Stylosanthes capitata


Scientific name

Synonyms

    

Family/tribe

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

Common names

capitata.

Morphological description

Short-lived perennial, erect, ascendant to decumbent sub-shrub, to 1 m diameter and high, multi-branched, stems occasionally woody at the base, with variable pilosity, sometimes with bristles.  Leaves trifoliolate;  leaflets elliptical to oblong, sometimes obovate, very variable to 30 (rarely 40) mm long, 12-15 mm wide, apex acute or mucronate, variable pilosity on both faces;  petiole densely piloseInflorescence capitate, oblong to obovate, to 7 cm long and 1.5-2 cm wide;  bracts oblong, 9-13 mm long including teeth, variable pilosity, bristles sometimes present.  Multi-flowered inflorescences borne in dense terminal or axillary clusters.  Papilionaceous flowers bright yellow, unstriated, standard to 7 mm diameter.  Pod 2-segmented, both segments fertile;  each 5-7 mm long, 2.2-2.5 mm wide, the upper segment with a 1 mm long, straight or recurved beak.  Seed of variable colour, almost black to yellow, sometimes spotted, 2 mm long.

Distribution

Native to:
South America:  Eastern Brazil, Venezuela.
Restricted distribution compared with that of the widespread species, Stylosanthes guianensis and S. humilis .  Occurs in treeless and open woodland savannah habitats, often in association with S. macrocephala , S. scabra , and 'fine-stemmed' forms of S. guianensis var. guianensis (also known as var. pauciflora).
Three ecotypes recognised in Brazil:
1) From Minas Gerais and the Federal District - prostrate plants with thick stems and large leaves, susceptible to anthracnose.
2) From Mato Grosso do Sul, Goias, Bahia - erect (sometimes prostrate ) plants, thinner stems, more branched, leafier, some resistance to anthracnose.
3) Northern Brazil (also Venezuela) - mostly prostrate plants, smaller leaves and inflorescences, greater anthracnose resistance.

Uses/applications

Permanent pastures for intensive grazing in grass-legume associations.

Ecology

Soil requirements

Occurs naturally on acid (pH <5), infertile, well-drained, sandy and sandy clay loam soils.  Only nodulates effectively at low soil pH.  Fails to nodulate and dies on soils of pH >5.5.  Tolerant of low P, and high levels of Al and Mn.

Moisture

Top

Average annual rainfall in the native habitat is 1,500 mm, with a 3-6 month dry season.  While best adapted to sub-humid to humid tropics (rainfall 1,000-2,500 mm/yr), it can also be grown successfully in the humid subtropics and semi-arid tropics with rainfall down to 500 mm/yr, providing soil conditions are suitable.  Intolerant of flooding or a high watertable.

Temperature

Occurs mostly from 21ºS in Brazil to 10ºN in Venezuela, from lowlands to 1,000 m asl .  Best performance in the tropics.  Killed by frost.

Light

Optimum production in full sunlight.

Reproductive development

Short-day flowering response.  Flowers April/May, with seed maturity late June/early July in southern hemisphere.

Defoliation

Moderately tolerant of low and frequent defoliation .

Fire

Top

Tops killed by fire, but due to free-seeding habit and high levels of soil seed bank, it re-establishes readily.

Agronomy

Establishment

High levels of hardseedednessScarification with concentrated sulphuric acid for 5 minutes reduces hardseededness and improves germination.  Good establishment may be obtained from 2 kg of acid scarified, dehulled seed per hectare.  The small seed should be sown no deeper than 1cm, and the sown area compacted with a roller to increase speed of germination and emergence.  Can nodulate effectively with native rhizobia, but best to inoculate with effective Bradyrhizobium strains such as CIAT 170 (= CB 3055).

Fertiliser

Tolerant of low fertility situations.  A standard fertiliser application on very infertile soils comprising P 20, K 20, Ca 100, Mg 14 and S 22 kg/ha at establishment, and maintenance dressings every two years of half this amount have given consistently good results.  Lime can have a detrimental effect on nodulation.

Compatibility (with other species)

Compatible with tussock-forming grasses, if shading is reduced by regular defoliation of the grass .

Companion species

Top

Pests and diseases

Forms of anthracnose disease caused by Colletotrichum gloeosporioides are a major threat to the use of Stylosanthes spp. worldwide, affecting both commercial pastures and seed production.  Severe outbreaks of the disease have been reported from all regions where the genus has been established.  Plant resistance is the only practical means of control.  Significant resistance to the disease can be found in geographically distinct groupings of S. capitata .  In general, Venezuelan provenances are lower yielding with high levels of anthracnose resistance, while the higher yielding Brazilian provenances are more susceptible to the disease.  Breeding programs have been undertaken to obtain the desired recombination of high dry matter and seed yields coupled with anthracnose-resistance (see cv. Campo Grande).
Seed yields can be drastically reduced by the stem -borer, Stegasta bosqueella.  Some genotypes are less affected by both stem -borers and budworms.

Ability to spread

A particularly important characteristic of S. capitata is the excellent seedling regeneration in cut and grazed swards.  It spreads naturally through seed drop, as well as through ingestion of seeding inflorescences by cattle over the dry season;  the seed is protected in the gut due to the high level of hard seed.

Weed potential

Due to its free-seeding habit, high seed yields, hardseededness , and a persistent soil seed bank, it can invade cultivated land.

Feeding value

Nutritive value

Top

CP level:  17.2% in leaf;  9.2% in stem;  16.5% in inflorescence .
IVDMD:  60% in leaf;  50% in stem;.64% in inflorescence .

Palatability/acceptability

Well accepted by all classes of animals, including chickens, ducks and pigs.

Toxicity

No record of adverse effects.

Production potential

Dry matter

Up to 12-13 t/ha/year DM under good conditions, but more often 3-6 t/ha DM.  Little dry season growth.

Animal production

Top

Annual liveweight gains for Andropogon gayanus - S. capitata from 145-350kg/ha and 110-200kg/animal in situations where the annual productivity of the native savannah is only 22 kg/ha.  In association with Brachiaria decumbens , stocked at 0.6-1.4 AU/ha, achieved 7-20% improvement in LWG/ha, and 10-23% improvement in LWG/hd, over grass alone.

Genetics/breeding

Tetraploid (2n = 4x = 40), self-compatible with 20% (up to 50%) out-crossing.  Evidence suggests it may be an allotetraploid derived from S. pilosa, S. bracteata, S. macrocephala , or S. ingrata.  It seems likely that genotypes of S. capitata evolved in Brazil and then dispersed to eastern Venezuela.  Both S. capitata and S. macrocephala have shown agronomic potential in Brazil, with the latter being found to be highly resistant to anthracnose.  Interspecific hybrids between these two species are unlikely as they differ in ploidy levels.  The main breeding strategy has entailed the production of synthetic populations by mixing resistant S. macrocephala accessions with productive S. capitata accessions.  It should be possible to transfer genes from S. macrocephala to S. capitata by crossing S. macrocephala and S. pilosa to synthesise allotetraploids, and then hybridising these artificial allotetraploids with those natural S. capitata genotypes.

Seed production

The species is a prolific seed producer, different ecotypes producing seed yields ranging from 650 to >1,000 kg/ha under various environmental conditions.

Herbicide effects

Tolerant of acifluorfen, bentazone, 2,4-D, 2,4-DB, fluazifop-butyl, and sethoxydim.  Susceptible to metsulfuron-methyl and glufosinate.

Strengths

  • Tolerant of low soil fertility .
  • Tolerant of moderately heavy grazing.
  • Productive.
  • High quality.
  • Free seeding.
  • Combines well with competitive bunch grasses.

Limitations

Top

  • Limited to very acid soils.
  • Not well suited to cut-and-carry.
  • May invade cultivated land.

Other comments

    

Selected references

Grof, B., Schultze-Kraft, R. and Muller, F. (1979) Stylosanthes capitata Vog., some agronomic attributes, and resistance to anthracnose (Colletotrichum gloeosporioides Penz.) Tropical Grasslands, 13, 28-37.
Schultze-Kraft, R. (1992) Stylosanthes capitata Vogel. In: 't Mannetje, L. and Jones, R.M. (eds) Plant Resources of South-East Asia No. 4. Forages. pp. 209-211. (Pudoc Scientific Publishers, Wageningen, the Netherlands).

Internet links

Cultivars

Cultivars

Country/date released

Details

'Campo Grande' Brazil (2000) Brazilian ecotypes of S. capitata produce 20-35% more dry matter than Venezuelan types, which, in turn, show better resistance to anthracnose.  A mass hybridisation scheme of 17 Brazilian x Venezuelan accessions resulted in a desirable recombination of forage traits, i.e.:  high forage and seed yields, coupled with anthracnose resistance.  Seed from the resultant hybrid is mixed 80:20 with seed of the highly anthracnose resistant S. macrocephala , to produce the multi-line cv. Campo Grande, which, with its diverse genetic make-up, has a wide application in acid-soil savannas.
'Capica'
(CIAT 10280, a mixture of CIAT 1315, 1342, 1693, 1728, 1943)
Colombia (1983) Largely superseded by 'Campo Grande'.

Promising accessions

Top

Promising accessions

Country

Details

CIAT 1914, 2261, 2814, 2815,  2819. Mato Grosso do Sul, Brazil Well adapted to soil and climate of the region;  highly resistant to anthracnose, DM yield in wet season:  10-12 t/ha.