Stylosanthes macrocephala M.B. Ferreira & Sousa Costa

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

macrocephala.

A perennial, fine-stemmed, many-branched, and tap-rooted sub-shrub, prostrate to semi-erect, 20-80 cm tall;  stems and branches hairy-bristly.  Leaves trifoliolate;  stipules obovate, 14-16 mm x 5-6 mm, with pointed teeth, pubescent to glabrous or bristly, with 11-13 pairs of veins;  petiole 1-2 mm long, villous;  leaflets lanceolate, 20-55 mm long, 10-19 mm wide, pubescent or glabrous, with 7-10 pairs of veins.  Inflorescence a terminal or axillary capitate spike, ovoid to almost spherical, 14-18 mm x 10-15 mm, with 10-30 flowers;  often several inflorescences in a cluster;  bracts imbricate, uni-foliate, elliptical-ovate, 10-12 mm x 8-9 mm, pubescent, with 11-15 veins, reddish;  flowers papilionaceous, small, yellow (sometimes with beige toning) with obovoid, striated standard 4-6 mm long;  axis rudiment and 2 inner bracteoles present.  Fruit 2-articulated, reticulately nerved;  both articles usually fertile;  the upper one glabrous, 3-4 mm x 2.5-3 mm, with a short, straight to uncinate beak;  lower article villous and smaller.  Seed yellow-brown, sometimes slightly mottled, to black.  500,000 seeds/kg (dehulled).

Distinguished from S. capitata by having more branched and finer stems, smaller and narrower leaflets and smaller inflorescences (1-2 cm vs 6-7 cm).

Native to:
Brazil:  Bahia, Espirito Santo, Rio de Janeiro, Goias, Mato Grosso do Sul, Minas Gerais in sub-humid and dryland savanna environments.

Used as forage in permanent pastures on poor soils.

Mostly found on sandy soils in savannas and heavier soils in the caatinga, with pH between 4 and 5 (rarely to 6), and Bray 1 phosphorus levels of 1-3 ppm (rarely to 5 ppm ).  Adapted to very acid, low-fertility oxisols and ultisols.

Savannah collections largely come from environments with 1,000-1,700 mm rainfall/yr and a 5-6 month dry season, while caatinga collections further north come from areas receiving <1,000 mm/yr and >6 month dry season.  Other collections come from the more humid coastal environment of northeast Bahia, which receives >1,900 mm rainfall , with a less well-defined dry season.

Limited to central and eastern Brazil from about 12-20ºS, and 38-50ºW.  Annual average temperature at collection sites ranges from 21-25ºC.  It has potential application in more tropical environments.

No data, although Stylosanthes spp. generally have little shade tolerance.

Floral initiation varies considerably among genotypes, from early to very late.  S. macrocephala produces abundant seed, with leaves shedding and inflorescences dislodging at maturity.  Seed is retained and disseminated in the inflorescence , germinating in the next wet season.

Moderately tolerant of low and frequent defoliation .

No information available.

Guidelines for the establishment and management of sown pastures.

In many respects S. macrocephala is similar to S. capitata .  Newly harvested seed may have to be treated to reduce hard-seededness.  It is sown at 4-5 kg/ha.  It is somewhat less productive than S. capitata , during both the rainy and dry seasons.  Seed set and seedling recruitment are essential for long-term persistence.  Nodulates effectively with native rhizobia in Brazil, but requires inoculation with strains such as CB 2898 or CB 3055 (CIAT 170) in Australia.

Although, in general, the species has a low P requirement, responses to applications of P vary with genotype.  Some give a yield response to applied P in soils of very low P status, but growth of others may be depressed by P application.

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

Grasses:  Andropogon gayanus , Brachiaria brizantha , B. decumbens .
Legumes:  Stylosanthes capitata , Cratylia argentea .

S. macrocephala is more anthracnose-tolerant than other Stylosanthes species.  In Colombia, it can be seriously affected by rhizoctonia foliar blight, and less so by cercospora leafspot (Passalora/Cercospora stylosanthis).  Budworm/pod borer/rednecked peanutworm (Stegasta bosqueella: Lepidoptera, Gelechiidae) may cause minor damage, but, like S. capitata , it appears resistant to stem borer (Caloptilia sp.) that is so damaging to other Stylosanthes spp.

S. macrocephala seeds prolifically and persists through extensive seedling recruitment.

No information, but due to its similarity to S. capitata in terms of its free-seeding habit and hardseededness , it probably has similar weed potential.

The nutritive value of 6-week-old regrowth of S. macrocephala is higher than that of S. capitata .  CP concentrations in leaves range from 14-22% (stems:  9-11%), and leaf DM digestibility from 66-75% (stems:  46-61%);  P concentrations are moderate to low, 0.17-0.25% in leaves and 0.13-0.25% in stems.  Unlike in many other legumes, CP levels of S. macrocephala are not improved by applications of P fertiliser.

No information available.

None reported.

Dry matter yields mostly in the range, 3-6 t/ha, although yields up to 14 t/ha DM are quoted.  S. capitata is equally well-adapted but mostly more productive.

No information available.

S. macrocephala is a diploid (2n = 20).  There is evidence that the tetraploid species, S. capitata (2n = 4x = 40), may be an allotetraploid derived from S. macrocephala , or S. ingrata as the maternal parent.  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 as in the composite cultivar, 'Campo Grande'.  It may 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.

S. macrocephala seeds fairly prolifically, different ecotypes producing seed yields ranging from 340-650 kg/ha under comparable environmental conditions.

No data available, but possibly similar tolerances and susceptibilities to those of the closely related S. capitata :
"Tolerant of acifluorfen, bentazone, 2,4-D, 2,4-DB, fluazifop-butyl, and sethoxydim.  Susceptible to metsulfuron-methyl and glufosinate."

• Adapted to low fertility soils, with high levels of Al and Mn.
• Tolerant of moderately heavy grazing.
• Moderately productive.
• Good quality.
• Free seeding.
• Combines well with competitive bunch grasses.

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

Chakraborty S. (ed.) (2004) High-yielding anthracnose-resistant Stylosanthes for agricultural systems. ACIAR Monograph No 111 . (Australian Centre for International Agricultural Research, Canberra).

EMBRAPA Gado de Corte. Estilosantes Campo Grande. Campo Grande, 2000 . (Embrapa Gado de Corte. Gado de Corte Divulga, 38).

EMBRAPA Gado de Corte. Estilosantes Campo Grande: estabelecimento, manejo e produção animal. Campo Grande, 2000 . (Embrapa Gado de Corte. Comunicado Técnico, 61).

Miranda, C.H.B., Fernandes, C.D. and Cadisch, G. (1999) Quantifying the nitrogen fixed by Stylosanthes. Pasturas Tropicales, 21, 64-69.

Schultze-Kraft, R., Costa, N.M.S. and Flores, A. (1984) Stylosanthes macrocephala M.B. Ferr. et S. Costa - collection and preliminary agronomic evaluation of a new tropical pasture legume . Tropical Agriculture (Trinidad), 61, 230-240.

Schultze-Kraft, R. (1992) Stylosanthes macrocephala M.B. Ferreira & N.M. Sousa Costa. In: 't Mannetje, L. and Jones, R.M. (eds) Plant Resources of South-East Asia No. 4. Forages. pp. 218-219. (Pudoc Scientific Publishers, Wageningen, the Netherlands).

Stace, H.M. and Edye, L.A. (eds) (1984) 'Biology and Agronomy of Stylosanthes '. (Academic Press: Sydney).

Thomas, D. and Grof, B. (1986) Some pasture species for the tropical savannas of South America. I. Species of Stylosanthes. Herbage Abstracts, 56, 445-454.

Valle, L.C.S., Silva, J.M. and Schunke, R.M. (2001) Ganho de peso de bovinos em pastagens de Brachiaria decumbens pura e consorciada com Stylosanthes spp. cv. Campo Grande. Reunião Anual Da Sociedade Brasileira de Zootecnia, 38, 175-176.

Winks, L. and Chakraborty S. (eds) (1997) International research and development on Stylosanthes. Proceedings of a Workshop held at the CSIRO Davies Laboratory, Townsville, Queensland, April 1996. Tropical Grasslands, 31, 385-528.

Wong, C.C. (1989) Review of forage screening and evaluation in Malaysia. Proceedings of the First Meeting of the Regional Working Group on Grazing and Feed Resources of Southeast Asia, 27 February-3 March 1989, Serdang, Malaysia. pp. 51-68.

http://www.fao.org/ag/AGP/AGPC/doc/Gbase/data/pf000495.htm
http://www.fao.org/waicent/faoinfo/agricult/aga/agap/frg/afris/absts/175.htm
http://www.fao.org/ag/AGP/AGPC/doc/PUBLICAT/GRASSLAN/51.pdf http://www.cnpgc.embrapa.br/~rodiney/series/estilosantes/estilosantes.htm
http://www.cnpgc.embrapa.br/publicacoes/divulga/GCD38.html
http://www.cnpgc.embrapa.br/publicacoes/cot/COT61.html
http://www.cnpgc.embrapa.br/publicacoes/cot/COT70.html

Cultivars	Country/date released	Details
'Campo Grande'	Brazil (2000)	A composite of S. capitata and S. macrocephala , with seed blended 80:20.  The S. capitata component, with caespitose growth habit, and growing to 1 m tall, flowers in mid-May at 20ºS, producing ripe seed at the end of June.  It was developed from a mass hybridisation scheme of 17 Brazilian x Venezuelan accessions, which resulted in a desirable recombination of forage traits, i.e. high forage and seed yields, coupled with anthracnose resistance (Brazilian ecotypes of S. capitata produce 20-35% more dry matter than Venezuelan types, which, in turn, show better resistance to anthracnose).  The S. macrocephala component, with decumbent growth habit (more erect to 1 m if competing for light), and narrower leaves than those of S.capitata, flowers in mid-April, producing ripe seed in mid-May.  It confers high anthracnose resistance to the composite, which with its diverse genetic make-up, has wide application in acid-soil savannas.
'Pioneiro' (CIAT 1281, ILRI-16562, CPI 75179, IRFL-2068, CNPGC-0760, CPAC-0139)	Brazil (1983)	From Planaltina, Brazil (15° 37'S, 47° 40'W, 1,040 m asl, rainfall 1,500 mm).  Grows to about 50 cm tall and 30 cm diameter.  Released for use in the Cerrados savanna region.

Promising accessions	Country	Details
None reported.