Archive for July, 2017

Iron Bamboo- Thyrsostachys Oliveri- Kanak Kainch

Thyrsostachys Oliveri, another of the few "Iron Bamboos", is native to the Thailand, South China and N.E India (Tripura area). It is one of the most important bamboo species, because of its near solid structure and fiber quality. Locally called the Kanak Kaich, its a fairly straight growing mid sized bamboo, with a small spread. Farmers in Katlamara in West Tripura cultivate this bamboo at close spacing of about 2.5 m x 2.5 m.

I found this IRON BAMBOO species interesting, due to its vigorous growth at a Nursery close to Dehradun. I have, thus planted a few in my little bambusarium, due to its possible applications in the handicraft sector.

Thyrsostachys oliveri is a short rhizomed, perennial, evergreen, clumping/sympodial tropical bamboo, with persistent culm-sheath, which is an identifying feature.

thyrsostachys oliveri consistent culm sheath

The almost straight/erect culms are about 15 - 25 m long; 50 - 70mm in dia and about 40 - 60cm internode.

Thyrrsostachys_oliveri

As an iron bamboo, its valued as an excellent material for house-beams and miscellaneous applications in construction. The culms are used for reinforcing concrete blocks. Local craftsmen use this bamboo for handicrafts- mat-making, basketry, broom handles etc. Its fiber has a dark brown lustre, which makes it a material of choice for handicrafts. In Thailand, the young shoots are harvested for the production of steamed bamboo shoots.

Habitat : This species originates on the low hills forest, open areas at an altitudinal ranges of 500–700 m.

Distribution : Thailand, Myanmar, China - introduced and cultivated in tropical / subtropical Asia (Gamble, 1896; Wu, 2006).

Silvi-cultural management techniques Propagated through air-layering, culm cutting or offset planting.

Local Names :

Thailand;Phai ruak dam

Burma-Thanawa. Thyrsostachys Oliveri is a Native of Burma. (Nayagarh & Ganjam Districts)

Manipur- Keirakwa

Tripura- Kanak Kaich, Busai, Nusai, Nala Bauns

 

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Bamboo Trails- Dendrocalamus Stocksii

I learnt about this near solid, iron-bamboo (Dendrocalamus Stocksii) from an article published by Institute of Wood Science and Technology. The interesting feature was its loose-clumping growth habit, along with a near absence of inter-nodal cavity, thereby making it a suitable candidate for consideration of use to replace wood in certain applications in the handicraft industry. Also alluded to, as an iron-bamboo due to its iron like strength, this species is practically non-existent in N. India. Scientists at FRI and various agricultural institutes need to study the viability of introducing Dendrocalamus Stocksii in the TARAI, which is pretty humid and moist, much like the costal area, where this bamboo is naturally found.

Classification

Dendrocalamus stocksii (Munro), synonym Oxytenanthera stocksii / Pseudoxytenanthera stocksiiaabsence (Munro), synonym Oxytenanthera stocksii / Pseudoxytenanthera stocksii

As per the alluded article, Dendrocalamus stocksii is naturally distributed in Central Western Ghats. Locally called - Chivari’, Mes, Konda, Oor-shema, Marihal, Manga etc. D. stocksii has medium sized, stout solid and strong culms. Though the natural distribution of this species is in humid tropics, this species has a wide adaptability and comes up well in tropical humid, sub humid and semi-arid conditions.

MORPHOLOGY

Culms are said to be about 8 to 9m, basal dia 25-58mm and internode of 15-30cm, light green in colour, loosely spaced and without thorns. They are solid at the base upto about half the culm height.

Anatomical and Mechanical Properties of Dendrocalamus stocksii

Specific gravity- 0.691

Fibre Diameter (μm)- 16.6

Fibre Lumen Diameter (μm)- 5.7

Fibre length (mm)-3.4

Fibre Wall Thickness (μm)- 10.9

Modulus of Rupture (MOR) (kg/cm2)- 620

Maximum crushing stress (kg/cm2)- 386

Vascular bundles per cm2- 281

(Source: Rao et al., 2004)

Species Specific gravity MOR (kg/cm2) Max. crushing stress (kg/cm2)
Dendrocalamus stocksii 0.691 620 386
Bambusa nutans 0.603 529 456
Bambusa bambos 0.584 836 572
Dendrocalamus strictus 0.631 734 359
Tectona grandis 0.604 959 532
comparison
kN/cm²   spruce   bamboo   steel St37
elastic modulus   1100   2000   21000
compressive compressive   4.3   6.2-9.3   14
tension strength   8.9   14.8-38.4   16
bending strength   6.8   7.6-27.6   14
shearing strength   0.7   2.0   9.2

Source- http://bambus.rwth-aachen.de/eng/reports/mechanical_properties/referat2.html

The compressive strength of bamboo is roughly situated between 40 and 80 N/mm2 which is twice to four times the value of most timber species. Bamboo with low moisture content has a higher compressive strength than one with higher moisture.

The shear strength of bamboo is often twice the value of popular timber species.

The bending strength of most bamboo species varies between 50 and 150 N/mm2 and is on average twice as strong as most conventional structural timbers

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