The young seedlings are unable to thrive under conditions of heavy shade. They may die due to heavy shade particularly that caused by weeds though a light shade protects them from drought and frost and helps the young seedlings to develop into full-fledged clumps. Fire and grazing are extremely harmful to the young regeneration.
Planting
: The seedlings are planted at 6 x 6 m spacing with a total of about 250 seedlings per ha. The seedlings are irrigated immediately after transplanting. Weeding is generally required during the first year (Shanmughavel et al., 1997). Most villagers generally cultivate bamboos by planting offsets or rhizomes as seeds are not readily available.Rhizomes or offsets are dug out carefully so that the buds are not damaged and then transported to planting sites.
Planting work is done immediately after the first showers of the monsoon. The plantations are ready for exploitation within 4-12 years, depending upon the prevailing climatic conditions (Negi and Naithani, 1994).
Harvesting:
The bamboo forests are managed on a four-year cutting cycle employing selective felling system. Extraction of the culms starts from 4-12 years after planting.The following felling rules are generally prescribed:
(i) Immature culms less than 2 years old should not be cut and removed.
(ii) Young twisted culms are cut so that new culms grow.
(iii) All the new culms and 25% of the old culms should be retained.
(iv) Cutting should begin from the side opposite to where new sprouts are emerging
(v) No clump should be clear felled except after flowering and when seeding has been completed.
(vi) Culms should be cut as long as possible leaving two internodes above ground, in any case not higher than 30 cm above ground level.
(vii) Rhizomes are not dug out and exposed.
(viii) No felling to be done during growing season viz. 1st July to 30th September in north India.
(ix) In a clump containing 12 culms or more, at least 6 mature culms over one year old should be retained.
(x) No culm should be cut from periphery of the clump even if they are mature or malformed.
Traditional users opt for selective felling system, as mature culms are unsuitable for basket weaving.
However, with the emergence of the pulp a paper industry as the major consumers of bamboo, the system has been affected badly as parameters have changed with payment being based on weight. This has resulted in indiscriminate exploitation.
weaponry etc. Besides being a convenient source of cellulose for paper manufacture and rayon, it supports a number of traditional cottage industries. Bamboo craft is one of the oldest of traditional cottage industries in India. The origin of this rural craft is traced from the beginning of the civilisation when man started cultivation of food crops thousands of years back. People started making baskets, mats and many other products of household use with bamboo that was abundantly available in nearby forests. Later, tribal and rural people in the vicinity of bamboo forest took up this as a means of livelihood. Now bamboo craft is spread in all rural areas of the country and it feeds millions of traditional workers.
Chinese have the practice of carving, Culms may be cut and hollowed into vases or drinkware, tubes, or pipes for liquids.Culms can also serve as pipes. The Bamboo are also used in making musical instruments.
Bamboo canes are normally round in cross-section, but square canes can be produced by forcing the new young culms to grow through a tube of square cross-section and slightly smaller than the culm's natural diameter, thereby constricting the growth to the shape of the tube. Every few days the tube is removed and replaced higher up the fast-growing culm.
The fibre of bamboo has been used to make paper in China since very early days. A high quality hand- made paper is still produced in small quantities.
The wood is used for knitting needles and the fibre can be used as yarn. Sharpened bamboo is also traditionally used to tattoo in Japan, Hawaii and elsewhere.
Bamboo is emerging as a major source of raw material for several processed products primarily due to its fast growth, wide spread occurrence and its multiple uses. The ten major species used in India for commercial purposes are Bambusa bambos, B. balcoa, B. nutans, B. tulda, Dendrocalamus strictus, D.
hamiltonii, Melocanna baccifera, Ochlandra ebracteata, O. scriptoria and O. travancorica.
The consumption pattern of bamboo (Tewari, 1992) is given in Table-3. Table 3: Consumption pattern of bamboos in India.
Uses Per cent consumption
Pulp 35.0
Housing 20.0
Non-residential 5.0
Rural uses 20.0
Fuel 8.5
Packing, including basket 5.0
Transport 1.5
Furniture 1.0
Others, wood working industries 1.0 Others, including ladders, mats etc. 3.0 Specific uses of some bamboo species are listed in Table 4.
Table 4: Important bamboo species and their uses SL.
NO.
SPECIES USES
1. Sinarundinaria falcata Basket work, fishing rods, Hooka pipes 2. Thamnocalamus spathiforus Pipes, mats and basket making.
3. Arundinaria racemosa Roof construction and matting for house.
4. Sinarundinaria wightiana Matting.
5. Bambusa bambos Rafters, house posts, ladders, tent poles, shafts of tongas, mat and basket making, scaffoldings, chicks, etc. besides pulping. Seed and shoots are used as food.
6. B. balcooa Pulping.
7. B. tulda Building material, scaffolding and roofing. Mats and baskets. Tender shoots used as food, paper making.
8. B. polymorpha Construction work and for thatching/roofing.
9. B. vulgaris Furniture, toys, cages and construction works.
Scaffolds and for roofing. Paper making.
10. Schizostachyum pergracile Building, mat making, fishing rods besides being an important source of paper pulp.
11. Dendrocalamus giganteus Building and for masts for boats. The culms when cut into sections can be used for water buckets and boxes.
12. D. hamiltonii Paper manufacture, construction work, basket works, mats etc.
13 D. longispathus Basket making.
14 D. strictus Universally used, house construction, basket making, mats, furniture, agricultural implements, tool handles and chicks. Paper and rayon manufacture.
15 Gigantochloa macrostachya Matting and basketwork.
16. Melocanna baccifera Building as well as for basket works, house constructions, matting and other purposes.
17. Ochlandra travancorica Agricultural implements and tool handles, paper pulp. Temporary huts and thatching.
18. O. scriptoria Mats and basket making sticks, baskets and umbrella handles.
19. Pseudoxytenanthera ritcheyi Tent poles, walking sticks, baskets and umbrella handles.
20. Gigantochloa rostrata Building huts and basketwork besides papermaking.
21. Schizostachyum polymorphum Baskets, umbrella handles and walking sticks.
The major products and uses of bamboo in India are mentioned below:
¾ Pulp and Paper: In Asia, India leads in the utilization of bamboo for paper manufacture. About 2 million tons of raw bamboo, which constitute over 40 per cent of annual production, was used for pulp. Dendrocalamus strictus is the main species, which is used for paper pulp in India and it, produces pulp of acceptable quality.
¾ House Construction: Bamboo has been used for house construction, especially in earthquake prone areas. It is employed in different ways as a building material for roof structure in form of purlins, rafters, reapers, as reinforcement in foundations, flooring, doors/windows, walling, ceiling, water storage tanks, man-hole covers and even for roads in slushy areas (Punhani and Pruthi,1991).
• Roofing: Bamboo trusses form a good substitute for supporting roof loads and transmitting them to the foundations through columns. Bamboo trusses are fabricated using culms having an outer diameter of 50-80 mm. Selected culms are placed in position and joining ends/faces are cut in such a way that the gap between any two members is minimum. The web and chord connections are fabricated with different devices.
• Bamboo reinforced mud wall: Mud wall gives protection against heat and cold. Now-a- days mud walls are constructed by reinforcing, with quartered split bamboo culms properly treated with hot bitumen. Properly kneaded mud mixed with rice husk, cinder and a little lime and water are fused layer by layer keeping the bamboo grid in the center which is later plastered and smoothened then white washed.
• Light bamboo wall: Common walls of rural housing in the form of bamboo boards are prepared by using flattened bamboo culms, which are then battened and nailed to form the wall. Mats made with skins from the outside of the bamboo are used for the exterior wall after applying a coat of coal tar on the outer surface for protection.
• Flooring: Rural houses on raised platforms use bamboo for flooring while bamboo culms used as floor joints and beams act as framework. Over this framework, covering sheathing of split bamboo, bamboo boards/mats, small full culms or flattened bamboo strips are suitably fastened.
• Doors and windows: Shutters made of bamboo mats, fixed on wooden or bamboo frame is common in rural housing. Small openings framed with bamboo or wood is provided in the walls to serve as windows.
• Scaffolding: The platforms made of timber planks can be replaced with bamboo culms.
Bamboo poles lashed together have also been successfully used as scaffolding in high rise buildings.
¾ Bamboo Mat Boards (BMB) and Bamboo Mat Veneer Composites (BMVC): Indian Plywood Industries Research and Training Institute, Bangalore, has developed a technology for manufacturing BMB and BMVC utilising bamboo mats produced manually by traditionally skilled artisans. About 85,000 cum of BMB were manufactured during 1998 from 8 factories with an installed capacity of 133,000 cum/annum. It is estimated that if 100,000 cum of timber is replaced with BMB or BMVC, 4,000 ha of forests would be saved while an employment of 10 million person-days is likely to be generated (Bansal 1999). This technology has been expanded further to produce Bamboo Mat Corrugated Sheets as a substitute for Asbestos corrugated sheets, which are considered to be health hazard and environment unfriendly.
• Handicrafts: A large number of cottage industries like manufacturer of tablemats, bamboo wares, trays are dependent on bamboo as raw material. Many articles of common domestic use like mats, baskets, toys, nets, wall plates, wall hangers, trays etc. are made from bamboo. Various bamboo species utilised for these items are given in Table 4. Bamboo articles with different sizes and shapes are made with bamboo strips for decorative arrangement of flowers and fruits. Flute, a common musical instrument in India is made out of bamboo. Dried and mature bamboo leaves are used for deodorizing fish oils. Sinarundinaria falcata and Schizostachyum pergracile are used for making fishing rods.