Schizostachyum zollingeri Steudel
Syn. pl. glumac. 1: 332 (1854).
Gramineae
2n = unknown
Origin and geographic distribution
S. zollingeri occurs naturally in Indonesia (Java, Sumatra), Peninsular Malaysia, Vietnam and southern Thailand. For map click: Map524.TIF. In Peninsular Malaysia it is also often cultivated in villages, especially in Perak and Perlis, in Indonesia (Java) in the eastern part of East Java.
Uses
The culms are commonly split and woven into screens which serve as walls, floors, roofs, mats and for handicrafts. They are also used for weaving baskets and fishing screens and to make rafts, small implements and containers to prepare the traditional rice food (lemang) in Malaysia. Young shoots are edible but not commonly eaten. S. zollingeri is sometimes planted for ornamental purposes.
Production and international trade
Production, consumption and local trade are probably considerable, especially in rural areas, but no statistics are available. The bamboo screens of S. zollingeri are very popular in housing and constructional work for parts that are not meant to carry weight. The only cultivation is small-scale.
Properties
The woven screens of split S. zollingeri culms are strong, flexible and versatile, but no figures on strength are known. The following chemical data for the culms have been reported: holocellulose 68.8-74.3%, lignin 20.1-22.7%, sugar 0.03-0.05%, starch 0.013-0.016%; the solubility in cold water is 2.7-5.4%, in hot water 3.7-6.5%, in alcohol-benzene 2.2-2.7% and in 1% NaOH 21.8-26.8%. The culms are reported as promising as a raw material for paper and pulp.
Description
Densely tufted, sympodial bamboo. Culm stiffly erect with slender drooping whip-like tips, (4-)10-15(-19) m tall, (1.5-)4.5-7.0(-10.0) cm in diameter, wall thickness 4.6-13.9 mm (base), 1.5-3.3 mm (apex), when young with short appressed pale hairs and a distinct pale white waxy zone just below each internode; internodes 46-80 cm long. Branches arising from the midculm nodes upward, comprising 25-30 slender subequal branches at each node. Culm sheath with rounded top, up to 15 cm long, stiff, long persistent, light brown or flushed with purple near top when young, the back more or less covered with appressed shiny dark brown to black hairs; blade rigid, erect, broadly triangular, 7-9 cm x 7-9 cm (lower ones wider than long), strongly convex, stiffly pointed, flushed with purple when young, upper surface covered with pale hairs; ligule up to 4 mm long, edge smooth or covered with short hairs; auricles up to 7 mm or more tall, spreading laterally beyond the width of the top of the sheath or sometimes smaller, margins with very close, curved, slender bristles. Young shoots light to dark brown. Leaf blade oblong-lanceolate, (12-)20-35(-40) cm x (1-)2-4(-6.5) cm, lower surface glabrous or slightly hairy, more or less rough to the touch, upper surface smooth; sheath hairy when young; ligule short; auricles usually well-developed, sometimes spreading laterally, brown, bearing many slender bristles. Inflorescence consisting of dense tufts of pseudospikelets 1-3 cm apart at the nodes on the rigid distal part of a leafy branchlet (or, in gregarious flowering, on long leafless branches); spikelet 15-20 mm long, comprising 2 basal glumes, 1 perfect floret and a rachilla extension bearing a small rudimentary floret. Caryopsis ellipsoidal, c. 6 mm x 3.5 mm, with persistent style of 9-10 mm, dark green to purplish.
Growth and development
About 4 days after sowing the coleorrhiza and primary root emerge from the base of the grain, followed by elongation of the primary root and emergence of the coleoptile. By the end of the 2nd week, shoot segmentation has become distinct with elongation of the shoot, and the first leaf has fully expanded. In the 6th week the 5th and 6th leaves develop and the culm is about 10 cm tall.
The rhizome is gradually built up by the successive emergence of new culms from the bases of preceding ones. Culms that emerge become progressively larger until they are of full size in mature clumps, a phase reached after some years. Many of the earlier culms have died by then.
Culm cuttings take about 1 year to establish and produce full size culms after 3 years.
Shoots of natural stands emerge above the ground during the onset of the rainy season and develop to their full height in 5-6 months. The lateral branches develop subsequently. A culm becomes mature in 3 or more years. A healthy mature clump has 50-70 culms.
S. zollingeri flowers sporadically every year in practically all areas. Annual gregarious flowering during the dry season and over a 2-3 month period is reported from the northernmost part of Peninsular Malaysia (Mata Air district). In sporadic flowering, fruit formation is rare, after gregarious flowering, fruits are abundant. During the flowering period, bees (Apis sp. and Trigona sp.) were active between about 9:30-10:30 a.m. in northern Peninsular Malaysia and in East Java. After flowering and fruiting a culm dies but the rhizome remains alive and regenerates new culms.
Other botanical information
S. zollingeri is a variable species. In Java the culms have a smaller diameter (1.5-5 cm) and in the florets the lemmas and lodicules are smaller. Also in Peninsular Malaysia culm diameter decreases in specimens collected from north to south. Young culms can be conspicuously glaucous or less so and bear sparse pale hairs. The culm sheath auricles are sometimes rather small. In general, S. zollingeri is easy to recognize by its drooping whip-like culm tips, the presence of the dark shiny hairs on the culm sheaths and the peculiar shape of the blades of the culm sheaths (inflated, 1-3 times as long as wide).
Ecology
In the wild, S. zollingeri can be found in primary forest (northern Peninsular Malaysia), but more often in disturbed areas (forest edges, forest clearings), normally between 50-200 m altitude, but up to 400 m altitude is possible. It will grow in any type of well-drained soil, preferring sandy loams or clay loams. In Peninsular Malaysia S. zollingeri is often growing together with Gigantochloa ligulata Gamble. In East Java, S. zollingeri is resistant to long droughts.
Propagation and planting
S. zollingeri can be propagated by seed and by rhizome or culm cuttings. Seed should be sown as soon as possible after harvesting but a short period of storage is possible (at 12-14ºC, moisture content about 15%: germination rate more than 80% after 1 month, more than 50% after 2 months). For large-scale planting, culm cuttings taken from the top and middle portions are commonly used and show nearly 100% survival. The propagules are raised in the nursery for about 5 months and transplanted in the field in the rainy season. They are planted in holes enriched with organic and chemical fertilizer at a spacing of 4-6 m x 4-6 m.
Husbandry
Young plants require regular watering during the period of establishment and in that period are weeded twice a year. For 2 years after planting the clumps are thinned by removing poor culms. Fertilizer is applied to mature clumps in two doses, one before and one during the rainy season. For average soils, per clump 100-600 g NPK (15:15:15) per year is recommended.
Diseases and pests
No disease or pest problems on S. zollingeri in the wild have been reported. In the nursery and at planting sites, however, leaf roller infestation may cause damage. This pest is the caterpillar of the butterfly Pyrausta coclesalis (Pyralidae). It can be effectively controlled by spraying with systemic insecticides.
Harvesting
Culms are usually harvested all year round but mostly in the dry season (in Perlis, northern Peninsular Malaysia, from November to April). Culms should be 3 years old or older. Harvested culms are air-seasoned.
Yield
A well-managed, mature clump can produce 5-8 culms/year, or, with 400 clumps, 2000-3200 culms/ha. A green culm weighs (2.0-)8.6(-17.7) kg. Branch and leaf weight averages 5.2 kg (1.6-9.5 kg). Green culm production per year can be 17-27 t/ha.
Genetic resources and breeding
In Lampung (Sumatra) a small germplasm collection of S. zollingeri is available. There are no breeding programmes.
Prospects
The prospects for S. zollingeri are very promising because the strong flexible screens made from its culms are in great demand. Many aspects, however, still require investigation, e.g. reliable cultivation methods, management of wild and cultivated populations, fertilizer requirements, harvesting and post-harvest technology. More germplasm collection is urgently needed.
Abd. Razak Othman
For additional information about author(s) see Contributors or Editors.