Gigantochloa robusta

Cultivation Details

This species grows in the perhumid tropics, where it is found at elevations from sea-level up to 1,500 metres^[1]. It is found in areas with an average annual rainfall of around 2,350 - 4,200 mm, temperatures of 20 - 32°c, and a relative humidity of over 70%^[1]. The plant normally grows on latosols (soils rich in iron and aluminium)^[1]. After planting of a cutting, 1 - 5 culms develop in the first year, gradually increasing up to 11 culms in the next years^[1]. One year after planting, culm height averages 4.7 metres and diameter 3.9 cm; these figures increase to 6.7 metres and 5.4 cm in the 2nd year and to 12.3 metres and 8.3 cm in the 3rd year, respectively^[1]. Bamboos have an interesting method of growth. Each plant produces a number of new stems annually - these stems grow to their maximum height in their first year of growth, subsequent growth in the stem being limited to the production of new side branches and leaves. In the case of some mature tropical species the new stem could be as much as 30 metres tall, with daily increases in height of 30cm or more during their peak growth time. This makes them some of the fastest-growing species in the world^[PFAF]. Young shoots grow rapidly at first and culms attain their maximum height in 2 - 4 months^[1]. Branching begins when the lengthening phase of the culm is over, usually at 8 - 11 nodes from the top, followed by 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 from 2 - 3 metres upwards^[1]. First harvesting may start 4 - 5 years after planting. It is recommended to harvest in the dry season by cutting mature culms just above the ground^[1]. A selective felling system in a 3-year cycle is recommended in Indonesia^[1]. It is estimated that a mature clump produces yearly an average of 6 mature culms (about 900 culms per ha at planting distance of 8 metres x 8 metres)^[1]. Traditionally, the culms are soaked in mud or running water for a few weeks and then air dried^[1]. The culms suffer heavily from borer attack; therefore, for large-scale production, chemical preservation treatment is necessary^[1]. Promising experimental results were obtained by soaking culms for 3 - 7 days in a solution of boron or wolmanit^[1]. It is said that the clumps of this species flower gregariously more than 50 years after planting. Flowers attract honey bees and other insects, but seed has never been observed^[1]. Bamboos in general are usually monocarpic, living for many years before flowering, then flowering and seeding profusely for a period of 1 - 3 years before usually dying.