Saccharum spontaneum (PROSEA)

Plant Resources of South-East Asia Introduction

List of species

Saccharum spontaneum L.

Protologue: Mant. pl. alt.: 183 (1771).

Family: Gramineae

Chromosome number: 2nvaries from 48 to 128

Vernacular names

• Indonesia: glagah (Javanese), tatebu (Timor)
• Papua New Guinea: pit-pit
• Philippines: talahib (Tagalog), tigbau (Bikol), sidda (Ilokano)
• Cambodia: 'âm'pëu préi
• Laos: ph'ông, lau
• Thailand: phong, lao
• Vietnam: co' lách.

Origin and geographic distribution

S. spontaneum originates from and is widely distributed in the warmer regions of the Old World, including South-East Asia.

Uses

It is used by villagers as a fodder for cattle, buffaloes and, in some places, elephants. It is also used to prevent erosion of sandy soils. The foliage is used for thatching and the plant is used as an ornamental and to produce paper pulp.

Properties

Nitrogen concentrations ranging from 0.5-1.4% have been measured in India and Thailand. It is relished by water buffaloes and elephants but is less attractive to cattle. In the Philippines it is claimed that N-fixing bacteria live in symbiosis with S. spontaneum .

Botany

Rhizomatous perennial, with culms 1-4 m tall or more, waxy below the nodes. Leaf-sheath tight, 20 cm or more long, overlapping, striate, often purplish, glabrous; ligule obtuse or triangular, about 2 mm long, shortly ciliate; leaf-blade linear-acuminate, 50-90 cm × 5-15(-40) mm, glabrous, margins scaberulous. Inflorescence a panicle, 20-60 cm long, axis hirsute; racemes 3-15 cm long, usually much longer than the supporting branches; spikelets paired, one sessile, one pedicelled, similar, lanceolate, 3-7 mm long, the callus bearded with silky white hairs 2-3 times as long as the spikelet; glumes ciliate on the margins above. Caryopsis about 1.5 mm long.

S. spontaneum is a polymorphic species of which its many forms are commonly grouped into two subspecies:

• ssp. spontaneum : leaf-blade narrowed to the midrib towards its base; ligule ca. triangular; mainly in tropical and warm temperate Asia;

• ssp. aegyptiacum (Willd.) Hack.: leaf-blade not narrowed at base; ligule crescent-shaped; mainly in Africa and the Middle East.

Seeds germinate poorly, but once germinated the seedlings resist harsh conditions and soon develop a strong root system. Large tussocks will form when grown on river banks or ditches, thereby colonizing large areas. It flowers towards the end of the rainy season.

Ecology

S. spontaneum grows from near sea-level up to 1700 m altitude. It prefers a high rainfall environment, usually in excess of 1500 mm per year, and is adapted to a wide range of soils, from alluvial soils on river banks to sandy soils of old mines.

Agronomy

S. spontaneum is easily propagated by division of rhizomes. The spikelets bear long silky hairs and are easily and effectively dispersed by wind. It is tolerant of heavy grazing. Regular grazing or cutting is required to keep plants in a leafy state so that they maintain their palatability. Burning also helps the plants to produce new shoots for grazing. It is normally grazed by village cattle and water buffaloes, but young leaves can also be cut and fed to the livestock. It is expected to give fairly high yields. Young leaves can also be made into hay for the dry season as is done with sugar cane tops. In Thailand it is reported to be a host for a downy mildew fungus that badly affects maize plants.

Genetic resources and breeding

It has been thought that S. spontaneum can cross naturally with sugar cane to produce a hybrid known as S. sinense Roxb. which is almost completely sterile. S. spontaneum is a very variable species but it is unlikely that any germplasm collections are being maintained.

Prospects

For forage purposes, cultivars with better palatibility and nutritive status are required. S. spontaneum has good prospects for use in controlling soil erosion and reclaiming mine waste.

Literature

• Backer, C.A. & Bakhuizen van den Brink, R.C., 1968. Flora of Java. Vol. 3. Wolters-Noordhoff, Groningen, the Netherlands. p. 585.
• Bor, N.L., 1960. The grasses of Burma, Ceylon, India and Pakistan. Pergamon Press, London. p. 214.
• 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. 224-226.
• Holm, J., 1971. Feeding tables. Nutrition Laboratory of the Thai-German Dairy Project, Livestock Breeding Station, Chiangmai, Thailand. p. 26.
• Skerman, P.J. & Riveros, F., 1990. Tropical grasses. FAO, Rome. pp. 649-651.

Authors

C. Manidool