Ischaemum timorense (PROSEA)

Plant Resources of South-East Asia Introduction

List of species

Ischaemum timorense Kunth

Protologue: Révis. gramin. 1: 369, t.98 (1830).

Family: Gramineae

Chromosome number: 2n= 20, 36

Synonyms

Ischaemum macrurum Stapf ex Ridley (1925).

Vernacular names

• Centipede grass, lucuntu grass (En)
• Indonesia: jukut jampang manggung (Sundanese), rumput apet (Sumbawa)
• Malaysia: rumput sarang buaya
• Vietnam: mô[m] timor.

Origin and geographic distribution

I. timorense is indigenous to tropical Asia and is widely distributed from India to Malesia and Polynesia.

Uses

I. timorense is a fodder species of minor importance in South-East Asia. It is useful for protecting soil against erosion and in providing material for mulch, but can be a weed in annual and perennial crops. Particularly in Indonesia it is a common weed in rainfed rice.

Properties

When well fertilized with N, P and K, three-week-old herbage had a N concentration of 3.2%, falling to 2.6% at 6 weeks. The N concentration of leaves was approximately double that of the stems.

Botany

A spreading stoloniferous perennial or annual, creeping and rooting in lower part, erect, slanting or scrambling in upper part with culms up to 1 m high. Leaf-sheath 3-6 cm long, white-hairy on the nodes and often with long hairs at the mouth, the outer margin and the back; ligule a short fringed membrane, sometimes long ciliate; leaf-blade lanceolate to linear-lanceolate, 2-16 cm × 3-15 mm, base obtuse or petiole-like, apex acute, adpressed long-hairy, or glabrous above. Inflorescence terminal, composed of 2(-3) closely opposed racemes, each 2-15 cm long; spikelets in pairs, one sessile, one pedicelled; alternately on one side of the triangular rachis; spikelets similar, 2-flowered, green or tinged with purple, lower floret male, upper floret bisexual; sessile spiklet 5-7 mm long, at the base swollen and stipe-like and white-hairy, lower glume with two acute lobes at apex, upper glume with a short 2-3 mm long awn, upper lemma 2-lobed with a 10-16 mm long awn in the middle. Caryopsis ellipsoid, 1-2 mm long.

The flowering season in Indonesia is April-November.

Ecology

As I. timorense establishes readily from seed and spreads by rooted stolons, it is an opportunistic colonizer of bare or disturbed areas. Hence it is common along roadsides, terraces, ditches and forest margins, and it is a weed in agricultural crops. It is found most frequently in areas with 800-2000 mm annual rainfall, but is not adapted to either dry or waterlogged sites or to heavy soils. It grows under full or partial (30-50%) sunlight. It is tolerant of high soil acidity and poor soil fertility.

Agronomy

I. timorense can be established by sowing 3-6 kg/ha into a well prepared seed-bed. If recently harvested seed is used, scarification may be required to break dormancy. It can also be established by spreading cut grass on to the surface of moist soil and disking it in.

There are no serious diseases or pests of I. timorense, although spikelets are often infected by smut.

I. timorense is usually harvested by grazing animals and only rarely by cutting. It is well grazed by cattle, horses and sheep. Some form of resting or rotational grazing may be required so that sufficient seeding can take place to ensure long-term persistence. It is not a particularly vigorous grass, although it is more productive in very fertile situations. Yields of 30 t/ha per year of fresh forage have been obtained. Both fresh and dry foliage can be used for composting and mulching, and it can be conserved as hay.

Genetic resources and breeding

It is unlikely that there are substantial germplasm collections and there are no known breeding programmes.

Prospects

Although I. timorense is a useful forage in specific situations, its dry matter yield is too low to warrant cultivation.

Literature

• Bogdan, A.V., 1977. Tropical pasture and fodder plants. Longman, London. p. 161.
• Gilliland, H.B., Holttum, R.E. & Bor, N.L., 1971. Grasses of Malaya. In: Burkill, H.M. (Editor): Flora of Malaya. Vol. 3. Government Printing Office, Singapore. pp. 264-265.
• Mehra, K.L. & Fachrurozi, Z., 1985. Indonesian economic plant resources: forage crops. Lembaga Biologi Nasional - LIPI, Bogor, No 31. p. 22.
• Soerjani, M., Kostermans, A.J.G.H. & Tjitrosoepomo, G., 1987. Weeds of rice in Indonesia. Balai Pustaka, Jakarta. pp. 442-443.

Authors

I.B. Ipor, B.B. Baki & C.P. Chen