Centrosema acutifolium Benth.

There are two distinct forms, not yet validly described:
var. orinocense and var. matogrossense (both as "nomen nudum ", i.e. not validly described).

Bradburya angustifolia (Kunth) Kuntze
Bradburya longifolia (Benth.) Kuntze
Centrosema longifolium Benth.
Centrosema simulans Standley & L.O. Williams

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

Var. orinocense:  Perennial, trailing-twining herb with slender pubescent stems, rooting at the nodes.  Leaves trifoliolate, leaflets distinctly purplish when young;  stipules deltoid-acuminate, pubescent;  petioles and petiolules pubescent, reddish at their base;  leaflets ovate to ovate-lanceolate, apically acuminate, puberulous to subglabrous on both surfaces;  central leaflet symmetrical, 5-8.5 cm long, 3-3.5 cm wide;  lateral leaflets somewhat smaller, asymmetrical.  Inflorescence an axillary raceme with up to 24 flowers inserted by pairs along the rachis;  peduncle conspicuously long, up to 19 cm, pubescent.  Flower papilionate, subtended by a pair of ovate-acuminate bracteoles shorter than the calyx;  calyx campanulate, 5-toothed, pilose, with short carinal and lateral teeth;  petals light violet, standard orbicular-emarginate, 28-35 mm x 32-40 mm, pubescent outside.  Pod linear, straight to slightly bent, up to 20 cm long, beaked, scabrid, with 10-15 seeds, dehiscent.  Seeds cylindrical, 5-7 mm long, ca. 3 mm wide, greenish yellow with dark, fine mottles.  14,000-20,000 seeds/kg.

Var. matogrossense:  leaflets more elongated;  peduncle not longer than 8 cm;  bracteoles slightly longer than calyx;  pod shorter, glabrous;  seeds yellow, never mottled.

Native to:
South America:  Brazil (Mato Grosso, Tocantins, Goias, Minas Gerais), Venezuela, Colombia.
Var. orinocense is restricted to the Orinoco region between 4º and 6ºN.
Var. matogrossense occurs in an extended area in central west Brazil.

Grazed pastures in mixture with a grass, as a legume -only protein bank and cut-and-carry.

Adapted to very acid, low- to medium-fertility soils, var. orinocense requiring lighter textured soils, and var. matogrossense preferring clayey, less well-drained soils.  Tolerant of high levels of available Al and Mn.

Sub-humid tropics with (800-) 1,000-2,500 (-3,000) mm rainfall with 3-5 months dry season;  drought tolerant.

Warm season growth only.  Average annual temperature in its native distribution is about 26ºC.

No significant shade tolerance.

Late flowering, probably induced by short days.

Susceptible to heavy grazing.

No information available.

Guidelines for the establishment and management of sown pastures.

Mechanical or acid scarification necessary to reduce the high level of hard-seededness.  Seed is normally sown at 3-4 kg/ha;  inoculation with an effective strain of Bradyrhizobium such as CIAT 3101 (= CB 3125 in Australia) is recommended.

Responds well to P and K, with per hectare rates of 22 kg P, 30 kg K, 20 kg Mg and 20 kg S at sowing, and a maintenance dressing of half this every two years, being effective on a very acid infertile soil.

Combines well with bunch grasses and other species that produce a more open stand.

Grasses:  Andropogon gayanus , Brachiaria brizantha , B. humidicola ,Panicum maximum .
Legumes:  Stylosanthes capitata , S. guianensis.

Mainly var. matogrossense:  Susceptible to Pseudomonas bacterial wilt  and little leaf disease (phytoplasma);  less susceptible to foliar blight (caused by Rhizoctonia solani) than is C. brasilianum .

No significant spread.

Probably none.

3-month old leaf:  CP 21-29%;  IVDMD 52-69%;  P 0.14-0.25%;  Ca 0.38-0.82%.

High.

None reported.

Rainy season:  1-3 (-5) t/ha/12 weeks DM.
Dry season:  <1 t/ha/12 weeks DM.
Annual:  5+ t/ha/yr DM.

Var. orinocense in mixture with Andropogon gayanus has produced daily LWG /steer of 530-670 g in rainy season and sustained LW in dry season at a stocking rate of 1.5 steers/ha.
Var. matogrossense in associations with A. gayanus or B. humidicola , increased milk yields of grazing Holstein cows by 15-20% over grass alone.

2n = 22;  autogamous;  no breeding projects.

Moderate to low, e.g. in Colombia 150-200 kg/ha handpicked, but potential yields up to 700 kg/ha.  With its late flowering habit, early onset of the dry season can seriously interfere with seed production.

No information available.

• Adaptation to very acid, high Al and Mn, low-fertility soils.
• High forage quality.
• Potentially high seed production.

• Lack of persistence.
• Low seed production in unsuitable environments.

Lascano, C.E. and Avila, P. (1991) Potencial de producción de leche en pasturas solas y asociadas con leguminosas adaptadas a suelos ácidos. Pasturas Tropicales, 13, 2-10.

Schultze-Kraft, R., Benavides, G. and Arias, A. (1987) Recolección de germoplasma y evaluación preliminar de Centrosema acutifolium. Pasturas Tropicales-Boletín, 9, 12-20.

Schultze-Kraft, R. and Clements, R.J. (1990) (eds) Centrosema: Biology, Agronomy, and Utilization. Centro Internacional de Agricultura Tropical (CIAT), Cali, Colombia.

Schultze-Kraft, R. (1992) Centrosema acutifolium Benth. In: 't Mannetje, L. and Jones, R.M. (eds) Plant Resources of South-East Asia No. 4. Forages. pp. 80-82. (Pudoc Scientific Publishers, Wageningen, the Netherlands).

http://www.fao.org/ag/AGP/AGPC/doc/Gbase/data/pf000471.htm

Cultivars	Country/date released	Details
'Vichada' (CIAT 5277, BRA-004162, BRA-004219, ILCA-12182, CNPGC-0692, CNPGC-0866, CPAC-1223, CPATU-00690, IRFL-4850, IRFL-4981, CPI 94327, CPI 121846)	Colombia, 1987	Var. orinocense.  From Vichada Province, Colombia (4º 53'N, 150 m asl, rainfall 2,130 mm).  High yielding, widely adapted.

Promising accessions	Country	Details
CIAT 5568	Colombia	var. matogrossense.
CIAT 15086	Colombia	var. orinocense.