Aeschynomene evenia


Scientific name

Aeschynomene evenia C. Wright

Subordinate taxa:
Aeschynomene evenia C. Wright var. evenia
Aeschynomene evenia C. Wright var. serrulata Rudd

Synonyms

    

Family/tribe

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

Common names

shrubby jointvetch, evenia Aeschynomene, evenia jointvetch.

Morphological description

An annual or short-lived perennial , 50 cm to 2 m tall, morphologically similar to A. indica with similar characteristic smell.  Stems sparsely hispidulous, often glabrate, 2-4 mm at base in shorter varieties.  Leaves pinnate, 2-4 cm long, 16-50 foliolate, petioles and rachises hispidulous, leaflets 2-9 mm long, 1-2 mm wide.  Inflorescences comprising 1-6 flowers;  flowers 5-7 (rarely -9) mm long, with standard about 6 mm long;  corolla generally yellow (sometimes greenish-yellow or mauve) with reddish-brown veins.  Pod 5-14 articulate, from 5-7.5 cm long, hispidulous, usually glabrate, entire on one longitudinal suture, sub-crenate (slightly scalloped) on the other;  articles 2.5-3.5 mm diameter, separating on the transverse suture , but retaining the seed.  Seed light brownish-yellow to brown or black, about 2 mm long and 1.5 mm wide;  200,000-370,000 (av. of 7 accessions 250,000) seeds/kg.

Distribution

Native to:
North America:  USA (Arkansas, Texas).
Mesoamerica:  Panama (Panama).
Caribbean:  Cuba, Dominican Republic, Haiti, Jamaica, Puerto Rico, St. Lucia.
South America:  Northwest Argentina, Bolivia, Brazil, Colombia, Venezuela.
Typically found in wet or moist areas at elevations below 500 m asl .

Uses/applications

Mostly used as a regenerating component in permanent pastures.

Ecology

Soil requirements

Found in sands to clay loams, but distribution is largely determined by moisture availability.  No data on pH or fertility requirements but presumably similar to those for A. americana .

Moisture

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Mostly found in areas with surface moisture or free water, but adapted to areas with a high water table as in Florida, USA.  Rainfall at collection sites ranges from 550-1,800 mm/yr.  Grows well in waterlogged and temporarily flooded areas.

Temperature

Occurs at relatively low altitudes between about 18ºS in Bolivia to 28ºN     This equates to a range in average annual temperature from 22-26ºC.

Light

No information available.

Reproductive development

Some types appear to flower throughout the growing season , suggesting a day-neutral flowering response.  However, later flowering, short-day types also exist.

Defoliation

A. evenia must be grazed heavily so that it does not become dominant in the pasture and to keep it at a more palatable stage of growth.  Cattle will not graze large and stemmy plants.

Fire

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No information available.

Agronomy

Establishment

Fresh seed-in-hull has a high level of hardseededness that is largely broken down by the dehulling process.  Although A. evenia is somewhat promiscuous in its rhizobium requirements, seed should be inoculated with a broad-spectrum cowpea-type inoculum such as CB 756.  Aeschynomene inoculum , CB 2312, may also be effective.  Sowing rates of 5 (precision planter on a clean-tilled seeded) to 8 kg of dehulled seed/ha (broadcast seeding, poorer seedbed) are recommended in Florida, although lower rates should still be effective.

Fertiliser

Liming to raise soil pH to between 5.5 and 6.0 may be necessary if pH is below 5.0.  In less fertile soils, applications of the order of 15 kg/ha P and 50 kg/ha K may be beneficial.  The need for Mo needs to be explored on more acid soils.

Compatibility (with other species)

Capable of growing with competitive species such as bahia grass (Paspalum notatum ), and may out-compete such species if allowed to grow rank.

Companion species

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Pests and diseases

Susceptible to anthracnose caused by Colletotrichum gloeosporioides.  Fork-tailed caterpillars (Selenisa sueroides: Noctuidae) feed on growing tips and inflorescences in Florida.

Ability to spread

Re-establishes readily from constant seed drop.

Weed potential

No information available.

Feeding value

Nutritive value

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Leaf: stem ratio varies from 0.8:1 to 1.7:1, depending on stage of growth.  CP values 9-15% and IVOMD 29-47 % (cf. 10-18% and 44-52% in Aeschynomene americana ).  CP of top 30 cm c. 27% with 67% IVOMD , compared with 16% and 51% for the next 30 cm.

Palatability/acceptability

It is not immediately palatable to cattle and they will only graze small plants.  Cattle will adapt to A. evenia with time, but will still prefer young growth.  Not as palatable as, and more woody than A. americana .

Toxicity

No information available.

Production potential

Dry matter

In association with Digitaria eriantha (pangloa grass ), A. evenia has comprised 29-66% of the pasture , compared with 29-54% for A. americana .  All legume yields were relatively low, ranging from 560-1,870 kg/ha.

Animal production

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At a stocking rate of 3 yearling steers/ha, animals gained an average of 0.7 kg/hd/day during the growing season on Paspalum notatum /A. evenia pasture .

Genetics/breeding

2n = 20.  No information on breeding system.

Seed production

Can produce two crops/year, of about 100 kg/ha.

Herbicide effects

No information available.

Strengths

  • Grows in wet situations.
  • Competes with vigorous grasses.
  • Not fertility demanding.

Limitations

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  • Not very palatable.
  • Must be intensively managed.

Other comments

    

Selected references

Bielig, L.M. (1997) Chromosome numbers in the forage legume genus, Aeschynomene L. Sabrao Journal, 29, 33-39.
Bishop, H.G., Pengelly, B.C. and Ludke, D.H. (1988) Classification and description of a collection of the legume genus, AeschynomeneTropical Grasslands, 22, 160-175.
Kretschmer, A.E., Pitman, W.D., Bullock, R.C. and Wilson, T.C. (1994) Aeschynomene evenia C. Wright (evenia aeschynomene), a perennial legume for grazing in South Florida. Soil and Crop Science Society of Florida, Proceedings, 53. pp. 52-59.
Rudd, V.E. (1955). The American species of Aeschynomene. Contributions from the United States National Herbarium, 32, 60-62.

Internet links

Cultivars

Cultivars

Country/date released

Details

'Evenia'
(IRFL 6945)
Florida, USA (1993) Adventive variety appearing following evaluation of IRFL 2345 and 2348 from Brazil.  Potentially taller growing type, to 2 m, with grey-green leaves and mauve flowers.  Can develop adventitious roots on prostrate stems in contact with wet ground.  Flowers and sets seed through much of the growing season .  Selected as an adjunct to A. americana , and may extend role of Aeschynomene into areas receiving early frosts.  Survives mild winters, putting up new growth in the spring.

Promising accessions

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Promising accessions

Country

Details

None reported.