Brachiaria mutica (PROSEA)
Brachiaria mutica (Forssk.) Stapf
- Protologue: Flora of Trop. Africa 9: 526 (1919).
- Family: Gramineae
- Chromosome number: 2n= 36
Panicum muticum Forssk. (1775), P. purpurascens Raddi (1823), Brachiaria purpurascens (Raddi) Henr. (1940).
- Para grass, Mauritius grass (En). Herbe de para (Fr)
- Indonesia: rumput malela, sukut kolonjono, jukut inggris
- Malaysia: rumput melela, rumput para
- Philippines: babaka-nalabaga, mara-kawayan (Ilokano)
- Cambodia: smau kôô
- Thailand: ya khon
- Vietnam: co' lông tây.
Origin and geographic distribution
The origin of para grass is probably tropical Africa. Today, the grass occurs naturally all over the tropical world, including South-East Asia and the Pacific region.
It is mostly grazed but can also be cut and fed to tethered animals or animals confined in stalls. It is suitable for erosion control at moist sites, e.g. on river banks. As a cover crop in plantations it is often considered too agressive.
Para grass is a palatable forage of reputedly high quality. Depending on plant age, N concentrations can range from 1.6-2.2% for leaves and from 0.5-1.0% for stems, and in vitro DM digestibility from 40-65%.
A robust, coarse, creeping perennial with short rhizomes and long stolons. Stems decumbent to ascending, rooting at nodes, densely covered with long, white hairs. Leaf-sheath hairy or glabrous on upper portion, with densely hairy collar; leaf-blade linear to lanceolate, 6-30 cm × 5-20 mm, flat, glabrous or slightly hairy. Inflorescence a panicle 6-30 cm long with 5-20 densely flowered racemes somewhat separated; racemes 2-15 cm long, basal ones generally branched; spikelets paired (often single in upper part), elliptic, 2.5-5 mm long, glabrous, in several untidy rows; fertile (upper) floret 3 mm long, pale yellow when ripe. Reproduction is mainly apomictic.
Under appropriate conditions, para grass is very competitive and vigorous, thus suppressing growth of weeds and making persistent associations with legumes difficult. Flowering and seed-setting occur, particularly at low latitudes and in humid environments. There is no formally released cultivar of para grass. Para grass closely resembles tanner grass ( Brachiaria arrecta (Th. Dur. & Schinz) Stent from tropical and southern Africa, but the latter species always has single spikelets.
Para grass is best adapted to poorly drained (swampy or periodically waterlogged) and wet areas of the warm tropics with soils of medium to high fertility; it tolerates salinity. As long as soil moisture is appropriate, it also thrives in well-drained areas. Growth is poor on dry sites. It can become a weed in irrigation ditches and drains.
Although establishment by seed is feasible (using 4 kg/ha), para grass is usually and easily established from stem cuttings with at least 3-4 nodes each, two of which should be buried 10-15 cm deep. Planting density depends on weed potential of the site and desired speed of ground cover, and should not be at spacings wider than 1 m × 1 m. If machinery is available, spread stem cuttings can be disked in. It responds to fertilization, mainly N but also P and K, which become particularly important if the grass is cut regularly. Legumes compatible with para grass at poorly drained sites are the annuals Macroptilium lathyroides (L.) Urban (phasey bean) and Aeschynomene americana L. (American jointvetch), and at well-drained sites the perennials Pueraria phaseoloides (Roxb.) Benth. (tropical kudzu), Centrosema pubescens Benth. (centro), and the shrub Leucaena leucocephala (Lamk) de Wit.
Para grass can be grazed continuously, or rotationally at intervals of 5-8 weeks, but a residual height of 15-20 cm should be maintained.
In Australia, para grass is attacked by a leafhopper which sucks the sap and severely reduces pasture productivity.
Para grass is harvested by grazing animals or cut for stall-feeding. It can be used for hay-making if environmental conditions allow but is difficult to dry. Depending on growth conditions, DM yields can range between 3-39 t/ha per year, mostly 5-12 t/ha per year. Animal production varies accordingly and annual liveweight gains of 300-800 kg/ha can be expected from para grass. Depending on N fertilization, seed yields of up to 60 kg/ha are possible. However, except in Australia, commercial seed production of para grass is practically non-existent because of the ease of establishment from stem cuttings.
Genetic resources and breeding
Para grass is not well represented in the major germplasm collections of tropical forage grasses held by CIAT (Colombia) and ATFGRC (CSIRO, Australia). The variability in the available gene pool is limited because of the species' apomictic reproduction and clonal propagation. However, important varietal differences have been observed in Thailand and Burma. Because of lack of a gene pool, there has been no description of the variation within para grass and no evaluation or breeding programmes to select improved lines.
Para grass will continue to be one of the most widely used good-quality forages for low-lying, seasonally waterlogged areas of the tropics. In Australia it has also become popular for use in "ponded pastures" (shallow earth dams) in drier environments. However, because of insect problems, it is gradually being replaced by B. humidicola (Rendle) Schweick. in the humid tropics of Australia.
- Blair, G.J., Ivory, D.A. & Evans, T.R., 1986. Forages in Southeast Asian and South Pacific agriculture. ACIAR Proceedings Series No 12. Canberra, Australia. 202 pp.
- Bogdan, A.V., 1977. Tropical pasture and fodder plants. Longman, London. pp. 59-62.
- Skerman, P.J. & Riveros, F., 1990. Tropical grasses. FAO, Rome. pp. 249-253.
- Toutain, B., 1985. Graminées fourragères des genres Brachiaria et Urochloa pour le Pacifique [Grass forages of the genera Brachiaria and Urochloa for the Pacific]. Revue d'Elevage et de Médecine Vétérinaire de Nouvelle Calédonie 7: 47-56.
R. Schultze-Kraft & J.K. Teitzel