Melocanna baccifera
VERNACULAR NAMES Assam - Tarai; Bengal - Muli; Cachar - Wati; Garo - Watrai; Manipur - Moubi; Mikir - Arten; Nagaland - Turiah; Sylhet - Bajail; Dhaka - Nali. DESCRIPTION Evergreen bamboo, clump diffuse. Culms 10-20 m high, 3-7 cm diameter, green when young, straw coloured when old; longest internodes 20-25 cm long. Culm-sheaths 10-15 cm long, yellowish green when young and yellowish brown on maturity, brittle, striate, truncate or concave at the tip, glabrous or sparsely with whitish appressed hairs on the back. Ligule very short with undulated or toothed margin, auricles small, sub-equal, membranous, fringed with silvery bristles; blade deciduous, usually 15-30 cm long, 2-3 cm broad, subulate. Young shoots smooth, light purple or purplish green; ligule with long hairs, soon caducous, blades linear, green. Leaves 15-30 cm long, 2.5-5 cm broad, oblong lanceolate, apex acuminate, leaf sheath thick, ligulate; auricles very small with silvery bristles. Inflorescence a large compound panicle of one-sided drooping, spicate branches, bearing clusters of 3 to 4 spikelets in the axils of short, blunt, glabrous bracts, empty glumes 2-4. Palea glabrous, convolute, mucronate, acuminate not keeled. Lodicules 2, narrow, linear-oblong, obtuse and erose-fimbriate at the tip. Stamens free at base or irregularly joined, filaments flat; anthers yellow,notched at the apex; ovary ovoid; style elongate, divided in to 2-4 hairy recurved stigmas. Caryopsis very large, fleshy, pear-shaped, the stalk is inserted at the thick end and the apex terminates in a curved beak. The species can be recognised easily by diffused clump habit, having culm-sheath straight for about two-third of the way up, then once or twice transversely waved with subulate flagelliform blade (Alam, 1982). Chromosome number 2n = 72. FLOWERING AND FRUITING Flowering has been reported during 1863, 1866, 1892, 1893, 1900-1902, 1910-1912, 1933 and 1960 (Chatterjee, 1960; Vaid, 1972). Sporadic flowering was reported in Cachar and Manipur in 1967 (Nath, 1968). Sharma (1992) reported flowering at FRI, Dehra Dun. Flowering and fruiting was observed at Pune during 1993. Length of flowering period according to Gamble (1896) is 30 years, according to Kurz (1876) is 30-35 years, according to Troup (1921) is about 45 years. Culms and rhizomes die after flowering. Profuse natural regeneration has been observed. Seed is green, smooth, sessile, very large having a mid length and diameter of 6.9- 7.2 cm and 4.1-4.3 cm, respectively; obliquely ovoid, thick fleshy, onion shaped and the apex terminating in a curved beak. There is no endosperm in the ripe seed, but it has a 7-13 mm thick white to creamy coloured fleshy pericarp filled with starch just below the green surface of the seed. A more or less round shaped white-coloured embryo with a broad fleshy cotyledonary body is present inside the seed cavity. The fruit is not a true caryopsis, it can be termed as a bacciform caryopsis. Vivipary is observed. DISTRIBUTION AND ECOLOGY The species is distributed in India, Bangladesh and Myanmar, cultivated in many Asian countries. In India, it is mainly seen in Assam, Manipur, Meghalaya, Mizoram, Tripura, West Bengal and other parts of Eastern India in the plains and low hills (Biswas et al., 1991). Also found in Singtam, East Sikkim. Seen in cultivation in Maharashtra and parts of Karnataka. It grows almost equally on the well-watered sandy clay loam, alluvial soil and on the well drained residual soils consisting of almost pure sand even at the summits of the low sand stone hills. It springs up in practically pure patches where natural forests have been cleared for agricultural purposes (McClure 1966). ANATOMY AND FIBRE CHARACTERISTICS The epidermis is made up of long cells alternating with short cells longitudinally. The long epidermal cells uniform in width (about 7.4 µm) with undulating walls, vary in length from 16.5 µm-122 µm. The cell wall thick and septa-like partitions absent. One pair of short cells alternate with an epidermal cell, two pairs of short cells present occasionally. The cork cells small and rectangular or reniform. Silica cells very small, angular or rectangular. The average number of short cell couples is 1894 per mm2. Bicellular and fan-like hairs common often occurring in place of short cells. Spines present, few, mostly solitary, as many as 22 per microscopic field (0.17 mm2). The average number of stomata 10 per field (Ghosh and Negi, 1960). In culm macerates three fibre types are seen; very thick, thick, and thin walled. Septate fibres absent, fibre tips pointed, blunt or forked and wall lamellation 4-7-layered. Slenderness ratio 142.2, flexibility ratio 75.6, Runkel ratio 0.8, fibre length 2.68 mm; fibre diameter 14.37 µm, lumen diameter 4.08 µm, wall thickness 5.15 µm, parenchyma 20 per cent (Singh et al., 1976). CHEMISTRY Proximate chemical analysis showed ash 1.9 per cent, cold water solubles 3.25 per cent. hot water solubles 6.4 per cent, alcohol benzene solubles 1.43 per cent, ether solubles 0.81 per cent, caustic soda solubles 18.97 per cent, pentosans 15.13 per cent, lignin 24.13 per cent, cellulose 62.25 per cent (Bhargava, 1945). Analysis of hemicellulose showed 17.3 per cent yield with the following sugars, pentosans 79.8 per cent, methoxyl 0.8 per cent xylose 79.4 per cent, arabinose 79.4 per cent, rhamnose 0.2 per cent, glucose 16.2 per cent, glucuronic acid 2.1 per cent (Rita Dhawan and Singh, 1982). Beating characteristics of the species showed caustic soda 25 per cent; kappa no.25; lignin in bamboo 27 per cent, in pulp 4.1 per cent, pentosans in bamboo 19.6 per cent, in pulp 15.5 per cent, pulp yield unscreened 43.9 per cent, screened 43.8 per cent (Bose et al., 1988). Spectral absorbance value of cellulose 0.275, lignin 0.255 (Sekar and Balasubramanian - personal communication). SILVICULTURE AND MANAGEMENT One clump produces about 5-7 Kilogram of seeds. Average seed weight is about 55.3 g. In a sample of 1000 seeds, the length, diameter and weight varied from 3.6- 10.9 cm, 0.2-6.1 cm and 7.8-150.6 g, respectively. Freshly collected seeds have high viability (78.4%). Under normal conditions the viability is for about 35 days. Storage under air dry condition prolongs viability to 45 days and storage in dry sand in jute bags upto 60 days (Banik, 1991). Seeds have a high germination percentage under shade (negatively photoblastic). Mature seeds germinate even in storage. Number of shoots produced from a single seed vary from 1-6. Fresh seeds start germination within 5-7 days and continue for the next 20-25 days. Shoots are thick (4-6 mm) soft and conical in shape. Germination is hypogeal. Survival and health of seedlings are influenced by seed weight. Seeds can be classified into three grades according to weight. Seedlings from the medium and light seeds develop abnormalities like stunted radicle, albino forms, leafless plumule and radicles growing upward. Generally 1 to 2 plumules develop and form 1-2 stems. Soon after 2-3 weeks of germination fibrous roots develop from the base of young shoot. Shoots emerge successively, new shoots are taller and bigger, biomass gradually increases, recording 86.7g in about 10 months. Rhizome development starts within 40 days after germination. The leaves produced by seedlings are bigger than the mature leaves (Banik, 1991). Seedlings are kept in the nursery for 10-12 months before planting in the next rainy season. To prevent interlogging between seedlings, they are transplanted to other beds after six months. Pruning of the three months old seedling stem tip induce bud activation. The excised seedlings become woody and it minimises seedling damage during transportation (Banik, 1991). This species is easy to regenerate from rhizomes. Rhizomes with one to two buds may be planted at a spacing of 4 to 5 m. Using culm cuttings rooting up to 75 per cent is obtained from two-year-old culms. Such propagules produce on an average 20 culms after 4 years of transplanting (Saharia and Sen, 1990). Treatment with growth regulating substances enhances rooting response. The offsets can be planted during April to June. Younger offsets of about oneyear-old showed better survival than the older ones. It is better to plant 2-3 offsets at a time than a single offset. Due to elongated rhizome necks, the culms are produced at varying intervals in all directions forming a diffuse and open type of clump formation, which can accommodate the space required for the increased number of culm production in later years. Due to this type of growth, the pattern of clump expansion is different in this species. PESTS AND DISEASES Root rot caused by Poria rhizomorpha, has been reported from North Bengal and Assam. Emerging culm mortality (about 10%) is reported (Banik, 1983). PHYSICAL AND MECHANICAL PROPERTIES Strength properties tested under air dry condition showed a moisture content of 12.8 per cent, specific gravity 0.751, fibre stress at elastic limit 43.4 N/mm2, modulus of rupture 57.6 N/mm2, modulus of elasticity 12.93 kN/mm2, compression strength parallel to grain 69.9 N/mm2. USES This species is used for building houses, for making woven ware and as an important source of superior paper pulp. Highly suitable for kraft paper making. The culms are strong, durable with inconspicuous nodes. 'Tabasheer' an ancient elixir of Manipur can be isolated from the culms and branches. Fruits are edible. The culms are used for making floats to transport wooden logs. Enormous logs can be transported by these floats. |
Fig. 54. M. baccifera.
M. baccifera - Natural growth
Mq. baccifera -
Internode with culm sheath
