Vigna oblongifolia


Scientific name

Vigna oblongifolia A. Rich.

Subordinate taxa:
Vigna oblongifolia A. Rich. var. oblongifolia
Vigna oblongifolia A. Rich. var. parviflora (Welw. ex Baker) Verdc.

Synonyms

Vigna oblongifolia A. Rich. var. oblongifolia
Vigna lancifolia A. Rich.
Dolichos dillonii Del.
Vigna wilmsii Burtt Davy
Vigna oblongifolia A. Rich. var. parviflora (Welw. ex Baker) Verdc.
Vigna parviflora Welw. ex Baker

Family/tribe

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

Common names

  

Morphological description

A variable annual or short-lived perennial species with trailing or weakly twining (rarely semi-erect) habit, to 0.8 m high, and with stems 1-5 m long.  Leaves trifoliolate, 1.5-12 cm long, 0.2-2.5 (-3.5) cm wide, rounded to acute at the apex, cuneate or rounded at the base, pubescent on both surfaces.  Inflorescence a raceme comprising 2-10 yellow or greenish-yellow flowers on a short, somewhat zigzag rachis on a hairy peduncle 2-35 cm long;  swollen glands at bases of pedicels.  Pods hanging downwards, linear cylindrical, compressed, slightly constricted between the seeds, covered with adpressed, reddish-brown/white hairs, 3-9 seeded.  Seeds greenish, brown or dark reddish-brown, often mottled with black;  irregularly oblong, ovoid or sub-globose, 2-4.5 mm long, 2-3.2 mm wide, and 1.5-2.2 mm thick;  aril eccentric.  30,000-110,000 seeds/kg.
var. oblongifolia:  leaflets ovate, oblong-lanceolate to lanceolate, up to 12 cm long, 2.2 cm wide.  Standard 10-11 mm long.  Pods 4-6.5 cm long.
var. parviflora:  leaflets ovate to linear-lanceolate, 1.5-8 cm long, 0.2-2.5 cm wide.  Standard 6-8 mm long.  Pods 2.3-4 cm long.

Distribution

Native to:
Africa:  Angola, Botswana, Burundi, Cameroon, Democratic Republic of Congo (Zaire), Ethiopia, Kenya, Malawi, Namibia, northern Nigeria, Rwanda, South Africa, Sudan, Tanzania, Uganda, Zambia, Zimbabwe.
Western Indian Ocean:  Madagascar.
var. oblongifolia:  Damp grassland and swamps, particularly with Echinochloa, also Acacia scrub;  800-1,900 m asl .
var. parviflora:  Grassland, thicket, woodland, cultivation areas, often on rocky soil, frequently near edges of lakes, stream banks or in swamps;  330-1,860 m asl .

Uses/applications

Pioneer in permanent pasture and for short-term pasture leys.

Ecology

Soil requirements

Found on clays, clay loams, loams and sands with pH of 5.2-7.4, and has been successfully cultivated on light and heavy clays with pH up to 8.5.

Moisture

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Collected from areas with rainfall ranging from 350-1,200 mm/yr, largely from areas of impeded drainage, high water table and swamp, but also from well-drained soils.  In cultivation, it has failed to persist in well-drained, low rainfall environments but has persisted and spread in more humid environments.

Temperature

V. oblongifolia extends from about 29ºS in South Africa to north of the equator in Ethiopia, and from 300-1,900 m asl.  Average annual temperatures at collection sites range from about 17-23ºC, experiencing frosts in the higher latitudes.  Annuals are killed by frost and therefore need to set seed early in order to regenerate.

Light

No information available.

Reproductive development

Accessions tested appear to be short day plants, commencing flowering in March/April at about 26ºS, with some variation between accessions.

Defoliation

Requires rotational grazing to allow for regrowth and seed set.  Little regrowth if cut back when mature.

Fire

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No information available.

Agronomy

Establishment

Although this species appears promiscuous in its rhizobium requirements, inoculation with a cowpea strain such as CB1015 or CB756 may be advantageous.  Seed is sown at 3-5 kg/ha into a well-prepared seedbed.

Fertiliser

No information available.  As with many other Vigna spp., V. oblongifolia will probably respond to P on soils low in this nutrient.

Compatibility (with other species)

Competes effectively with grasses and other legumes when sown together, but does not regenerate very successfully in competition with perennial grasses in sub-humid environments.

Companion species

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Pests and diseases

Leaves often have scattered to dense perforations caused by leaf-eating insects, although this rarely constitutes a serious problem.  Pods are not attacked to any extent by the legume pod borer (Maruca vitrata) and pod sucking bugs (Clavigralla tomentosicollis, Anoplocnemis curvipes and Riptortus dentipes) all of which cause significant damage in cowpea (Vigna unguiculata ).  The legume pod borer and pod sucking bugs can cause tremendous grain-yield losses in cowpea if appropriate control measures are not taken.  The results showed that some accessions of V. vexillata and V. oblongifolia have good levels of resistance to the insect pests that devastate cowpea.

Ability to spread

V. oblongifolia has significant capacity to spread, providing the defoliation pressure is fairly low.  Pods shatter violently, flicking seed some distance from the parent plant, and seed is also spread through ingestion by the grazing animal.

Weed potential

Although it can spread, it is insufficiently aggressive and too palatable to livestock to pose a significant weed threat.

Feeding value

Nutritive value

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No information available.  However, V. oblongifolia bears a superficial resemblance to Vigna parkeri with its high palatability, leafy canopy and fine, soft stems, it probably has similar nutritive value.

Palatability/acceptability

Highly palatable.

Toxicity

No record of toxicity in this or other Vigna spp.

Production potential

Dry matter

Produces from 2-6 t/ha/yr DM.

Animal production

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No information available.

Genetics/breeding

2n = 22.

Seed production

No information available.

Herbicide effects

No information available, but probably has tolerances and susceptibilities similar to those of Vigna parkeri .
"Trifluralin can be used for pre-emergent, and bentazone (at 2-4 leaf stage), the imidizolinones (imazethapyr, imazaquin), and flumetsulam for post-emergent broadleaf weed control, but there is the risk of some stunting of V. parkeri seedlings.  Fluazifop and sethoxydim can be used for selective grass control in seed crops.  Seedlings are susceptible to acifluorfen, 2,4-D and 2,4-DB."

Strengths

  • Easily established in cultivated, weed-free seedbeds.
  • Very palatable.
  • Tolerant of poor drainage.

Limitations

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  • Low to moderate productivity.

Other comments

  

Selected references

Clem, R.L., Brandon, N.J., Conway, M.J., Esdale, C.R. and Jones, R.M. (2001) Early stage evaluation of tropical legumes on clay soils at three sites in central and southern inland Queensland. Tropical Agriculture Technical Memorandum No 7. CSIRO Tropical Agriculture.
Gillett, J.B., Polhill, R.M. and Verdcourt, B. (1971) 'Papilionoideae (2)'. In: Milne-Redhead, E. and Polhill, R.M. (eds) Flora of Tropical East Africa, Leguminosae (Part 4). pp. 629-630. (Crown Agents for Overseas Governments and Administrations: London).
Hacker, J.B., Williams, R.J. and Pengelly, B.C. (1996) A characterisation study of the genus Vigna with regard to potential as a forage . Genetic Resources Communication No 22. CSIRO Division of Tropical Pastures, St Lucia, Qld, Australia.
Jones, R.M. (1998) Evaluation of a range of tropical legumes on two clay soils in south-east inland Queensland. Tropical Agriculture Technical Memorandum No 2. CSIRO Tropical Agriculture.
Jones, R.M. (2001) Evaluation of legumes and grasses in coastal south-east Queensland. Tropical Grasslands, 35, 85-95.
Pengelly, B.C. and Conway, M.J. (1998) The evaluation of tropical legumes for use in ley pastures in central and southern Queensland. Proceedings of the Ninth Australian Agronomy Conference, Wagga Wagga, NSW. Australian Society of Agronomy . pp. 163-166.
van Rensburg, H. J. (1967) Pasture Legumes and Grasses in Zambia. (Govt. Printer: Lusaka.)

Internet links

Cultivars

Cultivars

Country/date released

Details

None released to date.      

Promising accessions

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Promising accessions

Country

Details

CPI 121699 Queensland, Australia Var. parviflora From north of Maun, Botswana (20º 08'S, 23º 29'E, 940 m asl, rainfall 465 mm) Regenerating annual on heavy clay soil with potential as ley legume .
CPI 60433 Queensland, Australia From east of Kabale, Uganda (1º 15'S, 29º 41'E, 1,360 m asl, rainfall 950 mm).  Regenerating annual on heavy clay soil with potential as ley legume .
Q 25362 Queensland, Australia Origin uncertain.  Naturalised on sandy and clay soils in the humid subtropics.  Readily spread by cattle.
CPI 60430 Queensland, Australia From South Africa (Lat 29ºS, 1,212 m asl, rainfall 750 mm).
CPI 28763 Queensland, Australia Native of east Africa.  Introduced from the Grassland Research Station, Kitale, Kenya.