifoliate leaves are common on seedlings and not unusual toward the base of mature stems.
Leaflets smooth on the upper surface and hairy underneath, often with a light green to almost yellow watermark on the upper surface.  Terminal leaflet normally broadly elliptic, ovate or obovate, with tips generally retuse.  Inflorescence composed of densely flowered, terminal and axillary racemes;  flowers pink.  Pods erect or ascending, narrowly oblong, compressed and generally 4-8-jointed, turning from green to dark brown on maturity.  Articles quadrangular to semi-elliptic, straight along the upper suture , somewhat rounded below, separating and then dehiscing.  Seeds almost quadrate, cream to orange in colour, 2 x 1.5 mm.  700-800 seeds/g.

Distribution

Native to:
Pantropical and also subtropical in Old World:  Africa, Asia, Melasia, China, Taiwan Japan, Australia and Pacific.

Now naturalised elsewhere, and sown to a limited extent in Florida (southern states of USA).

Uses/applications

Practical and resilient long-term grass-legume pasture .

Ecology

Soil requirements

Range of well-drained soils of light texture, including the better-drained mineral soils of southern Florida.  Needs moderate soil P levels.
Can tolerate very low pH and high Al saturation.  Can suffer from trace element deficiency on neutral or alkaline soils.

Moisture

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AAR of 1,250-1,500 mm in Florida but up to 2,500 mm elsewhere.  Mature plants have some drought tolerance but seedlings are very susceptible.
The great drought of 2000-2001 was responsible for the loss of much carpon desmodium in central and southern Florida.
Carpon can survive up to a week of intermittent shallow flooding, but not extended periods.

Temperature

Carpon grows well in cooler conditions, as in Florida spring, but most growth (65%) is in summer.  Tolerates repeated light frosts and can grow to 2,500 m altitude in the tropics.

Light

No information available.

Reproductive development

No information available.

Defoliation

Tolerant of heavy grazing when it develops a prostrate growth habit with a very low protected crown.  When grown with aggressive grasses such as Paspalum notatum , heavy rotational (3-6 week) grazing is recommended to prevent grass dominance.

Fire

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No information available.

Agronomy

Establishment

In southern Florida, seed can be planted any time from after the last frost until August, but little or no seed will set during the first year unless germination occurs before July.  On clean seed beds, seeding rate is 3-5 kg/ha, but 5-10 kg/ha in established grass areas;  nodulates with native cowpea rhizobium .  Hard seed levels of 50-65%.
Seedling growth is slow, but once established, carpon can persist for more than 10 yeas without special grazing management.

Fertiliser

In southern Florida, recommendations are about 2.5 t/ha of lime, 45-50 kg/ha of P and K on virgin flatwood soils, with annual maintenance dressings of about 300 kg/ha of 0-10-20 (N:P:K).

Compatibility (with other species)

Carpon competes well with aggressive grasses provided they are grazed moderately heavily and not fertilised with nitrogen.

Companion species

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Grasses:  Digitaria eriantha , Hemarthria altissima , Paspalum notatum in Florida.
Legumes:  Combines well with white clovers (Trifolium spp.).

Pests and diseases

Free of major leaf diseases but sensitive to various leafspots (Cercospora sp., Pestalotiopsis versicolour).  Some damage from Colletotricum anthracnose in southern USA and South America.  Powdery mildew (Oidium sp.) and wilt (Sclereotinium rolfsii) have been recorded.  In Florida, carpon is susceptible to at least two species of root knot nematodes (Meloidogyne incognita and M. arenaria) and should not be planted in infested areas.  Cv. Florida is particularly susceptible.  Nematode attack has not been documented in southeast Asia.  Little leaf Mycoplasma has been recorded as moderate to severe in Central and South America.  Web-worms and other insects can attack the foliage and seed pods in long ungrazed stands during flowering and weed maturation, but are best controlled by grazing until mid-August and then closing for a short only seed-production period.

Ability to spread

Carpon can be spread through the dung of stock grazing the seed heads.  Resting the grass-legume pasture for the legume to seed and then introducing stock is recommended to maintain legume soil seed reserves for regeneration.  A bahia grass (Paspalum notatum ) pasture with a good stand of carpon desmodium had soil seed reserves of more than 300 seeds/m², equivalent to about 3 kg/ha.

Weed potential

No information available.

Feeding value

Nutritive value

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Less nutritious than legumes such as Aeschynome and Stylosanthes but easier to maintain in a pasture.  The foliage contains 1.5-3.2% N, depending on growth stage, while grass/legume mixtures average 9-10% CP.  Some 130 kg/ha/yr N has been measured in harvested forage , equivalent to 190-260 kg/ha N applied to pure pangola (Digitaria eriantha ) and bahia grass (Paspalum notatum ) pastures.
In vitro organic matter digestibility of the legume grass mixture ranged from 45-60%, depending on the grass and season of the year.  Tannin percentages from two cuts were 2.3 and 3.1%.  In vitro digestible OM of carpon desmodium leaves was low in summer (47.0 vs 51.2% for bahia grass (Paspalum notatum ) during the same period.  Carpon desmodium leaf CP averaged 17.6% (compared with 6.8% for bahia grass ).

Palatability/acceptability

No information available.

Toxicity

No information available.

Production potential

Dry matter

No information available.

Animal production

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Yearling steers continuously grazed a mixture of three tropical legumes with bahia grass (Paspalum notatum ) at three stocking rates.  Carpon desmodium (D. heterocarpon subsp. heterocarpon), which persists under grazing but is often difficult to establish, was combined with the short-lived legumes joint vetch (Aeschynomene americana ) and phasey bean (Macroptilium lathyroides ).  Joint vetch and phasey bean contributed to diets during the first summer, and carpon desmodium contribution was greater in the second summer.  Pasture mixtures can provide legume herbage from joint vetch and phasey bean in the first year and from carpon desmodium thereafter.

Genetics/breeding

Very poly-morphic due to cross-pollination .

Seed production

Cross-pollinating but self-pollinating if flowers are tripped.
In Florida, flowering begins in early September and seed matures by November.  Mature pods do not shatter readily, but grass/legume mixtures are mown when 85-90 percent of the pods are mature.  The herbage is allowed to dry for at least one day, and preferably 2-3 days, before pick-up threshing.  Pick-up threshing is preferable to direct heading because the vegetative material still has a high moisture content at this stage, and is likely to gum the threshing bars of the drum if direct headed.

Herbicide effects

No information available.

Strengths

  • Resilient, easy to manage.
  • Combines with aggressive grasses.
  • Cool season growth.

Limitations

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  • Susceptible to root-knot nematodes.
  • High tannin content.
  • Low quality.

Other comments

    

Selected references

Aiken, G.E., Pitman, W.D., Chambliss, C.G. and Portier, K.M. (1991) Responses of yearling steers to different stocking rates on a subtropical grass-legume pasture . J. An Sci., 69 , 3348-3356.
Kretschmer, A.E. Jr., Brolmann, J.B, Snyder, G.H. and Coleman, S.W. (1982) Registration of 'Florida' carpon desmodium (Reg. No. 24). Crop Sci., 22, 158-159.
Lenné, J. and Stanton, J.M. (1990) Diseases of Desmodium species. Tropical Grasslands, 24, 1-14.
Ohasi, H. (1973) The Asiatic species of Desmodium and its allied genera (Leguminosae). Ginkgoana, 1, 210-216.
Ohasi, H. (1991) Taxonomic studies in Desmodium heterocarpon (L.) DC. (Leguminosae). Journal of Japanese Botany, 66, 14-25.

Internet links

Cultivars

Cultivars

Country/date released

Details

'Florida'
(PI 217910)
Florida, USA (1979) From Forest Research Institute, Dehra Dun,Uttar Pradesh, India.

Promising accessions

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Promising accessions

Country

Details

None reported.