Axonopus compressus (PROSEA)
Axonopus compressus (Swartz) P. Beauv.
- Protologue: Ess. Agrost.: 12, 154, 167 (1812).
- Family: Gramineae
- Chromosome number: 2n= 40
Milium compressum Swartz (1788), Paspalum platicaulon Poiret (1804), Anastrophus compressus Schlechtendal ex Doell. (1877).
- Broadleaf carpet grass (En)
- Indonesia: rumput pahit (Indonesian), papahitan, jukut pahit (Sundanese)
- Malaysia: rumput parit
- Philippines: kulape (Tagalog)
- Thailand: ya baimaln, ya-malaysia.
Origin and geographic distribution
It is native to the southern United States, and from Mexico to Brazil, and has been introduced into many warm countries, including South-East Asia.
Broadleaf carpet grass is used for grazing, especially in plantation crops, particularly coconut. It is also a good lawn grass and can be used for controlling soil erosion. It can be a troublesome weed. Under dense shade in established oil palm and rubber plantations, it is often allowed to grow as a soil cover.
Nitrogen concentrations of broadleaf carpet grass range between 1-2%. It is reported to have an ability to fix atmospheric N through associated micro-organisms.
A perennial, stoloniferous, short spreading grass; stolons often long, branched, rooting at the nodes; culms geniculately ascendent, 20-50 cm tall, solid, laterally compressed. Leaf-sheath strongly compressed, finely hairy along the outer margin, the nodes densely pubescent; ligule very short, fringed with short hairs; leaf-blade lanceolate, flat, 2.5-38 cm × 2.5-16 mm, base broadly rounded, margin ciliate, apex obtuse. Inflorescence compound, 1-2(-8) peduncles exserting from the final sheath, each composed apically of 2 conjugate, one-sided spikes 3-11 cm long, lower down often with a third, rarely a fourth; spikelets oblong, rather acute, 2-3.5 mm × 1-1.25 mm, pale green or purplish tinged, 1-flowered, solitary on alternate sides of rachis and forming two rows, ciliate on the margins; lower glume absent, upper glume and lemmas equalling the spikelet in length. Caryopsis elliptical, 1.25 mm long, dorsally compressed, yellow-brown.
Broadleaf carpet grass flowers all year round, although little seed is produced in some environments. Young plants start growth in a circular patch. If it has no serious competition, the patch may reach a size of up to 1 m in diameter in one season. It often crowds out all other weeds and grasses and forms a dense mat-like cover.
Broadleaf carpet grass is best adapted to moist warm environments. It is moderately shade tolerant but grows well in full sunlight. It occurs in Indonesia up to 2300 m altitude. It is frequently noted as being one of the most persistent and productive native grasses in plantations and will persist under heavy shade where introduced grasses may not survive. It will not stand waterlogged conditions although it grows on a range of soil types, particularly sandy soils. It is dormant during cool periods.
Broadleaf carpet grass is usually vegetatively propagated by planting stolons. When seeded, a seeding rate of 6 kg/ha is recommended. Frequent grazing is preferred, to maintain its palatability and quality. It is encouraged by close grazing, and will oust other grasses. Broadleaf carpet grass is usually grazed by tethered or freely grazing animals; it is rarely used in a cut-and-carry system. When used as a lawn grass, it should be frequently mown. With mixed fertilizer application at 300 kg/ha it has yielded up to 5 t/ha of DM. Under oil palm plantations in Malaysia, yields up to 1 t/ha have been measured. In Brazil, Zebu steers grazing over 672 days achieved an average daily gain of 0.18 kg. A. compressus is an alternate host of Rhizoctonia solani. In Malaysia the grass as weed is controlled by spraying with 1.1 kg MSMA + 0.6 kg sodium chlorate in 273 l water.
Genetic resources and breeding
It is unlikely that any substantial germplasm collections are being maintained.
Broadleaf carpet grass is a useful forage source for livestock raised under plantation crops, particularly under heavy shade, and it is adapted to extremes in soil types. Studies are warranted to see if its productivity can be improved.
- Boonklinkjorn, P., 1979. Herbage production of grasses under coconuts in Southern Thailand. Thai Journal of Agricultural Science 12: 43-50.
- Bor, N.L. 1960. The grasses of Burma, Ceylon, India and Pakistan. Pergamon Press, Oxford. p. 278.
- Chen, C.P. & Bong Julita, I., 1983. Performance of tropical forages under closed canopy of oil palm. I. Grasses. MARDI Research Bulletin 11: 248-263.
- Holm, J., 1971. Feeding tables. Nutrition Laboratory of Thai-German Dairy Project, Livestock Breeding Station, Chiangmai, Thailand. p. 19.
- Holm, L.G., Plucknett, D.L., Pancho, J.V. & Herberger, J.P., 1977. The world's worst weeds: distribution and biology. The East-West Center, University of Hawaii Press, Honolulu, Hawaii, United States. pp. 180-184.
- Mehra, K.L. & Fachrurozi, Z., 1985. Indonesian economic plant resources: forage crops. Lembaga Biologi Nasional - LIPI, Bogor, No 31. p. 2.
- Skerman, P.J. & Riveros F., 1990. Tropical grasses. FAO, Rome. pp. 211-214.
- Soerjani, M., Kostermans, A.J.G.H., Tjitrosoepomo, G. (Editors), 1987. Weeds of rice in Indonesia. Balai Pustaka, Jakarta. pp. 388-389.