Dalbergia sissoo

Dalbergia sissoo, known as Shisham, is an erect deciduous tree, native to the Indian Subcontinent and Southern Iran. It is also called sissoo, sisu, sheesham, tahli and sometimes referred to as Indian Rosewood. In Persian it is called جگ Jag. It is state tree of Punjab state (India) and provincial tree of Punjab province (Pakistan). It is primarily found growing along river banks below 900 metres (3,000 ft) elevation, but can range naturally up to 1,300 m (4,300 ft). The temperature in its native range averages 10–40 °C (50–104 °F), but varies from just below freezing to nearly 50 °C (122 °F). It can withstand average annual rainfall up to 2,000 millimetres (79 in) and droughts of 3–4 months. Soils range from pure sand and gravel to rich alluvium of river banks; shisham can grow in slightly saline soils. Seedlings are intolerant of shade. It is also the wood that the Rajasthani percussion instrument 'Kartaals' are often made from.

Timber

Shisham is best known internationally as a premier timber species of the rosewood genus, but is also utilised as an important fuel wood and for shade and shelter. With its multiple products, tolerance of light frosts and long dry seasons, this species deserves greater consideration for tree farming, reforestation and agro forestry applications. After teak, it is the most important cultivated timber tree of the Bihar - which is the largest producer of shisham timber in India and Pakistan, although it is the provincial tree of the Pakistani Punjab. In Bihar, the tree is planted on roadsides, along canals and as a shade tree for tea plantations. It is also commonly planted in southern Indian cities like Bangalore as a street tree.

Dalbergia sissoo is known to contain the neoflavonoid dalbergichromene in its stem-bark and heartwood^[1].

Shisham is among the finest cabinet and veneer timbers. The heartwood is golden to dark brown, and sapwood white to pale brownish white. The heartwood is extremely durable (the specific gravity is 0.7 – 0.8) and is very resistant to dry-wood termites; but the sapwood is readily attacked by fungi and borers. It is used for plywood, agricultural and musical instruments, as well as skis, carvings, boats, floorings, etc.

Fuel wood

The calorific value of the sapwood and heartwood of 'excellent' fuel wood is reported to be 4,908 kcal/kg and 5,181 kcal/kg respectively. As a fuel wood it is grown on a 10 to 15-year rotation. The tree has excellent coppicing ability, although a loss of vigor after two or three rotations has been reported. Shisham wood makes excellent charcoal for heating and cooking.

Botany

D. sissoo is a medium to large deciduous tree with a light crown which reproduces by seeds and suckers. It can grow up to a maximum of 25 m (82 ft) in height and 2 to 3 m (6 ft 7 in to 9 ft 10 in) in diameter, but is usually smaller. Trunks are often crooked when grown in the open. Leaves are leathery, alternate, pinnately compound and about 15 cm (5.9 in) long. Flowers are whitish to pink, fragrant, nearly sessile, up to 1.5 cm (0.59 in) long and in dense clusters 5–10 cm (2.0–3.9 in) in length. Pods are oblong, flat, thin, strap-like 4–8 cm (1.6–3.1 in) long, 1 cm (0.39 in) wide and light brown. They contain 1–5 flat bean-shaped seeds 8–10 mm (0.31–0.39 in) long. They have a long taproot and numerous surface roots which produce suckers. Young shoots are downy and drooping; established stems with light brown to dark gray bark to 2.5 cm (0.98 in) thick, shed in narrow strips; large upper branches support a spreading crown.

Propagation

Propagation takes place most commonly by root suckers and also by seeds. The seeds remain viable for only a few months. Seeds should be soaked in water for 48 hours before sowing and 60% – 80% germination can be expected in 1–3 weeks. Seedlings require partial sun or full sun.

Toxicology

Ethanolic extract of the fruits of Dalbergia sissoo exhibited molluscicide effect against eggs of the freshwater snail Biomphalaria pfeifferi.^[2]

References