Bamboo in the Asia Pacific Proceedings 4th International Workshop, 1991

Rae, I.V.R.. Yusoff, A.M.; Rao, A.N. & Sastry, C.B. 1990. Sharma, O.P. 1986. Mass multiplication of Dendrocala- Propagation of bamboo and rattan through tissue culture. mus hamiltonii Munro- A critical evaluation. The Indian For- The IDRC Bamboo and Rattan Research Network. ester 112: 517-523.

Figure 1-16: In vitro culture of hami/tonii Munro

168 Micropropagation of Dendrocalamus hamlittonii Munro Using Single Node Cuttings Taken from Elite Seeding Bamboo in the Asia Pacific Proceedings 4th International Bamboo Workshop, 1991

Integrated Propagation of Dendrocalamus hamiltonii Munro by Using Partially Juvenile Culms

0.P. Sharma”

Observations Dendrocalamus hamiltonii Munro is a remarkable Adult versus partially juvenile culms clumped bamboo, that yields double harvest -- nutritive green fodder for cattle in winter, and economically attrac- A fully grown clump has a regular culming cycle, produc- tive culms of domestic and industrial importance ing every year in rainy season (July-September) one gen- (Sharrna, 1989). A native of tropical Eastern Himalaya eration of adult-sized culms characteristic of the clone. A and , it has long been cultivated in Himachal Pra- typical new culm takes 3-4 months to attain its full stat- desh (H.P.) State of on a small scale. It is so useful ure, bears distinctive deciduous culm sheaths throughout that it has entered the culture of Himachal people, who its length, and passes gradually into an insignificant leafy call it ‘Maggar’. Due to lack of a cheap and simple meth- twig. In case of culms produced in the early rainy season, od of propagation, it could not be planted on a large scale acropetally aerial roots, or perceptible root primordia, and so realise its full potential, primarily for fodder. have been seen to arise spontaneously in situ up to their fifteenth node in the regions of intercalary meristem, first Fractions of adult culms, in one form or another and with in complete rings and then in arcs opposite the buds. or without the use of root-promoting substances, have Clusters of precocious branchlets appear at the nodes next been in use for the propagation of clumped in March-April, but the production of principal primary general with varying degrees of success (Pathak, 1899; branches on a culm is spread over 3-4 years, for only some White, 1947; Dabral, 1950; McClure & Kennard, 1955; of the primary buds release their dormancy at random in a Cabandy, 1957; Abeels, 1962; Khan, 1972; Uchimura, season. The vigorous and elongate primary branches pro- 1978; 1979; Seethalakshmi et al. 1983; Surendran et al. duced during rainy season on one-year-old or older culms 1983; Sharma & Kaushal , 1985; Nath et al. 1986; Staple- give out from their condensed basal portions adventitious ton, 1987; Kumar et al., 1988). Despite its limitations, roots in situ. the method is preferred simply because it is less cumber- some than the more traditional offset method. To begin with, the new plants raised from offsets and cut- tings of adult culms are not under the clump influence, In D. hamiltonii, while resorting to the use of one-node and their culms revert to partial juvenility. They resemble cuttings (without any treatment) of vigorously branched the new adult culms in general appearance, but are mark- juvenile (reverted to partial juvenility) culms, Sharma edly thinner and shorter, attaining their full length in one (1986) noted that (i) markedly higher percentage of cut- to two months. Production of their principal primary tings rooted and survived, (ii) cuttings that failed to root branches is profuse, and takes place in the same or next belonged to distal culm region in a basipetal order, and growing season, imparting them a distinct feathery ap- (iii) most of the surviving cuttings culmed (produced pearance. The vigorous primary branches produced during clums) in the same year, each resulting in a complete rainy season are spontaneously rhizogenous in their con- (with roots, rhizome and culm). Since then an inte- densed basal portions, but the rooting intensity on differ- grated approach has been followed for large-scale nursery ent branch-bases of a culm gradually fades away raising by using partially juvenile culms. The plantations acropetally. When propagated further by one-node cut- raised by this method are now nearing the harvestable tings of partially juvenile culms, the culms of new plants stage, and the technology package is reported here. are similar in appearance, but are still thinner and shorter, attaining their full length in less than a month. The new plants produce only one generation of partially juvenile culms in a year, but the culming cycle is disturbed-- staggered, before during and after the rainy season. In Bamboo in the Asia Pacific Proceedings 4th International Bamboo Workshop, 1991 subsequent generations, while the culms gradually acquire Offsets their adult characteristics -- full stature, lesser branching and fixed culming cycle -- the elongate vigorous branches When the plants raised from culm cuttings have to be re- from the basal culm buds retain their juvenility and are tained in the nursery for another year, offsets derived from still suitable for propagation. The principal primary partially juvenile culms become available (Figure 3). branches that are (i) produced late in the season, and (ii) They are planted in the nursery in February-March with non-vigorous, herbaceous and leafy, even if of partially ju- 45 x 45 cm spacing. The survival is 70 - 80% and they venile culms, fail to root and are totally unfit for produce larger complete plants usually in one year. propagation. Branch-offsets Propagation technology Offset-like basal segments of principal primary branches, Culm cuttings supplemented by branch cuttings, offsets the single-branch cuttings of some authors (White, 1947), and branch-offsets are used as propagules without any are included here. Such branches occur on the basal butt treatment for raising the nursery. They have preformed, portion of culms with declining juvenility and can be se- visible or latent, roots. vered at their narrow bases by jerk - or cut - splitting from the otherwise intact culms. The branch-offsets are planted Culm cuttings in the nursery in February - March with 45 x 45 cm spac- ing The survival is 50 - 60%, but they produce larger Initially one-node cuttings of culms branched in first sea- complete plants (Figure 4) in one to two seasons. son only were used. Each cutting consisted of (i) a nodal segment with major length of its basal and minor of distal Plantation Technique internode, and (ii) a principal primary branch cut just above its third to fifth node. The precocious branchlets In practice the largest number of plants is contributed by were trimmed at their bases. Now the cuttings are taken culm cuttings. In February-March the dormant nursery from the culms branched in second season also, for they plants are suitably trimmed, dug out with least damage to perform almost equally well. The cutting is further relined roots, and transplanted in polythene envelops of suitable to minor length (3-4 cm) of internode on either side of sizes. While holding a plant in an envelope, it is filled node (Figure 1) bearing a primary branch trimmed just somewhat tightly with a mixture of equal parts of sandy- above its third node. This involves one additional culm loam soil and FYM. The plants in tubes are watered once cut per cutting, but the cutting is easier to handle and or twice daily according to need. without any adverse effect. With the onset of rainy season in June-July, the plants in The cuttings, made with a hand saw, are taken from the tubes (Figure 5) are outplanted at the permanent site in basal half to two-third culm lengths. They are planted pits of the size 60 x 60 x 60 cm (prepared well in time) (with the culm segment horizontal) 30 cm apart in rows in with 6 x 6 m spacing-- 285 plants per hectare. While pre- the nursery in February-March, with a row to row spacing paring a pit, the upper 15 cm of soil clods are put back up- of 45 cm. The site of a row is prepared by making 20 cm side-down at the bottom and the remaining pit is nearly deep trench, in which plenty of well rotten farm yard ma- filled with 12 - 15 kg of FYM mixed with soil. For water nure (FYM) is applied. Each cutting is covered to the conservation the natural drainage is directed into the pit middle of its first extended internode with soil, that is and its lower edge is raised, but water-logging is always pressed around. The plots are watered according to need avoided. In plantations thus raised (Figure 6), the culms adequately and frequently. On sprouting in April-June, of subsequent generations gradually acquire adult stature the branch-stumps strike roots from their bases and the (Figure 7). The clumps start yielding fodder are under- cuttings get established in June-July. In September- sized culms after 7-8 years, but full-sized culms are har- October they produce new culms from their condensed vestable after another 2-3 years. basal portions (Figure 1) and the process goes on till De- cember. The survival of cuttings is 70-80%, while 70-75% Discussion of the surviving cuttings culm in the same year, the re- In the present case, traditional types of propagules were maining in the second season. used for nursery raising, but they were taken exclusively from partially juvenile culms. The principal branches of Branch cuttings such culms have better root-striking potential and the The principal secondary branches produced on the buds on their basal condensed portions break their dor- primary-branch stumps of culm cuttings (planted in the mancy earlier. This has the critical advantage of getting nursery) develop adventitious roots at their bases in situ. complete plants in one year. The essential step in getting At the transplanting time in February-March, beheaded a new viable plant is the formation of a rooted shoot of primary branches, the progenitors of resultant plants, any rank and size, followed by culming from a basal bud yield one-node branch cuttings. They are planted in the (Sharma & Kaushal, 1985). The rooted shoot either arises nursery like the culm cuttings. The survival is 50-60%, afresh from a bud on the propagule, or already exists at but they yield smaller plants (Figure 2) that are easier to the planting time, as is the case in all the four types of handle and establish better. propagules used here. Treatment with root-promoting sub- stances can be effective in the former situation, for roots

170 integrated Propagation of Dendrocalamus hamiltonii Munro by Using Partially Juvenile Culms Bamboo in the Asia Pacific Proceedings 4th International Bamboo Workshop, 1991 initiate in the meristematic region only. According to Kumar, A.; Dhawan, M. & Gupta, B.B. 1988. Vegetative Nath et al. (1986), two-noded cuttings of one-year-old propagation of Bambusa tulda using growth promoting substances. Indian For. 114:569-575. (adult) culms of D. hamiltonii, when treated with IAA+ki- netin, responded best for induction of shoots and roots, McClure, F.A. & Kennard, W.C. 1955. Propagation of bamboo by whole-culm cuttings. Proc. Amer Soc. l-tort. giving 30% rooting of cuttings. Compared with this is the Sci. 65:283-288. 70-80% rooting and survival of juvenile-culm cuttings without any treatment. Nath, M.; Phulkan, U.; Barua, G.; Devi, M.; Barua, B. & Deka, P.C. 1986. Propagation of certain bamboo species from chemically treated culm cuttings. Indian J. For. As a short-term measure, this method is very useful for 9:151-156. multiplying the elite plants already under cultivation after Pathak, S.L. 1899. The propagation of the common male careful selection by the farmer. The new plantations, thus bamboo by cuttings in the Pinjaur-Patiala forest nurseries. raised, have the disadvantage of flowering with the parent Indian For. 25:307-308. stock. Unfortunately, the entire clump population in H.P. Seethalakshmi, K.K.; Venkatesh, C.S. & Surendran, T. has been raised vegetatively since introduction. For reju- 1983. Vegetative propagation of bamboo using growth venation, the planting stock must be raised from seed. promoting substances. Bambusa balcooa Roxb. Indian J. Since the seedlings are extremely heterogeneous, they are For. 6:98-l 03. unsuitable for economic planting. As a long-term strate- Sharma, O.P. 1986. Mass multiplication of Dendrocala- gy, a nursery should be raised from seed on a large scale, mus hami/fonii Munro A critical evaluation. Indian For. 112: outstanding seedlings identified, and the elites multiplied 517-523. rapidly for distribution to the farmer and forester. Once Sharma, O.P. 1989. Dendrocalamus hamiltonii Munro, the planted such clones will be harvestable for 50-60 years Himalayan miracle bamboo.: 189-I 95. In Trivedi, M.L.; without any fear of flowering. The selection of elite seed- Gill, B.S. & Saini, S.S. (eds) Plant Science Research in In- dia. Today and Tomorrows. Printers and Publishers, New lings and their clonal multiplication is already in hand. Delhi, India. Sharma, O.P. & Kaushal, S.K. 19. Exploratory propagation Acknowledgement of Dendrocalamus hamiltonii Munro by one-node culm cut- The author is extremely thankful to the Department of En- tings. Indian For. 111:135-l 39. vironment, Forests and Wild Life, Government of India, Stapleton, C.M.A. 1987. Studies on vegetative propagation of Bambusa and Dendrocalamus species by culm for financial support. cuttings.:146-153. In Rao, A.N.; Dhanarajan, G. & Sastry, C.B. (eds) Recent Research on Bamboos. The Chinese References Academy of Forestry, People’s Republic of & In- ternational Development Centre, Canada. Abeels, P. 1962. Multiplication of bamboos (translated from French by M.A. Waheed Khan). Indian For. Surendran, T.; Venkatesh, C.S. & Seethalakshmi, K.K. 88:481-487. 1983. Vegetative propagation of thorny bamboo Bambusa arundinacea (Retz.) Willd. using growth regulators. J. Tree Cabanday, A.C. 1957. Propagation of Kauayan-tink Sci. 2: 1 O-l 5. (Bambusa blumeans Schultes f.) by various methods of cutting and layerage. Philippine J. For. 13:81-97. Uchimura, E. 1978. Ecological studies on cultivation of tropical bamboo forest in the Philippines. Bull, For. & For. Dabral, S.N. 1950. A preliminary note on propagation of Prod. Res. Inst. 301:79-118. bamboos from culm segments. Indian For. 76-313-314. Uchimura, 1979. Studies on multiplication of bamboo by Khan, M.A.W. 1972. Propagation of Bambusa vulgar-is- its different growth types of bamboo rhizomes. Rep. Fuji scope in forestry. Indian For. 98:359-362. Bamboo Gdn. 23:36-52. White, D.G. 1947. Propagation of bamboo by branch cut- tings. Prod. Amer. Soc. Hort. Sci. 50:391-394.

Integrated Propagation of Dendrocalamus hamiltonii Munro by Using Partially Juvenile Culms 171 Bamboo in the Asia Pacitic Proceedings 4th International Bamboo Workhop, 1991

Figures 1-4: Propagules taken from partially ‘uvenile culms. Figures 1,2, & 4: Planted in February-March and sampled in S eptember-October. Figure 1: One-node culm cutting Figure 2: One-node branch cutting. Figure 3: Offs&s. Figure 4: Branch -offset

172 Integrated Propagation of Dendrocalamus hamiltonii Munro by Using Partially Juvenile Culms Bamboo in the Asia Pacific Proceedings 4th International Bamboo Workshop. 1991

Figures. 5-7: Plants raised from one-node cuttings of partially juvenile culms. Figure 5: Trans- ferred to polythene envelopes. Figure 6: A segment of three-year-old plantation. Figure 7: A clump base from six-year-old plantation lntegratd Propagation of Dendrocalamus hamiltonii Munro by Using Partially Juvenile Culms 173 Bamboo in the Asia Pacific Proceedings 4th International Bamboo Wokhop, 1991

Tissue Culture Alternatives in Bamboo Improvement Li-Chun Huang and Bau-Lian Huang*

Chang (1986a, b), were tried unsuccessfully and tentative- Introduction ly abandoned. Newly emerged laterals, 1-2 cm long, from Conventional breeding methods have been impractical in young culms served as explant donors. The apices were bamboo improvement because of absence or untimeliness excised after disinfecting (20 minutes in 0.5% NaOCl) of flowering; laboratories have been focused on develop- and trimming donor shoots. The explant included apical ment of tissue culture procedures as parasexual alterna- meristem, all leaf primordia and few soft, pale-white, un- tives. The effort thus far has concentrated on establishing furled leaves. One shoot apex was planted per culture. callus cultures, growing cells in liquid suspensions, isolat- ing and culturing protoplasts, and regenerating plants ad- Throughout the investigation, the basal medium ingredi- ventitiously. Callus and liquid suspensions usually ents were Murashige and Skoog mineral salts (1962) and, precede protoplast manipulations. They have been in mg/l: sucrose, 30,000; i-inositol, 100; thiamine HCl, 1; employed in screening somaclonal variants. Protoplasts nicotinic acid, 0.5; pyridoxine HCl, 0.5; and glycine, 2. are mainly intended for hybridization or cybridization by Media were galled with either 0.8% or Bi fusion and transformation by insertion of recombinant agar or 0.2% The pH was set at 5.7 before add- DNA. Adventitious plant regeneration is critical for any of ing gelling agent. Sterilization was achieved by autoclav- these steps to be useful. When plant regeneration is possi- ing at 1.05 for 10 minutes. Heat labile substances ble, ancillary benefits include elimination of viruses and were filtered through 0.2 urn membrane filters, then added rapid clonal propagation of superior stocks. to culture media. Much of our findings has already been published else- For callus culture and plant regeneration experiments, where (Huang and Murashige, 1983; Huang, Chen and glass tubes, 25 x 150 mm, were employed as culture ves- Huang, 1988; Huang, Chen and Huang, 1989; Huang, sels. Each tube contained 25 ml of gelled medium and was Huang and Chen, 1989; and Huang, Huang and Chen, capped with Bellco kaput?. Tubes of gelled media were 1990); thus, this report serves to bring them together and cooled as 30” slants, Bellco 125 ml DeLong flasks capped update their current status. with Micro were used for liquid suspension cul- tures. The flasks contained 25 ml of nutrient solution. Cell Materials and methods plating was done in 15 x 90 mm plastic Petri dishes, each with 10 ml pre-sterilized medium. Protoplasts were cul- Four species, Bambusa oldhamii Munro, B. multiplex tured by embedding in l-ml drops of 1.6% Sea (Loureiro) Raeuschell, Phylfostachys aurea A- and C. Ri- agarose, contained in 1.5 x 5.5 cm plastic dishes, and viere, and Sasa pygmaea (Miquel) E. G. Camus, were flooding dishes with 7 ml of feeder-cell suspension. Multi- employed in key experiments. Attempts were made to ex- plication of regenerated plants was accomplished in 500 tend some findings to B. ventricosa McClure, Dendroca- ml Erlenmyer flasks with 100 to 150 ml Erlenmyer flasks lamus latiflorus Munro, P. makinoi Hayata, P. nigra with 100 to 150 ml of gelled nutrient medium. These (Lodd.) Munro, and additional two cultivars of B. ofdha- flasks were closed with Micro Plugs. mii. D. latiforus and P. makinoi are fairly large bamboo, cultivated on Taiwan and elsewhere for their edible All cultures were incubated at 25 2°C. Callus cultures shoots; the others are smaller, landscape omamentals. and plated cells were kept in constant darkness. Liquid suspension and protoplast cultures were exposed 16 hour Shoot apices, 0.8 - 1.2 mm tall, were used as explants. daily to 22.5 illumination from Toshiba F1-40 Young infiorescences of B. oldhamii, as used by Yeh and SBR/38 fluorescent lamps; cultures for plant regeneration

* Institute of Botany, Academia Sinica,Nankang,Taipei.Taiwan.ROC Bamboo in the Asia Pacific Proceedings 4th International Bamboo Workshop, 1991 were similarly illuminated, but with twice the intensity, or Suspension cultures of B. oldhamii and B. multiplex were 45 umol/m2sec. composed of preponderantly small cell aggregates and lesser portion of large aggregates, Those of P. aurea and At least 10 cultures were used per experimental variable S. pygmaea were dominated by large aggregates; dissoci- and data analyzed by standard errors of means and 95% ation was not improved by higher 2,4-D concentrations. confidence limits of binomials (Steel and Torrie, 1960). Cell plating Findings Cell plating was achieved by simply mixing suspensions callus cultures of sieved cells in warm nutrient agar, then pouring the mixture into culture dishes. A density of 100,000 cells/ml Two kinds of callus emerged from the shoot-apex ex- was apparently critical in plating bamboo cells (Figure 2). plants, depending on hormonal supplementation. A truly unorganized, highly friable, creamy white callus devel- Protoplasts oped in media containing a sole auxin excellent for initiat- ing liquid suspension cultures. The suspension culture The following protocal was the result of and extensive se- from this callus served highly satisfactorily as source of ries of experiments with suspension cultured B. multiplex protoplasts. Unfortunately, no subsequent manipulations and B. oldhamii cells as protoplast donors. Donor cells of auxins and cytokinins could induce organogenesis in are prepared by transferring l-2.5 g cells from stock sus- this callus, except for occasional root differentiation. A 3 pension culture to 25 ml of fresh nutrient solution and cul- mg/l concentration of 2,4-D was optimum for creamy- turing a further 5 days. Samples of 2.5 g pelleted cells are white callus development in all four key species. Piclo- then placed in 10 ml volumes of digestion solution, the ram was 10 times more effective than 2,4:D, but repeated composition of which is as follow: 0.5 - 2% Cellulysin, 1 - use in subcultures eventually led to cell death; hence, this 2% Driselase, 0.5 - 1% Pectolyase Y23, 0.7 M mannitol, auxin has been excluded from bamboo media. Figure 1 50 mm arginine HCl, 0.1% BSA, 0.05% Difco Bacto malt shows the typical creamy-white bamboo callus. The callus extract, Murashige and Skoog salts, 1 mgll pyridoxine has been maintainable in stock by subculturing 300 mg HCl, 2 mg/l glycine, 100 mg/l i-inositol, 3 mg/l 2,4-D, quantities at 4-week intervals. Proteins separated by poly- and 10 mm MES. Digestion mixture are placed in 50 ml acrylamide gel electrophoresis showed clearly distinguish- Erlenmyer flasks and flasks immersed in water-bath shak- able isozymes of glutamate-oxaloacetate transaminase er set at 12°C and 80 rpm. Digesting at low temperature among the four species, suggesting that isozyme differ- has been critical. After 16 hours, digests are filtered ences might serve as maskers in identifying parasexual through 40-urn nylon cloth and filtrates centrifuged at 250 hybrids from protoplast fusions. Histological examinations g for 5 minutes. The pellet is resuspended in 9 ml of revealed that origin of creamy-white callus was mainly above solution, but without enzymes, layered onto 1 ml of confined to leaves of the explant. enzyme-less solution prepared with 0.5 M sucrose instead of mannitol, and centrifuged at 250 g for 5 minutes. Pro- Shoot apices in media supplemented with a combination toplasts band at the mannitol-sucrose interface and are of the auxin NAA and the cytokinin BA produced a collected and rinsed by resuspending in 10 ml of enzyme- granular, or nodular, callus. Under illuminated conditions less solution, prepared with mannitol, and recentrifuging. the callus appeared green to greenish yellow. This tissue Rinsing is performed at 10” C and repeated twice, the pel- regenerated plants, but was unsatisfactory for liquid sus- let being retained each time. The final pellet is resus- pension cultures and protoplast isolation. Histological ex- pended at a rate of 1.5 x 105 protoplasts/ml in nutrient amination disclosed the granular callus also differs from solution containing 0.6 M mannitol. Completeness of cell the creamy white callus originating in axillary buds and wall removal can be verified with Calcofluor White, and bud primordia of the explant, rather than in leaves. indication of viability can be measured with fluorescein diacetate. A sample of isolated protoplasts can be seen in Liquid suspension cultures and cell Figure 3. plating When culturing protoplasts, the cell suspension culture Liquid suspensions were easily initiated by transferring medium is used with additional supplements of 0.1% the creamy white callus to liquid medium and agitating BSA, 50 mm arginine HCl, 10 mm MES, and progres- cultures continuously. An agitation rate of 150 rpm on a sively reduced levels of mannitol. The protoplasts are dis- gyratory shaker (New Brunswick Scientific Model G 10 persed in 1 ml drops of Sea Prep agarose (1.6%) and the shaker) was about optimum for cell dissociation and rapid drops allowed to gel in the center of 1.5. x 5.5 cm plastic growth. When subculturing, larger aggregates were ex- dishes. After the agarose has solidified, the dishes are cluded by sieving suspensions through 40 mesh screens. flooded with 7-ml volumes of feeder-cell suspension. Sus- Sieved cells were pelleted at 200 g for 10 minutes, and pension cultures of B. multiplex cells, no older than 1 500-mg quantities were removed to fresh nutrient solu- week since subculturing, has been satisfactory as feeder tions. The optimum interval for subculturing suspensions for both B. oldhamii and B. multiplex protoplasts. The was 3 weeks. Unlike callus on gelled medium, cells. in feeder suspension contains 1 g cells/ml. The flooding liquid suspension were stimulated by illumination. solution’s composition is altered in this sequence: feeder cells and 0.6 M mannitol the first 2 weeks; feeder cells

Tissue Culture Atternatives in Bamboo Improvement 175 Bamboo in the Asia Pacific Proceedings 4th International Bamboo Workshop, 1991 and 0.4 M mannitol the next 2 weeks; withdrawal of feed- latiflorus, P. nigra and three cultivars of B. oldhamii. er cells but retention of osmoticurn at 0.4 M mannitol for Figure 8 shows tillering in B. ventricosa. and additional 2 weeks; mannitol reduced to 0.2 M for 1 week; and finally, no osmoticum. Plates must be rinsed The key techniques for use of tissue culture alternatives in thoroughly with feeder-less flooding solution to remove all bamboo improvement, namely establishing callus, cultur- feeder cells when replacing flooding solutions. Sustained ing cells in liquid suspension, isolating and culturing pro- division leading to callus growths has been observed in coplasts, and regenerating plants adventitiously, have been 40% of B. oldhamii and 60% of B. multiplex protoplasts. demonstrated. Nevertheless, they have not been achieved A sample culture after 8 weeks can be seen in Figure 4. In an integrated sequence, with the same species, or Callus growths are removed individually when they are among a range of species. Thus, hybridization or cybri- 1 - 2 mm in diameter and cultured further. dization by protoplast fusion and transformation by inser- ion of recombinant DNA into cultured cells or protoplasts Plant regeneration remain beyond reach. The information gained serves merely as basis for considerable further investigation. No manipulation of auxin and cytokinin, kind and con- centration, has resulted in organogenesis, except for occa- The findings are adequate for ancillary applications in vi- sional rooting, from protoplasts or their donor cells that rus exclusion, rapid clonal propagation, and somaclonal originated in callus generated by culturing shoot apices in variant isolation for a few bamboo species. 2,4-D medium. This experience has been contrary to that of callus established with 2,4-D in cultures of inflores- Acknowledgements cences (Yeh and Chang, 1986a, 1986b) or embryos (Rao, Rao and Narang, 1985). Transfer of intlorescence or em- The investigation has been supported by research grants bryo callus to media devoid of 2,4-D has resulted in emer- from the National Science Council and the Council of gence of adventitious embryos. Agriculture of the Republic of China. The authors also acknowledge cooperation of the Tainan and the Taoyuan Plant regenerating callus has been established by culturing District Agricultural Improvement Stations with field excised shoot apices in media containing the auxin NAA, evaluations. in place of 2,4-D, in combination with the cytokinin BA. The optimum level of NAA has been uniformly 1 mg/l for References the species examined, but the BA requirement has varied. Huang, L.C., and T. Murashige. 1983. Tissue culture in- The optimum BA addendum for B. multiplex and S. pyg- vestigations of bamboo. I. Callus cultures of Bambusa, maea has been 1 mg/L; for B. oldhamii, 3 mg/l; and for P. Phyllostachys and Sasa. Botanical Bulletin of Academia aurea, 10 mg/l. Intense cell division within axillary buds Sinica 24:31-52. and bud primordia resulted in swelling and eventual Huang, L.C., W.L. Chen, and B.-L. Huang. 1988. Tissue bursting of tissue. New shoot primordia differentiated in culture investigations of bamboo. Il. Liquid suspension superficial layers of the swollen tissue, specifically in re- cultures of Bambusa, Phyllostachys and Sasa. Botanical Bulletin of Academia Sinica 29: 177-l 82. gions that retained the epidermis. The epidermis contin- ued its development in the new primordium. The Huang, L.C., W.L. Chen, and B.-L. Huang. 1989. Tissue culture investigations of bamboo. Ill. A method for viable granular, or nodular, texture was attributable to intersper- protoplast isolation from’ Bambusa cells of liquid suspen- sions of buds of varying stages in development in hard sion culture. Botanical Bulletin of Academia Sinica callus. Subculturing the callus in fresh medium at timely 30:49-57. intervals maintained the tissue as a mixture of organized Huang, L.C., B.L. Huang, and W.-L. Chen. 1990. Tissue and unorganized tissues. When left unsubcultured, ad- culture investigations of bamboo. V. Recovery of callus ventious shoots emerged (Figure 5). Separated shoots from protoplasts of suspension-cultured Bambusa cells. readily rooted in unsupplemented medium or medium Botanical Bulletin of Academia Sinica 31:29-34. containing NAA. Plants reproduced by this process have Murashige, T., and F. Skoog. 1962. A revised medium for tested free of bamboo mosaic virus, even though explants rapid growth and bioassays with tobacco tissue cultures. Physiologia Plantarum 15473-497. had originated in infected plants (Huang and Lin, unpub- lished). Virus tested B. oldhamii plants are currently un- Rao, I.U., I.V. R. Rao, and V. Narang. 1985. Somatic em- bryogenesis and regeneration of plants in the bamboo. dergoing agronomic evaluation (Figure 6). Somaclonal Plant Cell Reports 3: 191-194. variants with salt (NaCl) tolerance have also been isolated Steel, R.G.D., and J.H. Torrie. 1960. Principles and proce- by screening shoot regenerating cultures (Figure 7). These dures of statistics. McGraw-Hill, New York, Toronto and plants remain to be field tested. London. Pp. 454-457. For simple rapid clonal propagation, lateral buds from Yeh, M.L., and W.C. Chang. 1986a. Plant regeneration through somatic embryogenesis in callus culture of green young culms can be stimulated to tiller in media contain- bamboo (Bambusa oldhamii Munro). Theoretical and Ap- ing cytokinin, usually BA or combinations of BA and thi- plied Genetics 73: 161-l 63. diazuron. Tillers are subsequently separated and rooted. Yeh, M.L., and W.C. Chang. 1986b. Somatic embryogene- This method is being used to increase B. ventricosa, D. sis and subsequent plant regeneration from inflorescence callus of Bambusa beecheyana Munro var. beecheyana. Plant Cell Reports 5:409-411.

176 Tissue Cutture Alternatives in Bamboo Improvement Bamboo in the Asia Pacific Proceedings 4th International Bamboo Workshop. 1991

Figure 1: Friable, creamy-white B. oldhamii callus resultant from culturing the excised shoot apex on a medium supplemented with 3 mg/l 2,4-D.

Figure 2: lnoculum density effects on regrowth of callus following platin of L3. multiplex cells liquid suspension culture. Left to right, u per row: 50,000, 10 ,000 and 200,000 cells/ml; lower row: 4,000 and 8000 cel s/ml.

Figure 3: Protoplasts freshly isolated from suspension cultured cells of B. oldhamii.

Tissue Culture Alternatives in Bamboo Improvement 177 Bamboo in the Asia Pacific Proceedings 4th international Bamboo Workshop, 1991

Figure 4: Callus regrowths from B. multiplex protoplasts cultured in Sea Prep agarose drops and employing diverse osmotica. Left to right, upper row: sucrose, mannitol and inositol; lower row: glucose and sorbitol

Figure 5: Cultures showing reen ranular B. Figure 6: NaCl tolerant somaclonal variant oldhamii callus, obtained from plant of B. oldhamii obtained by screenin adventitiously regenerated shoots. P otographed cultures were

178 Tissue Culture Alternatives in Bamboo Improvement Bamboo in the Asia Pacific Proceedings 4th International Bamboo Workshop 1991

Figure 7: Four-year-old planting of tissue culture-derived B. oldhamii at Yun-Lin Branch of Tai- nan District Agriclutural improvement Station. Following standard cultural practice, culms have been thinned to force new growths of edible shoots.

Figure 8: Tillering of B. ventricosa shoot cultures in medium supplemented with 1 mg/l BA

Tissue Culture Alternatives in Bamboo Improvement 179 Properties and Utilization

Proceedings 4th International Bamboo Workshop, I991 Bamboo in the Asia Pacific Proceedings 4th International Bamboo Workshop, 1991

Effect of Age on the Physico-Mechanical Properties of Philippine Bamboo

Zenita B. Espiloy*

Materials and methodology Housing is one of the basic needs of man. The over ex- Three culms each of 1 to 5 year old bamboo species, ploitation and depletion of the forests especially in the sub namely: B. blumeana, B. vulgaris, D. merrillianus, G. as- tropical and tropical areas is accompanied by timber pera, G. Ievis and S. lumampao, were collected from dif- shortage. Many people now realize the great potential of ferent places. Physico- mechanical properties such as bamboo in the context of dwindling timber resources. relative density, moisture content, shrinkage characteris- tics, static bending and maximum crushing strength The natural distribution of bamboo encompasses mainly parallel to grain were determined from sections of the tropical, sub-tropical and mild temperate zones of the butt, middle and top portions of the whole round bamboo world, with the tropical belt having the maximum number culms at green condition. In general, the standard test of bamboo (Mohanan and Liese, 1990). Over 75 genera procedure of the American Society for Testing Materials and 1250 species were reported to occur in the world (ASTM, 1972) for small clear specimens of timber was (Balakrishnan Nair 1988). According to a bamboo inven- followed as far as practicable. tory (Sharma, 1985), the Philippines has 55 species, and 6 with commercial value are presented in this paper. Results and discussion Strength, lightness with extraordinary hardness, abun- The species averages by age for all physico-mechanical dance, easy propagation and short maturation period make properties, viz., relative density, moisture content, shrink- bamboo suitable for a variety of uses. Yet very little is age characteristics, static bending and maximum crushing known about several aspects of this resource which is giv- strength parallel to grain, are shown in Figures 1 to 4. en a high priority in the research activities of bamboo specialisits. The 3 year age had the highest level of relative density and lowest moisture content as well as shrinkage values. The properties of the bamboo culm are determined by its Modulus of elasticity in bending and maximum crushing anatomical structure (Liese, 1980) since the distribution of strength parallel to grain with both nodes and internodes cell types within the culm is influenced by the shape, size, were, likewise, at their peak with relative density in the 3 arrangement and number of vascular bundles. These fac- year old bamboo. Generally, bending and compressive tors contribute to the bafnboo’s relative density, moisture strengths increase with height and age increment. content, shrinkage characteristics and strength properties. Anatomically, relative density is regarded as a function of Age, according to Mohmod et al. (1990), has a strong in- the ratio of cell wall volume to cell void vcolume; as such, fluence on the anatomical, physical and mechanical prop- it is affected by cell wall thickness and structure, cell erties of bamboo and can serve as a- guide in strength width, relative proportions of different types of cells and propertv determination. Licsc (1980) stated that in over- the kind and amount, of extractives present (Elliott, 1966). mature culms, the vessels and sievc tubes can become im- Moreover, relative density is a measure of the strength permeable due to depositions of gum-like substances and properties of a material. These considerations agree with tylosoid-like outgowths. This can cause bamboo to bccomc some findings of other researchers like Espinosa (1930), brittle and no longer pliable. With age increment, there is Suzuki (1948), Heck (1956), Janssen (1988), Espiloy a corresponding increase in fiber length and this can be a (1985), Widjaja et al. (1985), Prawirohatmodjo (1988) basis for determining the period of harvest and recycling Mohmod et al. (1990).

* Forest Products Research and Development Institute(FPRDI),College,Laguna 4031,Philippines Bamboo in the Asia Pacific Proceedings 4th International Bamboo Workshop, 1991

(Chengzhi and Guoen, 1985). According to Kitamura chengzhi, S. and X Guoen. 1985. Fiber morphology and (1962, 1963) there is a decrease in fiber content from the crystallinity of Phyllostachys pubescens with reference to age 247-249. In: A.N. Rao, G Dhanarajan and C.B. outer to the inner part of the culm, which becomes greater sastry (eds.). Recent Research on Bamboo. CAF, China as culm height increases. Such variation in fiber contents and IDRC, Canada. October 6-14, 1985, Hangzhou, Peo- at different ages is not much observed but the amount of ple's Republic of China. cellulosic substances greatly affects shrinkage. Espiloy Elliott, G.K. 1966. density in conifer. Technical (1983, 1985) disclosed that there is an increase in relative zommunication No. 8, Commonwealth Forest Botany, Ox- density values, percentage silica content and frequency of ford England. fibro-vascular bundles as culm height increases in a 3 year Ispiloy, Z.B. 1983. Variability of specific gravity, silica .old B. blumeana. content and fiber measurements in kauayan-tinik (Bambusa blumeana). NSTA Technical Journal 8(2):42-74. . 1985. Physico-mechanical properties and Conclusion anatomical structure relationships of some Philippine Generally, bending and compressive strengths increase bamboo. 257-264. In: A.N. Rao, G. Dhanarajan and C.B. Sastry (eds.). Recent Research on Bamboo. CAF, China with height and age increment. Modulus of elasticity in and IDRC, Canada. October 6-14, 1985, Hangzhou, Peo- bending and maximum crushing strength parallel to grain ple's Republic of China. at both nodes and internodes are at maximum levels with Espinosa, J.C. 1930. Bending and compressive strengths relative density in the 3 year old bamboo. In contrast, of the common Philippine bamboo. PhilippineJournal of- moisture content and shrinkage properties are observed Science 41:121-135. lowest for the same age. Heck, G.E. 1956. Properties of some bamboo cultivated n the Western hemisphere. FPL Report No. 01765. The distribution of cell types within the culm as well as JSDA, Madison 5, Wisconsin. the shape, size, arrangement and number of vascular Janssen, J.J.A. 1988. The importance of bamboo as a bundles contributes to the different physico-mechanical building material. 235-241. In: I.V. Ramtinuja Rao, R. properties of bamboo. Snanaharan and C.B. Sastry (eds.). Bamboo Current Re- search. KFRI, India and IDRC, Canada. November 14-18, The increasing demand for bamboo often leads to prema- 1988, Cochin, India. ture felling and this reduces the biological productivity of Kitamura, H. 1962. Studies on the physical properties of the plant for new shoots. Moreover, the prematurely har- bamboo. Part 9: On the fiber content of Phyllostachys reti- vested culms are more prone to splitting, collapse and bio- culata . Japan Wood Research Society Journal logical attacks. B(6):249-252. 1963. Studies on the shrinkage of bam- Based on the tests conducted for physico-mechanical boo. Bulletin Niigata University of Forestry 2.1. properties, the 3 year age is the most appropriate time to Liese, W. 1980. Anatomy of bamboo. 161-164. In: G. harvest bamboo for maximum utilization in furniture, Lessard and Chouinard (eds.). Bamboo Research in Asia. building and general construction. IDRC and IUFRO, Canada. May 28-30, 1980. Singapore. Mohanan, C. and W. Liese. 1990. Diseases of bamboo. KFRI Scientific Paper No. 179, International Journal of Acknowledgement Tropical Plant Diseases 8:1-20. , India. Samples came from ERDB and tested for physico- Prawirohatmodjo, S. 1988. Comparative strengths of mechanical properties at the FPRDI. green and air-dry bamboo. 218-222. In: I.V. Ramanuja Rao, R. Gnanaharan and C.B. Sastry (eds.). Bamboo Cur- rent Research. KFRI, India and IDRC, Canada. November References 14-18, 1988, Cochin, India. Abdul Latif Mohmod, Wan Tarmeze Wan Ariffin and Fau- Sharma, Y.M.L. 1985. Inventory and resource of bam- zidah Ahmad. 1990. Anatomical features and mechanical boo. 4-17. In: A.N. Rao, G. Dhanarajan and C.B. Sastry properties of three Malaysian bamboo. Journal of Tropical (eds.). Recent Research on Bamboo. CAF, China and Forest Science 2(3): 227-234. Forest Research Institute of IDRC, Canada. October 6-14, 1985, Hangzhou, People’s Malaysia. Republic of China. Annual Book Of Astm Standards (Part 16). Standard Suzuki, Y. 1948. Studies on the bamboo. Part 3: The dis- methods of testing small clear specimens of timber. ASTM tribution of specific gravity and bending strength in the Designation 0143-52 (Reapproved 1972). stem of Phyllostachys pubescens grown at several parts of Japan. Bulletin Tokyo University of Forestry 36: 188-199. Balakrishnannair, N. 1988. In: I.V. Ramanuja Rao, R.Gna- naharan and C.B. Sastry (eds.). Bamboo Current Re- Widjaja, E.A. and Z. Risyad. 1985. Anatomical properties search (Foreword). KFRI, India and IDRC, Canada. of some bamboo utilized in Indonesia. 244-246. In: A.N. November 14-18, 1988, Cochin, India. Rao, G. Dhanarajan and C.B. Sastry (eds.) Recent Re- search on Bamboo. CAF, China and IDRC, Canada, Octo- ber 6-14, 1985, Hangzhou, People’s Republic of China.

Effect of Age on the Physico-Mechanical Properties of Philippine Bamboo 181 Bamboo in the Asia Pacific Proceedings 4th International Bamboo Workshop, 1991

3

(Years) AGE ( Years 1 AGE

Figure 1: Avera e moisture content at different ages Figure 2: Average relative density values at differ- of PhiB lppine bamboo ent ages of Philippine bamboo

Tangential Shrinkage Radial Shrinkage

AGE (Years) AGE (Years)

Figure 3: Average shrinkage properties at different Figure 4: Average strength properties at different ages of Philippine bamboo ages of Philippine bamboo

182 Effect of Age on the Physico-Mechanical Properties of Philippine Bamboo Bamboo in the Asia Pacific Proceedings 4th International Bamboo Workshop, 1991 . Effect of Age and Height Position of Muli (Melocanna baccifera) and Borak (Bambusa balcooa) Bamboo on Their Physical and Mechanical Properties

M. A. Sattar, M.F. Kabir and D.K. Bhattacharjee*

investigation. Five bamboo were used for each age group Introduction for replication of tests. Bamboo is an important raw material for construction, bridges and variety of other purposes in Bangladesh. Be- cause of acute scarcity of timber for housing bamboo has a Shrinkage very significant importance as a substitute for wood both The specimens for wall thickness shrinkage were prepared at the village and urban levels. in the form of 2.5 cm wide rings while the specimens for diameter shrinkage were the internodes of the culm Information on the physical and mechanical properties of bamboo is necessary for assessing its suitability for vari- bounded by nodes at the extremity. A total of three rings ous end products. Numerous studies were conducted on and three internodal culms were cut from the butt, middle the physical and mechanical properties of different bam- and top of each bamboo. The green wall thickness was de- boo species grown in the neighbouring countries and other termined at two perpendicularly marked positions and the places. In India, Rehman and Ishaq (1947) reported the diameter shrinkage was measured along the two diameters results of shrinkage and seasoning of nine bamboo spe- perpendicular to each other. The specimens were first cies. The strength and shrinkage properties were deter- dried to about 12% moisture content (mc) and then the mined by Limaye (1952) Kishan ef al (1958), Sekhar and wall thickness specimens were dried gradually from 60°C Bhartari (1960) and Sekhar and Rawat (1964). Espiloy finally to 103 + 2°C. All measurements were taken to the (1983, 1987) reported the results of physical and mechani- nearest 0.005 cm. The shrinkages were calculated at 12% cal properties of several Philippine bamboo species. He mc and oven dry condition based on green dimension. also correlated these properties with some anatomical characteristics. Zhow (198 1) studied the influence of age on the strengths of Chinese bamboo. Liese (1986) made a Moisture content and specific gravity comprehensive literature survey on the anatomical, chemi- The specimens for moisture content and specific gravity cal and physico-mechanical properties. No information, were taken in the form of a pair of 2.5 cm rings from each except on the physical properties of bariala (Bambusa vul- garis) and mitinga (Barmbusa tulda). is available for the of the height positions. Moisture content was determined Bangladesh species (Talukdar and Sattar, 1980). In the by weighing the specimens in green condition and then lack of relevant data, bamboo are being used in Bangla- oven drying them. The specific gravity was determined on desh based on the knowledge of the traditional selection the basis of both green and oven dry volumes, The initial for different purposes. It is, therefore, considered neces- volume was taken in green condition and the specimens sary to find out the properties which may help in the prop- were then oven dried, weighed, soaked in melted paraffin, er use of bamboo. To begin with, one forest species, muli and oven dry volume was determined. In both the cases, (Melocanna baccifera) and one village species, borak the volume was ascertained by the water displacement (Bambusa balcooa) were selected for the study. These spe- method. cies are relatively important from the standpoint of their utilization. Mechanical properties Materials and methods There is no universal standard method of tests for evaluat- ing the mechanical properties of bamboo. Different coun- Muli bamboo were collected from the bambusetum of the tries, however, have standardised some specifications to Bangladesh Forest Research Institute, Chittagong. Borak suit their purposes. In the present study the Indian method bamboo were procured from a village grove of Chittagong. (Anon, 1973) was followed. Five age groups, from one year culm to five years culm, were taken for each species. Three height positions - butt, The static bending test was performed on full diameter middle and top of the culm were also considered for each specimens of 75 cm length bounded by two nodes. Paired specimens were prepared for each height position; half of the specimens were tested in green condition and the other

*Bangladesh Forest Research Institute, P,O.Box 273,Chittagong,Bangladesh Bamboo in the Asia Pacific Proceedings 4th International Bamboo Workshop, 1991 half were tested in air dry condition at about 12% mc on a higher specific gravity at the top of the culm may be at- universal timber testing machine. The modulus of rupture tributed to the presence of higher proportion of scleren- and modulus of elasticity were evaluated from this test. chyma tissue/fibrovascular bundle at this position, Espiloy, 1987 and Janssen, 1987. The age was observed to The compression parallel to grain test was made on full have direct relation with the specific gravity in all cases. diameter specimens without any node material. The The younger bamboo were less dense than the older ones. length of the specimen was taken 10 times the average The maximum value was observed in the case of 3 year wall thickness of the culm. Paired specimens were pre- old culm and after three years there was no increase in the pared from the butt, middle and top of each bamboo. The value of specific gravity (Table 1). specimens were tested in green and air dry conditions on a timber testing machine with a platen equipped with a hemispherical bearing to obtain uniform distortion of load Shrinkage over the ends of the specimens. The maximum compres- Unlike wood, bamboo shrinks right from the beginning of sive strength parallel to grain was determined from this drying, Rehman and Ishaq, 1947. An appreciable shrink- test. age was thus found in both wall thickness and diameter at 12% moisture content (Table 2). Further increase in shrinkage was observed at oven dry condition. Both types Results of the shrinkages were found to be about double in borak The average moisture content at each position of the culm compared to muli. The higher percentage of shrinkage in of bamboo of individual age is shown in Table 1. The spe- borak may be related with higher percentage of moisture cific gravity based on green and oven dry volume is given content compared to that of muli. The effect of height in the same table. The shrinkage in wall thickness .and di- along the culm was also pronounced in shrinkage values. ameter was expressed as percentage of green dimension. The highest shrinkage was recorded in the butt in all cases The average values of shrinkage are contained in Table 2. (Table 2). This may be related to the variation in distribu- The modulus of rupture and modulus of elasticity were de- tion of moisture content in different height positions. As termined from the static bending according to Indian stan- regards the effect of age, shrinkage changed with the age, dard Anon, 1973. The compressive strength values were but it did not follow any definite trend. also evaluated using the same Indian method. These me- chanical properties are presented in Tables 3 and 4. All Mechanical properties physical and mechanical properties were statistically ana- lysed to note the etfects of age and the height position It is evident from Tables 3, 4 and 6 that the mechanical along the culm. The results of these analyses are summa- properties, viz., modulus of rupture, modulus of elasticity rized in Tables 5 and 6, and compressive strength varied significantly with the height of the culm. The butt was the strongest in modulus of rupture while the top showed the lowest value in all the Discussion cases. Similar result was found by many workers, Espiloy, 1987, Janssen, 1981, Limaye, 1952 and Sanyal et al. Moisture content 1988, but no plausible reason is available for this. Limaye, It is observed in Table 1 that the moisture content of borak 1952, correlated this with the higher wall thickness of the bamboo was substantially higher than that of muli bam- culm near the ground. This also does not seem to be rea- boo. In both the species the moisture content changed sig- sonable since the strength is calculated taking the wall nificantly with the culm height (Table 6). Considering the thickness into consideration because of varying wall thick- bamboo of all the five age groups, the moisture content of ncsses at different parts of the culm. The modulus of elas- muli varied from 111% to 97% for butt, 95% to 84% for ticity and compression parallel to grain, however, showed middle and 82% to 78% for top position. Similar variation different trends. These properties were found to increase of moisture content was observed in the values of borak along the culm from the butt to the top. The highest val- bamboo (Table 1). Rehman and Ishaq 1947, also observed ues were noted at the top position in all cases of both the that the moisture content decreased with the height of the species. This was attributed to increasing specific gravity culm from the ground; confirmed by the subsequent study, along the culm associated with higher percentage of scler- Kishan et al 1958. Regarding the effect of age, moisture enchyma tissue. content was found to vary significantly in case of borak (Table 6). The younger culms, however, showed higher Espiloy, 1987, Janssen, 1987 and Liese, 1986; Sanyal et percentage of moisture content in both the species. al. 1988, observed in ten bamboo species that the modulus of elasticity in bending decreased as the diameter of culm increased and vice versa. This supports the present find- Specific gravity ings as well. The diameter of muli bamboo was much less The specific gravity of muli and borak bamboo was found than that of borak. As such its modulus of elasticity values were substantially higher compared to those of borak to increase from the butt to the top position based on both (Table 3). green and oven dry volumes (Table 1). Other investigators also noted the increase in specific gravity with increasing Age is considered to be an important factor influencing height, Espiloy 1987 and Liese, 1986. The reason for the strength properties. There was a gradual increase of

184 Effect of Age and Height Position of Muli (Me/ocanna baccifera) and Borak (Bambusa balcooa) Bamboo on Their Physical and Mechanical Properties Bamboo in the Asia Pacific Proceedings 4th International Bamboo Workshop, 1991 the strength from the culms of 1 year to 3 years. The Espiloy, Z.B. 1983. Variability of specific gravity, silica maximum bending strength was observed in the 3 year old content and fibre measurements in kawayan tinik bamboo. Above 3 years strength values declined. The (Bambusa blumeans). NSTA Technology Journal, 8(2): compressive strength was, however, maximum at the age 42-74 of 4 years for muli, but borak showed this value at 3 years. Espiloy, Z.B. 1987. Physico-mechanical properties and While summarising the literature on properties and uti- anatomical relationships of some Philippine bamboo. lization of bamboo, Liese 1986, reported that bamboo ma- Proc. Intern. Bamboo Workshop, Hanghhou, China on Re- ture at about three years and reach their maximum cent Research on Bamboo. 257-264 strength. Janssen, J.J.A. 1981. Bamboo in building .structures. Doc- toral thesis, Eindhoven Technical University, Netherlands. Limaye, 1952, reported that the strength properties of 253 PP Dendrocalamus strictus reached maximum at the age of Janssen, J.J.A. 1987. The mechanical properties of bam- more than 2.5 years. The influence of age on strength boo. Proc. Intern. Bamboo Workshop, Hangzhou, China properties has not been clearly explained by any investiga- on Research on Bamboo. 250-456 tor. It may, however, be correlated with specific gravity al- Kishan, J; Ghose, D.P. and Rehman, M.A. 1958. Studies though in the present study no uniform trend of on moisture content, shrinkage, swelling and intersection correlation is observed (Table 5). It requires further point of mature Dendrocalamus strictus. Indian Forest Re- investigation. cords (New Series), For. Res. Inst., Dehra Dun, India. 2(l): 1 l-28 Liese, W. 1986. Characterization and utilization of bam- Conclusion boo. Proc of IUFRO World Congress, Lijudljana, Yogosla- 1. The moisture content and shrinkage of muli via on Bamboo Production and Utilization. 11-16 (Melocanna baccifera) and borak (Bambusa balcooa) Limaye, V.D. 1952. Strength of bamboo (Dendrocalamus were significantly affected by the height of the culm. strictus). Indian Forest Records (New Series), For. Res. Age has a substaintial effect on these physical proper- Inst., Dehra Dun, India. l(1): 1-17 ties for borak, but not for muli. Rehman, M.A. and Ishaq, S.M. 1947. Seasoning and shrinkage of bamboo. Indian Forest Records (New Series), 2. Specific gravity differed significantly with height and For. Res. Inst. Dehra Dun, India. 4(2): l-22 age. It attained the highest value at the age of 3 years Sanyal, S.N; Gulati, A.S. and Khanduri, A.K. 1988. for both the species. The top portion was found to be Strength properties and uses of bamboo - a review. Indian the most dense in all cases. Forester, 114( 10): 637-649 3. Mechanical properties, viz., modulus of rupture, mo- Sekhar, A.C. and Bhartari, R.K. 1960. Studies on strength dulus of efasticity and compressive strength were also of bamboo. A note on its mechanical behaviour. Indian affected by the height and age. Both species were ob- Forester. 86(5): 296-301 served to attain maturity in respect of bending Sekhar, A.C. and Rawat, M.S. 1964. Some studies on the strength at 3 years. The 4 year old muli showed maxi- shrinkage of Bambusa nutans. Indian Forester. 91: 182- 188 mum compressive strength while this property was maximum at 3 years for borak. Talukdar, Y.A. and Sattar, M.A. 1980. Shrinkage and den- sity studies on two species of bamboo. Bano Biggyan Pa- trika. 9( l&2): 65-70 References Zhou, F.C. 1981. Studies on physical and mechanical Anon. 1973. Method of tests for round bamboo. Indian properties of bamboo . Jour. Nanjing Technological Standard: .6874. 14 pp College, For. Products, 2: l-32

Table 1: Moisture content and specific gravity values of two bamboo species at different height positions and age (average of five bamboo)

Moisture content (%) Specific gravity Species and age butt middle top butt middle top green vol. ovendry vol. green vol. ovendry vol. green’vol. ovendry vol. Muli (Melocanna baccifera) 1 year 111.00 95.00 82.00 0.48 0.64 0.55 0.69 0.61 0.72 2 years 107.00 88.00 76.00 0.52 0.69 0.58 0.70 0.62 0.73 3 years 102.00 88.00 71 .00 0.55 0.70 0.60 0.71 0.64 0.75 4 years 99.00 87.00 73.00 0.54 0.70 0.60 0.70 0.63 0.74 5 years 97.00 84.00 78.00 0.55 0.68 0.60 0.68 0.62 0.73 Borak (Bambusa balcooa) 1 year 187.00 154.00 129.00 0.38 0.73 0.43 0.78 0.49 0.80 2 years 146.00 123.00 108.00 0.46 0.76 0.49 0.78 0.54 0.81 3 years 128.00 106.00 100.00 0.50 0.76 0.61 0.80 0.69 0.82 4 years 117.00 106.00 97.00 0.53 0.73 0.61 0.78 0.67 0.82 5 years 119.00 111.00 102.00 0.50 0.74 0.59 0.78 0.55 0.81

Effect of Age and Height Position of Muli (Melocanna baccifera) and Borak (Bambusa balcooa) 185 Bamboo on Their Physical and Mechanical Properties Bamboo in the Asia Pacific Proceedings 4th International Bamboo Workshop, 1991

Table 2: Shrinkage values of two bamboo species at different height positions and ages

1 years 8.70 7.00 5.40 11.30 9.30 8.50 5.20 4.40 3.60 2 years 9.30 7.60 5.10 11.60 10.50 7.80 4.70 3.80 2.60 3 years 9.50 5.60 4.80 11.00 8.20 7.00 5.40 4.10 2.90 4 years 11.40 11.20 10.10 13.90 13.30 12.30 3.70 3.50 2.80 5 years 7.60 6.60 5.60 10.30 9.10 8.10 4.60 3.60 2.60 Borak (Bambusa balcooa) 1 year 26.20 22.40 15.60 29.40 26.20 18.30 11.20 7.90 5.00 2 years 21.30 19.10 16.80 25.10 22.20 21.10 10.30 7.30 5.30 3 years 23.30 16.90 11.70 26.80 19.90 14.90 7.50 5.60 5.10 4 years 20.20 11.90 7.60 22.50 14.50 10.50 7.10 5.00 2.20 5 years 24.30 20.30 16.90 27.40 23.90 20.80 11.60 8.70 6.30

Table 3: Strength properties of two bamboo species from the static bending test at different height, Posi- tions and ages

1 year 570.00 658.00 503.00 547.00 478.00 544.00 128.00 154.00 141.00 175.00 165.00 238.00 2 years 594.00 679.00 566.00 633.00 505.00 556.00 128.00 156.00 147.00 178.00 226.00 239.00 3 years 728.00 782.00 647.00 700.00 622.00 687.00 178.00 188.00 191.00 228.00 237.00 281.00 4 years 653.00 751.00 579.00 672.00 570.00 682.00 129.00 166.00 172.00 205.00 248.00 280.00 5 years 635.00 728.00 506.00 644.00 542.00 666.00 139.00 169.00 149.00 185.00 220.00 275.00 (Borak (Bambusa balcooa) 1 year 611.00 628.00 545.00 599.00 503.00 624.00 53.00 83.00 71.00 99.00 %.oo 105.00 2 years 689.00 748.00 647.00 691.00 588.00 630.00 81.00 92 .00 1 03.00 104.00 105.00 113.00 3 years 890.00 990.00 813.00 872.00 718.00 733.00 105.00 117.00 110.00 127.00 116.00 137.00 4 years 836.00 924.00 696.00 819.00 580.00 666.00 76.00 89.00 88.00 102.00 98.00 109.00 5 years 1 647.00 708.00 558.00 602.00 428.00 529.00 58.00 71.00 72.00 83.00 84.00 89.00

Table 4: Compressive strength values of two bamboo species at different height positions and ages

top Green airdry

1 year 348.00 380.00 393.00 430.00 434.00 489.00 2 years 366.00 456.00 414.00 495.00 ~430.00 522.00 3 years 370.00 464.00 421 .OO 479.00 442.00 551.00 4 years 391 .00 575.00 419.00 611.00 460.00 647.00 5 years 363.00 468.00 415.00 517.00 473.00 525.00 Borak (Bambusa balcooa 1 years 206.00 288.00 249.00 388.00 313.00 444.00 2 years 291 .OO 398.00 346.00 485.00 382.00 563.00 3 years 360.00 440.00 403.00 516.00 427.00 652.00 4 years 343.00 367.00 387.00 480.00 420.00 515.00 5 years 242.00 298.00 268.00 382.00 292.00 451.00

186 Effect of Age and Height Position of Muli (Melocanna baccifera) and Borak (Bambusa balcooa) Bamboo on Their Physical and Mechanical Properties Bamboo in the Asia Pacific Proceedings 4th International Bamboo Workshop, 1991

Table 5: Co-relation coefficients of different properties of two bamboo species and their test of significance

inkage in wall Sp.gr. Modulus of Sp.gr, Modulus of Spgr; Compressive thickness thickness rupture elasticity Muli Borak Muli Borak Muli Borak. Muli Borak 1 +0.62* +0.85* -0.62* -0.88* +0.32 ns -0.53* +0.23 ns +0.61* +0.85* -0.86* 2 +0.51 n s +0.95* -0.52* -0.96* -0.31 ns +0.26 ns +0.66* +0.64* +0.63* +0.96* 3 +0.61* +0.64* -0.71* -0.36 ns -0.51 ns +0.23 n s +0.43 n s +0.65* +0.51 n s +0.65* 4 -0.06 ns +0.76* -0.07 ns -0.77* -0.69* -0.67* +0.64* +0.42 ns +0.50 n s +0.66* 5 +0.92* +0.32 ns -0.49 nsl -0.27 ns -0.35 nsl -0.77* +0.45 n s +0.49 n s +0.19 n s +0.30 n s

Remark: * = Significant at the 5% level ns = Not significant

Table 6: Results of analysis of variance and least significant difference on different properties of two bam- boo species

Properties M uli Borak Variance ratio Mean diffenerce Variance ratio mean difference Height .Height Age. Height Age Height I. Moisture content 1.5 ns 28.3* all* 9.4* 6.4* 1 (2,3,4)* b-t* 2-4* 4-5* 2. Specific gravity (gr.vol) 2.88* 38.2* 1(2,3,4)* all* 30.9* 30.5* 1 (2,3,4)* all* 2-4* 2(3/J)* 3. Shrinkage-wall thickness (gr.to 19.6* 23.5* 1-4* all* 13.4* 47.4* 1 (2,3,4,)* all* airdty) 2-3* 2-4* 3-4* 3-4* 4-5* 4. Shrinkage-diameter (gr. to airdty) 1.6 ns 16.6*all* 4.4* 15.8* 1(3,4)* all* 2(3,4)* 3-5* 4-5* 5. Modulusof rupture (green) 9.9* 12.1* 1(3,4)* bm* 8.6* 8.8* all* 2-3* bt* 2-3* 3-4* 3-5* 4-5* 5. Modulus of rupture (airdty) 8.9* 10.7* 1 (3,4,5)* bm* 7.6* 6.6* bt* 2(3,4)* b-t* 2-3* 3-5* 4-5* 7. Modulus of elasticity (green) 5.7* 37.9* 1 (3,4,5)* all* 14.5* 13.8* 1(2,3)* all* 2-3* 2(3,5)* 3(4,5)* 3(4,5)* 8. Modulus of elasticity (airdry) 5.3* 50.0* 1 (3,4)* all* 7.9* 5.0* I-3* b-m* 2-3* 2(3,5)* 3-4* 3(4,5)* 4-5* 9. Compressive strength (green) l.0ns 18.8* all* 13.9* 8.2* 1 (2,3,4)* b-m* 2(3,5)* b-t* 3-5* 4-5* 10. Compressive strength (airdry) 13.2* 6.6* 1 (2,3,4)* b-t* 2.2 ns 4.5* all ns bm* 2-4* b-t* 3-4* 4-5* Remark: * = Significant at 5% level, ns = Not significant, b = butt position, m = middle position, t = top position; 1,2,3,4 and 5 in- dicate the age of bamboo

Effect of Age and Height Position of Muli (Mebcanna baccifera) and Borak (Bambusa 187 Bamboo on Their Physical and Mechanical Properties Bamboo in the Asia Pacific Proceedings 4th International Bamboo Workshop, 1991

Physical and Strength Properties of Dendrocalamus strictus Grown in Kerala, India*

R. Gnanaharan**

moisture content, density, tangential shrinkage and Introduction strength tests was done as shown in Figure 1. Strength Even though more than 100 species of bamboo are occur- tests were limited to samples from positions 1 and 2 (base ring in India, only few species like Bambusa arundinacea, and 25% height of the culm) as the wall thickness was B. balcooa, B. nutans, B. tulda, Dendrocalamus strictus, less than 10 mm at higher lcvcls. D. hanriitonii are commercially important. Of these, B. arundinacea and D. strictus occur almost throughout the Standard procedures were followed for determining the country and their physical and strength properties have physical properties. Strength properties were determined been studied estcnsively( Limaye, 1952; Sekhar and Bhar- by carrying out static bending and compression parallel to tari, 1960, 196l; Sekhar and Gulati, 1973; Sanyal et a/, grain tests on split samples in air-dry condition as per the 1988; Shukla et al, 1988). These studies have shown that Indian standard IS:8242 (BIS, 1976). After carrying out there is a wide variation in strength properties depending the tests, a small sample was cut near the place of failure on the locality from which the bamboo was collected. and density was determined. The physical and strength While Barnbusa arundinacea is the most common species properties data were statistically analysed. occurring throughout Kerala State, Dendrocalamus stric- I tus occurs only in few pockets. Review of literature re- Results and discussion vealed that strength properties of Kerala grown D. strictus had not been evaluated so far. It was decided to evaluate Physical properties D. strictus from different localities of Kerala for physical and strength properties. Culm length The culm length varied from 6.3 m (Palakkad) to 10.8 m Material and methods (Nilambur). The average length from the three localities is given in Table 1. Palakkad, which is fairly dry and hot, Three mature culms (three years and above in age) from rccordcd the lowest culm length. This shows that the one or more clumps from three different localities were growing conditions (climate and soil) play a major role in collected. Details of the localities as to altitude and rain- the culm length, fall are given below. Internode length Place Altitude(m) Annual rainfall (mm) Nadugani (Nilambur) 1,000 2,500-3,000 It was observed that culms from Nilambur which had Pudussery (Palakkad) 200 1,000-l ,500 longer culm length eshibited higher intcrnodcs also (Table 1). In general, internodc length increased from Thuvanam (Chinnar) 800 1,000-l ,500 base to about 50% of the height and then decreased After measuring the full length of the culms, 2-noded (Figure 2). Both locality and position of the culm had portions from base (0%, (l), 25%(2), 50%(3) and 75%(4) highly significant effect on the internode length (Table 2). of the culm length were brought to the laboratory. Culms from Nilambur had the highest internode length, followed by Chinnar and then Palakkad. Also. internode The internode length and diameter (two opposites) of length of base was significantly lower than that of other these portions were noted. After cutting off the nodes, the positions (Table 3). Variation in internode length from wall thickness was measured in four places. Sampling for 25% to 75% of the culm length is minimal. Sekhar and

* KFRI Sclentific Paper “Kerala Forest Research Institute, Peechi 660 653, Kerala, India Bamboo in the Asia Pacific Proceedings 4th International Bamboo Workshop, 1991

Bhartari (1961) reported an internode length of 285 to to 9.7%). In wood, higher the density, higher is the 340 mm for Madhya Pradesh grown D. strictus. Kerala- shrinkage. However, a reverse trend, though not pro- grown D. strictus, this study showed, had lower internode nounced, was noticed in the case of D. strictus (Figure 2). length, 210 to 289 mm. Correlations Diameter Simple linear correlations were examined for possible Diameter decreased from base to top. The decrease in di- relationships between the different physical properties and ameter was more steep in the culms from Palakkad. The the correlation coefficients (r) are given in Table 4. Al- ratio of diameter at 75% and at 0% was 0.46 whereas that though a number of r-values are highly significant, r2 val- of Nilambur was 0.62. Both locality and position of the ues are less than 0.5. That means, not even 50% variation culm had highly significant effect on diameter (Table 2). in the dependent variable is explained. Culms from Nilambur had significantly larger diameter than those of other two localities. Diameter at each posi- Green moisture content and basic density are strongly tion was significantly different from one another (Table negatively correlated (r = -0.946). This clearly shows that 3). The average diameter observed for Kerala grown D. higher the density, lower will be the green moisture con- strictus (38.4 to 44.1 mm) was within the range (3 1.6 to tent which agrees with the behaviour of wood. Also, culm 78.8 mm) reported for D. strictus grown in different loca- diameter and wall thickness are highly positively corre- lities of India (Sekhar and Gulati, 1973). lated (r = 0.84). This means, higher the diameter higher is the wall thickness. As diameter decreased from base to Wall thickness top, wall thickness also decreased. As in the case of diameter, wall thickness also decreased A multiple linear regression was run to see whether di- from base to top. Locality did not have any significant ef- ameter and internode length, two parameters which can be fect on wall thickness (Table 2). However, wall thickness measured externally, can predict density. The R2 value decreased significantly with each position of the culm was only 0.219. Adding wall thickness improved R’value from base to top. The rate of decrease in wall thickness only marginally (0.273). from 0% to 25% was more than that of from 25% to 75% of culm length. Even though base had a wall thickness of Strength properties 20.0 mm, it rapidly reduced to 12.5 mm at 25%, 8.5 mm at 50% and 6.0 mm at 75% of culm length. Fibre stress at limit of proportionality (FSLP), modulus of rupture (MOR) and modulus of elasticity (MOE) obtained Average wall thickness of Kerala grown D. strictus from static bending test and maximum crushing stress ranged from 11.1 to 12.3 mm. Sekhar and Gulati (1973) (MCS) obtained from compression test are presented in reported a wall thickness of 8.3 to 18.7 mm for D. stric- Table 5. tus grown in different localities of India. Sekhar and Bhartari (1960) tested D. strictus in split Green moisture content form. They reported FSLP of 119 N/mm2, MOR of 189 N/mm2 and MOE of 17,170 N/mm’. These values are There was a wide variation in moisture content along the much higher than the highest values obtained for the bam- length of the culm of Palakkad (from 46.6 to 108.3%). boo from Chinnar. The corresponding values are 109, 153 Otherwise, there was very little variation in moisture con- and 11,270 N/mm2 respectively. Abang Abdullah (1984) tent (Table 1). As the locality position interaction was reported MOR, MOE and MCS values for Bambusa vul- highly significant, means among the localities and posi- garis tested in split form. The values are 102, 9,600 and tions of the culm were not compared. 45 N/mm2 respectively. B. vulgaris is slightly weaker than Density D. strictus in MOR and MOE. MCS of B. vulgaris was within the range of values obatined for D. strictus (42 to Basic density varied widely from 540 to 780 kg/m3 in the 57 N/mm’). Generally, the strength values reported in the culms of Palakkad whereas the variation in density of literature are average for the whole culm (average of bot- culms of other two localities was from 630 to 720 kg/m3 tom, middle and top) tested in round form. As tests were only (Table 1). The density values reported in the litera- carried out in this study on split bamboo from base and ture ranged from 430 to 780 kg/m3 (Sanyal et al 1988). 25% height of the culm, strict comparison is not possible While it increased from base to top in the case of culms of Palakkad, it increased to some distance (25 to 50%) and The ANOVA showed that locality had a significant effect then decreased in the case of culms of Nilambur and on FSLP, MOR and MOE. The means are compared in Chinnar (Figure 2). Table 6. MCS was not affected either by locality or by position of the culm. Tangential shrinkage The strength values of bamboo grown in a dry place The green to oven-dry tangential shrinkage did not follow (Palakkad and Chinnar) were much higher than that of any pattern from base to top (Figure 2). While position of bamboo grown in a place which receives fairly good rain- culm did not have any significant effect on shrinkage, fall, Nilambur. This shows that climate plays a major role culms of Chinnar had significantly lower shrinkage (6.1 in determining the strength properties of D. strictus. The

Physical and Strength Properties of Dendrocalamus strictus grown in Kerala, India 189 Bamboo in the Asia Pacific Proceedings 4th International Bamboo Workshop, 1991

MOR and MOE values of Kerala-grown teak are 94 knowlcdged. The author is thankful to Mr. P.K. Thulasi- N/mm2 and 11,720 N/mm2 respectively (Chowdhury and das for his help in sample collection and laboratory Ghosh, 1958). D. stricfus from Palakkad and Chinnar are investigations. much stronger than teak in MOR; D. strictus from Chin- nar compared well with that of teak in MOE. References The relationship between density and the different Abang Abdullah A.A. 1984. Development of basic me- strength properties was not strong enough (Table 7). Also chanical tests for Malaysian bamboo. Pertanika examined was whether ultimate strength (MOR) can be 7(2):13-17. predicted by any property either singly or in combination. Bureau of Indian Standards (BIS). 1976. Methods of tests The R2values of multiple regression are tabulated in Table for split bamboo. lS:8242-1976. New Delhi, India. 8. As can be seen, FSLP explains 73.3% variation in Chowdhury K.A. and Ghosh S.S. 1958. Indian Woods: MOR and in combination with MOE, 81.2% variation. Their identification, properties and uses. Vol. I. Govt. of In- Adding density did not improve R2 value. dia Press, Delhi. 304 pp. Limaye V.D. 1952. Strength of bamboo (Dendrocalamus strictus). Indian Forester 78:558-575. Conclusion Sanyal S.N., Gulati A.S. and Khanduri A.K. I 988. This study has shown that climatic conditions affect some Strength properties and uses of bamboo: A review. Indian of the physical and strength properties. Dendrocalamus Forester 114:637-649. strictus growing in a moist area has longer internodes, Sekhar A.C. and Bhartari R.K. 1960. Studies on strength larger diameter and poorer strengths in MOR and MOE. of bamboo: A note on its mechanical behaviour. Indian Forester 86:296-301. D. sfrictus grown in a dry place is much stronger even though culm length, internode length and diameter are Sekhar A.C. and Bhartari R.K. 1961. A note on strength of dry bamboo (Dendrocalamus strictus) from Madhya Pra- lower. Where strength properties are critical, bamboo desh. Indian Forester 87:611-613. should be selected from a dry locality. Sekhar A,C. and Gulati A.S. 1973. A note on physical and mechanical properties of Dendrocalamus strictus from Acknowledgements different localities. Van Vigyan 11(3&4):17-22. Shukla N.K., Singh R.S. and Sanyal S.N. 1988. Strength This study was carried out as part of a project, Bamboo- properties of eleven bamboo species and study of some India, funded by the International Development Research factors affecting strength. Journal of Indian Academy of Centre, Canada. The financial support is gratefully ac- Wood Science 19:63-80.

Table 1: Physical properties data of D.strictus Tangential Culm length Internode Diameter Wall thick- Moisture Den&y shrinkage Locality (m) Position ( %) length(mm) (mm) ness (mm) content (%) (kg/m3) (%) Nilambur 10.40 0.00 208.00 52.40 18.76 79.30 630.00 10.37 25.00 325.00 48.10 11.64 76.50 650.00 10.90 50.00 338.00 43.50 8.42 69.30 680.00 12.70 75.00 285 .00 32.50 5.68 76.70 630.00 12.74 Paakkad 7.30 0.00 160.00 54.10 21.69 108.30 540.00 12.00 25.00 220.00 42.80 13.32 88.30 600.00 11.38 50.00 243.00 33.50 8.33 82.40 710.00 10.78 75.00 217.00 25.00 5.71 46.60 780.00 10.92 Chinnar 8.70 0.00 I 78.00 48.70 19.54 77.90 640.00 7.39 25.00 277.00 42.40 12.58 66.70 720.00 6.09 50.00 288.00 36.90 8.74 71.40 690.00 7.57 75.00 262.00 25.30 6.60 71.60 690.00 9.72

Table 2: Significance of F-values of the physical properties data Source of Tangential variation Internode length Diameter Wall thickness Moisture content Density shrinkage

Locality (L) ** ns ns ns ** ** Position (P) ** ** ** ** ** ns LXP ns ns n s ** ns ns Remark ns=not significant; *=significant at 5%; ** =significant at 1%

190 Physical and Strength Properties of Dendrocalamus strictus grown in Kerala, India Bamboo in the Asia Pacific Proceedings 4th International Bamboo Workshop, 1991

Table 3: Comparison of treatment means between localities and positions

Locali Position Nilambur Palakkad Chinnar 1 2 3 4 o Int length (mm) 289 210 182" Diameter (mm) 44.1" 51.8 38.V Wall thickness (mm) 11.1” 12.3" 11.9 20.0" 8.5' Mois. content 75.50 76.40 71.90 88.50 77.20 67.70 65.00 Density [Tang. shrinkage 11.7 11.5” 9.9 9.50” 10.4 11.5' Remark Values in a row having the same superscript are not significantly different

Table 4: Correlation coefficients of simple linear correlation of different variables

Variable Internode length Diameter Wail thickness : Moisture content Density Tangential shrinkage- Internode length 1.00 Diameter -0.16 1.00 Wall thickness -0.581" 0.840" 1.00 Moisture content -0.19 0.551" 0.581.' 1.00 Density 0.15 -0.462" -0.946'. 1.00 Tangential shrinkage 0.00 0.02 -0.10 0.18 -0.29 1.00

Table 5: Average strength properties in

Locality Position MOR MOE MCS Nilambur 0% 25.30 50.00 5998.00 47.40 25% 39.60 54.30 6125.00 57.30 kkad 0% 78.40 124.30 7272.00 41.50 25% 66.00 127.60 11094.00 42.40 Chinnar 0% 81.10 141.60 11789.00 48.40 25% 109.10 152.90 11270.00 48.30

Table 6: Comparison of treatment means between localities

Property N/mm2) Nilambur _ tbtakkad Chinnar FSLP 32.4 95.1' MOR 52.1" 1 147.3' MOE 6056" Remark Values in a row having the same superscript are not different

Table 7: Correlation coefficient (r) of relationships between different variables

I Dependent MOR MOE Density 0.39 0.32 0.06 0.567"

Table 8: Multiple re ession with MOR as dependent variable (y) and and density as independent variab es . Independent variable Y 0.73 Y 0.33 Y 0.10 Y + 0.81 Y + 0.73 Y 0.41 Y x,+x,+x, 0.81

Physical and strength of grown in Kerala, India 191 Bamboo in the Asia Pacific Proceedings 4th International Bamboo Workshop, 1991

Figure 1: (a) Sampling pattern for positions 1 and 2 and (b) for positions 3 and 4

Internode length 350

300

250

200

150

800

-700

-600

-500 Tangential shrinkage

0% 25% 5 0 % 75% Culm length N Niombur, C hinnqr )

Figure 2: Variations in different physical properties along the culm length

192 Physical and strength properties of Dendrocalamus strictus grown in Kerala, India Bamboo in the Asia Pacific Proceedings 4th International Bamboo Workshop, 1991

Anatomical Characteristics of Taiwan Giant Bamboo and Moso Bamboo

Shuen Chao Wu & Jung Sheng Hsieh*

Materials and methods Taiwan is located in the subtropical zone, and is more The bamboo studied are Taiwan giant bamboo suitable for bamboo growth than the temperate zone. (Dendrocalamus latiflorus Munro) and Moso bamboo Bamboo are distributed vertically from sea level up to (Phyllostachys pubescens var. pubescen). The sample 3,300 meters in elevation as seen in the Central Mountain culms were collected form the Experimental Forest of Na- Range of Taiwan. According to investigations, there are tional Taiwan University in central Taiwan, approx. about 15 genera, 40 species, 3 varieties and 10 cultivars elevation 800-1000 M. While the age of bamboo is not rc- (Lin, 1981) or 71 species (Tai, 1982), only six of them lated to DBH and height, the wall thickness has signifi- Long branch bamboo (Bambusa dolichoclada Hay.), cant influence on the anatomical structure. Five hundred Green bamboo Bambusa oldhamii Munro ), Thorny bamboo culms of each species was investigated to detcr- bamboo (Bambusa stenostachya Hackle), Taiwan giant mine the mean diamtcr, which is 8.9cm for Moso bamboo bamboo (Dendrocalamus latiflorus Munro), Makino’s and 8.3cm for Taiwan giant bamboo; one-four year old bamboo (Phyllostachys makinoi Hay.) and Moso bamboo healthy bamboo were collected depending on the mean (Phyllostachys pubescens var. pubescens) are of great eco- diameter. nomical value. Samples were obtained by taking the middle part of the Taiwan giant bamboo and Moso bamboo are two of the second internode above the ground, further samples were most important commercial and native bamboo species in also taken from the sixth, tenth, fourteenth and further Mainland China. The vertical distribution of Taiwan giant up, to the top of culm. bamboo is from sea level up to 1000 meters and the Moso bamboo is from 150 meters up to 1800 meters (Jiang, To studying fiber length, picccs of culm were macerated 1987; Lin, 1987). The main use of these two bamboo spe- by using 1:5:4 hydrogen pcroside : acetic acid : distilled cies are shoot production and culm utilization. The prop- water mixture at room temperature. Separated fibers were erties of the culm are determined by its unique anatomical thoroughly mised and stained with 5% saframin-0. structure in the vertical and horizontal direction of culm Length measurements of 50 unbroken fibers were taken wall, such as length, diameter, thickness and their distri- from each internode. The culm wall was microtomed in bution of vascular bundle and fiber. In some properties, transverse, tangential and radial directions in 10 to 20um the Moso bamboo are better than those of the Taiwan thicknesses. The image analysis system for personal com- giant bamboo, therefore the fine texture of Moso bamboo puter was used to measure the fiber length, diameter of is used in rotary cutting production, handicraft articles, vessels, density of vascular bundles and other anatomical veneer and laminated bamboo with high economical properties. value. The Taiwan giant bamboo is used in bamboo raft, provin- Results and discussion cial furniture, tools for farm, fishing or pasturage and handicraft articles; the residual materials of these two Measurement of length and thickness bamboo culms were generally used for religious paper The variation of internode length and diameter making. The length of first internode above the ground and the The main purpose of this study of these two bamboo spe- masimum, for the one to four year old of the two bamboo cies is investigate properties, as : culm wall, vascular species are represented in Table 1. The comparison of bundles and fiber, Moso bamboo and Taiwan giant bamboo revealed that the internode length of Moso bamboo is significantly shorter than that of Taiwan giant bamboo, no matter whether in the first internode or maximum; it was shorter by about Bamboo in the Asia Pacific Proceedings 4th International Bamboo Workshop, 1991

50% at the first internode above the ground and about epidermal layer from the base to the top of culm were 23% at the maximum length of internode. shown in linear regression models listed in Table 2. Al- though the thickness of base internode above ground of Along the culm axis, the average internode length in- Moso is thinner than that of Taiwan giant bamboo, the creased from the base to about the middle part, and then thickness of epidermal layer of Moso bamboo is twice as decreased to the top of culm as shown in Figure 1. The thick as that of Taiwan giant bamboo. maximum average length of internode is at the twelfth for Taiwan giant bamboo and 24th for Moso bamboo. The Parenchyma of pith periphery height above the ground of maximum average length of internode in the culm is 6.86 meters for Moso bamboo and The thickness of parenchyma of pith periphery at the in- 4.23 meters for Taiwan giant bamboo. The height of ner part of culm wall is called “Bamboo yellow”, it means maximum length of internode for Taiwan giant bamboo is the yellow part of bamboo culm viithout vascular bundle lower than that of Moso bamboo and with longer length of layer. The average thickness of this layer is 314 urn for internode. Taiwan giant and 698 urn for Moso bamboo at the middle part of the second internode above the ground. It dc- The logitudinal variation of internode length along the creases to 188 urn for the former and 505 um for the latter culm was described by using curvilinear regression mod- at the top part. The variation of the thickness of pith pe- els, in which the curves were fitted on average values of ripheral layer of Moso bamboo is more than twice that of ages (Figure 1 and Table 2). The variations of average in- Taiwan giant bamboo. The regressional analysis between ternode diameters from the base to the top of culm were the average thickness of the pith peripheral layer and in- shown in linear regression models listed in Table 2. tcrnode number from the base to the top of culm were de- scribed by using linear regression models listed in Table According to the investigation of Sasa bamboo on the in- 2. ternode length from the base to the top of the culm showed that the internode length of the base and the top of The percentages of the epidcrmal layers and the pith pc- the culm are shorter than that the internode at the middle ripheral layers to the whole culm thickness increases from part of the culm. The culm diameter decreases from 17.2 the base to the top of the culm and the latter is significant- mm for the base to 8.6 mm for the top of the culm, Ka- ly greater than the former, irrespective of the epidermal wase 1981. layers or the pith peripheral layers, . The comparison of the thickness percentage on the two bamboo species The thickness of the culm wall showed it was greater in Moso than in Taiwan giant Whole culm wall bamboo.

The average thickness values of the culm wall at the se- Vascular bundles cond internode above the ground was 14.0 millimeters for Taiwan giant bamboo and 12.7 millimeters for Moso bam- The tangential length boo; the thickness decreasing from the base to the top of The vascular bundles occur inside the cortical layers. The the culm. In the 22th internode, the figures were 3.8 mm tangential length is small near the outer part of the culm for Taiwan giant, and 7.2mm for Moso bamboo. wall andincreases toward the inner part of the culm wall The average culm diameter of Taiwan giant bamboo is (Figure 2) and reaches maximum length at the inner most smaller than that of Moso bamboo but larger for the culm part of the vascular bundles layer. The size of vascular wall thickness in the base of culm. The thickness of the bundle in Taiwan giant is greater than that of Moso bam- culm wall at the 22th internode of the Moso bamboo is boo at each internode, and it’s about two to three fold at more than that of Taiwan giant bamboo, The variations of the inner most part of the vascular bundle layer. The ra- average culm wall thickness from the base to the top of dial variations of tangential Icngth of vascular bundle at culm were shown in linear regression models listed in Ta- the second internode of bamboo culm wall were described ble 2. by using linear regression models as listed in Table 3.

Epidermal layer The average tangential lengths of one to four year old of two bamboo species are 436.521.7 urn, 489.317.5 um, The epidermal layer of bamboo culms is called “Bamboo 513,628-l um and 463.536.8 um for Moso and 547.340.6 green”, it means the green part of bamboo at the outer part um, 536.260.6 urn, 509.943.2 urn and 438.796.4 urn for of culm wall which does not contain the vascular bundle Taiwan giant bamboo. The average tangential length is layer. The thickness of this layer is 83um for Taiwan giant 475.7 um for Moso and 517.3 um for Taiwan giant bam- bamboo and 187um for Moso bamboo at the second intcr- boo. The variation along the logitudinal direction of the node above the ground. The thickness decreases to 53um culm of two bamboo species arc different. Taiwan giant for Taiwan giant bamboo and 108um for Moso bamboo at bamboo increases from the base to the 6th intcrnodc and the 22th internode and the trend continues to the top of then dccreascs to the top of the culm, the variation of the culm wall. The ratios of decrease are 36.14% and Moso bamboo increases from the base to the top of the 42.25% at the 22th internode for Taiwan giant and Moso culm. bamboo respectively. The thickness variations of

194 Anatomical Characteristics of Taiwan Giant Bamboo and Moso Bamboo Bamboo in the Asia Pacific Proceedings 4th International Bamboo Workshop, 1991

Density vere shown in linear and curvilinear regression models listed in Table 4. The density is the number of vascular bundle occuing in one mm unit area, and varied from the epidermal layer to- Zenita, 1985, found the average diameter of vessles of ward the pith peripheral layer. At the first millimeter in- Bambusa blumeanea is 186.3 um at the base internode of side the epidermal layer, there are significantly high he culm decreases to 136.6 urn toward the middle part densities of vascular bundles with 8-10 for Taiwan giant and increases to 173.6 um at the top of the culm. Howev- and 7- 8.5 for Moso bamboo. The density decreases rapid- er, the variation of G. levis differ from the B. blumeanea ly at the second millimeter, 2.5-3.5 for Taiwan giant and he average vessel diameter decreases from the base to- 3.5-4.5 for Moso bamboo. The size of vascular bundles at ward the top of the culm. the second millimeter is larger than that at the first milli- meter and the rest can be deduced accordingly. From the Fiber middle part of culm wall of the second internode above Length the ground of the two bamboo species, the number of vas- cular bundles decreases to about 1-2 toward the inner part Radial direction of the culm. According to the average density of each height internode, one to two vascular bundles occur at dis- The fiber length was measured at every one millimeter tance about 5mm from the epidermal layer. Figure 3 From the epidermal layer to the pith peripheral layer. Fig- shows radial density variation of different internodes of ure 5A, 5B showed the radial variation of fiber length at Taiwan giant and Moso bamboo. the central part of the second internode above the ground of two bamboo species. The shortest fiber length occurred Wu & Wang (1976) studied the density of vascular bundle in the first millimeter of the outer culm wall. The fiber at the middle part of the culm wall and found that there is length increases toward the middle part of the culm wall. one vascular bundle per unit area for Taiwan giant and about 3-4 for Moso bamboo. Along the axis of the culm - At the distance about 5-7 mm from the epidermal layer of there are 3.80 for the top and 1.74 for the base of the Taiwan giant bamboo, the fiber length increases from Bambusa blumeana E and Gigantochloa levis E. The re- 1.619 mm to between 2.028 and 2.759 mm. The fiber sults showed the density of vascular bundle at the top is length decreases from the middle part to the inner part of larger than that at the base of the culm (Zenita, 1985). the culm wall. The average fiber length of the first milli- meter at of the outmost culm wall for Moso bamboo is Diameter of vessels 1.43lmm. At the distance about 6-8 mm from the epider- Radial direction ma1 layer of the Moso bamboo, the length increases to 2.095 mm, and then decreases to 1.736 mm at the inner- Figure 4 shows the diameter of vessels increases from the most of the culm wall. According to the variation of the epidermal layer to the inner pith cavity of the culm wall. fiber length across the culm wall, the maximum average The average diameters of 6th, 14th and 22th internodes fiber length occured at one third to one half distance from are 18.8 um, 15.0um and 15.2 urn respectively at the outer the epidermal layer of the culm; it is 2.456 mm for Tai- part of Taiwan giant bamboo culm wall. The average di- wan giant and 2.175 mm for Moso bamboo. The relation- ameter increases to 164.6 urn, 151.4 um and 132.0 um at ships between fiber length and distance from the the middle part of the culm wall and increases further to epidermal layer were shown in curvilinear regression 205.0um, 202.4 um and 176.4um at the inner part of the equation models listed in Table 5. culm wall. The average diameter of vessels at the same three internodes of the Moso bamboo culm wall from out- Some other descriptions showed the variation of fiber er to inner part, increases from 25.8 urn, 28.3 um and length in the radial direction with the same trend (Kawase 23.0 um to 126.0 urn, 128.0 urn and 138.0um and in- 1981), and the fibers length in the inner part are always creases further to 137.3um, 160.3um and 176.3 urn. Com- much shorter about 20 - 40% to the middle part of the parison of the diameters at the same part between the two culm wall (Liese, 1985). Sun, 1985, studied Moso bamboo bamboo species showed that the diameter of Moso bamboo and found that irrespective of age, the shorter fibers occur is larger than that of Taiwan giant bamboo at the outer at the peripheral layer. part of culm wall and this is reversed at the middle and Axial direction inner part. The longitudinal variations of fiber length along the axial Axial direction culm of different age are shown in Figures 5C & 5D. The Along the culm axis, the largest average diameter of ves. length increases from the base of the culm and reaches sels is 124 um at the sixth internode above the ground for maximum at the l0-14th internode for Taiwan giant and Taiwan giant bamboo, The average diameter decreases the 14-18th internode for Moso bamboo and in both de- from the sixth internode to the top of the culm. The varia- creases to the top of culm. The average fiber length is tion of vessel diameter for Moso bamboo increases from 2.247 mm at the base internode for Taiwan giant and the base to the top of the culm. The diameter variation! 1.924 mm for Moso bamboo and the maximum average along the axis of the culm from the base to the top of culm fiber length is 2.566 mm for Taiwan giant and 2.341 mm for Moso bamboo. The maximum fiber length occurs at

Anatomical Characteristics of Taiwan Giant Bamboo and Moso Bamboo 195 Bamboo in the Asia Pacific Proceedings 4th International Bamboo Workshop, 1991 height range 3.77-5.60 m above ground level for Taiwan giant, and 3.17-4.56 m for Moso bamboo which shows the Conclusions height of Moso is lower than that of Taiwan giant bam- 1. The internode length is shorter at the base and in- boo. The variations of fiber length in longitudinal direc- creases with height of the culm; in Taiwan giant bam- tion from the base to the top of culm were shown in boo it can reach 60 centimeters at 4.23 meters and in curvilinear regression models listed in Table 6. Moso bamboo, 40 centimeters at 6.86 meters above the ground level. When height increases further a Liese, 1985 said that along the axis, with increasing slight reduction in internode length occurs. height of the culm there only slight reduction occurs in fi- 2. The thickness of the whole culm wall, epidermal layer ber length. Sun 1985, found half and in one year old bam- and parenchyma of pith periphery all decrease from boo the fiber length in the base are slightly longer than the top of the culm, but the three and seven year old bamboo the base to the top of culm. While the culm diameter the longer fiber at the middle and the top of the culm. of Taiwan giant bamboo is smaller than that of Moso bamboo the culm wall of the former is thicker than the Eight species bamboo grown in Taiwan were studied at latter. The thickness of the epidermal layer and the the diameter breast height, one third, one half and two thirds height of the culm for fiber length (Huang, 1968). parenchyma of pith periphery of Moso are twice as large as Taiwan giant bamboo. The percentage of epi- The longest fiber at one half and one third of culm height dermal layer and the parenchyma of pith periphery to for Taiwan giant and two thirds of height for Moso bam- the whole culm wall increase from the base to the top boo are the same as this study. The fiber length increases of the bamboo culm. with increasing age for Moso bamboo (Sun, 1985), but not for Taiwan giant bamboo (Huang, 1968). 3. The tangential length of vascular bundles and the ves- sels increase from the cpidermal layer to the pith cav- Single internode ity in the radial direction of the culm wall. The The variation of fiber length within one internode is very diameter of vessels can reach to about 200um for Tai- wan giant and about 150um for Moso bamboo respec- significant, the shortest fibers are always near the nodes, the longest in the middle part of internode (Figure 5E). tively. Along the culm the variation of average vessel The fiber length at the lower node of second internode diameter of Taiwan giant incrcascs from the base to the lower middle part, and then decrcascs to the top of above the ground is 1.522 mm for Taiwan giant bamboo the culm. The variation of Moso bamboo increases and 1.401 mm for Moso bamboo, the upper node of the from the base to the top of the culm. same internode is 1.385 mm and 1.251 mm for two bam- boo species. In the middle part of internode, the maximum 4. The density of the vascular bundle in the radial scc- fiber length reaches to 2.491 mm for Taiwan giant bam- tion of culm wall dccreascs from the epidermal layer boo and 1.986 mm for Moso bamboo respectively. to the middle part and remains constant, to the pith cavity. The density dccrcascs from about 7-10 to The variation showed thaf the shorter fibers occured from 1-2/sq.mm. node to about 2-4 centimeter near the node, and the rest 5. The shortest fiber lenglh occurs at the peripheral layer part of internode contains the longer fibers. of the culm and reaches masimum length at one half or one third of the culm wall; the fiber length de- Occupation ratio creases to the inner part of culm wall. In the longitu- The fibers occur in the internodes as sheaths of vascular dinal direction the longest fiber length of about bundles, and in Taiwan giant bamboo also as isolated 2.480mm occurs at the l0th-14th internode for Tai- strands. The fiber ratio of bamboo constituent often de- wan giant, and about 2.280mm at 14-18th for Moso creases across the culm wall from the epidermal periphery bamboo. Shorter fibers occur at the base and top of the towards the inner part (Table 7). The fiber ratio from the culm. Within one internode the shortest fibers are al- outer to the inner part of culm wall is about one half, third ways near the nodes; the longest fibers are in the and fourth for Taiwan giant, and one half, fourth and middle part of the internode. The variation showed seventh for Moso bamboo. Sometimes the outer ratio is that the shorter fibers occur from the node to about twice as large as that of the inner part of the culm (Wu, 2-4 centimeter near the node, and the rest of the inter- 1974). A comparison of ratios from one fourth distance node has the longer fibers. from the periphery, with that of the one fourth distance of 6. High ratios of fiber cells occur at the outer part and the inner part of the culm wall, snows about three fold dif. decrease toward the inner part of the culm wall. The ference of ratios (Wu & Wang, 1976). ratio is about one half, one third and one fourth at out- With increasing height of the culm, only a slight increase er, middle and inner part of the culm for Taiwan in fiber ratio occurs. At the 6th, 14th and 22th internode giant, and one half’, one fourth and one seventh for above the ground, the fiber ratios are 32.68%, 35.84% and Moso bamboo. Comparison of the two bamboo species 38.3 1% for Taiwan giant and 24.63%, 30.11% and shows that the amount of fiber in Moso, is less than 30.85% for Moso bamboo respectively. The same result! that of Taiwan giant bamboo. were obtained by Wu, 1974 and Jules, 1981.

196 Anatomical Characteristics of Taiwan Giant Bamboo and Moso Bamboo Bamboo in the Asia Pacific Proceedings 4th International Bamboo Workshop, 1991

Lin, W.C. & G.M. Leu. 1987. The cultivation and manage- References ment of Moso bamboo. Xiandai Yulin 2(2):3-22. Huang W.H. 1968. Study on the mechanical properties of Sun, Chengzhi & Xie Guoen. 1985. Fiber Morphology and some commercial bamboo species in Taiwan. Master the- Crystallinity of Phyllostachys pubescens with Reference to sis, National Taiwan University. Age. Recent Research on Bamboo 247-249. In: Proc. of Jiang, T. 1987. The cultivation and management of Tai- the International Bamboo Workshop, Ed. A.N. Rao. wan giant bamboo. Xiandia Yulin 2(2): 23-42. Hangzhou, China. Jules. J.A. Janssen. 1981. The Relationship Between the Tai, K.Y. & T. Jiang. 1982. The management and utiliza- Mechanical Properties and the Biological and Chemical tion of bamboo resource in Taiwan. Council for Agricul- Composition of Bamboo. Bamboo Production and Utiliza- tural Planning and Development Excutive Yuan. pp76. tion 27-32. In: Proc. XVII IUFRO Congress Group 5.3. E.d. Wu, S.C. 1974. Studies on the determination of the cutting T. Hignchi Kyoto, Japan. rotation of bamboo based on their mechanical properties. Kawase Kiyoshi. 1981. Distribution and Utility Value of Bulletin of National Taiwan University in Co-operation with Sasa Bamboo. Bamboo Production and Utilization 92-97. Taiwan Forest Bureau No. 4 In: Proc. XVII IUFRO Congress Group 5.3. Ed. T. Higuchi, Wu, S.C. & H.H. Wang. 1976. Studies on the structure of Kyoto, Janpan. bamboo grown in Taiwan. Bulletin of National Taiwan Uni- Liese, W. 1985. Anatomy and Properties of Bamboo Re- versity in co-operation with National Science Council, and cent Research on Bamboo 196-208 In: Proceeding of the Joint Commission on Rural Reconstruction No. 16 pp79. International Bamboo Workshop, Ed. A.N. Rao. Hanzhou, Zenita B. Espiloy. 1985. Physico-Mechanical Properties China. and Anatomical Relationship of Some Philippine Bamboo. Lin, W. C. 1981. Subfamily Bambusoideae - Flora of Tai- Recent Research on Bamboo 257-264. In: Proc. of the In- wan. Vol 5 pp.706-783. ternational Bamboo Workshop, Ed. A.N.Rao. Hangzhou, China.

Table 1: The average length (cm) of the maximum and the first internode above the ground for the dif- ferent age of the two bamboo species

First Internode Maximum Internode Moso bamboo Taiwan giant bamboo Moso bamboo Taiwan giant bamboo I 13.40 26.60 34.20 61.50 12.20 27.80 36.60 52.30 1 4.50 24.00 42.20 38.80 15.30 26.50 39.00 46.20 13.90 26.20 38.00 49.70

Table 2: Regression uations for longitudinal variation in internode length (cm), internode diameters (an), thickness of who e culm wall (mm), thickness of epidermal layer (urn), thickness of pith periphery (urn) of the two bamboo species, where X= internode number above the ground

Items Species Equations P(%) F value Taiwan giant bamboo Y=25.61+2.89X-0.11 X 2 95.00 285.65** Internode length 2 IMoso bamboo Y=l0.40+2.05X-0.04X 99.00 3,287.31** Internode diameter Taiwan giant bamboo Y = 10.04-0.28X 98.00 575.82** Moso bamboo Y=10.95-0.19x 99.00 1,491.73** Culm wall thickness Taiwan giant bamboo Y= 12.74-0.42X 83.00 151.40** Moso bamboo Y= 12.48-0.23X 94.00 512.80** Epidermal layer Taiwan giant bamboo Y= 78.0-l .2. X 44.00 24.24** thickness Moso bamboo Y= 171 D-2.4 X 49.00 31.27** Pith periphery thickness Taiwan giant bamboo Y=308.0-5.7 71 .00 75.40** Moso bamboo Y=700.0-7.9 x 41.00 22.50**

Anatomical Characteristics of Taiwan Giant Bamboo and Moso Bamboo 197 Bamboo in the Asia Pacific Proceedings 4th International Bamboo Workshop, 1991

‘on equations for radial variation in tangential length of vascular bundle (urn) at the second bamboo species, where X=internode number above the ground, where X = number of vascular bundle from the epidermal layer. Age P(%) F value Taiwan giant bamboo 1 Y= 81.6 + 49.9 X 97.00 390.2** 2 Y= 21.8 + 52.9 X 99.00 1,100.4** 3 Y= 40.0 + 49.4 x 98.00 911 .0**

4 Y=119.0 + 34.5 x 96.00 389.6** Moso bamboo 1 Y=233.0 + 23.6 X 85.00 84.4** 2 Y=229.4 + 29.6 X 93.00 164.4** 3 Y=260.2 + 25.0X 91 .00 127.9** 4 Y=200.1 + 25.3 X 89.00 105.6**

Table 4: Regression equation for avera e diameter of vessel in the longitudinal direction from the base to the top of the culm, X=internode num r above the ground

Species Equation P(%) F value 2 Taiwan giant bamboo Y=111.34+2.11X-0.12X 63.60 27.09**

IMoso bamboo I Y= 93.34+0.72x I 60.70 I 49.50** I

Table 5: Regression equation for average fiber length in the radial direction from the epidermal layer to the inner culm wall, X=distance from the epidermal layer to the inner culm wall (mm)

Species Equation P(%) F value 2 Taiwan giant bamboo Y=l.686+0.1 75x-0.010X 36.20 20.47** 2 Moso bamboo Y=1.329+0.235x-0.01 7X 64.80 I 38.68** I

Table 6: Regression equation for avera e fiber length in the longitudinal direction from the base to the top of culm, X=internode number above e the ground.

Species Equation r2(%) F value Taiwan giant bamboo Y=2.221 +o.040x-0.002X^2 45.0 12.66** Moso bamboo IY=l.884+0.046X-0.001X^2 52.0 I 17.58** I

Table 7: The fiber ratio of bamboo constituent varied from outer to inner part of the culm wall of two bam- boo species.

Species Outer(%) Middle(%) Inner(%) Taiwan giant bamboo 43.00 * 59.25 30.31 - 40.94 19.65 - 27.58

Average 48.98 34.55 23.30

Moso bamboo 37.90 - 52.18 18.18 - 29.25 10.99 - 18.24

Average 46.86 24.36 14.37

198 Anatomical Characteristics of Taiwan Giant Bamboo and Moso Bamboo Bamboo in the Asia Pacific Proceedings 4th International Bamboo Workshop 1991

The Ultrastructure of Taiwan Giant Bamboo and Moso Bamboo

Jung Sheng Hsieh* Shuen Chao Wu**

Introduction serial alcohol, and dried through the critical drying point, mounted on aluminum stubs, sputter coated with a 20 nm There are significant differences in growth characteristic thick layer of gold, and observed with a Hitachi SEM at between bamboo and trees. Due to differences in the vas- 20KV. cular bundle, the trunks of trees can increases diameter year by year. However, the bamboo culm cannot. There- fore, the structure, properties and even lifespans differ. Results and discussion Because the diameter of bamboo culm is below 20 cm and There are several classification methods in tissue structure the pith is empty, the trend of bamboo tissue is towards of bamboo culm in different utilization or classification simplification. The culm comprises 11.3 -16.5% conduct- systems. First, the bamboo culm is separated into two ing tissue (vessels and sieve tubes), 29.7035.2% fiber, and parts according to purpose. The outer green part of the about 50% parenchyma, Liese 1987. No radial cell ele- culm is named “Bamboo green” and the yellow part of the ments, as wood ray tissue, exist in the internode. The culm is called “Bamboo yellow”. structural characteristic of Gramineae and the difference of percentage of tissue constituent determine the special Second, the yellow part of bamboo further is divided to properties of the culm. In Figure No. 49 shows the varia- two parts. The middle part containing the vascular bundle tion of internode length and culm diameter; Figure No. 50 called is “bamboo material”. The periphery zone of inner shows the dimensional variation of vascular bundle in the culm around the pith cavity called is “Bamboo yellow”. cross section of the culm wall at different age; Figure No. The third classification is according to plant anatomy. 51 shows the density of vascular bundle in the cross sec- The classification system that we used in this paper is the tion of different internode; Figure No. 52 shows the varia- third method and the results obtained as follow. tion of vessel diameter in the radial and longitudinal direction; and Figure No. 53 shows the variation of fiber length in the radial and longitudinal direction of the culm Wax and cutin and in one internode of Taiwan giant bamboo and Moso The main functions of the epidermis of the culm are water bamboo. retention and cell protection. Therefore, the epidermis of the culm must have water proof walls. Materials and methods Bamboo achieve this effect by depositing a layer of the hy- The subject of this study are two species of bamboo grown drophobic material cutin on the outer epidermal wall. The in the central part of Taiwan, the Taiwan giant bamboo mixture of cutin plus epidermis wall material is called the (Dendrocalamus latiforus) and Moso bamboo cuticular layer. It is distributed evenly between epidermis (Phyllostachys pubescens var. pubescens). Small block and waxy layer. The cutin is a complex, high molecular samples were cut off in the middle part of the internodes weight lipid polyester that results from the polymerization at the second and the sixth node above the ground. The of certain fatty acids. The cutin can be separated into small block samples of bamboo were boiled in distilled three classes based on the nature of the fatty acids mono- water; thin sections of transverse, radial and tangential mers in the angiosperm (Holloway, 1982): (1) cutins that (three dimensions) were obtained by using razor blades; contain mostly fatty acid that are 16 carbons long; (2) cu- the samples were then macreated in 70% Sodium hypoch- tins with mostly 18 carbon long fatty acids; and (3) cutin loride until the surface lost color, Meylan & Butterfield that contains more or less equal amounts of both type of 1978. The sections, were then washed thoroughly with fatty acids. The cutins of the gymnosperms and the cryp- distilled water for at least 24 hours, dehydrated by using a togams seem to lack the 16 carbon long monomer. The pure cutin on the outer epidermal wall is known as the Bamboo in the Asia Pacific Proceedings 4th International Bamboo Workshop, 1991 cuticle proper. It is sometimes separated from the fibril and 35-65 um for Moso bamboo. The short cells are in- material of the epidermal wall by a larger of pectin terspered among long shaped cells. There are two kinds (Mauseth, 1988). The cuticular layer tends to have a fi- of short cells, the cork cells and the silica cells. The cork brillar proganization, due at least in part to the presence cells are roughly square shaped in Taiwan giant bamboo of cellulose fibrils. The cuticle proper may be homoge- and circle shaped or irregular for Moso bamboo. (Figure neous and amorphous, lamellate or reticulate (Mauseth, 1,2), in tangential section. It appears triangle shaped in 1988). radial section of epidermis. The silica cells are flat or small circle shaped in tangential view, and appear triangle The thickness of the cuticular layer may be affected by the shaped in radial section. However the bottom side is on habitat. The cuticular layer is usually thin but can be as the outer wall of epidermis, just opposite to cork cells, and much as 0.5um thick in xerophytes. The cuticle proper the size of silica cells is smaller than the cork cells. The can frequently be 5 um or more in thickness. The cuticular silica cells contain large amounts of silicon dioxide which layer of Moso bamboo is between about 0.6-1.6 urn. An serves to strengthen the epidermal layer and to prevent epidermis containing a cuticular layer of such thickness damage from the enviroment. This layer serves the same offers sufficient protection to the epidermis. function in bamboo that bark serves in dicotyledons. Wax is a universal adjunct to the outer wall of the epider- Stomata and guard cells mal wall. Wax is not a specific compound but rather an extremely heterogeneous polymer that results from the in- The stomata are distributed evenly all over the epidermis teraction of very long-chain fatty acid (up to 34 carbons), to control inflow and outflow of water and carbon dioxide. aliphatic alcohols, and alkalines in the presence of oxy- The guard cells together with the adjacent cells are dis- gen. There are two kinds of wax: (1) epicuticular wax cov- tinct in size, shape or cell contents. They are termed the er on the surface of the cuticle proper, and (2) subsidiary cell, and are arranged in paracytic type. This is intercuticular wax, which occures as particles within the one of the five most common types (Mauseth, 1988). The cutin matrix. The intracuticular waxes are mostly com- guard cells and subsidiary cells are arranged vertically posed of short chain (18 carbon) monomers, rather than parallel to the epidermis. Therefore the epidermis of the long chain monomers. bamboo culm is also arranged vertical. The scanning electron microscope was used in this study The stomatal cavity on the epidermis of one year old Tai- to investigate the epcuticular wax on the epidermal wall wan giant bamboo are formed by the build up of wax. The (Figure 3,5,6). The wax on the epidermall wall polymer- structure of stomata1 cavity can reduce moisture losses at izes into plates (Figure 4,8), rods, granules (Figure 5) or normal air diflusion levels, because the interior surface other forms. The irregular arrangement of rods and plate- area of the cavity increases the surface area available for lets makes them effective sunscreens, most light striking moisture diffusion (Figure 3). In Moso bamboo, because of their surfaces will be reffected away from the tissues. The the climate of the site, the stomata1 cavity will not form wax of Taiwan giant bamboo formed stomata1 cavity wax deposits. The elevation of the site of Moso bamboo is around the stoma (Figure 3,5), and the waxy layer over- higher than Taiwan giant bamboo. Moreover because the laps irregularly all over the outer epidermal wall except weather is always foggy and humidity high, the evapora- the stomatal pore. The waxy layer of Moso bamboo differs tion is slight. The number of stomata is another difference significantly from Taiwan giant bamboo in that its plate between two bamboo species. There are 40 stomata/sq.mm structure do not touch each other and the surface is in Moso bamboo, but four times that number for Taiwan smooth (Figure 4,8). giant bamboo. The stomata are found on all parts of the plant body, especially the leaves and stems. The adaxial Epidermal tissue surfaces of leaves typically have about 100 stoma- ta/sq.mm; in many deciduous trees the density can be ten The epidermal tissue is the outermost layer of cells and times as high. Very low densities occur in certain cloud with some other high molecular weight materials. The forest plant, for example, 22 stomata/sq.mm in Peperomia main functions of the epidermis are water retention and emargineflu (8.17). The size of stomata are much the shielding the DNA of the cells from ultraviolet light. Cu- same in the two bamboo species; the width is about tin is completely indigestible. No known substance can 15.20um and the vertical length is about 25-30 urn. metabolize it. Thus, it provides an excellent protection against fungi and bacteria (Mauseth, 1988). Opening and closing of the stomata are controlled by changing the water potential of the cells by potassium Epidermis ions. The basic type of guard cells occuring in bamboo is There are two kinds of cells in the epidermis of the two dumb bell shaped (Figure 7). The wall adjacent to the pore bamboo species (Figure 1,2). The long shaped cells are (the ventral wall) is thicker than the opposite wall (the vertical arrangement. The long shape cells of the Moso dorsal wall). The opening of these stomata is caused by bamboo are larger than those of the Taiwan giant bamboo. the swelling of the adjacent guard cells which arch into a The diameter in radial is about 4-8 um for Taiwan giant crescent shape. A more recent hypothesis has proposed bamboo and 5-10 um for Moso bamboo. The length in that the orientation of the microfibrils in the ventral wall, longitudinal of cells is 12-42 urn for Taiwan giant bamboo when the dorsal wall swell outward, the microfibrils allow

200 Anatomical Characteristics of Taiwan Giant Bamboo and Moso Bamboo Bamboo in the Asia Pacific Proceedings 4th International Bamboo Workshop, 1991

it to pull the ventral wall with it to open the stoma, Pale- Primary phloem vitz & Hepler, 1976. The guard cells and the pore are to- gether called stoma, and the stoma together with the Protophloem subsidiary cells called the stomata1 complex. Transmis- The protophloem mature earlier than the metaphloem. As sion between these two cell types depends on the differ- the bamboo matures, the protophloem is displaced to the ence of potassium ions, hydrogen ions and sugars. outer side of phloem by the division and growth of me- taphloem cells (Figure 23,24). The cells are small and Vascular bundles cannot be distinguished from the cells of metaphloem. On All tissues of bamboo develop from the apical meristem. the other hand, the function of protophloem diminishes as The speed of development of apical meristem is faster and the metaphloem forms. matures earlier than the intercalary meristem. The inter- Metaphloem node of the culm also possesses developmental ability but the meristem in the internode is called intercalary meris- The metaphloem consists of large sieve tube cells and tern (Tsai, 1982). The whole culm growth is attributable small companion cells (Figures 23, 24). They derive from to these two meristems and with primary tissue only. De- the same original mother cells. The largest son cell di- pending on the stage of maturity, the primary xylem con- vides into several sieve tube cells. Other cells divide sists of protoxylem and metaxylem and primary phloem several times into small companion cells. The sieve tube consists of protophloem and metaphloem. The arrange- cells and the companion cells are parcnchyma tissue, ment of xylem and phloem in the vascular bundle is col- without secondary wall. The middle lamella and primary lateral vascular bundle type. The two species of bamboo wall between the companion cells and sieve tube cells can- have the same type. This kind of vascular bundle has not be easily distinguished or scpcratcd even after being equal parts of xylem and phloem. The xylem is at the in- treated with dissolving solution (Tsai, 1982). ner side and the phloem is at the opposite side. The ar- rangement of vascular bundle in the culm wall is of the The shape of the phlocm varies only slightly between the atactostele type, The vascular bundle is scattered in the two bamboo species. The Taiwan giant bamboo is pomelo culm wall and the bundle is arranged parallel with each (elliplical), and the Moso bamboo is oval or circular other in longitudinal direction. shaped (Figure 24). The number of sieve tube cells ap- pearing in a cross section of the culm wall of Taiwan The vascular bundle is scattered in the stele, and the shape giant bamboo is above 20 and the Moso bamboo is below and size varies significantly at different parts of the culm 15. wall. The variation of the vascular bundle at the outer, middle and inner part of the two culm walls is shown in Primary xylem Figures 9-14. The fiber sheath of vascular bundles are Protoxylem very greatly variate in shape at outer part of the culm wall. The size of vascular bundles and sheath’s fibers of the Tai- The protoxylem is located between two large metaxylic wan giant bomboo is bigger than the Moso bamboo vessels and towards the pith cavity, its size varies accord- (Figure 9,10). The amount of fiber at xylic fiber sheath of ing to its location on the culm wall. It performs the func- this part is much greater than the middle and inner part. tion of water conduction in the early. stage of shoot Figure 11 and 12 shows the difference of vascular bundle development. The tracheary cell is thickened by the annu- in the middle part of wall between the two bamboo spe- al ring and spiral thickening (Figure 21). The metaxylic cies. The size of vascular bundle increases in this area es- vessel controls the functions of the protoxylic trachcary pecially at the side of metaxylem vessel and mctaphloem. cell while the metaxylcm is forming in both Taiwan giant Beside the variation of shape, size and amount of fiber, bamboo and in Moso bamboo. The tracheary element is there are solitary fiber strands occuring in the Taiwan filled with tyloses in Moso .bamboo. The amount and dis- giant bamboo. tribution of pits in the cell wall of tyloses is irregular. The protoxylic tracheary almost losses conductibility as the ty- The xylem of vascular bundles in the two bamboo species loses form. Escept for the different shape and size of fiber are always toward the pith cavity. However, some of the sheath and tracheary, the protoxylic tracheary is different Taiwan giant bamboo’s vascular bundles are irregular. in the two bamboo species. The tangential diameter of Figures 13,14 show the arrangement of vascular bundles protoxylic tracheary at the outer part of the culm wall in around the pith cavity. The metaxy1em vessel and the Taiwan giant bamboo and Moso bamboo is about one fifth phloem are still enlarging, but the fiber strand becomes and one eighth of the inner part respectively. Therefore small or disappears. The three dimensional structure of there are plenty of tyloscs in the inner part of the Moso the two bamboo species are shown in Figures 15,16. The bamboo’s culm. vascular bundle appear scattcrcd in the ground tissue of culm wall. Metaxykm The metaxylem of bamboo consists of two large vessels at the side of the vascular bundle (Figures 9-16). The main function of the vessels is \\ater transportation. The

The Ultrastructure of Taiwan Giant Bamboo and Moso Bamboo 201 Bamboo in the Asia Pacific Proceedings 4th Internationnl Bamboo Workshop, 1991 perforation formed between the vessel clement significant- Few pits occur in the fiber wall, the simple pit pair is the ly influences moisture conduction. The two bamboo spe- only type between the fiber cell. Another special structure cies are provided with simple perforation plates (Figure of fiber which occurs in Taiwan giant bamboo is scptate 18, 20), but there is a middle perforation plate type be- fiber, this does not occur in Moso bamboo. tween scalariform and reticulate, in Taiwan giant bamboo (Figure 19). The simple perforation has the most efficient Ground tissue conduction in four different kind of perforation. On the other hand, the diameter of vessels is closely related to Cortical parenchyma transportation capacity, and the diameter increases from T’he cortical parenchyma is located between the epidermal outer part of culm wall to inner (Wu & Hsieh, 1991). and the vascular bundle, tissue layers (Figure 29, 30). It There are several small parcnchyma cells between xylem contacts with the culm parcnchyma without an cvidcnt and phloem, and the outer circles of vascular bundle con- boundary. The shape of the parenclyma cells change, es- pecially with respect to size, from cortical to inner culm. sists of fiber sheath. The fiber sheath of phloem and xy- lem do not touch each other; otherwise nutrition and The cortical parenchyma ccl1 of Taiwan giant and Moso water could not reach the parenchyma cells. bamboo appear circle shaped in cross section (Figure 29, 30). The average diamctcr of outer cortical parenchyma is Pits occur in the vcsscl wall that communicate with the about 9.1 um for Taiwan giant and 11.4 um for Moso side of the protoxylcm and phlocm. The inner aperture of bamboo. The average diamctcr of inner cortical parenchy- the pit is oval shaped and the arrangement is mostly oppo- ma is about 14.3 for Taiwan giant and 16.6um for Moso site pitting and a little alternate pitting (Figure 20). There bamboo. Analysis showed that the size of coflical paren- is no pit between the vessel wall and fiber (Figure 19). chyma of Moso bamboo is larger than the cortical paren- Fiber sheath chyma in Taiwan giant bamboo. The ro\vs of cortical parenchyma differ in Taiwan giant bamboo and Moso The vascular bundle is scattered in the vascular bundle bamboo. The former has 6-8 rows and the latter has 9-11 tissue layer between the cortical layer and parenchyma of rows. Cortical parenchyma cells arc characterized by thick the pith periphery. The size of the vascular bundle is walls with a polylamcllate structure. There are 5-7 lamel- small at the inner side of the cortical layer; generally the latcs for Taiwan giant bamboo and the outer part of Moso vascular bundle of Moso bamboo does not have tracheary bamboo. The inner part of cortical parenchyma cell wall cells. Taiwan giant bamboo has very few tracheary cells. have 7-9 lamcllatcs, decreasing from the outer cortical pa- This little tracheary vascular bundle consists of fiber cells rcnchyma to the inner. (Figure 9, 10). The shape of the fiber sheath varies ac- cording to its location on culm wall (Figures 9-14). The The cells showed different shapes viewcd from a radial fiber sheath of protoxylem and metaxylem touch each oth- section appearing square or short rectangular for Taiwan er, but the sheath of phloem and xylem do not touch. The giant and rectangular for Moso bamboo (Figure 3 1, 32). fiber sheath of protoxylem, metaxylem and phloem do not The pits of cortical parenchyma occur both in the longi- touch either at the middle and the inner part of culm wall, turdinal wall and also in the end wall (Figure 35, 36). The for easy material exchange. diameter of the pit aperture is about 0.4-0.6 urn; some- In the outer and middle part of the culm wall, the radial times the inner aperture is larger than the outer. There are length of the vascular bundle is longer than the tangential intercellular spaces in the cortical parenchyma of the two length. However, at the inner part of the wall, the radial bamboo species. length is the same as tangential lenglh of the vascular bundle. The ratio of the radial length to the tangartial Many large, thin walled parcnchyma exist under the sto- length of the vascular bundle at the outer part of culm ma of epidermis, for air diffusion (Figure 33). In Figures wall in Moso bamboo is 1: 1.7. At the middle part of the 33 and 34, the triangle shaped cells in the epidermis are wall the ratio decreases to 1: 1.5. It decreases to almost 1:l cork cells. Figure 35 shows the newly formed primary cell at inner part of wall. The ratio in Taiwan giant bamboo wall after cell division. from outer to inner part is about 2:1, 1:1.7 and 1:2 resec- tively. The shape of the vascular bundle varies significant- Culm parenchyma ly in different kinds of bamboo. The vascular bundles arc scattered in this ground tissue. Bamboo fibers are all in the fiber sheath and fiber strand. The total culm comprises about half of the culm parenchy- The size and amount of fiber will be different in the outer, ma with some variation according to spccics. The the middle and inner part of the culm. A small diameter of fi- culm parenchyma arc small in the outer parts of the culm ber is about 2-G um in fiber strands at the outer part of culm. The middle and inner part is about 4-20 urn. The wall and become large towards the pith cavity. Diamctcr fiber of fiber strands in Taiwan giant bamboo can bc up to ranges from about l0-65 um. 40um. The fiber of fiber strands are larger in diamctcr in The culm parcnchyma cells arc almost cylindrical and thin cell walls (Figure 27) than the fiber in the sheath mostly vertically clongatcd (Figures 37-40). Another type (Figure 25, 26). of cell are short cylindrical ones intcrspcrscd in bctwccn. The mean cell wall thickness of the two bamboo species is

202 Anatomical Characteristics of Taiwan Giant Bamboo and Moso Bamboo Bamboo in the Asia Pacific Proceedings 4th International Bamboo Workshop, 1991 about 2.5 um for Moso and 1.2 um, for Taiwan giant bam- The morphlogy and the distribution of the two bamboo boo (Figure 39,40). species is quite different and thus the results of anatomical studies also differ. The parenchyma cell in the vascular bundles and ground tissue are characterized by a polylamellate wall, which Large amounts of cutin and wax cover the epidermis. consists of alternately wide and narrow lamcllates. The The cutin and wax deposits form stomata1 cavities number of lamellates is about 3-11 layers (Hsieh, 1985); around the stomata in Taiwan giant bamboo, but not some of them can reach 15 lamcllates (Parameswaran & in Moso bamboo. The epidcrmal layer consists of two Liese 1976). The width of the wide lamellates is about type of cells, one is rectangular and the other type has 0.1-0.45 urn; the narrow ones about 0.05- 0.25 urn. two kinds of short cells. The cells of Moso bamboo are larger than the cells of the Taiwan giant bamboo. Parenchyma of pith periphery The short cells consist of cork cells and silica cells. There is a complete pith in the early development of bam- The density distribution of these cells in the epider- boo shoots consisting of thin walled parenchyma. The mis is about 40 cclls/100 sq.um for Taiwan giant process of cell division and enlargement around the pith bamboo. The density distribution of stoma is about causes the cell of pith to form a cavity. The parenchyma of 160/sq.mm for Taiwan giant and 40/sq.mm for Moso pith periphery is oriented in the tangential direction bamboo. The shape of guard cells is kidney shaped, (Figures 41-46). The shape from culm parenchyma to pith the arrangement of subsidiary cells is parcytic type. periphery, changes gradually (Figures 43-44); the culm The size of stomata1 comples of the two bamboo is parenchyma is circle shaped and the parcnchyma of pith 25-30 um long and 15-20 um wide. periphery nearly rectangular in cross section (Figure 41, The vascular bundle in the bamboo culm consists of 42). xylem with a protoxylen tracheary and two large me- tax-lit vessels and phloem with sieve tubes connected The radial length of parenchyma in the pith periphery is to companion cells and fiber sheath. around the 12-30 urn for Taiwan giant and 25-40 um for Moso bam- bundles. The vascular bundles are interspersed in boo. The longitudinal height is about 8-22 um for Taiwan ground tissue culm parcnchyma cell, and the shape giant and 50 to 60 um for Moso bamboo. The wall thick- varies in different parts of the culm wall. Except in ness of parenchyma in the pith periphery is about 1.5 the change of trachcary diamctcr, the shape and size times greater than that found in ground tissue culm paren- of fiber sheath and the intcrccllular space of fiber va- chyma. The study showed the parcnchyam of pith periph- ries significantly. ery is small but possesses a thick wall. The percentage of cell wall is higher than the parcnchyma in the culm. After the functioning of the protoxylem, the ring Therefore, the specific gravity is also higher in this arca thickening process continues in Taiwan giant bam- (Wu & Hsieh, 1990). boo, and tyloses form in Moso bamboo. Simple perfo- ration is the typical structure in metaxylic vessels of the two bamboo species, and there is a middle type of Membrane tissue of pith cavity perforation bctween scalariform and reticulate in Tai- There is a thin fibrous layer inside the pith cavity, located wan giant bamboo. The vessel diameter of Taiwan between the pith cavity and the parenchyma cells (Figure giant is larger than the Moso bamboo. The protoph- 47, 48). The membrane layer of Taiwan giant consists of loem is squeezed to the outer side of phloem by divi- many strips of fibrous wall overlaping each other (Figure sion and growth of metaphloem cells and small thin 47), and the structure of Moso bamboo’s is made up of a walled. unlignificd sieve tubes. The shape of phloem complete piece of fibrous membrane (Figure 48). The is pomelo shaped for Taiwan giant and oval shaped function of the membrane tissue over the parenchyma of for Moso bamboo. The number of sieve tubes of Tai- the pith periphery is to prevent the exposure of cells - like wan giant bamboo is above 20 and the Moso bamboo the function of the cuticle layer and wax over the epider- is less than 15 in transverse section of the culm wall. mis. The enviroment in the pith cavity is milder than the 4. The proportion of radial length to tangential length of enviroment of the outside surface of bamboo, so the struc- vascular bundle from the outer, to inner part of culm ture of the membrane does not demand materials such as wall is 2:1, 1:1.7 and 1:2 for Taiwan giant, and 1:1.7, cutin and wax. 1:1.5 and 1:l for Moso bamboo respectively. The fi- ber walls are thick in Moso bamboo, but in Taiwan Conclusion giant bamboo some walls are thin and the fiber Bamboo belongs to the monocots and the characteristic of septate. growth is different from trees, which dcpend on the divi- 5. The ground tissue consists of cortical parenchyma, sion and development of the apical and intcrcalary mcris- culm parenchyma and peripheral pith parenchyma. tern. Maturation of bamboo from shoots to complete culm The first two former are mostly vertically enlongated, growth occurs very rapidly, in just two to three months. the third is arranged horizontally. The cortical parcn- Since the maturation process occurs so quickly, the tissue chyma and peripheral pith parenchyma have only one structure of bamboo must be very simple. type of cell; the culm parenchyma has two types. The diameter of cortical parenchyma is about l0-15 urn;

The Ultrastructure of Taiwan Giant Bamboo and Moso Bamboo 203 Bamboo in the Asia Pacific Proceedings 4th International Bamboo Workshop, 1991

the shape of Taiwan giant bamboo is short cylindrical Lyshede, 0. B 1982. Structure of the Outer Epidermal and the Moso bamboo is long cylindrical. The mean Wall in Xerophytes. In: The Plant Cuticle. ed. D.F. Cutler. Academic Press. London. diametre of culm parcnchyma is about 65 urn with simple pit and the walls are of a polylamellate struc- Mauseth. J, D. 1988.-GET12 -E Plant Anatomy. The Benjamin/Cumming Publishing ture. The parenchyma of pith periphery is more than 10 rows. The cell walls of Moso bamboo is thicker Meylan, B A. & B.C. Butterfield. 1978. The structure of New Zealand woods. Science Information Division, SIR. than the cell wall of the Taiwan giant bamboo. There Wellington is a thin fibrous membrane over the inner side of the Palevitz, B. A., & P. K. Hepler. 1976. Cellulose Microfibril pith periphery to protect the parenchyma around the Orientation and Cell Shaping in Developing Guard Cells of pith cavity. AIlium: The Role of Microtubules and Ion Accumulation. Planta 132:71-93. References Parameswaran, N. 8 W. Liese. 1976. On the Fine Struc- Grosser, D. 8 W. Liese. 1971. On the Anatomy of Asian ture of Bamboo Fibers. Wood Science and Technology. Bamboo, with Special Reference to Their Vascular Bundle. 10:231-247. Wood Science and Technology. 5:290-312. Parameswaran, N. & W. Liese. 1977. Occurrence of Warts Holloway, P. J. 1982. The Chemical Constitution of Plant in Bamboo Species. Wood Science and Technology. Cutin. In: the Plant Cuticle. ed. D. F. Cutler. Academic 11:313-318. Press. London. Preston, R. D. & K. Singh. 1950. The Fine Structure of Howard, R. A. 1969. The Ecology of an Elfin Forest in Bamboo Fibers I. Optical Properties and X-ray Data. J. Puerto Rico 8. Studies of Stem Growth and Form and of Experimental Botany. l(2) 214-227. leaf Structure. J. Anorld Arbor. 50:225-267. Ting, I. P. 1982. Plant Physiology Addision-Wesley: Hsieh. J. S. 1985. Ultrastructure of bamboo grown in Tai- Reading. Massachusetts. wan. Master Dissertation, National Taiwan University. Tsai, S. H 1982. Plant anatomy. World Bookshop Publi- 97 PP . cation. Taipei. pp. 358. Liese, W. 1987. Research on Bamboo. Wood Science Wu. S. C. and J S. Hsieh. 1991. Anatomical characteristic and Technology.21:189-209. of Taiwan giant bamboo and Moso bamboo. In: IV Interna- tional Bamboo Workshop, 27.30 Nov. Chiangmai, Thailand.

Figure 1: The structure of epidermal tissue showing the waxy layer, epidermis and cortical cell from the upper left to the lower right of the photo (Taiwan giant) Figure 2: The structure of epidermal tissue showing the waxy layer, epidermis and cortical cell from the upper left to the lower right of the photo (Moso bamboo) Figure 3: The stomatal cavity formed by the waxy layer (Taiwan giant bamboo) Figure 4: The distribution of wax around the stoma of the culm surface (Moso bamboo)

204 Anatomical Characteristics of Taiwan Giant Bamboo and Moso Bamboo Bamboo in the Asia Pacific Proceedings 4th International Bamboo Workshop, 1991

Figure 5: The structure of wax on the epidermis was granule (Taiwan giant bamboo) Figure 6: The structure of wax on the epidermis was plate (Moso bamboo Figure 7: The structure of stamata and guard cells (Taiwan giant bamboo) Figure 8: The silica cells of epidermis (Moso bamboo)

Figure 9: The tissue arrangement and shape in the outer part of culm wall (Taiwan giant bamboo) Figure 10: The tissue arrangement and shape in the outer part of culm wall (Mos bamboo) Figure 11: The tissue arrangement and shape in the middle part of culm wall (Taiwan giant bamboo) Figure 12: The tissue arrangement and shape in the middle part of culm wall (Moso bamboo)

The Ultrastructure of Taiwan Giant Bamboo and Moss Bamboo 205 Bamboo in the Asia Pacific Proceedings 4th International Bamboo Workshop, 1991

Figure 13: The tissue arrangement and shape of pith periphery in the inner part of culm wall. (Taiwan giant bamboo) Figure 14: The tissue arrangement and shape of pith periphery in the inner part of culm wall. (Moso Figure 15: Three-dimentional structure of Taiwan giant bamboo Figure 16: Three-dimentional structure of Moso bamboo

Figure 17: Oblique perforation plate in the metaxylem vessel of Taiwan giant bamboo Figure 18: Simple perforation in the metaxylem vessel of Taiwan giant bamboo Figure 19: Part of perforation between scalariform and reticulate type in the metaxylem vessel of Taiwan giant bamboo Figure 20: Simple perforation in the metaxylem vessel of Moso bamboo

206 Anatomical Characteristics of Taiwan Giant Bamboo and Moso Bamboo Bamboo in the Asia Pacific Proceedings 4th International Bamboo Workshoo. 1991

Figure 21: The ring thickening formed in the protoxylem (Taiwan giant bamboo) Figure 22: The tyloses formed in the protoxylem of Moso bamboo Figure 23: The sieve cells and companion cells of the vascular bundle near the pit periphery (Taiwan giant bamboo) Figure 24: The sieve cells and companion cells of the vascular bundle near the pit periphery (MOM bamboo)

Figure 25: Thicked wall fiber in the inner of fiber sheat (Taiwan giant bamboo) Figure 26: Thicked wall fiber in the inner of fiber sheat (Moso bamboo) Figure 27: Thin wall fiber in the fiber strand of vascular bundle (Taiwan giant bamboo) Figure 28: The septate fiber of Taiwan giant bamboo (Taiwan giant bam boo

The Ultrastructure of Taiwan Giant Bamboo and Moso Bamboo 207 Bamboo in the Asia Pacific Proceedings 4th International Bamboo Workshop. 1991

Figure 29: The structure of epidermis and cortical parenchyma (Taiwan giant bamboo) Figure 30: The structure of epidermis and cortical parenchyma (Moso bamboo) Figure 31: The structure of radial section in the outer part of culm wall (Taiwan giant bamboo) Figure 32: The structure of radial section in the outer part of culm wall (Moso bamboo)

Figure 33: The enlargement of several layers in the radial section of epidermal tissue showed structure of stomatal complex (Taiwan giant bamboo) Figure 34: The enlargement of several layers in the radial section of epidermal tissue (Moso bamboo) Figure 35: The structure of cortical cells showed the new cell wall formation after cell division (Taiwan giant bamboo) Figure 36: The structure of cortical cells (Mom bamboo)

7.08 Anatomical Characteristics of Taiwan Giant Bamboo and Moso Bamboo Bamboo in the Aria Pacific Proceedings 4th International Bamboo Workshop, 1991

Figure 37: The structure of culm parenchyma cells in logitudinal section (Taiwan giant bamboo) Figure 38: The structure of culm parenchyma cells in logitudinal section (Moso bamboo) Figure 39: The structure of culm parenchyma cells in cross section (Taiwan bamboo) Figure 40: The structure of culm parenchyma cells in cross section (Moso bamboo)

Figure 41: The sbucture of parenchyma of pith periphery in cross section (Taiwan giant bamboo) Figure 42: The strucutre of parenchyma of pith periphery in cross section (Moso bamboo) Figure 43: The structure of parenchyma of pith periphery in longitudinal section (Taiwan giant bamboo) Figure 44: The structure of parenchyma of pith periphery in longitudinal section (Moso bamboo)

The Ultrastructure of Taiwan Giant Bamboo and Moso Bamboo 209 Bamboo in the Asia Pacific Proceedings 4th International Bamboo Workshop, 1991

Figure 45: The structure of parenchyma of pith periphery in tangential section (Taiwan giant bamboo) Figure 46: The structure of parenchyma of pith periphery in tangential section (Moso bamboo) Figure 47: The structure of thin membrane over the surface of pith cavity (Taiwan giant bamboo) Figure 48: The structure of thin membrane over the surface of pith cavity (Moso bamboo)

2 68 12 16 18

Figure 49: The variation of internode length and culm diameter of Taiwan giant bamboo Moso bamboo Figure 50: Dimentional variation of vascular bundle in the cross section of the culm wall at different age of Taiwan giant bamboo and Moso bamboo

210 Anatomical Characteristics of Taiwan Giant Bamboo and Moso Bamboo Bamboo in the Asia Pacific Proceedings 4th International Bamboo Workshop, 1991

Taiwan giant bamboo Moso bamboo

6 4

0 2 4 6 lo 2 4 68 ! " 2 30 PROM THE TO PERIPHERAL LAYER (mm)

Figure 51: The density of vascular bundle in the cross section of different internode of Taiwan giant bam- boo and Moso bamboo

0 24

0 I 16

. I . Taiwan giant bamboo Moso bamboo 0 16 24 0 12 20

VESSEL FROM

Figure 52: The variation of vessel diameter in the radial and longitudinal direction of Taiwan giant bamboo and bamboo

The of Taiwan Giant Bamboo and Bamboo 211 Bamboo in the Asia Pacific Proceedings 4th International Bamboo Workshop, 1991

Second internode of Taiwan giant bamboo Second, internode, of Moso, bamboo 4 8 12

FROM TO LAYER (mm)

C

Taiwan giant bamboo Moso bamboo I '0 I !# $ INTERNODE NUMBER FROM THE BASE OF CULM

One-year-old E

%# Taiwan giant bamboos !# Moso bamboo DISTANCE FROM THE BASE TO THE TOP OF SECOND INTERNODE (cm)

Figure 53: The variation of fiber length in the radial and longitudinal direction of the culm and in one inter- node of Taiwan giant bamboo and Moso bamboo

212 Anatomical Characteristics of Taiwan Giant Bamboo and Moso Bamboo Bamboo in the Asia Pacific Proceedings 4th International Bamboo Workshop, 1991

Structure and Functions of the Nodes in Bamboo

W. Liese* and Y. Ding**

height)!. The ..nodal area includes 10-15mm below and Introduction above the sheath scar. Sections and mazeratcd material Quite a number of investigations have dealt with the were investigated by light and scanning electron micros- structure of the internodes of a bamboo culm, which form copy (for details Ding and Liese, 1992). the main material resource. Consequently a rather good knowledge exists about the anatomical pattern of a culm wall, especially the composition of the vascular bundles, Results and discussion the variation in Iibre length as well as fine structural as- pects, Grosser and Liese, 197 1, 1974; Parameswaran, Gross morphology of nodes Liese, 1980; Jiang and Li, 1985; Rao 1985; Hsieh et al. The node of a bamboo culm consists of the nodal ridge, 1986; Wen and Chou, 1985; Widjaja and Risyad, 1985. the sheath scar and the diaphragm (Figure 1). Most of the The composition and structural details of the nodes, how- bamboo have permanent nodal ridges, which differ in ever, were hardly analysed so far. Only few papers deal form among species. The shape of the diaphragm can vary with certain aspects, Haga, 1922; Weatherwax, 1967; at various hight levels of a culm and even more between Grosser and Liese, 1971; Zee, 1974; Hsiung et al. 1980. species. It may be plane or in its central part formed up- Difficulties in the preparation of the material and the wards, downwards or folded. complex anatomical structure may have contributed to this neglect. Vascular bundles The nodes bear special signilicance for the intcrcalary A perspective of the three dimcnstional structure of the growth and for the function of the culm. They enable the vascular system at the nodal region has been obtained necessary communication for the cross-transport of water from serial sections (Figure 2). Most of the axial vascular and nutrients as in the internodes no such conduction cells bundles pass directly through the node. In the peripheral exists because their vascular bundles are isolated from zone of the culm they bend slightly outwards branching each other by the ground parenchyma. The nodal structure partly into the sheath, whereas in the inner zone they bc- is also of interest for understanding the liquid movement come connected with those in the diaphragm. Especially during drying and preservation as well as the physical and the vascular bundles in the upper part of the node, e.g. be- mechanical properties of the culm. tween level b and c of Figure 2, appear swollen and vascu- lar anastomoses develop intensively. Some secondary branches of vascular bundles connect the inner zone with Material and methods the periphery. At the upper edge of the diaphragm many The nodal structure was investigated on six bamboo spe- small vascular bundles exist, which turn horizontally and cies from China. Three belong to the pachymorph type twist repeatedly. Some of them run from one side of the (Sinocatamus affinis McCl., Bambusa textilis McCl., nodal culm to the other. At a cross section of the nodal Schizostachyum pseudolimo McCl.) and three to the lepto- culm wall the typical vascular bundle structure of bamboo morph type (Phyllostachys pubescens, Maze1 ex H. Le- disappears (Figure 3). The different arrangement of flbre haie, Pleioblastus rnaculata McCl., CD. Chu et C.S. bundles in pachymorph and lcptomorph bamboo vanishes Chao, Sinobambusa Iaeta McCl.). and the characteristic isolated fibre strand in pachymorph species is absent. The position of xylem and phloem with- Samples of nodes and internodes were taken from mature in the bundles can be variously changed because of three years old culms from bottom (second internode), distortion. middle (l/3 height of the culm) and top portion (213

*Ordinariat fur Holzbiologie,Universitat Hamburg,Germany **Forsetry University,Nanjing,Botany Department,China Bamboo in the Asia Pacific Proceedings 4th International Bamboo Workshop, 1991

Whereas in the internodes the xylem of the vascular Cell structures bundles consists of the protoxylem, characterized by tra- cheids with helical or annular thickenings and the two Finally, size and form of the various cell types in the nod- metaxylem vessels with intensively pitted walls, in the al area were determined in sections and mazerated materi- nodal region this composition is partly changed. At the al. The metaxylem vessels appear quite different in the branching of vascular bundles abundant vessels develop. nodal region. They are much shorter than in the inter- Smaller cells with an intensive reticulate pitting may com- nodes (210 um versus 670 pm). Also their average diame- pletely surround the metaxylem vessels. It is assumed that ter is smaller (115 um versus 140 u m these cells form an “accessory tissue” which may have In the longitudinal view the ground parenchyma of the in- special functions with regard to the water transport. ternodes can be differentiated in two morphological types, Details of the vascular pattern of the branching points of i.e. rectangular elongated cells and fewer shorter ones the vascular bundles in the nodes of the Gramminae were (Figure 8). In contrast, the parenchyma cells of the nodal not known so far. By means of mazeratioo, the special region are often irregular, partly with bizzare forms structures of the conducting tissue can be recognized. A (Figure 9). remarkable feature appears to be the intensive branching The parenchyma around the vascular bundles has a spe- of the vessels. The protoxylem tracheids show shorter up cial structure. One layer of parenchyma surrounds the me- to longer forks in the nodal region (Figure 4). The meta- taxylem vessel. These cells of only about 8 p diameter are xylem vessels in contrast possess several large simple per- intensively pitted towards the vessel with large pit aper- forations on their side walls for the contact between tures, so that most of the wall is covered with pits. Braun vessels in addition to the normal simple perforation of the 1984, considered such cells around vessels in hardwoods endwalls (Figure 5). Their cell wall is often covered with as “contact parenchyma” or “accessoTy tissues”. One layer numerous small size pits with an alternating arrangement. of contact parenchyma cells around metaxylem vessel and These pits appear open giving direct contact between ves- protosylem tracheids exists also in the rattan palms sels. Sometimes they concentrate on a part of the cell wall (Weiner and Liese, 1990). Net like pitted cells were also and form an aperture area. Many small vessels are observed surrounding the phloem. The parenchyma cells deformed. at greater distance to the vessels bear lesser pits, although A striking feature of the protoxylem tracheids in the nodes such pitting is quite different from the few and small pits is their tyloses. Whereas in internodes of leptomorph bam- of the ground parenchyma around the vascular bundles in boo these cells are blocked with many small tyloses, in the internodes. In the early stage of development in the nodes, nodes they can be filled with only few large ones. This transfer parenchyma was reported (Zee, 1974). In the ma- phenomenon appears in leptomorph but also in pachy- ture culms of our material no such cells were found. morph bamboo species where tyloses have not reported so The fibres across a culm wall are shortest at the outer part, far, Grosser and Liese 1971; Jiang and Li, 1985; Wen and longer at the centre and decrease again at the inner part. Chou, 1985; Hsieh et al. 1986. This pattern is present within the internode as well as In the diaphragm the xylem consists of only metaxylem above and below the node which is agreement with other vessels, protoxylem vessels are not developed. studies, Liese and Grosser 1972. The shortest fibres are always above and below a node, as found also for other In the phloem a branching of sieve tubes has not been ob- bamboo species. The same trend exists in rattan palms served, but abundant lateral sieve areas facilitate the (Weiner, 1992). During the expansion of an internode due cross-transport in the nodes. At the branching point agg- to intercalary growth Hsiung et al. 1980, distinguish five lomeration structures of filiform elements connect the stages. It is assumed that the fibres immediately above a phloem of the axial vascular bundles to that of the node are the youngest and therefore shorter. Such assump- branched ones. In a longitudinal section the cells are ar- tion does not explain the shorter fibres immediately below ranged in a storied like pattern with three to five sub units the node. Further investigations should clarify whether (Figure 6) and the individual cells are interconnected by growth processes occur also in this region. numerous pits (Figure 7). Axial sieve tubes directly con- nected with these cells change from their plane simple At the nodal level the fibres are considerably shorter than sieve plate with regular arranged sieve pores into a bulb within the internode and shortest at the diaphragm. Table form with irregular arranged sieve pores. This structure 1 illustrates the results for two species Phyllostachys pu- enables the connection between sieve tubes and the small bescens as leptomorph and Batnbusa textilis as pachy- filiform cells. Behnke 1965a, b, calls similar structures in morph. The shortest fibres are at the diaphragm at all the node of Dioscoreaceen as “Phloem Beckenzellen”. levels - (bottom, middle, top). The fibre length at the dia- Braun and Sauter, 1964 found such cells containing more phragm of approx. 340 u is only about l/3 of the length at phosphatase and assume a special significance for the as- the nodal part of the wall. Mechanical elasticity is reduced similate transport. due to the shorter, thicker and also forked fibres (Figure 10) in the nodal part, so bamboo culms under tension of- ten break at the node.

214 Structure and Functions of the Nodes in Bamboo Bamboo in the Asia Pacific Proceedings 4th International Bamboo Workshop, 1991

Hsiung, W.Y, Ding, Z.F., Li, Y.F. 1980. lntercalary meris- Acknowledgement tern and internodal elongation of culm shoots. Acta Silva The investigations were carried out during a research Sinica 16, 81-89. study of the second author at Hamburg, partly supported Jiang, X., Li, Q. 1985. Observations on vascular bundles by the VW Foundation. of bamboo native to China. In: Recent Research on Bam- boo. Proc. Intern. Bamboo Workshop. Hangzhou, P.R. References China, 227-229. Li, C.-L., Chin, T.C., Yao, H.S. 1963. Further anatomical Behnke, H.D. 1965a. Uber das Phloem der Discoreaceen studies of some Chinese bamboo. Acta Botanica Sinica, unter besonderer Berucksichtigung ihrer Phloembecken. I. 10: 17-28. Lichtoptische Untersuchungen zur Struktur der Phloem- becken und ihrer Einordnung in das Sprobleitsystem. Z. Liese, W., Grosser, D. 1972. Untersuchungen zur Variabi- Pflanzenphys. 53:97-125 1965b: II. Elektronenoptische litat der Faserlange bei Bambus. Holzforschung Untersuchungen zur Feinstruktur des Phloembeckens. Z. 26:202-211. Pflanzenphys. 53:214-244. Parameswaran, N., Liese, W. 1980. Ultrastructural as- Braun, H.J. ,1984. The significance of the accessory tis- pects of bamboo species. Cell. Chem. Technol. sues of the hydrosystem for osmotic water shifting as the 14:587-609. second principle of water ascent, with some thoughts con- Rao, A.N. 1985. Anatomical studies on certain bamboo cerning the evolution of trees. IAWA Bulletin n.s., growing in Singapore. In: Recent Research on Bamboo 5:275-294. Proc. Intern. Bamboo Workshop. Hangzhou, P.R. China, Braun, H.J., Sauter, J.J. 1964. Phosphatase-Lokalisation 209-226. in Phloembeckenzellen und Siebrohren der Dioscoreaceae Wen, T.-H., Chou, W.-W. 1985. A study on the anatomy und ihre mogliche Bedeutung fur den aktiven Assimilat- of vascular bundles of bamboo from China. In: Recent Re- transport. Planta 60:543-557. search on Bamboo. Proc. Intern. Bamboo Workshop. Ding, Y., Liese, W. 1992. On the nodal structure of bam- Hangzhou, P.R. China, 230-243. boo. IAWA Bull. ns. 12, in preparation. Weatherwax, P. 1967. The nodal complex in grasses. In- Grosser, D., Liese, W. 1971. On the anatomy of Asian diana Academy of Sciences 77: 132-I 35. bamboo with special reference to their vascular bundles. Weiner, G., Liese, W. 1990. Rattans - stem anatomy and Wood Sci. Technol. 5:290-312. taxonomic implications. IAWA Bulletin n.s. 1:61-70. Grosser, D., Liese, W. 1974. Verteilung der Leitbundel und Weiner, G. 1992. Zur Stammanatomie der Rattanpalme. Zellarten in Sprobachsen verschiedener Bambusarten. Doktorarbeit, Universitat Hamburg (in preparation). Holz Roh- Werkst. 32:473-482. Widjaja, A.F., Risyad, Z. 1985. Anatomical properties of Haga, A. 1922. Uber den Bau der Leitungsbahnen in Kno- some bamboo utilized in Indonesia. In: Recent Research ten der Monokotyledonen. Rec. Trav. Bot. Neerland, on Bamboo. Proc. Intern. Bamboo Workshop. Hangzhou, 207-218. P.R. China, 244-246. Hsieh, R.S., Wu, S.C., Wang, H.H. 1986. Studies on the Zee, S.Y. 1974. Distribution of vascular transfer cells in tissue structure of leptomorph rhizome and pachymorph the culm nodes of bamboo. Can. J. Bot. 52:345-347. rhizome bamboo. For. Prod. Industrie, 5:49-61.

Table 1: Mean values of the fibre length across the wall at the nodes, internodes and diaphragma in urn

T Species location Internode Diaphragm

f’hyllostachys pubescens TOP 1484.00 842.00 324.00 Middle 1884.00 1046.00 374.00

Bottom 908.00 794.00 370.00

Bambusa textilis TOP 2046.00 1166.00 324.00

Middle 2082.00 1157.00 420.00

Bottom 1980.00 1002.00 334.00

Anatomical Characteristics of Taiwan Giant Bamboo and Moso Bamboo 215 Bamboo in the Asia Pacific Proceedings 4th International Bamboo Workshop, 1991

level c upper edge of diaphragm nodal ridge sheath acarcar s level b diaphragm level a

Figure 1: Illustration of nodal morphology Figure 2: lllustration of vascular anastomeses with- in the node

Figure 3: Irrgular arrangement of vascular bundles, nodeal region, Schizostachyum pseudo/ima

Figure 4: Branched proto lem tracheid at the Figure 5: Metaxylem vessel with large, simple perfo- node, phyllostachys Pubescens rations, pleioblastus maw

216 Strure and Functions of the Noes in Bamboo Bamboo in the Asia Pacific Proceedings 4th International Bamboo Workshop, 1991

Figure 6: Fiiiform phloem elements as “Phloem Beck- Figure 7: Sieve pores connecting the sieve tubes, enzellen at a node, Sinocalamus affins Sinobambusa laeta

Figure 8: Regulay arrangement of Figure 9: Irregular shaped paren- Figure 10: Forked fibre, ground parenchyma with- chyma cells at a node, Bambusa textilis in a internode with longer Phyllostachys pubescens and shorter cells,

- Structure and Functions of the Nodes in Bamboo 217 Bamboo in the Asia Pacific Proceedings 4th International Bamboo Workshop, 1991

Fiber and Chemical Properties of Bambusa vulgaris Schrad.

Jamaludin Kasim and Ashari Abd. Jalil*

Introduction were macerated according to the Franklin’s method (1945). The fibers were stained with safarinin-o and Lignocellulosic materials such as wood and bamboo are mounted onto glass slides. Fiber measurements of cell di- an assemblage of fibers and other cells, cemented by lig- ameter, lumen width, and fiber length were made on a nin and hemicelluloses into a rigid and strong material. projection microscope. For each portion a total of 100 fi- The shape, length, diameter and cell wall thickness of the bers were measured. fibers and chemical constituents are of great importance in paper making. Chemical analysis Variability between different kinds of plant material arises The chemical analysis was carried out in accordance with due to differences in the anatomical, physical and chemi- TAPPI Standard Methods. The following physical and cal properties. Variability within a single species is more chemical properties were analyzed; subtle and is a product of a complex system that occurs : Tappi T-18 during tree growth. Patterns for the variation of fiber ele- a. Specific Gravity ments, physical and chemical properties are fairly well es- b. Cold water solubility : Tappi T-207 tablished for normal trees grown under forest conditions c. Hot water solubility : Tappi T-207 (Panshin and de Zeuuw, 1970). Variations of anatomical d. Alcohol benzene solubility : Tappi T-204 features, physical and chemical properties in a tree can be e. 1% NaOH solubility : Tappi T-212 described in terms of : (a) changes which occur in the ra- f. Ash content : Tappi T-15 dial direction, and (b) changes that occur along the axis. : Tappi T-222 This paper discusses the variation of fiber and chemical g. Lignin Content properties of Bambusa vulgaris according to bamboo por- h. Holocellulose content : Wise et al 1946 tion location. i. Alpha cellulose content : Tappi T-203

Materials and method Results and discussion Results of the experiments were analyzed using SAS for Bamboo samples ANOVA and Duncan multiple range t-test for the effects Thirty bamboo culms were selected from three bamboo of bamboo portion on fiber properties and chemical con- clumps on the riverbank of Sungei Benus, Bentung, Ma- stituents of Bambusa vulgaris. laysia. The bamboo were divided into three equal portions to represent the base, middle and the top portions. The Effect of bamboo portion on fiber bamboo portions were then converted into chips using a properties Taihei disc chipper. After chipping, representative sam- Table 1 shows the analysis of variance of cell wall thick- ples from each portion were taken and ground in a Wiley’s ness (CWT.), fiber length (LENGTH), Runkel ratio (RR), mill to produce woodmeal. The woodmeal were then slenderness ratio (SR) and flexibility ratio (FR). It was screened and those retained on a 60 BS mesh sieve were observed that bamboo portion had a highly significant ef- used for chemical analysis. Chips from each portion were fect (1% probability level) on cell wall thickness, fiber again selected and cut into matchstick size. This bamboo length and slenderness ratio. No significant effect on RR sample was used to determine the fiber morphology. and FR was observed. The mean values for cell wall thickness, fiber length, Runkel ratio, Slenderness ratio Determination of fiber morphology and Flexibility ratio were 0.0054 mm, 2.82 mm, 5.30, Bamboo sample of matchstick sizes were used for the de- 218.48, and 18.60, respectively (table 1). termination of fiber morphology. The bamboo samples Bamboo in the Asia Pacific Proceedings 4th International Bamboo Workshop, 1991

The effects of bamboo portion location On the fiber Prop- Specific gravity is important as a measure of the relative erties of Bambusa vulgaris are shown in table 2. From the amount of solid cell wall material and is the best index table it was observed that cell wall thickness, fiber length that exists for predicting the strength properties of wood. and slenderness ratio decreased while Runkel ratio and In softwood pulps, the properties of paper are said to be flexibility ratio were not affected. Fiber elements from the related to the specific gravity of wood and is a good in- base portion gave the longest fiber length (3.51 mm), dication of the properties of thick walled and thin walled thickest cell wall (0.0059 mm) and the highest Slender- fibers (Britt, 1970). ness Ratio (244.7) while values for Runkel Ratio and flexibility ratio were not significantly different. In this study, the variation in specific gravity was found to decrease uniformly (Table 4) from the base to the top of The importance of morphological characteristics, proper- the bamboo as found out by Abd. Latif et al. (1990) for ties and dimensions of wood fibers have been demon- Bambusa blumeana. This was consistent with one of the strated by scientific studies in determining the suitability trends observed by Panshin and de Zeuuw (1970) for of any species for a particular use (Dadswell et al, 1959, wood. In their study, two other trends in specific gravity Mulpsteph, 1960, Tamolang, 1967, Zamuco et al, 1969 were also noted: (i) decreasing in the lower trunk, and in- and Brit,t 1970). The influence of cell wall thickness of creasing in the upper trunk, and (ii) increasing along the fibers on papermaking properties has been indicated in the stem from base to the top in a nonuniform pattern. Varia- above literature. Fibers with thin walls gave compact, tion in specific gravity of a species is influenced by the well-bonded sheets of paper whereas thick walled fibers variation in cell wall thickness. Fibers with thicker walls gave bulky and stiff paper of low strength. Flexibility ratio will give higher specific gravity and produces stronger (lumen diameter/cell diameter) directly influenced the timber. tensile and bursting strengths of paper while tearing re- sistance was directly influenced by the relative fiber According to Panshin and de Zeuuw (1970) the cellulose length (Fiber length/fiber diameter) or the Slenderness content in Pinus decreased along the trunk. The decrease Ratio. The higher the flexibility ratio, the higher were the although small, was significant in some species. In tropi- tensile and bursting strengths; the higher the Slenderness cal hardwoods there appears to be a relationship between Ratio, the higher was the tearing resistance. In this study, height of tree and its cellulose distribution. Li (1983) re- the flexibility ratio was found to be very low but it was ported that there was no definite trend of holocellulose compensated by the high slenderness ratio which indi- content in Phyllostachys pubescens. Holocellulose content cated its ability to form well bonded papers. as found in this study increases with bamboo portion in accordance to the finding of Maheswari and Satpathy Because of the widespread interest in fibers for papermak- (1983), and Montalvao et al. 1986. However, there was ing, fiber length has been widely investigated According no definite relationship between the alpha-cellulose con- to Panshin and de Zeuuw (1970), fiber length increased tent of Bambusa vulgaris with bamboo portion location.. directly with increasing height to a maximum value, In wood, Panshin and de Zeuuw (1970) stated that above which the length decreased with increasing height. changes in lignin content with height along the stem axis For bamboo, several researchers found that fiber length were not at all clear. Maheswari and Satpathy, 1983 found decreased with increasing height (Maheswari and Satpa- that the lignin content of bamboo (Dendrocalamus stric- thy, 1983, Liese, 1985, Montalvao et al, 1986 and Abd. tus) decreased with increasing height. Li (1983) reported Latif et al, 1990). In this study it was found that variation that there was no definite trend for lignin, ash and alcohol in fiber length is in accordance to the latter’s findings. benzene solubles in P. pubescens but showed that hot wa- ter solubles and 1% NaOH solubles decreased with bam- Effect of bamboo location portion on boo height. The lignin content of Bambusa vufgaris in chemical properties this study was found to be unaffected by changes in bam- boo portion location. Similarly, cold water solubility, hot Table 3 shows the analysis of variance for specific gravity water solubility, alcohol benzene solubility and alpha cel- (SG), Cold water solubility (CW), Hot water solubility lulose solubility showed no definite trend. (HW), Alcohol benzene solubility (AB), 1% NaOH solu- bility (NaOH), Ash content, Lignin (LIG), Holocellulose content (HOL) and Alpha-cellulose content (ALP). It was Conclusion observed that the tree portion had a highly significant ef- Results from the statistical analysis of fiber morphology fect on Holocellulose content and Ash content. The por- and chemical analysis indicated that bamboo portion loca- tion location also had a significant effect on specific tion had highly significantly effect on cell wall thickness, gravity and 1% NaOH solubility. However, it was found fiber length, slenderness ratio, holocellulose content, and that no significant effect was observed for the other ash content. The base portion showed significantly long- chemical properties of Bambusa vulgaris. The mean val- er fiber length (3.50 mm); highest slenderness ratio ues for SG, CW, HW, AB, NaOH, ASH, LIG, HOL and (245.0); lowest holocellulose content (70.8%) and highest ALP were 0.58 g/cm’, 8.31%, 10.18%, 5.57%, 26.08%, 1% NaOH solubility (26.5%). Other properties did not 2.63%, 26.08%, 74.34% and 62.33% respectively. show any definite trend.

Structure and Functions of the Nodes in Bamboo 219 Bamboo in the Asia Pacific Proceedings 4th International Bamboo Workshop, 1991

Bambusa vulgaris exhibited considerable variation in its Britt, K.W. 1970. Handbook of Pulp and Paper fiber and chemical properties as affected by bamboo por- Technology. 2nd Ed. Van Nostrand Reinhold Company. tion location. The variation is probably due to factors as- Dadswell, H.E and A.B. Wardrop. 1959. Growing Trees sociated with its growth. The variation of fiber and with Wood Properties Desirable for Paper Manufacture. chemical properties followed closely the trends exhibited APPITA 12 (4) : 129-l 36. in some woody and other bamboo species. Franklin, F.L. 1954. Nature 155, 3924, 51. Li. 1983. Report to Institute of Wood Industry, Chinese Academy of Forestry, Beijing. Acknowledgement Liese, W. 1985. Anatomy and Properties of Bamboo. Pro- The authors would like to extend their deepest appreci- ceedings of the International Bamboo Workshop. Oct 6 - ation to En. Ahmad Khambali Khalil and En. Anuar 14. China pp. 200 - 201. Mohd. Yaccob for the assistance rendered during the Maheswari, S. and K.C. Satpathy. 1983. Papermaking collection and preparation of the bamboo samples. Characteristics of Top, Middle and Bottom Portions of Thanks are also due to En. Mohd. Noor Jurimi for the Bamboo. Indian Pulp and Paper. Aug-Sept. pp. 5-9. chemical determinations and fiber measurements. A note Montalvao Filho, A. Gomide, J.L. Conde, A.R. 1986. Text- a appreciation is also extended to ITM and FRIM for the book of the Chemical Constituents and Dimensional Char- acteristics of Bambusa vulgaris Fibers. ABCP Congr. use of available facilities without which this study would Annual 19th (Sao Paulo) : 15-32, Not. 24-28. not have been possible. Panshin, A.J and Carl de Zeuuw. 1970. Textbook of Wood Technology Vol. I pp. 237-258. References Tamolang F.N., F.F. Wangaard and R.M. Kellogg. 1967. Strength and Stiffness of Hardwood Fibers. TAPPI Abd. Latif Mohmod, Wan Taemeze Wan Ariffin and Fauzi- dah. 1990. Anatomical Features and Mechanical proper- 50(2):68-72. ties of three Malaysian Bamboo. Journal of Tropical Forest Wise, M and D’addieco. 1946. Paper Trade Journal, 122, Science: 227-234,‘Anon. 1979. TAPPI Official Test Meth- 2. pp. 35. ods. USA Zamuco, I.T, R.R. Valbuena, C.K. Lindayen and L.R. Rob- erto. 1969. Fiber Morphology: It’s Role in Pulp and Paper Research. The Philippine Lumberman 15(l): 24-26.

220 Structure and Functions of the Nodes in Bamboo RR Length SR, FR Bamboo in the Asia Pacific Proceedings 4th International Bamboo Workshop, 1991

Table 1: Mean squares from analysis of variance for cell wall thickness, Runkel ratio, Slenderness ratio and Flexibility ratio. r df CWF Length RR SR FR Portion 2 0.000030** 38.50** 9.074NS 56024.96** 23.906NS Error 297 O.OOOOO23 0.80 5.74 4904.16 66.45 Total 297 O.OOOOO25 1.05 5.77 5246.11 66.16 Mean 0.0054 2.82 5.30 218.48 18.60 Standard deviation 0.0016 1.03 2.40 72.43 8.13 Minimum 0.0025 1.04 0.83 79.04 6.67 Maximum 0.0113 5.28 14.00 502.86 54.55 Remark NS = Mean squares were not significantly different ** = Mean squares were significant at the 1% probability level

Table 2: Mean values* of cell wall thickness, fiber length, Runkel ratio, Slenderness ratio and Flexibility ra- tio according to bamboo portion.

8amboo portion M(mm) Length (mm) RR SR FR Base 0.0059a 3.51a 5.55a 244.66a 19.14a Middle 0.0053 b 2.65b 5.38a 212.22b 18.41a Top 0.0049b 2.31c 4.96a 198.58b 18.21a Remark: ‘Mean with the same letter down the column were not significantly different. Mean values were averages based on 100 observations

Table 3: Mean squares from the anal sis of variance of specific gravity, cold water solubility, hot water solu- bility, alcohol-benzene solubility, 1% aOH solubility, ash content, lignin, holocellulose and a alpha-cellulose

SG CW HW AB NaOH ASH LIG HOL ALP Portion 2 0.0012* 1.897NS 3.056NS 1.049NS 0.671** 0.61 l** 0.568NS 31.167** 1.663 NS Error 6 0.0002 0.462 3.079 0.996 0.112 0.007 0.263 0.551 0.805 Total 8 0.0004 0.821 3.073 1.009 0.252 0.158 0.339 8.205 1.020 Mean 0.58 8.31 10.18 5.57 26.08 2.63 26.08 74.34 62.33 Standard deviation 0.021 0.910 1.750 1.000 0.501 0.400 0.580 2.860 1.010 Minimum 0.55 7.27 6.64 4.47 25.30 2.01 24.80 70.20 61 .00 Maximum 0.62 10.01 12.46 7.61 26.90 3.08 26.80 78.40 64.40 Remark: NS = Mean squares were not significantly different * = Mean squares were significant at 5% probability Ievel ** = Mean squares were significant at 1% probability level

Table 4: Mean values of specific gravity cold and hot water solubility, alcohol-benzene solubility, 1% NaOH solubility, ash content, lignin, holocellulose and alpha cellulose content according to bamboo portion

Base 0.60a 8.55ab 10.9oa 4.92a 26.5Oa 2.82a 25.7a 70.80~ 62.57a Middle 0.58ab 7.43 b 9.02a 5.7Oa 25.57b 2.96a 26.5a 75.13b 61.5Oa Total 0.56b 8.96a 10.6Oa 6.08a 26.17ab 2.12b 26.Oa 77.1Oa 62.93a Rematic Mean values with the same letter down the column were not significantly different Means were averages of 3 replicates.

Structure and Functions of the Nodes in Bamboo 221 Bamboo in the Asia Pacific Proceedings 4th International Bamboo Workshop, 1991

Structural Variability of Vascular Bundles of Some Exotic Bamboo Species Yi Chung Wang; Jung Sheng Hsieh; Shuen Chao Wu*

The different kinds of cells were measured at 3 different Introduction heights respectively. The results are shown in Table 3. Bamboo are valuable commercial plants The average percentage of parenchyma, fiber cells and used as edible food and in bamboo processing as raw ma- conducting tissue are 56.6, 29.3 and 14.1 respectively. terial. The typical feature of monocotyledon plants is the The range of average parenchyma percentage varies from vascular bundles diffusing in the whole culm (Liese, 51.0-58.0, fiber cells are from 29.7-35.7% and conducting 1987). tissue is 11.3-16.5% while Gu. angustifolia is not in- cluded in this range. Parenchyma percentage decreases Anatomical characteristics of vascular bundles including from base to the top except for Gu. angustifolia. Conduct- size, shape and number are a prominent basis for taxono- ing tissue increases with height of bamboo. The variation my of bamboo. The vascular bundles change in size and of fiber cells is not very clear. GM. angustifolia shows a percentage with different culm positions, therefore due to particular variation of cell percentage. The percentage of the variation of the vascular bundle, specific gravity, me- conducting tissue is similar to other species, but the fiber chanical strength and processing properties are affected. cell percentage is much lower, which means its parenchy- With an understanding of the variabilities of the vascular ma percentage is the highest in all 9 species, correspond- bundles we can identify the properties of bamboo. ingly its mechanical strength will be lower due to it containing less sclerenchyma. Materials and methods The size of vascular bundle Samples of nine bamboo species, introduced from Central The size of vascular bundle decreases from 455-680 urn and South America and Southeast Asia in 1980 and 1981 for the second internode to 220-470 urn for the 26th inter- were collected in 1984. These had been planted in Chia- node. The largest vascular bundle is in the central part of Yi, southern Taiwan. Detailed data of sample bamboo are the culm wall at each internode. The thickness of culm listed in Table 1. Specimens were taken from the base, wall decreases from base to the top and the transverse size middle part and the top of each species. Samples measur- of vascular bundle has the same variational trend. From ing lcm in length were taken from the central internode the results of observation, the size of vascular bundle and in each portion. Observations of the shape of vascular internode number show close correlation. Further analysis bundles were made from the 2nd internode to the top, at show that the thickness of culm wall and internode num- intervals of 4 internodes. ber influence the size of vascular bundle. The multiple The specimens were softened and microtomed to obtain linear regression equation is Y = a+bXl+CX2, where Y = the size of vascular bundle, Xl = internode number and 15-25pm thickness of cross section for observation, Wu & X2 = the thickness of culm wall. The analysis results of Wang, 1976. Cell percentage and the size of vascular nine species are shown in Table 4. The coefficient of de- bundles were examined by image processor connected termination is higher than 0.928, which indicates signifi- with light microscopy. The variations of structure and cant correlation exists between the thickness of culm wall shape of vascular bundle were observed under light and internode number and the size of vascular bundles . microscopy. Shape of vascular bundle at different Results and discussion positions Figure 1 shows the variation of vascular bundle shape in Anatomical features of vascular bundles Bambusa dissemulator at different internode positions. The anatomical features of vascular bundle are based on The value inside parenthesis indicates internode number. samples from the 6th internode from the base of each spe- The vascular bundle shows continuous change in its size cies. The shape, size and thickness of different kinds of from the epidermis to the cavity of bamboo, Fiber sheath cells are shown in Table 2. is larger in the central culm wall of the 2nd internode, but by the 6th internode the fiber sheath is normalized. The change is very obvious in the size at transverse section. Cell percentage Due to increasing the thickness of culm wall from top to The culm wall of bamboo consists of parenchyma, fiber the base, the whole culm wall from base to the top in- cells and conducting tissue, Liese 1985; Wang & Tang, creases the number of vascular bundles and the shape 1988, variation is even greater, Wang & Tang, 1988. Bamboo in the Asia Pacific Proceedings 4th International Bamboo Workshop, 1991

The shape variation of a vascular bundle is shown in Fig- the fiber percentage is lower. The vascular bundles need ure 2 in B. textilis. The solitary fiber sheath shown in the to perform more supporting and conducting function, so central culm wall of the internode disappears near the the size of vascular bundle is larger than in other species; cavity of bamboo. Meanwhile the conducting tissue em- the size of vascular bundle near the epidermis increases by bedded by fiber sheath gradually separates when the vas- 50% as compared with other species. The shape of the cular bundle is near the center of culm wall. The size of vascular bundle of central culm wall is the same from the fiber sheath adjoining the protoxylem vessel is larger. 2nd to the 30th internode, but the size of the vascular bundle decreases with the number of the internode. The The variation of the vascular bundle in the central culm variation is shown in Figure 8. The size of the vascular B. tulda wall at different internodes in is shown in Figure bundle varies from 230-500 um, which is the mid size in 3. The 2nd and 6th internode have two solitary fiber sheaths located around the phloem and xylem, but above 9 species. The size of the vascular bundle is larger when close to the cavity of bamboo, as shown in Figure 9 in the 6th internode the fiber sheath around the phloem dis- S’chizostachyurn zollingeri. appears. The radial size of the vascular bundle evidently decreases from the 2nd to the 30th internode. The base of a bamboo culm may need more mechanical support, so two solitary fiber sheaths occur near the base. Conclusion The results indicate that the largest vascular bundle is lo- The variation of vascular bundle in B. tufdoides is similar cated in the central part of the culm wall at each internode to B. textilis as shown in Figure 4. Vascular bundles be- and the size of the vascular bundle decreases from the se- come flatter near the cavity of the bamboo where the soli- cond internode varying from 455-680 um to the 26th in- tary fiber sheath disappears. The size of the fiber sheath of the central culm wall is larger, which is important to pro- ternode, varying from 220-470 um. tect the functions of the conducting tissue. The constituent percentage of parenchyma, fiber cells and 23. variegata is the only species which shows both paren- conducting tissue i s 51.0-58.0%, 29.7-35.7%, a n d chyma and sclerenchyma in its fiber sheath in the central 11.3-16.5%, but Guadua angustifolia has a special value culm wall of the 2nd internode. The variation of the vas- with 77.0%, 9.0% and 14.0% respectively. cular bundle is shown in Figure 5. The size of the vascular bundle increases from epidermis to the central culm wall A significant correlation exists between the thickness of and then decreases to the cavity of bamboo, which means culm wall, internode number and the size of vascular the vascular bundle shows the largest size in the central bundle. culm wall. Solitary fiber sheaths occur from base to 14th internode. References Gigantochloa apus is a species of larger culm diameter Grosser, C. & W. Liese, W. 1971. On the Anatomy of and has a thicker culm wall. Two solitary fiber sheaths ex- Asian Bamboo, with Special Reference to Their Vascular ist in the vascular bundle of the 2nd internode from near Bundles. Wood Science and Technology 5290-312. the epidermis to the cavity. One solitary fiber sheath but located around the phloem at the inner cavity of the 6th Hsieh, J.S., Wu, S.H. & Wang, H.H. 1986. Studies on the internode disappears; from 10th internode, only one soli- tissue structure of Leptomorph and Pachymorph Rhizome tary fiber sheath exists in the vascular bundle from the Bamboo. Forest Products Industries 5(2):49-62. epidermis to the cavity of bamboo. The detailed variation Liese, W. 1985. Anatomy and Properties of Bamboo, Re- is shown in Figure 6. The innermost culm wall bundles do cent Research on Bamboo, Proceeding of the International not possess the solitary fiber sheaths from the 10th inter- Workshop. pp. 196-208 node to the top. Liese, W. 1987. Research on Bamboo. Wood Science and The structural features of Gi. verticillate are similar to Gi. Technolgy 21: 189-209 apus as shown in Figure 7. Only two fiber sheaths show in McClure, F.A. 1966. The Bamboo, A Fresh Perspective. the central culm wall. From the 10th internode, one soli- Harvard University Press 347pp. tary fiber sheath shows in the vascular bundle of the cen- tral culm wall. Wang Y.S. &Tang, J.L. 1988. Studies on the Structure of Introduced Bamboo. Forest Products Industries Guadua angustifolia belongs to the pachymorph group, 7( 1): 53-640 which indicates one or two fiber strands in its vascular Wu, S.C. 8 Wang H.H. 1976. The Structure of Bamboo bundle, Hsieh et al, 1986; Grosser and Liese, 197 1; Species Grown in Taiwan. Cooperative Research Report McClure, 1966. Owing to the lack of solitary fiber sheath, no.16 of National Taiwan University.

Table 1: Country of origin and date introduced Scientific Name Introduced year Country Barnbusa dissemulator McClure 1980 Nicaragua Bambusa textilis McClure 1981 U.S.A. Bambusa tulda Roxburgh 1980 El Salvardor Bambusa tuldoides Mu nro 1980 Costa Rica Bambusa variegata 1981 Singapore Gigantochloa apus (Schultes) Kurz 1980 El Salvardor Gigantochloa Verticillata (Willdcnow) Munro 1980 El Salvardor Guadua angustiflolia Kunth 1980 Colombia Schizostachyum zollingeristeydel 1980 Malaysia

Structural Variability of Vascular Bundles of Some Exotic Bamboo Species 223 Bamboo in the Asia Pacific Proceedings 4th International Bamboo Workshop, 1991

Table 2: Anatomical features of vascular bundle in various bamboo species

The number of vascular bundle in lmm The shape of vas- cross short. cross short cross triangle triangle short cross short cross triangle short cross cular bundle The diieterof 120-150 70-80 120-150 150-200 80-110 110-160 90-160 110-150 90-125 m etaxylem vessel The thickness of 5.00 2.00 3.50 4.0-5.0 2.50 3.00 3.50 2.50 2.50 metaxvlem vessel 7-9 4-7 8-12 8-12 6-8 4-7 4-7 4-6 4-7 of fiber cell around

3-7 3-7 3-6 5-8 2-5 3-5 3-6 3-6 3-5 of fiber cell around

The number of lo-17 1 13-17 16-20 7-13 12-17 10-18 l0-15 11-17 13-15 sievetube The layer number 11-16 12-15 8-148-14 lo-13l0-13 6-136-13 6-96-9 5-75-7 11-1511-15 7-107-10 of fiber cell around I I phloem The number of 1 1 1.2 1 1 1 1,2 1,2 none 1 solitary fiber sheath

Table 3: The constituent percentage of nine bamboo species at different parts of culm wall

Base Middle top Average Species P. F. C P. F. C P. F. C. P. F. C B. dissemulator 60.50 30.00 9.50 56.50 30.00 13.00 57.00 31.50 11.50 58.00 30.70 11.30 B. textilis 54.50 35.50 10.00 47.50 36.00 16.50 51.00 34.00 15.00 51.00 35.20 13.80 B. tulada 63.20 25.80 11.00 52.00 35.00 13.00 39.00 37.00 24.00 51.40 32.60 16.00 B. tuldoide 67.80 22.50 9.70 50.00 33.00 17.00 46.50 33.50 20.00 54.80 29.70 15.50 B. variegata 62.50 30.00 7.50 50.00 34.00 16.00 50.00 37.50 12.50 54.20 33.80 12.00 G/: apus 64.00 28.70 7.30 54.00 30.50 15.50 50.00 33.80 16.20 56.00 31.00 13.00 Gl: verticillata 60.00 30.00 10.00 50.00 35.00 15.00 47.00 30.00 23.00 52.30 31.70 16.00 Gu. angustifolia 74.00 14.50 11.50 76.00 7.00 16.50 81.00 5.50 14.00 77.00 9.00 14.00 s. zollingeri 57.50 32.00 10.50 54.00 30.00 16.00 50.00 27.00 23.00 53.80 29.70 16.50 Average 62.80 27.80 9.40 54.50 30.10 15.40 52.40 30.00 17.60 56.60 29.30 14.10

Table 4: The relationship between size of vascular bundle, and internode number and culm wall thickness

Species Multiple linear regression equation R2 B. dissemulator = 0.96 B. textilis Y2 = 0.98 B. tulda Y3 = 0.95 B. tuldoides Y4 = 0.97 8. variegata Y5 = 0.94 Gi. apus Y6 = 1.00 Gi. verticillata Y7 = 0.99 Cu. angustifolia Y8 = 0.93 S. zollingeri = 1.00

224 Structural Variability of Vascular Bundles of Some Exotic Bamboo Species Bamboo in the Asia Pacific Proceedings 4th International Bamboo Workshop, 1991

Figure 1: The variation of vascular bundle in the transversal and longitudinal directions of Bambusa disse- mulator by internode order

Figure 2: The variation of vascular bundle in the transversal and longitudinal directions of Bambusa textilis

Figure 3: The variation of vascular bundle in the transversal and longitudinal directions of Bambusa tulda

Figure 4: The variation of vascular bundle in the transversal and longitudinal directions of Barnbusa tuldoides

Figure 5: The variation of vascular bundle in the transversal and longitudinal directions of Bambusa variegata

Structural Variability of Vascular Bundles of Some Exotic Bamboo Species 225 Bamboo in the Asia Pacific Proceedings 4th International Bamboo Workshop, 1991

Figure 6: The variation of vascular bundle in the transversal and longitudinal directions of Gigantochloa apus

Figure 7: The variation of yascular bundle in the transversal and longitudinal directions of Gigantochloa ve/tririta

2 6 10 14 16 22 26 30 I I

Figure 8: The variation of vascular bundle in the transversal and longitudinal directions of Cuadua angustifolia

Figure 9: The variation of vascular bundle in the transversal and longitudinal directions of Schizostachyum, zollingeri

226 Structural Variability of Vascular Bundles of Some Exotic Bamboo Species Bamboo in the Asia Pacific Proceedings 4th International Bamboo Workshop, 1991

Carbohydrates in Commercial Malaysian Bamboo

Abd. Latif Mohmod, Khoo, K.C. & Nor Azah Mohd. Ali*

potential uses, predicting their behaviour towards Introduction grading agents and promoting their acceptance in com- In Malaysia, bamboo is found in abundance although mercial application. widely scattered in about 5% of the total forest reserves, Abd. Latif 1987, Abd. Razak & Abd. Latif, 1988. Until recently, it has, however, received relatively little atten- Materials and methods tion as far as research is concerned. Due to the current demand for disposable bamboo products, the bamboo in- Source of materials dustries which were traditionally established to supple- Two species of bamboo, viz. Barnbusa blumeana (buluh ment the needs of handicraft and agriculture, have been duri), and G. scortechinii (buluh semantan) were used in suddenly tailored to machine intensive type, Abd. Latif et this study. Samples of the bamboo (one to three year old) al. 1989. As a result, bamboo which was once considered the growth of which has been recorded since their sprout- a weed in forestry practice, Medway 1973, Ng 1980, has ing stages, were obtained from wild clumps in the grounds been extensively exploited to meet the demand from con- of the Forest Research Institute Malaysia (FRIM). Each sumers countries, particularly Japan, the Republic of Tai- bamboo sample was divided into three portions, namely wan and Korea. Although the number of mills has the butt, middle and top at an interval length of 4m. increased, many reports have been received on the poor quality and durability of the locally made bamboo prod- Determination of starch content ucts produced for export. This industrial set back was mainly related to indiscriminate harvesting of bamboo The method devised by Humphrey and Kelly, 1960, was without giving respective thought to its properties and fi- adopted to determine the starch content through the basic reaction of the starch present with iodine and measuring nal usage, Abd. Latif et al. 1990. the absorption of the colour developed by a colorimeter. The selection of bamboo for industrial use and structural Bamboo samples were first ground to pass through a 200 purpose is closely related not only to the physical and me- chanical properties but also to the chemical composition mesh sieve. Triplicate samples of 0.4 gramme each were (particularly starch and free sugars) of this material. This dried for 72 hours in a dessicator oven containing concen- is important as the properties could be associated with age trated sulphuric and and added with 4-7 ml of 7.2 M perchloric acid in a 50 ml beaker. Reactions were allowed and culm heights which thus affect the final use of the bamboo, Abd. Latif 1987, Abd. Latif et al. 1990. Further- to continue for 10 minutes with occasional stirring. The contents were then transferred into a 50 ml volumetric more, carbohydrate content of a woody material plays an flask and made up to the volume with distilled water. important role in its durability and service life. Many sci- entists have confirmed its relationship with mold and fun- After centrifuging, l0m1 aliquot were placed in a 50ml gal stain, Liese, 1985, Simatupang, 1989, and borer volumetric flask together with a drop of phenolphtalein attacks, Plank, 195 1, Purusotham et al. 1953, Tamolang, and made alkaline with 2N sodium hydroxide. Then 2N 1980, Sulthoni, 1987. acetic acid was added until the colour was discharged. This was followed by the addition of 2.5ml acetic acid, From the utilization point of view, high level of starch and 1.5ml of 10% wight over volume potasium iodide and 5ml sugar contents can also influence the quality of cement- 0.01N potasium iodide. Colour was allowed to develop for bonded particle board produced, Schwarz & Simatupang, 15 minutes before the absorption at 650 urn was mea- 1984. This is due to the fact that the sugars and starch contain hydro?.,yl groups which could retard the absorption sured. A blank was prepared wirh starch aliquot. The starch content was then calculated by applying the rate of hydrosonium ion on the cement mineral surfaces formula:- and thus slow down the setting reaction, Rahim et al. 1989. % starch = 0,368 X (E reading + 0.008) X 50 x 100 Oven-dried weight of sample 100 In this study, the carbohydrate content of some wild Ma- laysian bamboo were examined as a guide to their

* Forest Research Institute Malaysia (FRIM), Kepong, 52109 Kuala Lumpur, Malaysia Bamboo in the Asia Pacific Proceedings 4th International Bamboo Workshop, 1991 where E = difference of absorption between sample and sucrose, glucose and fructose in B. blumeana were ob- blank. served to be in the range of 0.81-5.18%, 0-02-1.34% and 0.03-0.38% respectively, those in G. scortechinii were in Total available sugar content the range of 0.73-2.03% of sucrose, l.0l-1.79% of fruc- tose and only traces and up to 1.83% of glucose. The method developed by Simatupang as reported by Ra- him and Khozirah, 1988, was adopted in determining the The highest value of the total sugars from this study was sugars in the bamboo based on 0.4 gramme of each found in G. scortechinii (5.60%) followed by B. blumeana ground bamboo sample that had passed through a 200 (5.36%). This is probably due to the smaller radial/tan- mesh sieve. The sample was then extracted with 40ml of gential ratio and less dispersion of the vascular bundles 75% methanol overnight with regular shaking at a room (higher distribution of parenchyma cells in G. scortechinii temperature. The volume of the mixture was then made up than B. blumeana, Abd. Latif et al. 1990. to 50 ml and filtered through a cubicle glass no. 3. Thir- tyml of the filtrate was then evaporated in a petri dish Further regression analysis on the relationship of carbohy- placed in an oven for overnight before being redissolved drate contents with age and height of the culm is given in in 3ml distilled water. Table 4. While the total amount of sugars in all the bam- boo species increase or decrease insignificantly (r = 0.399 The aqueous solution was then filtered through a 0.45 um and -0.385 for the respective B. blumeana and G. scorte- micro prep-disc membrane filter into a sampling bottle. chinii), it is, however, correlated significantly with the in- The amount of sugar was detected by Reactive Index De- crement of culm height (respective r = 0.48 and 0.577). tector (Model 1037A) of a High Performance Liquid This could be related to the photosynthesis process which Chromatography (HPLC) system using Aminex HPX-87P takes place in the leaves, i.e. the higher portion of bamboo column at 0.48 ml/min flow rate with double distilled wa- culm, Anon, 1962. ter as the mobilizer. Sucrose, fructose, glucose, xylose and arabinose (analytical Reagent D+) were used as standards. The highest total sugars content in each bamboo species occured at the top portion particularly in the two year old G. scortechinii (5.60%) and middle portions of the three Results and discussion year old B. blumeana (5.36%). The amount of total sug- The carbohydrate contents of the two bamboo species are ars, however, was observed to be lowest at the basal por- given in Table 1. The respective summary of analysis of tions of the two year old B. blumeana (0.81%) and three variance and Duncan Multiple Range Test are given in year old G. scortechinii (2.52%). This could be associated Table 2 and 3. to the process of culm maturity which might begin within or after the second growth year. Within this growth year, The results indicate that the starch contents of the bamboo furthermore, bamboo establishes its root system and starts differ significantly with species, age, culm height and the to branch (Abd. Razak Othman, personal communica- interactions of species with age and culm height. The tion). A one year old culm normally relies on food supple- starch contents of the bamboo, regardless of age and culm ment from the rhizome of the maternal plant but a two height, vary between 0.29 and 8.38%; and 0.07 and year old bamboo starts to utilize all the carbohydrate con- 4.50% in G. scortechinii and B. blumeana respectively. tents, particularly sugar, for the development of its culm. The results (Tables 1 and 3) further show that the highest It might be the point where bamboo starts to synthesize its mean starch was generally present in the middle portions, own food requirement. Detailed studies on the growth particularly in the three year old G. scortechinii and B. characteristics, localities, seasonality and environmental blumeana (8.38% and 4.50% respectively). This is prob- effect on variation of the total sugars contents, however, is ably due to the middle portion containing less vascular needed for better explanation. bundles (Espiloy, 1987, Abd. Latif et al. 1990) but more parenchyma where the food storage of the living plant is From the utilizational aspect, as most of the bamboo sam- concentrated. Furthermore, older bamboo have more ma- ples possessed more than 0.6% total sugar, they would tured tissues which are involved in the photosynthesis probably produce low quality cement bonded particle process than the younger culms which rely mainly on food board unless treated, Weber, 1985. As the high carbohy- supplement from the rhizome of the maternal plant, drate content could also attract borer and fungal attacks, Anon, 1962. bamboo should be treated adequately. Nevertheless, the variation in both the starch and total sugars contents with- The total sugars contents of the bamboo differ significant- in and between the culm of bamboo species towards de- ly with age, species, culm height and their interactions caying agents should be further investigated to classify (Table 2). As mentioned by Liese, 1985, the chemical their natural durability. composition varies according to the individual character- istic of the species, its growing condition, age and part of the culm. Conclusion The starch content of bamboo was significantly correlated The composition of the free sugars is also shown in Table with age while the total sugars content was observed to 1. Sucrose is the main free sugar in all the bamboo sam- correlate significantly with the increment of culm height. ples followed by glucose and fructose. While the levels of The variability that exist within the height and species of

228 Carbohydrates in Commercial Malaysian Bamboo Bamboo in the Asia Pacific Proceedings 4th International Bamboo Workshop, 1991 bamboo may probably be due to the age of the culm, the Ng, F.S.P. 1980. Bamboo Research In Malaysia. Pp. photosynthesis process which takes place predominantly 31-95 in G. Lessard 8 A. Chouinard (Eds.). Bamboo Re- search in Asia. A Seminar held in Singapore, 28-30 May, at the top portion, and the particular characteristics of the 1980. International Development Research Center and In- individual bamboo species. ternational Union of Forestry Research Organization. G. scortechinii was observed to possess the highest Noggle, R.G. and Fritz, J.G. 1979. Introductory Plant Physiology. New Delhi: Prentice Hall Biological Science amount of starch and total sugars in almost all the three Series, 687 p. age groups compared with B. blumeana. Plank, H. 1951. Starch and Other Carbohydrate In Rela- tion to Powder Post Beetle Infestation in Freshly Har- References vested Bamboo. Journal Econ. Entom. 44(l): 73-75. Abd. Latif, M. 1987. Guidelines on Blind and Satay Stick Purusotham, A., Sudan, S.K. & Sagar, V. 1953. Preserva- Manufacturing. FRIM Technical Information No. 2. Forest tive Treatment of Green Bamboo Under Low Pneumatic Research Institute Malaysia, Kepong. 8 p. (Malay). Pressure. Indian For, Bulletin 178: 1-21. Abd. Latif, M., Roslan, A. & Razak, W. 1989. Current Sta- Rahim, S. & Khozirah, S. 1988. Sugar Content Analysis tus of Machine- Intensive Bamboo Industries in Peninsular for Wood Cement Boards - A Comparison Study. Paper Malaysia. International Bamboo Congress held in Hangz- presented at Malaysian Chemical Conference 1988 held in hou, China, 12-17 August 1989. Chinese Academy of Johore Baharu, Malaysia, 9-12 August 1988. Forestry. Rahim, S., Chew, L.T., Ong, C.L. & Zakaria, M.A. 1989. Storage Effect of Rubber-wood on Cement-bonded Abd. Latif, M., Wan Tarmeze, W.A. & Fauzidah, A. 1990. Parti- Anatomical Features and Mechanical Properties of Three cleboards. Journal Tropical Forest Science l(4): 356-370. Malaysian Bamboo. Journal Tropical Forest Science 2(3): Razak Osman 1988. Personal Communications Agrofo- 227-234. rester of Forest Research Institute Malaysia, Kepong, Se- Abd. Razak, M.A & Abd. Latif, M. 1988. Prospects of langor on 24 th Sept. 1988. Small-scale Wood- based Industries. Paper presented at Schwarz, H.G. & Simatupang, M.H. 1984. Suitability of the Seminar on Opportunity in Small-scale Industries held Beechwood for the Manufacture of Cementboard Wood in Kuala Lumpur, Malaysia, 28-29 March 1988. Composite. Holz alz Roh und Werkstaff 42: 265-270. Anonymous 1962. Studies on the Physiology of Bamboo Simatupang, M.H. 1989. Some Notes on the Chemical with Special Reference to Practical Application. Resource Composition of Rattan Extractived. Pp. 216-224 in A.N. Bureau Science and Technics Agency. Prime Minister Of- Rao & I. Vongkaluang (Eds.). Recent Research on Rattan. fice, Japan. 167 p. Proceedings of the International Rattan Seminar held in Chiangmai, Thailand, 12-14 Nov. 1987. Faculty of Forest- Espiloy, Z.B. 1987. Mechanical Properties and Anatomical ry, Kasetsart University, Thailand and International Devel- Relationship of Some Philippines Bamboo. Pp 257-265 in A.N. Rao, G. Dhanarajan & C.B. Sastry (Eds.). Recent Re- opment Research Centre, Canada. search on Bamboo. Proceedings of the International Sulthoni, A. 1987. Traditional Preservation of Bamboo in Workshop. Hangzhou, China. October 6-14, 1985. Java, Indonesia. Pp 349-358 in A.N. Rao, G. Dhanarajan & C.B. Sastry (Eds.). Recent Research on Bamboo. Pro- Humphrey, F.R. & Kelly, J. 1960. A Method for the Deter- mination of Starch. Wood Analytical Chem. Act. 24: ceedings of the International Workshop. Hangzhou, China. October 6-14, 1985. 66-70. Liese, W. 1985. Bamboo - Biology, Silvics, Properties and Tamolang, F.N., Valbuena, R., Lomibao, A.B., Artuz, A.E., Utilization. Eschborn: Deutsche Gesselschaft fir Tech- Kalaw, C. & Tangacan, A. 1980. Fiber Dimension of Cer- tain Philippine Broadleaves Woods and .Bamboo. TAPPI nische Zusanimenarbeit (GTZ) Gmblt, pp. 13-l 26. 40(8): 671-678. Medway, L. 1973. Research at the University of Malaya Weber, H. 1985. International Construction System. Hand- Field Studies Centre, Ulu Gombak - Bamboo Control. Ma- lay. Forester 33( 1): 70-77. book of Element Construction with Cement Boards and Other Types of Boards. Bison- Werke, Springe, pp 93-l 04.

Carbohydrates in Commercial Malaysian Bamboo 229 Bamboo in the Asia Pacific Proceedings 4th International Bamboo Workshop, 1991

Table 1: Carbohydrate contents (%) of bamboo 1 year 2 year Species Nutrient Butt Middie Top Butt Middle Top Butt Top B. blumeana starch 0.13 0.09 0.07 0.10 0.23 0.80 1.14 4.50 3.12 Sucrose 1.34 1.69 2.01 0.81 2.19 2.16 1.50 5.18 3.52 Glucose 1.34 0.24 0.28 t 0.02 0.08 t 0.10 0.04 Fructose 0.38 0.34 0.26 t 0.03 0.29 t 0.08 0.05 Xylose t t ttt t t t t Ara binose t t ttt t t t t Total sugar 3.06 2.27 2.55 0.81 2.24 2.53 1.50 5.36 3.61 G. Scortechinii Starch 0.77 0.51 1.28 0.66 7.69 0.29 5.25 8.38 5.56 Sucrose 1.67 1.82 1.78 0.96 1.98 2.03 0.73 1.79 1.67 Glucose 1.03 1.10 1.24 1.19 0.36 1.83 t 0.40 0.27 Fructose 1 .01 1.15 1.12 1.60 1.40 1.74 1.79 1.55 1.51 Xylose t tttt t ttt Ara binose t tttt t ttt Total sugar 3.71 4.07 4.14 3.75 3.74 5.60 2.52 3.74 3.45 Remark: t = trace amount

Table 2: Summary of ANOVA on carbohydrate contents B. blumeana and G. scortechinii

Mean squares and statistical significance Source of Carbohydrate contents variation DF Species starch Total sugar Sucrose Glucose Age 2 14.50** 4.30** 4.75** 0.55** 0.08* I 47.17** l.96** 0.16** 1.66** 0.36** Portion

Age x 4 1.92** 1.86** 1.38** 0.33** 0.03ns Portion 10.11** 0.74** 0.17** 0.39** 0.04ns Remark a = Bambusa blumeana b = G. scortechinins = not significant at P<0.05 * = significant at P<0.05 ** = sig- nificant at P<0.01 Table 3: Mean values of carbohydrate contents of bamboo at different age and height levels (% by weight of oven-dry material)

Means percentage Species Parameter Starch Total Sugar 1 Sucrose Glucose Fructose B. blumeana Age 1 2 3 Portion Butt 0.45 7a Middle 1.608c Top 1.327b G. scortechinii Age 1 0.857a 2 2.883 b 3 6.398c Portion Butt 2.228a 3.325a 1 .188a 0.807a 1.508a Middle 5.530b 3.84013 1.955c 0.822a 1.503a TOP 2.380a 4.395c 1.875 b 1.195b 1.507a Remark Means followed by a common letter(s) are not signific ntly; different at P<0.05

230 Carbohydrates in Commercial Malaysian Bamboo Bamboo in the Asia Pacific Proceedings 4th International Bamboo Workshop, 1991

Table 4: Correlation coefficients of carbohydrates contents with age and height

Linear equations . R I (St) a -1.689 + 1.41 (age)

b -2.162 + 2.77 (age)

0.260 + 0.435 (portion) St= 3.23 + 0.08 (portion) sugars 1.348 + 0.602 (age)

4.57 0.36 (age)

1 + 0.723 (portion) 2.78 + 0.53 (portion) (SC) a 0.653 + 0.79 (age)

b

0.865 + 0.682 (portion) 0.473 *

b 0.99 + 0.33 (portion) 0.733 0.211 (age) -0.421 ns 1.88 0.47 (age)

0.568 0.128 (portion)

0.55 + 0.19 (portion) F= 0.419 0.098 (age) -0.503 * 1.03 0.24 (age) 0.114 + 0.054 (portion) 1.51 0.0008 (portion) a = b = ns = not significant at * = significant at ** = significant at

Carbohydrates in Commercial Malaysian Bamboo 231 Bamboo in the Asia Pacific Proceedings 4th International Bamboo Workshop, 1991

Variation in Physical Properties of Two Malaysian Bamboo

Abd. Latif Mohmod, Wan Tarmeze Wan Arifin, Hamdan Husain*

Introduction portion before the samples were transported to the labora- tory. This was done in order to reduce evaporation and For the past six to seven years, Malaysia had seen her prevent fingal and insect attacks. bamboo industries grow from cottage level to machine- intensive, i.e. from incense stick, vegetable baskets and chicken coop (Salleh & Wong, 1987) to chopstick, skew- Determination of physical properties er, toothpick and other higo products (Abd. Latif 1989). The methods used for the determination of moisture con- Research and development have been embarked and di- tent, oven-dry density and shrinkage of bamboo were rected towards promoting the resources into higher level based on IS 6874. of utilization such as furniture, panelling, flooring and other building materials. Determination of mechanical properties The importance of physical properties control and its in- The methods used for the determination of shear, com- fluence on bamboo and bamboo products cannot be over- pression parallel to grain, stress at proportional limit, mo- looked. Moisture content for example, influences the dulus of rupture (MOR) and elasticity (MOE) were based dimensional stability of woody materials thus is often as- on IS 6874 - Testing of Round Bamboo. sociated with its toughness, density, strength, working properties and durability (Brown et al. 1952, Panshin & Results and discussion De Zeeuw, 1970, Grewal, 1978). The general characteristics of the test species and their Density, on the other hand, measures the amount of wood physical properties are presented in Tables 1 and 2. Sum- substance per unit volume. It helps to determine the physi- mary of analysis of variance and Duncan’s New Multiple cal and mechanical properties which characterize different Range test on the physical properties are given in Tables 3 kinds of wood and woody materials for their intended and 4, respectively. usage (Mitchell, 1964, Gurfinkel, 1973). In this study, the moisture content, density, shrinkages and mechanical Variation in initial moisture content properties of Bambusa blumeana and Gigantochloa scor- techinii natural stands were determined. The inter- Regardless of age and height, the initial moisture content relationship of age, height and mechanical properties in (Table 2) varies between 57.3 to 97.04 percent and 75.96 relation to physical properties were evaluated as a guide to to 108.34 percent in B. blumeana and G. scortechinii, re- their potential application. spectively. Further statistical analysis (Table 3) shows that the initial moisture content differs insignificantly (P<0.05) with age, height and the interaction of age and Materials and methods height. The Duncan’s New Multiple Range tests (Table 4), however, pointed out that the moisture content in both Source of materials bamboo is highest in the basal but decreases towards the Two species of bamboo, namely B. bfumeana and G. scor- top portion of the culms. Espiloy (1987) in her study on B. techinii of known age (1-3 years old) whose growth has bfumeana and G. levis also found a similar pattern of been recorded in the vicinity of the Forest Research Insti- variation. This is probably due to the decreased in per- tute Malaysia (FRIMJ, were used in this study. centage of parenchyma cells (higher frequency of vascular bundle), the site of water storage (Liese 1987). Field procedure The analysis further indicates that both bamboo possesses Nine bamboo samples from each species were cut at about the highest moisture content at a younger age. B. blumea- 30 cm above ground level. The diameter, thickness, girth na, however, possesses the lowest moisture content at age and standing height were measured from the cut base to 2, while at the age of 3 year old in G. scortechinii. This the tip. Each stem was then marked and cut at about 4.0 implies more thick-walled fibres and a greater concentra- m interval into basal (B), middle (M) and top (T) portion. tion of vascular bundle distributed in the mature tissues of Paraflin wax was applied to the cut surfaces of each the older bamboo (Abd. Latif et al. 1990). Bamboo in the Asia Pacific Proceedings 4th International Bamboo Workshop, 1991

Variation in oven-dry density properties with culm height. This could be related to the fact that the parenchyma cells decrease accordingly from The density of green bamboo was observed to be in the the basal to the top portion (Liese, 1987). range of 400 - 600 kg/m3. The results (Table 4) indicate that the highest mean oven-dry density was near the top The regression analysis further indicates that with the ex- portion of the three-year old B. blumeana (599 kg/m3) and ception of MOR, the mechanical properties in both bam- G. scortechinii (597 kg/m3). The density, however, in- boo are strongly correlated with the oven-dry density. creases from 13 to 16 percent in the one- to three-year-old However, with the exclusion of stress at proportional lim- culms. With regards to culm height, it appears that the it, the orientation of correlation in B. blumeana is totally density of bamboo does not vary with height, but it tends reversed from that of G. scortechinii. This could be attrib- to have a higher value near the top of the culm. This could uted to the similar variation of density between both bam- be related to the thicker culm wall of B. blumeana than of boo where the orientations are totally reversed from each G. scortechinii (Abd. Latif & Wan Tarmeze, 1990). other. The results further suggest that in both bamboo, shear, compression parallel to grain and the modulus of Variation in radial and tangential elasticity should increase towards maturity and the upper shrinkage portion of the culms. Regardless of age and height, radial and tangential shrinkage varies from 5.68 to 10.05 percent and 6.32 to Effects of moisture content and density 20.0 percent in B. blumeana; and about 6.60 to 14.55 per- on shrinkages cent and 14.05 to 19.15 percent in G. scortechinii, Table 6 shows the correlation coefficient of moisture con- respectively. tent and density with shrinkage. The results indicate that moisture content correlates positively with radial and tan- The results further indicate that the magnitude of shrink- gential shrinkage. This suggest that the bamboo with age in the bamboo species was almost similar, in that it higher moisture content, i.e. higher percentage of paren- generally decreases with age and height of the culm. The chyma cells, should shrink more. A similar result pattern one-year-old bamboo was observed to shrink at an average was also reported by Espiloy (1987) on two Philippine of 15-22 percent more compared to the three-year-old bamboo: B. blumeana and G. levis. bamboo in the respective radial and tangential surfaces, thus indicating that the dimensional stability of the older The density of both bamboo is highly correlated with the bamboo is greater than the young ones. This is probably radial and tangential shrinkage. However, the correlation correlated with the high density and low initial moisture is positive in B. blumeana and negative in G. scortechinii. content within the older bamboo. Regardless of age and Again, this could be due to the variation in density be- species, the radial and tangential shrinkages of the bam- tween both the bamboo species. boo were also found to decrease according to height of the culm. While the average radial and tangential shrinkage at the basal portion of the three bamboo species were Conclusion about 11 and 23 percent respectively, the shrinkage values Results in this study suggest that with its lower moisture at the top portion were approximately 12 percent on both content, higher density and smaller shrinkage values, B. radial and tangential surfaces. Again, the higher density bfumeana is a better bamboo than G. scortechinii, at least due to the relative higher amount of vascular bundle in the in terms of strength in application. inner culm wall and low initial moisture content could The variation of moisture content between age and height contribute to the minimal shrinkage in the top portion. was found to be insignificant. It is however found to influ- ence the strength and dimensional stability of the bamboo Effects of physical properties on strength significantly. of bamboo The variation of density between age and height, and its The effect of physical properties on the strength of bam- boo are presented in Table 5. The results indicate that ex- effect on strength and shrinkages are totally contradictory between both bamboo species. Further research should be cept the stress at proportional limit (in B. blumeana) and modulus of rupture (MOR), all the incchanical properties intensified to clarify this uncertainty; and external factors correlate negatively with moisture content. such as soil condition and climatic changes which might contribute this variation should be taken into account. Moisture content could be correlated positively with the amount of parenchyma cells present. As stated by Janssen References (1981), the parenchyma cell is the weakest point in the bamboo tissues. This suggests that bamboo with higher Abd. Latif, M. 1987. Perusahaan Membuat Bidai dan Pe- nyucuk Satay. FRIM Technical Information 2. Forest Re- percentage of parenchyma cell (lower vascular bundle dis- search Institute of Malaysia, 8 p. (Malay). tribution) should have lower values of shear, compression Abd. Latif, M. 1989. Current Status of Machine-intensive parallel to grain, stress at proportional limit and the mo- Bamboo Processing Industry in Peninsular Malaysia. In- dulus of elasticity. A previous study by Abd. Latif et al. ternational Bamboo Congress held in Nanjing, August (1990) revealed the increase in the above mechanical 1989.

Variation in Physical Properties of Two Malaysian Bamboo Bamboo in the Asia Pacific Proceedings 4th International Bamboo Workshop, 1991

Abd. Latif, M., Wan Tarmeze, W.A. & Fauzidah, A. 1990. Janssen, J.J.A. 1981. The Relationship Between the Me- Anatomical Features and Mechanical Properties of Three chanical Properties and the Biological and Chemical Com- Malaysian Bamboo. Journal of Tropical Forest Science position of Bamboo. Proceedings of the XVII IUFRO World 2(3): 227-234. Congress Proc. Div. 5. Kyoto, Japan: IUFRO, pp. 27-32. Abd. Latif, M. & Wan Tarmeze, W.A. (1990). On the Me- Liese, W. 1987 . Anatomy and Properties of Bamboo. Pp. chanical Properties and Anatomical Relationship of Some 196-208 in A.N. Rao, G. Dhanarajan and C.B. Sastry Natural Stand Malaysian Bamboo. Paper presented at IU- (eds.) Research on Bamboo. Proceedings of International FRO XIX World Congress held in Montreal, Canada, 4-12 Bamboo Workshop held in Hangzhou, China, Oct. 6-14, August 1990. 1985. Chinese Academy of Forestry and IDRC. Brown, H.P., Panshin, A.J. & Forsaith, C.C. 1952. Text- Mitchell, H.L. 1964. Patterns of Variation in Specific Grav- book of Wood Technology. 1st. ed. New York-Toronto- ity of Southern Pines and Other Coniferous Species. TAP- London; MC Graw Hill Book Co. Inc., 785 p. PI 47: 276-283. Espiloy, Z.B. 1987 . Mechanical Properties and Anatomi- Panshin, A.J. 8 De Zeeuw, C. 1970. Textbook of Wood cal Relationship of Some Phillipines Bamboo. Pp. 257-265 Technology. New York: MC Graw-Hill ‘Book Co., Vol. I. in A.N. Rao, G. Dhanarajan and C.B. Sastry (eds.) Re- 705 p. search on Bamboo. Proceedings of International Bamboo Salleh, M.N. & Wong, K.M. 1987. The Bamboo Resource Workshop held in Hangzhou, China, Oct. 6-14, 1985. Chi- in Malaysia: Strategies for Development. Pp. 45-49 in A.N. nese Academy of Forestry and IDRC. Rao, G. Dhanarajan and C.B. Sastry (eds.) Research on Grewal, G.S. 1978. Kiln Drying Characteristics of Some Bamboo. Proceedings of International Bamboo Workshop Malaysian Timber. Malaysian Forest Service Timber Trade held in Hangzhou, China, Oct. 6-14, 1985. Chinese Leaflets No. 42, 42 p. Academy of Forestry and IDRC. Gurfinkel, G. 1973. Wood Engineering. New Orleans, Louisiana: Southern Forest Products Assoc., 540 p.

Table 1: General characteristics of the bamboo

1 2 3 Bamboo BMT B M I T BM T Outer diameter (cm) a 8.40 8.22 7 . 6 9 8.18 7 . 7 8 7.26 8 . 5 1 8.68 8.09 (0.11) (0.10) (0.70) (0.12) (0.40) (0.61) (0.10) (0.20) (0.09) b 7.80 8.74 8.48 7 . 1 2 7 . 1 5 6.06 7.20 7 . 5 3 6.39 (0.13) (0.13) (0.20) (1 .00) (0.30) (0.40) (0.50) (0.20) (0.70) Thickness (cm) a 1 . 1 4 0.86 0 . 7 1 1.10 0 . 7 2 0.76 1 . 4 6 1 . 0 3 0 . 8 2 (0.10) (0.02) (0.02) (0.04) (0.03) (0.12) (0.30) (0.50) (0.30) b 0.92 0.66 0.60 0 . 8 3 0.64 0.48 0 . 9 2 0 . 6 3 0 . 4 5 (0.09) (0.02) (0.10) 90.080 (0.02) (0.10) (0.11) (0.05) (0.06) Girth (cm) a 25.99 26.55 24.68 25.20 24.50 23.50 27.00 2 7 . 3 1 26.27 (0.10) (0.51) (0.18) (0.31) (0.51) (0.54) (0.55) (0.19) (0.27) b 23.25 27.02 26.10 22.04 22.75 19.06 22.09 22.35 18.96 (0.25) (0.70) (0.40) (0.41) (0.25) (0.60) (0.90) (0.15) (0.33) Internode diameter (cm) a 10.67 11.33 10.33 11.33 11.33 10.67 11.75 9 . 7 5 12.00 (0.47) (0.47) (0.94) (0.47) (0.47) (0.94) (0.83) (0.83) (0.71) b 12.00 11.75 12.00 13.00 12.75 11.80 12.00 12.67 12.50 (0.71) (0.43) (0.82) (0.71) (0.43) (0.40) (0.82) (0.47) (0.50) Internode length (cm) a 21.20 33.35 18.25 26.45 34.05 25.05 30.50 35.00 29.90 (0.60) (0.15) (1.15) (0.65) (0.15) (1.55) (0.90) (0.20) (0.70) b 47.55 62.65 49.80 51.65 62.95 45.30 57.55 60.00 53.45 (1.35) (1.25) (1.10) (1.05) (0.25) (1.10) (0.75) (0.30) (0.75)

234 Variation in Physical Pmpetties of Two Malaysian Bamboo Bamboo in the Asia Pacific Proceedings 4th International Bamboo Workshop, 1991

Table 2: Physical properties of the bamboo species

a 97.04 87.35 79.32 79.57 57.53 (21.62) (16.95) (15.47) (11.63) (11.96) b 108.34 96.20 90.51 91.47 75.96 (8.66) (11.09) (10.92) (7.12) (7.96) Ovendrydc a 43.00 46.33 49.67 49.33 62.00 (10.00) (5.00) (5.00) (5.65) (5.01) b 47.50 50.50 53.50 52.50 64.50 (3.50) (4.40) (3.30) (3.50) (4.50) Radial shrinkage (%) a 10.05 6.34 6.45 8.85 6.37 6.00 8.07 6.05 5.68 (0.55) (0.56) (0.25) (0.05) (0.07) (0.22) (0.05) (0.50) (0.28) b 14.55 10.65 9.85 14.40 10.60 9.40 12.20 9.95 6.60 (0.25) (0.25) (0.05) (0.20) (0.22) (0.51) (0.60) (0.15) (0.10) Tangential shrinkage (%) a 20.00 11.97 9.89 19.45 10.60 9.42 17.98 9.04 6.32 (0.10) (0.22) (0.09) (0.15) (0.20) (0.12) (0.11) (0.50) (0.10) b 19.15 17.40 15.55 18.23 16.60 14.90 18.35 15.70 14.05 (0.25) (0.20) (0.25) (0.56) (0.31) (0.30) (0.05) (0.10) (0.15) Remark: a = B. Wumeana b = G. scortechinii B = Butt M = Middle T = Top 0 = standard deviation Table 3: Summary of analysis of variance on physical properties of the bamboo species

Moisture content Density Age 2 535.86ns 15672.22** 1.532** 12.839** 409.78ns 13338.89* 8.004** 2.696** Height 2 a 1024.19ns 13605.56** 16.250** 190.390* * b 303.76ns 8822.22ns 40.1 go** 21.076** Age x Height 4 60.85 ns 3280.55** 0.403ns 0.566** ii 11.59ns 222.22ns 6.910** 0.189ns Remark: a = B.Wumeana b = G. scortechnli’ ns = not significant at P< 0.05 * = significant at P<0.05 ** = highly significant at P<0.01

Variation in Physical Properties of Two Malaysian Bamboo 235 Bamboo in the Asia Pacific Proceedings 4th International Bamboo Workshop, 1991

Table 4: Duncan’s new multiple range test on the, physical properties of the bamboo species

Moistum!content 64.72A (T) 79.OOA (M) 77.61A (3) 90.82A (B) 87.91A (1) 81.78A (T) 83.O9A (3) 89.11A (M) 85.45A (2) 96.OOA (B) 98.35A (1) 47.9OA (8) 46.35A (1) a 53.22A (M) 48.44B (2) 56.56A (T) 59.9oc (3) 51.83A (B) 50.5OA (1) b 55.83A (M) 57.OOA (2) 59.5OA (L) 59.67A (3) Radii Shtinkage 6.04A (rj 6.6OA (3) 6.25A (M) 7.07AB (2) 8.99B (B) 7.61 B (1) 8.61A (T) 9.58A (3) 10.40B (M) 11.478 (2) 13.71C (B) 11.68B (1) Tangential Shrinkage 8.54A (T) 11.12A (3) a 10.54B (M) 13.16B (2) 19.14C (B) 13.95c (1) 14.83A (T) 16.03A (3) b 16.578 (M) 16.58A (2) 18.58C (B) 17.37B (1) Remark: a = B. blumeana b = G. scortechinii(Means followed by the same letter(s) are not significantly different at P<0.05)

Table 5: Correlation Coefficients of physical properties on strength of the bamboo species

MOE a b Density a * b = b = ns = not significant at * = significant at ** = highly signifi- cant at

Table 6: Correlation of physical properties, on shrinkage of species . . : . . .

Moisture Content

Density *

= B. b = ns = not significant at * = significant at ** = highly sig- nificant at

236 Variation in Physical Properties of Two Malaysian Bamboo Bamboo in the Asia Pacific Proceedings 4th International Bamboo Workshop, 1991

A Hand Operated Bamboo Slicing Tool

Grewal, S., Mohd. Rashid Samad & Abd. Latif Mohmod*

Introduction Springs (Figure 12) Simple hand tools, in the traditional conversion of raw Two springs with an approximate compressive strength of 2 bamboo into various end-products commonly involve no 30 kg/cm should first be assembled with other compo- more than a machete or parang and a small knife. The nents. This is to ensure that any variation in the spring di- slicing of bamboo strips by these manual devices to the re- mensions can be adjusted accordingly in the ‘springbase quired thickness of about 0.2mm for the making of fine saddle’ (Figure 10) and the ‘spring bracket rest’ (Figure basketries and novelty items often requires longer time 13). and considerable skill. In order to obtain accurate and re- The purpose of the springs is to press down firmly and producible size strips, using a sharper knife may not ade- evenly (with the aid of the two spring holding down quate as this manual intensive slicing process could screws) the incoming feed-stock of the bamboo splits. This generate a fair amount of wastage and ununiform strip in turn will ensure the uniform size of the splits near the dimensions. cutter knife. In an attempt to produce uniform dimension (width and thickness) bamboo strips, a few bamboo sizing devices Bicycle Chain (Figure 1) were initially tried and modified. One set of thicknessing A bicycle chain of about 270mm length is required to pro- and width sizing tool was obtained from the Handicraft vide the drive. The chain should be obtained prior to mak- Training Centre in Kuala Pilah, Negeri Sembilan and ing the brass bearing holes (in Figure 2, they are shown another set of a different design was made based on draw- 75mm apart) and the ‘sprocket wheels’ (Figure 8). If the ings supplied by the Intermediate Technology Develop- length of the chain is somewhat in variance, either the 75 ment of England. These devices were predominantly mm spacing or the diameters of the sprocket-wheels have thickness and width sizers rather than slicers. Despite to be changed. To minimise any dimensional changes it some modifications, their performance was not found to is suggested that the above length be closely adhered to. be satisfactory. As a result of this modification failure, a new semi mechanised tool which could produce slices was designed and a prototype of this device is described in this Brass bearings (Figure 9B) paper. These can be easily turned and shaped as shown in the drawings. In this prototype, the brass bearings are made Bamboo slicing tool from the off cuts of the brass block Bl. Two general views of the tool are illustrated in Figures 1 and 2. The individual components of the tool are listed in Pressure feeder roller (Figure 9C) Table 1 and the detailed engineering drawings of the vari- This is turned from a 32mm diameter bar. The splints are ous parts are shown in Figures 3 to 16. Details of the im- about 3 mm high but the spacing (pitch) of 8mm should portant parts are given below: preferably be reduced to a give a less jerky feed.

Brass Blocks (Figure 3) Cutter-knife (Figure 16) The whole parts of the tool are assembled on two solid An ordinary wood planer of a 3mm thick, 50mm wide and brass blocks of a 50 mm square section. The main reason 165 mm long is used in this prototype. for using this brass block is to provide a smooth surface The knife may blunt fairly rapidly and during hand sharp- for the feeding and shaving of the bamboo splits. In pre- ening it is difficult to retain a perfect straight edge. Pref- liminary experiments using mild steel, it was found that erence should be given to a high-speed-steel knife and any the slicing process was disrupted due to the rough surfaces attempt to sharpen it should be done on a proper grinding of the block. machine having the facility to grind to variable angles - in The cost of brass can be reduced by using it only for the this case 15’. top surfaces with the remaining bulk being made up of The actual dimensional size of the knife is not critical. mild steel. It is suggested to use brass of about 10 mm in The thickness can vary from about 3 to 5mm and the thickness which is firmly screwed to a mild steel base. Bamboo in the Asia Pacific Proceedings 4th International Bamboo workshop, 1991 length can be as short as 60mm. The width, however should be 50mm; otherwise otherwise the configuration of General remarks the tool as a whole has to be changed. The position of the As designed, the tool can handle up to about 80 mm thick- knife-holding down Allen screws (see Figure 1) may have ness of the bamboo stock for the final output of 0.2mm to be adjusted for a different length knife. The screws thickness. nearest to the knife cutting edge should be retained and The stock piece should first be sized to the appropriate only the back screws could be shifted. The knife should It is important not to use dry be held down firmly to eliminate chatter. width before feeding in. bamboo as it could affect the bluntness of the cutter-knife. Furthermore, dry bamboo splits will not be suitable for in- Other components tricate basketry where considerable bending is required. The remaining parts of the tool are made from mild-steel The tool can also be motorised (a one-eight horse-power plates or bars of the appropriate thickness or diameter. motor will probably be adequate) with appropriate gear- The actual dimensions of the various screws and in some ing. The whole tool should be fixed to a heavy base by case their position is not too critical. The most important means of the brackets K, and then used at a convenient position is between the bottom roller and the knife cutting height. edge which should be on the very top of the free moving roller (Figure 16). The brass block Bl should not be too The total cost of the prototype, inclusive of the cutter, is far behind the knife edge as the former gives the necessary about M$ 280 (US$ 100). The cost can probably be re- support. duced by batch order or by the reduction of the brass- blocks to the suggested size.

Table 1: List of parts for fabricating the bamboo slicing tool Amount Figure 2 M 2 SIDE-BRACKET made of 5 mm thick plate(s). E welded bracket 2 mm plate. 3 L 2 SIDE-BRACKET made of 5 mm thick plate. 4 1 each BLOCKS made of mm solid square block 5A R 2 ROLLER HOLDING BRACKET made of 5 mm thick plate. 5B 1 ROLLER made of 20 mm diameter bar with a 6 mm diameter hole being drilled through. 6 K 2 HOLDING DOWN BRACKET made of 5 mm thick plate or cut out from the angle iron 7 1 HAND DRIVE ASSEMBLY consists of one 170 mm long, 25 mm wide handle and a brass grip turned from the off-cut of brass block plus a bolt and nut a S 2 SPROCKET WHEEL TURNED 55 mm diameter bar with shaped teeth to into the bicycle chain. ASSEMBLED FEED ROLLER, BRASS BEARINGS AND SPROCKET WHEEL. 0 4 BRASS BEARING turned, shaped and bored from the off-cut of brass block . 2 PRESSURE FEEDER ROLLER turned from 32 mm diameter bar with integral shaft. Shaft or left (Figure 1) is mm longer to the driving handle. 10 ss 2 SPRING BASE-SADDLE made by welding together the 4 mm thick plate with the upper (which turned from 32 mm bar). This dimensions of this portions depend on actual con figuration spring of the spring 11 N 2 SPRING HOLDING DOWN SCREW the screw is manually turned from a 15 mm bar. 12 2 SPRING with a compress& strength of about 30 13 2 BRACKET REST turned from a 30 mm bar. 14 Q 1 TOP BRACKET made of 5 mm thick plate. The top portion is turned from a 18 mm which consists of the threaded hole of 11 mm diameter. 15 2 SPACING BAR made of 15 mm diameter bar with 6 mm diameter hole tapped through. 1 BICYCLE CHAIN 270 mm long 16 1 CUTTER KNIFE a high-speed steel cutter with cutting angle of about 15”. 4 ALLEN SCREWS 5 mm diameter and 25 mm long for holding down the cutter knife. 32 SCREWS 6 mm diameter of about 15 mm 3 NUTS 6 mm internal thread (2 piece used at T position and 1 for brass-hand grip). 2 ALLEN SCREWS 5 mm diameter and 5 mm long to hold the sprocket wheel on shaft

A Hand Operated Bamboo Slicing Tool Bamboo in the Asia Pacific Proceedings 4th International Bamboo Workshop, 1991

Note: (i) Most unseen parts not shown (ii) Counter sunk screw positions of A, 9, C, D, HB not critical but should match corresponding threeded hole in brass blocks for screwing in (iii) F, G - are screws to hold bracket M in place through threaded bar & M on other side (may not be necessary) (iv) N should be positioned to centre on brass bearings (v) All screw holes countersunk and flush with surface for neat appearence

Figure 1: Assembled side view of Bamboo Slicer

Notes: (i) The bracket can be made from single 5 mm thick plate or two plates welded as indicated (ii) The side angle is preferably welded on to M (iii) The bearing holes are drilled accurately to receive brass bearings and partially filed level for smooth vertical movement of bearing (iv) F and G (corresponding to screws in assembled DRG. 1 ) are 6 mm holes for holding M steady in place with spacer

Figure 2: Top side Bracket (two pieces) M.

Notes: (i) Holes A, B, C, D for screwing bracket into brass blocks. Actual positions not important (after making bracket, clamp .to brass-blocks and drill together for proper centering) (ii) Side angle to bracket can be formed from separate piece by welding (iii) Allen headed nut (knurled for hand turning) is about 5 mm diameter (iv) Hole E is to receive hole from top side-bracket (of bracket Q) and screwed together to brass block 92

Figure 3: Bottom side Bracket (two pieces) (L)

A Hand Operated Bamboo Slicing Tool 239 Bamboo in the Asia Pacific Proceedings 4th International Bamboo Workshop, 1991

SIDE VIEW OF BRASS BLOCKS

Top VIEW OF BRASS BLOCKS

Figure 4: Brass Blocks (B1 and 82)

with far shaft

Figure 5A: Roller Holding Bracket (2 pieces) R Figure 5B: Roller (RR)

I . L 5mm thick ---50mm- - angle

SIDE VIEW FRONT VLEW

OBOVE BRACKEIS A R C SCREWED INT0 B R A SS BL OCKS (B1 AND 8 2 ) AND THEN SCREWED T O WORK TABLE.

Figure 6: jig Holding Down Bracket (2FC) [K] Figure 7: Hand Drive Assembly

240 A Hand Operated Bamboo Slicing Tool Bamboo in the Asia Pacific Proceedings 4th International Bamboo Workshop, 1991

------25

I

Figure 8: Sprocket wheel (2 pieces) (S) shape is Figure 9A: Shaft Bearin and Feed Roller with approximate only Sprodcket Wheel Assembly (2 pieces)

In housing Roller side 30 mm dia(to hold spring saddle) Shaft (12 mm dia)

Figure Brass Bearing 88 (16 mm long) Figure 9C: Pressure Feeder Roller FR

Figure 10: Spring Base Saddle (2 pieces) (SS) Figure 11: Spring Holding Down Screw (2 pieces) N

to fit rut.

Figure 12: Spring (2 pieces) Figure 13: Bra&et Rest on top of Spring (2 pieces)

A Hand Operated Bamboo Slicing TooI 241 Bamboo in the Asia Pacific Proceedings 4th International Bamboo Workshop, 1991

fur 0 0 0

0 I

Figure 14: Top Bracket Q (2 pieces)

Figure 15: Spacing Bar (for screws F.G) Figure 16: Cutter Knife (in relation to Brass Block and Roller)

242 A Hand Operated Bamboo Slicing Tool Bamboo in the Asia Pacific Proceedings 4th International Bamboo Workshop, 1991

Field Evaluation of Preservative Treated Bamboo

R. Gnanaharan*

Introduction The preservative treatment, for ready acceptability by the Bambusa arundinacea, the thorny-bamboo, is the most rural people, should be simple to carry out; the chemicals commonly occurring bamboo in Kerala. Like any other should be readily available and safe to handle and the cost major bamboo species, this also has hundreds of uses. One of treatment should be minimal. From the available in- use is as banana prcps. Commercially important banana formation in the literature, the simplest methods for treat- plants laden with heavy bunch are prone to dislodging ing dry bamboo and green bamboo are soaking and during heavy wind. Bamboo poles, in round form or steeping respectively. In the soaking method, dry bamboo half round form, are generally used as props. As the is kept completely immersed in water borne preservative poles are in contact with wet ground, they are highly sus- solution for a period of time till adequate chemical is ceptible to decay. The service life of such poles does not picked up. In the steeping (sap displacement) method, extend beyond one or two seasons (about six to eight green bamboo culms are allowed to stand vertically in the months each). If the service life of bamboo could be in- preservative solution till the chemicals displace the sap. creased, the farmer can bring down the cost of cultivation However, in a rural set up, both these methods may not be of banana and increase the net profit. suitable. It may not always be possible to get green bam- boo in the market. On the other hand, the soaking method The thorny branches are used as fence material. To keep for treating air dry bamboo calls for a large tank which the branches in place, bamboo strips (quarter split bam- could cover the full length of the pole to be treated. As a boo) are used. They are susceptible to the attack to borers compromise, it was decided to treat only the butt ends of and fungi. Maintenance cost of the fence can be brought the air dried bamboo poles by keeping the poles vertically down if the service life of these strips is extended. in the preservative solution in an old oil drum. Even though the treatment by this method would not be that ef- Untreated bamboo, in ground contact, has only one to two fective as that of complete soaking or sap displacement years service life (Tewari and Singh, 1979). However, the method, it was decided to evaluate this simple method. service life can be increased by treating the bamboo. Also, treated bamboo props do not need to last for 15-25 There are two major categories of treatment - non- years because handling the props after every season and chemical and chemical (Liese, 198 1). Non-chemical treat- weathering will lead to mechanical failure much before ment include traditional methods like clump curing, that. What we need is for bamboo to last for about six to smoking, white washing, soaking, etc. Sulthoni (1987) eight seasons (4-5 years effective service life). The advan- claimed the adequacy of immersing Dendrocalamus asper tage are, old drums are easily available and portable, and in water for a month to protect it from powder post the treatment of partially dried or dried bamboo can be beetles. To get effective protcctron, bamboo should be carried out anywhere. The same method is applicable to treated with preservative chemicals; a number of methods green bamboo also. are available to treat bamboo either in green condition or in air dry condition (Liese, 198 1). Materials and methods Purushotham et al (1953) improved the Boucherie method Bambusa arundinacea poles were purchased form the for treating green bamboo by employing pneumatic pres- market. Some poles were split into two and some into sure. This helped in reducing the treatment time to few four depending on the wall thickness. The round and hours instead of several days. Singh and Tewari (1980; half-round poles were evaluated in ground contact, the 198 la; 198 lb) tried different methods like sap displace- quarter split strips in out of ground contact. ment, soaking, osmose diffision, double diffusion, and steaming and quenching for treating green bamboo. They The following unisalt and multisalt preservative chemicals tried soaking, open tank (hot and cold bath) and pressure were used for the treatment: A) copper sulphate; B) zinc methods for treating air dry bamboo (Singh and Tewari, chloride; C) boric acid borax; D) chromated zinc chloride; 1979). E) acid-cupric chromate (ACC) and F) copper chrome bo- ric (CCB). A 10% solution of the above chemicals was prepared and the butt ends of the poles were kept

*Kerala For&t Research Institute, Peechi 660 653, Kerala, India Bamboo in the Asia Pacific Proceedings 4th International Bamboo Workshop, 1991 immersed in the chemical solution for seven days. The One control pole lasted about one year and by the end of quarter split strips were inverted every 24 hours. Also, two years all the round poles and three of the half round the chemical solution was poured on the middle portion. poles of control failed. This shows that untreated B. arun- The retention of dry chemical in the treated bamboo was dinacea poles, in ground contact, have a service life of determined. about one to two years. The butt ends of the treated poles and control (4 each) 4t the end of two years, boric acid treatment did not give were brushed with one coat of waste engine oil and placed satisfactory performance. It is possible that most of the bo- in ground contact. The treated strips and control strips ric acid would have leached out. However, addition of so- were placed on a stand and kept in the open. Observa- lium dichromate, either to copper sulphate (ACC) or zinc tions on insect and fungal attack were make on the poles :hloride (Cr-ZnCl2) to fix these chemicals, did not im- and strips every month in the first year and then quarterly. prove their performance. The unisalt preservatives, copper Whenever the poles dislodged due to decay, termite at- sulphate and zinc chloride performed better than tack, etc., they were noted down. chromium-based multisalts, ACC and Cr-ZnCl2. At the end of 24 months, the out-of-ground contact strips After two years, rate of dislodging of poles was much fast- were ground to powder and solubility in 1% caustic soda er. Boric acid (C) and chromated zinc chloride (D) was determined as per the ASTM method (ASTM 1981). reached 75% failure at the end of 27 months. Acidic cop- per chromate combination gave protection to 25% of the The results were statistically analysed. poles for about 33 months. Zinc chloride treatment, which gave better performance at the end of 24 months Results and discussion did not perform well at the end of 36 months, resulting in 75% failure. Preservative treatment The total number of months of service life obtained for the By the time the poles (3 m long) were brought to the labo- poles in each treatment at the end of 39 months was ana- ratory from market, about 10 days had gone by since fell- lysed statistically (Table 3). ing the culms and the average moisture content was 13.8%. Control was not significantly different from chromated zinc chloride or boric acid treatment. Among the other The retention of dry chemical (as percentage of dry four treatments, CCB, ACC and zinc chloride did not dif- chemical weight to dry bamboo weight) in the treated fer from each other significantly. Treatment with copper bamboo is given in Table 1. It varied widely form 0.27 to sulphate differed significantly from other treatments ex- 1.19% in round bamboo, from 0.22 to 1.67% in half round cepting zinc chloride. Between copper sulphate and zinc bamboo and from 3.58 to 7.67% in quarter-split strips. chloride, retention of zinc chloride was at a higher level. CCB pickup was the lowest in all the three cases. In gen- Also, copper sulphate is much cheaper compared to zinc eral, copper sulphate based preservatives had low chemi- chloride. As it is a fungicide, copper sulphate would have cal pickup. This may due to the tendency of copper a better control of decay than zinc chloride, which is basi- sulphate to precipitate in contact with the hydroxyl groups cally an insecticide. Even if a major portion of copper of bamboo. Diffusible chemicals like boric acid had the sulphate (average dry salt per pole was about 35 to 45 g) highest pickup. In half-round poles, as compared to round gets leached out into the soil when the poles are used as poles, chemical pickup increased in the case of zinc chlo- banana supports (banana is planted in 2 m x 2 m spacing ride, chromated zinc chloride and boric acid. and the amount of soil available for each plant up to 1 m depth is 5 to 6 tonnes), it will not be harmful (45 g CuSo Even though chemical retention in round and half-round 4 in 5 to 6 tonnes will be less than 10 ppm) to the banana poles is low, when we consider that most of these chemi- plant. cals are in the butt ends, the dry salt retention in the butt ends could be in the order of 10 to 20 kg/m’. Chemical pickup of dry bamboo will be lower in the dipping method Out-of-ground contact as compared to soaking method. However, soaking meth- No borer attack was noticed on the strips. As the strips od will result in having lot of chemical in the above were kept on a stand, there was no termite attack also. ground portion of the pole also which may not be The major deteriorating factor was decay. necessary. Data on solubility in 1% caustic soda at the end of 24 Ground contact months are shown in Table 4. Higher the solubility, high- er is the degradation. In general, there was no borer attack on the poles. Decay was the major causal agent deteriorating the bamboo. All the treatments fared better than control. No chemical Termite attack was also quite prevalent. The progression treatment (A-F) was statistically different from one anoth- of the poles dislodged (out of four each) with time is given er. Boric acid, which has both and insecticidal in Table 2. properties, can be preferred over other chemicals. Also, it is one of the cheaper chemicals and easily available. As

244 Field Evaluation Of Preservative Treated Bamboo Bamboo in the Asia Pacific Proceedings 4th International Bamboo Workshop, 1991

the treated strips are not in ground contact, leaching of boric acid will not be a major problem. References Liese, W. 1981. Bamboo: Methods of treatment and pres- ervation. Gate No. pp 9-l 1. Conclusion Purushotham, A.; Sudan, S.K. and Sager, B. 1953. Pre The field experiment on the efficacy of chemical treatment servative treatment of green bamboo under low pneumatic has shown that treating bamboo poles with 10% copper pressures. Indian Forester sulphate solution (keeping the butt ends immersed in Singh, B. and Tewari, M.C. 1979. Studies on the treatment chemical solution for seven days) can extend its service of bamboo by steeping, open tank and pressure pro- cesses. Journal of the Indian Academy of Wood Science life in ground contact considerably. For strips in out of ground contact, treatment with boric acid will give ex- Singh, B. and Tewari M.C. 1981a. Studies on the treat- tended service life. ment of green bamboo by different diffusion processes. Part I Dip diffusion and Osmose process. Journal of the The treatment method suggested in the study can be car- Timber Development Association of India ried out for treating both green bamboo and dried bamboo. Singh, and Tewari, M.C. 1981 b. Studies on the treat- It is easy to treat and as oil drum used for treatment is ment of green bamboo by different diffusion processes. portable, the treatment can be carried out anywhere. Part II Steaming and quenching and double diffusion. Journal of the Timber Development Association of India 2): 38-46. Acknowledgements Sulthoni, A. 1987. Traditional preservation of bamboo in This work was carried out as part of a project funded by Java, Indonesia. In AS Rao, G Dhanarajan and CB Sastry the International Development Research Centre, Canada (Eds), Recent Research on Bamboo. CAF, China and and the financial support is gratefully acknowledged. Mr. IDRC, Canada. pp 349-357. Thulasidas provided technical help in carrying out Tewari, M.C. and Singh, B. 1979. Bamboo their utilisation the study and this is acknowledged with thanks. and protection against biodeterioration. Journal of the Timber Development Association of India

Field Evaluation Of Preservative Treated Bamboo 245 Bamboo in the Asia Pacific Proceedings 4th International Bamboo Workshop, 1991

Table 1: Retention of chemical (as percentage of chemical weight to bamboo weight)

Round A) 0.39 0.30 4.65 1.09 1.67 7.67 1.19 1.50 7.21 0.69 1.06 7.13 ACC 0.49 0.42 6.10 0.27 0.22 3.58

Table 2: Poles in ground-contact dislodged with progression time (in months)

Time G 0 U 0 U 12 1 15 1 18 2 21 2 24 4 27 1 4 30 1 4 33 1 4 36 3 4 39 3 4 A B C D E ACC; F CCB; Control; o round pole; u half round

Table 3: Service life of poles in ground contact (at the end of months)

Treatment Service life (months) 34.9

ACC CCB

Control 1 Values having the same superscript are not significantly different

Table 4: in 1% caustic soda

Treatment Control 33.1" CCB

ACC

Fresh bamboo 18.2' Remark Values having the same superscript are not significantly eferent

246 Field Evaluation Of Preservative