Chukrasia chickrassa (Roxb.) J.Schultze-Motel

Chukrasia tabularis is a deciduous, monoecious, medium-sized, sometimes fairly large tree up to 30 (max. 40) m tall; bole branchless for up to 18 (max. 32) m, with a diameter of up to 110 (max. 175) cm, without buttresses; bark surface rusty brown or deep brown, deeply fissured or cracked, with lenticels, inner bark reddish. Leaves paripinnate, with 4-6 pairs of alternate, entire, asymmetrical and acuminate leaflets (imparipinnate and lobed or incised when juvenile), glabrous or with simple hairs. Flowers unisexual, in axillary (sometimes appearing terminal) thyrses, tetramerous or pentamerous, up to 16 mm long; calyx lobed; petals free, contorted, reflexed in open flowers, white. Fruit an erect woody ovoid or ellipsoid capsule opening by 3-5 valves from the apex; valves separating to a woody outer and inner layer, apex of those in the inner layer deeply bifid; locules appearing as 1 locule due to the breaking of the septae; columella with sharp ridges. Seeds 60-100 per locule, flat, with terminal wings arranged in layers.

C. tabularis is monoecious, flowers are unisexual. It flowers and fruits annually; in Southeast Asia, seeds are ripe in January-March. The winged fruits are disseminated by wind.

It is usually found on well-drained soil in the plains and on hills.

C. tabularis is usually found scattered in lowland evergreen forest or deciduous forest. It is a dominant tree, occurring in top canopy in natural forests. In peninsular Malaysia, it occasionally occurs as a colonizer of bare land, including road cuttings. In Sarawak, it is notably found on limestone. C. tabularis usually avoids heavy and wet soils. It is regarded as a pioneer species and common in former shifting cultivation areas.

Chukrasia consists of 1 or possibly 2 species. Major stands of C. tabularis are found in India, Bangladesh, Thailand and Malaysia. It has been planted in many countries outside Southeast Asia such as Nigeria, Cameroon, South Africa, Hawaii, Puerto Rico and Costa Rica.

C. tabularis regenerates naturally through seed, which is generally satisfactory, as well as through coppice. Capsules are dried in shade until they split open, and the seeds are released by gentle tumbling or shaking. Direct sun drying should be avoided, as it may cause overheating and desiccation of the sensitive seeds. Seeds require no pretreatment and are sown with overhead shade in light porous soil. Germination is fair: in Malaysia 35% of the seeds sown germinated in 1-2.5 weeks, in India 80-90% in 1-4 weeks. Where seed is plentiful, the best method is broadcast sowing in strips 0.6 m wide and 1.8 m apart. Best results have been obtained by raising seedlings in well-drained boxes and pots before transplanting. Seedlings are pricked out and transplanted to the nursery beds when about 1 month old and 6-8 cm high. The species can also be propagated by air-layering, entire transplants or stumps.

In India, growth of seedlings proved moderately fast over the 1st 2 years. After 2 years, the plants had reached a height of 1.2-2.1 m; after 3 years, 2.8-3.4 m with a diameter of 4-5 cm; after 6 years, 5.5 m tall and a diameter of 15 cm, indicating a mean annual increment of 2.5 cm. Another source in India records a height of 13 m and a mean diameter of 5.2 cm for 5-year-old plants. A planting trial in western Java, using seeds from Sumatra, showed a mean height of 13 m and a mean diameter of 18 cm 10 years after planting. The tree coppices particularly well. First major thinning is required in the 4th year and thereafter every 5 years. The 1st thinning should be comparatively light as the species tends to branch and fork.

Like most species of the subfamily Swietenioideae, the shoot borer Hypsipyla attacks C. tabularis. It is also attacked by Hypsipyla spp. in plantations in Africa and Central and South America. It has been observed that the trees recover after the 7-8th year, with no more damage afterwards. Some larvae are known to bore into dead wood, while others bore into living stems or defoliate. White fibrous rot and brownish butt rot attack the trees. In unfenced plantations, deer browse the trees and cause severe debarking problems.

Seed storage behaviour is orthodox; loss in viability after 1 year of hermetic air-dry storage at room temperature; little loss in viability (by 4%) following 6 months of hermetic storage at 10 deg. C with 6% mc. Fresh seed retain its viability for a relatively short period, about 3 months. There are about 100 000 seeds/kg.

Intercropping: The straight bole and self-pruning ability of C. tabularis make it a suitable tree for growing in combination with crops, such as banana, Citrus spp. and guava. Its coppicing and pollarding ability make it particularly suitable for home gardens.

Fuel: The wood can also be used as a fuel. Timber: Heartwood is pale reddish-brown, yellowish-red to red, darkening to dark yellowish-brown, reddish-brown to medium dark brown on exposure, sharply differentiated from the yellowish-white, pale yellowish-brown, pinkish-brown or greyish-brown sapwood; dark streaks may be rather prominent. The density is 625-800 kg/cubic m at 15% mc. The grain is interlocked and sometimes wavy, producing a rose figure; texture moderately fine but uneven. Freshly cut wood has a fragrant odour, but dried wood has no characteristic odour or taste. Planed surfaces have a high lustrous satiny sheen. The timber is highly prized for high-grade cabinetwork, decorative panelling, interior joinery such as doors, windows and light flooring, and for carving, toys and turnery. It is also used for railway sleepers, ship and boat building, furniture, musical instruments (including pianos), packing cases, sporting goods, lorry bodies, mallet heads, anvil blocks, brush wares, drawing equipment, rifle butts, veneer and pulp. In India, the timber is also used for light to medium-heavy construction work, such as for posts, beams, scantlings and planks. The wood peels well and gives exceedingly fine veneer. It is suitable for commercial and moisture proof plywood. Gum or resin: A yellow, transparent gum exudes from the trunk and is marketed in admixture with other gums. Tannin or dyestuff: The flowers contain a red and a yellow dye. The young leaves and bark contain 22% and 15% of tannin respectively. Medicine: An extract of the bark has powerful astringent properties and has been used as a febrifuge.