Gigantochloa albociliata

Gigantochloa albociliata (Munro) Kurz

Forest flora of British Burma 2: 555 (1877).
2n = unknown

Origin and geographic distribution
G. albociliata is a native bamboo of Burma (Myanmar) (Pegu, Martaban, Tenasserim) and Thailand where it is widely distributed in dry forest hills in the central and northern parts of the country. It has been introduced in India (e.g. West Bengal, Assam, Arunachal Pradesh) and Indo-China (e.g. common in Laos). For map click: Map27.TIF.

Culms of G. albociliata are used in light construction (cottage walls, frames of thatched roofs), as trellises for climbing vegetables, for fence construction (typical in western part of central Thailand), tool handles (basal culm parts), furniture (with proper firing culms can be bent like rattan), woven wares and as raw material for paper and board. Young shoots are eaten as a vegetable. G. albociliata is also grown as an ornamental plant in gardens.

Production and international trade
Production and trade of culms and young shoots of G. albociliata is considerable in its native area, but no statistics are available. In Thailand, young shoots are also canned and exported (e.g. to Japan). Farmers receive about 0.07 US$/kg for young shoots.

Densely tufted, sympodial, evergreen or deciduous bamboo. Culm elongate arcuate-decurved, (5-)10(-16) m tall, 2-7 cm in diameter, wall up to 1 cm thick, greyish-green with white stripes, hispid when young; internodes 15-60 cm long; nodes prominent. Branches arising at nodes especially in upper part, usually erect and almost solitary, nearly as strong as the culm. Culm sheath 10-20 cm x 15 cm, folded and coriaceous at the base, apex truncate and narrow, covered with dense, tawny, appressed hairs when young, becoming glabrous and smooth; blade lanceolate, 10-20 cm long, spreading, acuminate, membranous; ligule 1.5-2.5 cm long, truncate, toothed; auricles small, indistinct. Young shoot with reflexed blades and short, pointed apex. Leaf blade linear-lanceolate, 15-20 cm x 2-2.5 cm, base rounded, apex subulate-acuminate, glabrous, chartaceous, glaucescent beneath; sheath striate, smooth; ligule long, hairy; auricles indistinct. Inflorescence large, consisting of a main branch with slender spreading branchlets bearing clusters of 10-20 pseudospikelets at each node, supported by yellow, chaffy, white ciliate bracts; spikelet elongate-linear, more or less curved, rarely straight, 1.5-2 cm x 2-2.5 mm, glaucous-green, comprising 1-2 empty glumes, 1-2 male florets and 1-2 hermaphrodite florets. Caryopsis elongate-oblong, cylindrical, acuminate, glabrous.

Growth and development
A 6-year-old clump raised from a rhizome cutting produced 27 culms with average height 10.5 m (ranging 5-16 m), and average diameter 2 cm (ranging 1-3 cm). A mature clump in natural stanas in Thailand bears 50-60 culms.
G. albociliata flowers sporadically and gregariously. In Thailand, sporadic flowering is common and occurs usually from October to December. Mature seeds are available from February to April. Gregarious flowering is very rare. A flowering cycle of 30 years has been reported from Assam (India).

Other botanical information
In the dry season, G. albociliata often sheds its leaves.

The natural habitat of G. albociliata is the dry tropical mixed forest at low to medium altitude, with average annual rainfall of 800-1300 mm, annual mean temperature of 28ºC and well-drained soils of poor to medium fertility. In Burma (Myanmar) it is common in low altitude mixed forest, but does not enter savannas.

Propagation and planting
G. albociliata can be propagated by seed and by rhizome cuttings (offsets). Seed is usually available because of the common sporadic flowering. Rhizome cuttings are planted, using portions of culm 30-50 cm long. For small-scale planting seedlings are also collected from the forest. No large-scale plantations exist, because rich natural stands are available.

Weeding is necessary, especially during the rainy season, until a plantation is fully established. Fire control and regulation of grazing of domestic cattle are important for the management of natural stands. Chemical and organic fertilizers stimulate growth and productivity. Thinning and spacing of clumps (removing of culms older than 3 years, and shoots growing too closely) are recommended.

Diseases and pests
No serious diseases or pests of G. albociliata are known. Wild hogs may cause considerable damage by grazing young shoots and uprooting small clumps. After harvest, culms are prone to fungi and borer attack.

Normally, 3-year-old culms are harvested in a 3-year felling cycle, usually at the end of the dry season. Culms used for furniture are harvested when 2 years old, and cut close to the ground (basal 1-2 m part is most useful because of thicker wall), because 3-year-old culms are too stiff to bend and younger culms normally shrink during firing. Culms harvested at the end of the dry season are more resistant to borer attack. Young shoots are harvested in the rainy season.

In Thailand, annual culm production in natural stands is 9-46 t/ha.

Handling after harvest
Traditional and chemical treatments are employed to preserve culms. Traditionally, culms are submerged in running water for 10-20 days. The culms are cleaned by rubbing with coconut husks or rice straw dipped in wet wood ash for a shiny surface, otherwise sandpaper is used. Chemical treatments include boiling the culms for 15-20 minutes at 95ºC in a solution of 0.2% sodium carbonate or 0.1% calcium hydroxide, or at 80ºC in a 0.3% copper sulphate solution. After the treatments, culms are washed with water, dried in the sun for 1-2 days, and stored in well ventilated rooms. Young shoots, mainly collected from natural stands, are cleaned, sliced, cooked and canned for export.

Genetic resources and breeding
No germplasm collections or breeding programmes for G. albociliata are known.

G. albociliata is an under-utilized natural resource of Burma (Myanmar) and Thailand although its natural stands are often over-exploited and degraded. More research is needed to investigate the industrial potential of the culms. In Thailand, G. albociliata might become important for the furniture industry. Germplasm collection and research towards management of sustainable natural stands are recommended.
For other South-East Asian countries, G. albociliata is potentially interesting for the production of edible shoots and the development of a furniture industry.

S. Duriyaprapan and P.C.M. Jansen

For additional information about author(s) see Contributors or Editors.