Aeschynomene brasiliana


Scientific name

Aeschynomene brasiliana (Poir.) DC.

Subordinate taxon :
Aeschynomene brasiliana (Poir.) DC. var. brasiliana

Synonyms

Aeschynomene biflora (Miller) Fawcett & Rendle
Aeschynomene guaricana Pittier
Aeschynomene paucijuga DC. var. subscabra DC.
Cassia biflora Miller
Cassia houstoniana Colladon
Hedysarum brasilianum Poir.
Hedysarum hirtum Vell. Conc.

Family/tribe

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

Common names

Brazilian jointvetch, pega pega.

Morphological description

Prostrate or decumbent herb with stems to about 2 m, glandular-hispidulous (bristly and sticky), also crisp-pubescent, woody near the crown.  Leaves pinnate, 2-3 cm long, to 22 foliolate, with leaflets obovate-elliptic to oblong, 5-15 mm long and 3-8 mm wide, sparsely pubescent to glabrous on the upper surface.  Inflorescence comprising 1-8 yellow flowers, calyx hispidulous, standard about 6 mm long.  Pod with 2-5 segments, crisp-pubescent and also glandular-hispidulous, each article about 2.5-3 mm long and 2-3 mm wide.  Seeds dark brown, about 2 mm long and 1-1.5 mm wide;  200,000-300,000 seeds/kg.

Distribution

Native to:
North America:  Mexico (Jalisco).
Central America:  Belize, Costa Rica, El Salvador, Guatemala, Honduras, Mexico (Chiapas), Nicaragua, Panama.
Caribbean:  Cuba, Trinidad and Tobago (Trinidad).
South America:  Bolivia, Brazil (Amapá, Pará, Bahia, Goias, Ceará, Rio de Janeiro), Colombia, Ecuador, French Guiana, Guyana, Paraguay, Peru, Suriname, Venezuela.

Widespread in tropical America, along roadsides, in brushland, savannah and open pine-oak woods.

Uses/applications

Legume enhancement of poor quality grassland.  No value for cutting systems due to sticky nature of stems and fruit.

Ecology

Soil requirements

Mostly collected from sandy soils of near neutral pH .  Although showing best performance on friable, sandy-surfaced soils, A. brasiliana has also persisted on well-drained soils with hard-setting surface.  Appears to have adaptational range approaching that of Stylosanthes scabra .

Moisture

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Rainfall at collection sites ranges from 650-2,200 mm/yr, but mostly between about 800 and 1,000 mm/yr.  Although one collection site was subject to flooding, A. brasiliana does not appear to tolerate more than short-term waterlogging .

Temperature

Occurs from about 23ºN in Mexico and Cuba to about 23ºS in Paraguay, at low and high altitude (up to about 3,000 m) in the tropics, but only at low altitude in less tropical areas.  This places most collection sites as having an annual average temperature in the range 24-27ºC, and less in the extreme upland tropics.  Tops are killed by frost but established plants usually recover with the onset of warm conditions.

Light

No information available.

Reproductive development

Appears to have short day flowering response, those accessions tested flowering mid to late March at 21ºS.

Defoliation

Tolerates regular defoliation but generally not selectively grazed by stock.

Fire

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Established plants survive fire, and hard seededness of soil seed reduced by fire.

Agronomy

Establishment

Mechanical scarification of hand-harvested seed may be necessary to overcome high levels of hardseedednessA. brasiliana appears to be somewhat promiscuous, but may nodulate more effectively with CB 2312.

Fertiliser

No data, but like many other Aeschynomene, A. brasiliana will probably respond to P applications in low P soils.

Compatibility (with other species)

Grows with less fertility demanding, less competitive species.

Companion species

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Pests and diseases

Botrytis stem rot caused by Botrytis cinerea is most pronounced in seed crops, because development of the disease is favoured by flowering, and the moist conditions that often prevail at flowering time.  Seed yields may be markedly reduced in affected crops, although disease incidence can be minimised by growing crops under irrigation in less humid areas.

Ability to spread

Spread readily by virtue of sticky pods, and through seed being ingested by livestock.

Weed potential

Its ability to develop high soil seed reserves (up to 2,000-3,000 seeds/m2 after 5 years, compared with 500 seeds/m2 in Stylosanthes scabra under comparable conditions) together with its relatively low palatability and fairly wide adaptation indicate weediness potential.

Feeding value

Nutritive value

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One tip sample comprising 70% leaf yielded the following:
 leaf:  18% CP, 0.18% P, 23.6% ADF
 stem:  9.5% CP, 0.15% P, 46.7% ADF .

Palatability/acceptability

A. brasiliana is not well accepted by cattle, particularly in the first season.  However, cattle that have grazed it during winter or the dry season, tend to eat it more readily the following growing season .  Observation suggests it is not much less palatable than S. scabra .  It sheds its leaf in the dry season, but cattle "lick up" the fallen leaf.

Toxicity

No record.

Production potential

Dry matter

Yields in grazed pastures may be as low as 100 kg/ha DM.  However, estimated yields of pure stands growing under ideal conditions are in excess of 5,000 kg/ha DM.

Animal production

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No information available.

Genetics/breeding

Single accession from Colombia had chromosome number of 2n = 20.

Seed production

During the growing season, leaf and stem material becomes quite sticky due to glandular exudates.  The presence of this non-water soluble exudate is an impediment to direct header harvesting of a seed crop.  However, seed yields of 400-600 kg/ha can be obtained and up to 800 kg/ha with follow-up suction harvesting.

Herbicide effects

Susceptible to 2,4-D, 2,4-DB, MCPA, bentazone, fluroxypyr and dicamba. Tolerant of imazethapyr.

Strengths

  • Drought hardy.
  • Persistent.
  • Good seed yields.

Limitations

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  • Fairly low palatability .
  • Presence of sticky exudate.
  • Leaf drop with moisture stress.

Other comments

Should be tested under sufficiently controlled conditions to facilitate eradication should the need arise.

Selected references

Bielig, L.M. (1997) Chromosome numbers in the forage legume genus, Aeschynomene L. Sabrao Journal, 29, 33-39.
Rudd, V.E. (1955) The American species of Aeschynomene. Contributions from the United States National Herbarium, 32, 76-80.

Internet links

  

Cultivars

Cultivars

Country/date released

Details

None released to date.      

Promising accessions

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Promising accessions

Country

Details

CPI 92519, CIAT 8253 Australia From Rio Grande do Norte, Brazil (6.5ºS, 160 m asl, rainfall 650 mm).  Selected as an alternative to Stylosanthes scabra - similar adaptation.
CPI 93592, IRFL 2009 Australia From Mato Grosso do Sul, Brazil (21.25ºS, 300 m asl, rainfall 1,550 mm).  Slightly earlier flowering and heavier seed-set than CPI 92519;  also more viscid plant parts, less palatable and greater weed threat.