Arundinaria pusilla (PROSEA)

Plant Resources of South-East Asia Introduction

List of species

Arundinaria pusilla A. Chevalier & A. Camus

Protologue: Bull. Mus. Hist. Nat. Paris 27: 450 (1921).

Family: Gramineae

Chromosome number: 2n= unknown

Vernacular names

• Bamboo grass (En)
• Philippines: utod (Igorot)
• Cambodia: rüssèi préïch
• Laos: ph'ek
• Thailand: ya-phek, ya-phet
• Vietnam: le, truc th'ao.

Origin and geographic distribution

A. pusilla occurs in South-East Asia, particularly between latitudes 13-17°N in Thailand and Indo-China.

Uses

A. pusilla is primarily used for traditional grazing of village cattle and buffaloes, particularly on new growth at the onset of the rainy season.

Properties

Leaves are palatable but stems rapidly become woody and unacceptable to livestock. Leaves collected at the beginning of the rainy season contain up to 1.7% N with 52% organic matter digestibility. The average dry matter intake by sheep is 620 g/head per day. When mixed with Stylosanthes hamata (L.) Taub. cultivar "Verano" and Arundinaria ciliata A. Camus, it can produce enough feed to support cattle at 1.2-1.8 animals per ha throughout the dry season of north-eastern Thailand.

Botany

A shallow rooting, erect, perennial bamboo with short, strong woody rhizomes; leafy stems 0.5(-1.5) m tall and up to 8 mm diameter, branching at the nodes. Leaf-blade 8-14 cm × 1 cm, contracted into a short stalk at the junction with the sheath, pubescent, acuminate at the top. Flowering stems 15-75 cm long, often fascicled on the rhizome clumps of burned plants, usually without leaves. Inflorescence narrow, consisting of 2-8 groups of 1-5 spikelets in the axil of a glume-like bract or sometimes on a short stalk. Spikelets 3-4 cm long with 7-9 florets, the lowest 3-5 bisexual, the upper ones male, the terminal one sterile; styles 3, stamens 6. Little or no seed is produced.

In Thailand, it flowers in February and March.

Ecology

A. pusilla is adapted to warm environments with a short wet and a long dry season at altitudes from sea-level to 1500 m. It tolerates moderate shade but is intolerant of waterlogging. It is usually found in Dipterocarpus forests, growing as a lower canopy, on moderately acid upland soils.

Agronomy

A. pusilla spreads naturally by short rhizomes, but can be propagated by dividing clumps of roots and stubble, or by stem cuttings. Light grazing is recommended as it is intolerant of heavy grazing. It is not used in cut-and-carry systems and is not suitable for making hay or silage. Edible DM yields range between 0.8 and 2.5 t/ha per year.

Genetic resources and breeding

It is unlikely that substantial germplasm collections are being maintained.

Prospects

A. pusilla is usually not cultivated and its use is limited to grazing. Its value increases when grown with suitable legumes.

Literature

• Camus, E.G. & A., 1923. Graminées. In: Lecomte, H. & Gagnepain, F. (Editors): Flore générale de L'Indo-Chine. Tome 7(5). pp. 585-587.
• Gutteridge, R.C., Shelton, H.M., Wilaipon, B. & Humphreys, L.R., 1979. A comparison of cattle liveweight gains on native and improved pastures in northeast Thailand. Annual Report Faculty of Agriculture. Khonkaen University, Thailand.
• Manidool, C., 1989. Natural grassland and native grasses of Thailand [in Thai]. Technical Bulletin No 1301-26-32. Division of Animal Nutrition, Department of Livestock Development, Bangkok. 45 pp.
• Manidool, C. & Tor Sakool, P., 1971. Digestibility of pek grass (Arundinaria pusilla). Thai Journal of Agricultural Science 4: 119-124.
• Robertson, A.D. & Humphreys, L.R., 1979. Effects of frequency of heavy grazing and P supply on Arundinaria ciliata association oversown with Stylosanthes humilis. Thai Journal of Agricultural Science 9: 131-138.

Authors

C. Manidool