Leucaena leucocephala (Lam.) de Wit.

Description :

A fast growing, evergreen shrub or small tree 5 to 20 m tall. Diameters to 20 cm are common, spending on whether tree or shrub like form. Foliage is feathery-like and the leaves are compound. Leaves are 7 to 15 cm long, while the leaflets are small, 3 cm long. The flowers are small, white, look like "powder puffs", and occur between June and November. The pods are in bunches, flat and long. They are brown when ripe and mature between September and December. It can be reproduced both from seed and by vegetative means. Seed can be stored without special considerations for several years and maintains its viability. Pre-treatment of seed with a water soak will speed up germination. Young plants need protection from grazing and frost. Because of its tolerance and seed habit it can quickly become a weed problem. It has straight grained wood with yellowish-brown colour and medium fine texture. Its wood very resilient and strong in character.

Distribution :

The tree is native to Mexico. It has been successfully planted throughout tropical parts of the world. In Pakistan it is cultivated in the plains and foothill areas. This aggressive, tolerant tree grows on a variety of sites. It is quite adaptable, growing on steep hill sides with shallow soils and marginal mountainous gravelly and sandy soils. It will also row on saline and alkaline soils (PH. 6.5 and above). It requires a summer precipitation zone of 500 to 1000 mm/yr. It prefers a moist tropical climate with a temperature range of 2 to 45°C at elevations up to 500 m. Grazing can be a problem. Seedlings tolerate light frost. No known pests or diseases have been reported in Pakistan. However a defoliator, Psylid spp., is creating serious problems with Leucaena in other parts of the world.

Uses :

It is fast growing and highly productive. Yields of 30 m³/ha/yr have been recorded for rotations of 10 years. Growth in irrigated plantations has been excellent. This tree is adapted to a variety of sites and soils. Both acid and alkali soils are suitable for this tree. It coppices readily, is a good nitrogen fixer, and also for irrigated plantations. It is a useful tree in farm forestry programs. Also used as fodder, fuel, nitrogen fixing, poles and construction, agricultural implements, apiculture, furniture, and soil stabilization.