A tree of langsat
Synonyms: Aglaia dookoo, Aglaia domestica, Aglaia aquea
Other names: Duku, kokosan, Lansones
Langsat is a fruit from the South East Asia. It is planted sporadically throughout the tropics; commercial production is mostly in Thailand, Malaysia, Indonesia, the Philippines, and Vietnam. It is also planted on small scale in South India.
Fruits of langsat
A large tree upto 30 m tall (5-10 m only when under cultivation), trunk 75 cm in dia.; bark mottled grey and orange, furrowed, containing milky sticky resinous sap.
Leaves alternate, odd pinnate, 30-50 cm long, glabrous to densely pilose, petiole upto 7 cm long; leaflets alternate, 6-9, elliptical to oblong, 9-21 cm x 5-10 cm, glossy.
Leaves of a langsat tree
Flowers bisexual, sessile to pedicelled, solitary, small; borne on fascicles of 2-10 on trunk or large branches; calyx fleshy, cup-shaped; petals fleshy, erect, ovate, white to pale yellow.
Fruits an ellipsoid or globose berry, upto 3-7 cm x 2-5 cm, yellowish, pubescent, calyx persistent with reflexed lobes; fruit wall of variable thickness (1-6 mm).
Seeds 1-3, enveloped by a closely adhering, thick, flesh, translucent white aril which is the edible portion.
Fruiting on a langsat tree
The fruit is always eaten fresh out f hand. Seedless fruits may be bottled in syrup. The pulp constitutes 60% of the total fruit weight. It has a delicious sub acid taste. Analysis of 100 g of edible portion gave the following values in grams:
Langsat fruits being sold in Thailand
Moisture, 86.5; protein, 0.8; ether extract, 0.3; carbohydrates, 9.5; fiber, 2.3; total minerals, 0.6; calcium 20.0 mg; phosphorus, 30.0 mg; iron .05 mg; carotene (as vitamin A), 13 i.u.; thiamine, 89 µg; and ascorbic acid, 1.0 mg.
Langsat fruits do not keep well. However these can be stored upto 14 days in cold storage at 52-55 F.
Wood is tough and durable and is put to various uses.
Langsat is propagated from seed. Seedlings are quite slow growing during the first year. Propagation from cuttings is using green wood is also possible but requires a lot of care. Trees are also propagated by air layering. This is done to get larger plants by layering large branches. But the success in this method is not very high and there is a lot of mortality.
Trees are planted at a distance of 8 – 10 metres depending upon the area. Young trees have to be looked after quite carefully.
The demand for langsat fruits in most countries exceeds the supply. So this fruit requires further promotion not only in South East Asia but other warmer countries too.