Vietnam has over 400 000 ha of Acacia plantations,
including over 220 000 hectares of clonal Acacia
hybrid (Acacia mangium × Acacia auriculiformis).
Acacia hybrid has been planted extensively in the
southern provinces of Vietnam, and is becoming
one of the main species for industrial plantations.
Acacia hybrid plantations have the potential to
provide several environmental benefits, with fastgrowing
Acacia plantations expected to reduce the
pressure on native forests as a source of industrial
raw materials. Acacias also have the valuable ability
to fix atmospheric nitrogen. The capacity of Acacia
hybrid to improve infertile soils could provide an
economic benefit to subsequent rotations of Acacia or
other crops in terms of lower fertiliser requirements
(Kha 2001). The hybrid’s branching behaviour differs from Acacia
mangium and Acacia auriculiformis in that the tree
has many small, light branches that can be easily
pruned. Similarly, its main stem, though not as
straight as that of Acacia mangium, is much straighter
than the main stem of Acacia auriculiformis. Unlike
the stem of Acacia mangium, that of the Acacia
hybrid has no angles or ribs (Darus and Ghani 1989,
Kijkar 1992). Its phyllode is about 4–6 cm wide and
15–20 cm long, with four veins similar to those of
Acacia mangium, with the vein on the outer edge of
the crescent difficult to see. Flowers come out in July
and August and again in November and December.
Acacia hybrid begins to set flowers at about 3 years.
The flowers are creamy to whitish and arranged in a
straight, or slightly bent, 8–10 cm spike. Since male
flowers in the hybrid are usually situated towards