Gigantochloa atter

Gigantochloa atter (Hassk.) Kurz

Nat. Tijdschr. Ned. Ind. 27: 226 (1864).
2n = 72 (hexaploid)

Origin and geographic distribution
The origin of G. atter is unknown. In Indonesia G. atter is widely cultivated in rural areas of Java; on the other islands it mostly occurs wild. In the Philippines it is cultivated in Davao, Mindanao Province. It is also planted in Brunei and probably also in Sarawak (Malaysia). For map click: Map399.TIF.

The culm of G. atter is much used for building material (framework, fences, walls). It is also used to make household utensils (e.g. furniture, beds, cooking utensils), meat skewers, chopsticks, toothpicks and handicrafts (e.g. basketry, lampshades). In West Java it is used as a substitute material for bamboo musical instruments when culms of G. atroviolacea Widjaja are not available. In the Philippines culms of G. atter are used to stake banana infructescences, although not as much as Bambusa sp. (laak=). The young shoots are eaten as a cooked vegetable and said to be as delicious as those of Dendrocalamus asper (Schultes f.) Backer ex Heyne.

Production and international trade
As a locally common bamboo in Indonesia, production and local trade are considerable, but no statistics are available. Some export of chopsticks and toothpicks from Indonesia to Japan and Taiwan exists.

Densely tufted, sympodial bamboo. Culm up to 25 m tall, 5-10 cm in diameter, wall up to 8 mm thick, bluish-green with distinct pale rings on the nodes; internodes 40-50 cm long, on upper part with dark brown appressed hairs; lower nodes with a few aerial roots. Branches arising from nodes above 2-3 m from the ground. Culm sheath narrowly triangular with truncate apex, 21-36 cm long, black hairy on the outer side, deciduous but usually lower ones rather persistent; blade lanceolate, about 10 cm x 3 cm, deflexed, deciduous; ligule 3-6 mm long, irregularly toothed; auricles rounded to slightly curved outward, 6-9 mm wide, 3-7 mm long, with bristles 4-6 mm long. Young shoots slender, green to dark green, with appressed black hairs. Leaf blade oblong-lanceolate, 20-44 cm x 3-9 cm, glabrous; ligule 2 mm long; auricles firm and low, 2 mm x 1 mm. Inflorescence borne on leafy branches with pseudospikelet groups at the nodes, each with up to 35 pseudospikelets; spikelet ovoid-lanceolate, 9-12 mm x 3-4 mm, containing 4 perfect florets and one terminal imperfect one. Caryopsis unknown.

Growth and development
After a cutting has been planted it may develop up to 24 culms in 3 years; the height of the culms increases from 2.1 m in the first year to 6.5 m in the second and 9 m in the third year, and the diameter from 2.3 cm to 4.2 cm and to 6.7 cm, respectively.
Young shoots grow rapidly at first and culms attain their maximum length in 2-4 months. Branching begins when the lengthening phase of the culms is over, usually at 8-11 nodes from the top, followed by the growth from the next two nodes down, and then development continues both up and down the culm from this area until branches have been produced from all nodes above 2-3 m from the ground. Usually one branch is dominant in each group. In Indonesia it has been recorded that G. atter flowers gregariously about 50-60 years after planting, and subsequently dies.

Other botanical information
G. atter was formerly united with G. atroviolacea Widjaja, G. pseudoarundinacea (Steudel) Widjaja and G. robusta Kurz in one complex species G. verticillata. G. atter can easily be distinguished from the 3 related species by its rounded and slightly outward curved culm sheath auricles.

G. atter is found in the tropics from sea-level up to 1400 m altitude. It grows well in areas with an annual rainfall of more than 2500 mm, but unlike many other Gigantochloa species it also tolerates drier environments with annual rainfall of 1000 mm. It prefers latosols but can be grown also on alluvial, limestone, and sandy loam soils.

Propagation and planting
G. atter is only propagated vegetatively by rhizome or culm cuttings. In an experiment in Indonesia with 2-noded culm cuttings, survival rate was 60%. It is recommended to protect cuttings in the nursery from heavy rain and to transplant one-year-old plants when 75 cm tall. Planting is done preferably at the beginning of the rainy season. Recommended planting distance for culm production is 7-8 m x 7 m, giving 180-200 clumps per ha.

Watering and weeding are necessary in the first years after planting. When the clump becomes too crowded it should be thinned. Regularly cleaning clumps of old culm remnants and loosening the soil stimulates the development of young shoots.

Diseases and pests
No serious diseases or pests are known to damage G. atter. Often a witches' broom (Epichloe bambusae) develops in G. atter, without causing apparent damage, however.

Harvesting of culms may start 4-5 years after planting. It is recommended to cut 2-3-year-old culms just above the ground, preferably in the dry season.

In Indonesia the average yield of a G. atter clump is estimated at 6-7 culms per year, or, with 200 clumps per ha, 1200-1400 culms per ha per year.

Handling after harvest
In certain areas, harvested culms are traditionally soaked in water for some weeks. Better preservation can be obtained by soaking culms in chemical solutions.

Genetic resources and breeding
A small germplasm collection of G. atter is available in Indonesia in Lampung, Sumatra. Collections from other areas are needed to conserve the variability of this bamboo. No breeding programmes have so far been initiated.

The prospects for G. atter are promising because of its wide utility (vegetable, furniture, construction, handicrafts). More research is needed regarding its properties, the feasibility of cultivation at plantation scale, and its improvement.

M.A. Rifai

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