Previous Page Table of Contents Next Page


MILICIA EXCELSA*

DISTRIBUTION

A large deciduous forest tree of lowland forest and wet Savannah. It is widespread throughout tropical Africa and is very common in many of the wetter lowlands of Tanzania. It is a forest pioneer species and survives in the mature forest as a canopy tree (Sommerlatte 1990). It is found as a scattered tree in foothills of the coastal mountains, and in areas around Lake Malawi and Lake Victoria, below 1000 m (RSCU 1992), including the Coast, Tanga, Morogoro, Dodoma, Iringa, Tabora, Ruvuma, and Kigoma. It can grow with about 700 mm annual rainfall if it has access to a supplementary source of water.

Status: M. excelsa is a reserved tree in Tanzania. It is endangered in parts of its range due to extensive cutting.

Minimum Altitude (m):

0

Maximum Altitude (m):

1200

Minimum Rainfall (mm):

1000

Maximum Rainfall (mm):

2000

Minimum Temperature (C):

20

Maximum Temperature (C):

35

REQUIREMENTS

Soil Requirements: Tolerate a wide range of freely drained soils (Forest Division 1984). It prefers deep, fertile, and moist loams (Borota 1975); freely drained light red loams; or freely drained, sandy soils of neutral to alkaline reaction. It can tolerate fairly high salinity.

Light Requirements: Strongly demanding.

Influential Factors: Does not tolerate waterlogging, and is susceptible to attacks by a gall insect.

PROPAGATION

Means of Propagation: Can be propagated from stumps, seed, coppice, and root suckers.

Seeds per kg:

350000

Germination Rate (%):

80

Germination Length:

14-18 days

Seed Sources:

200 per kg - Tanzania National Seed Centre 1991.

Seed Treatments: Fruits are collected from the ground in January and seeds should be extracted immediately by soaking in water (Borota 1975). Soak fully ripe fruit for 4 days to remove pulp, then dry and sow seed. Longer soaking reduces seed viability. Since seed loses viability quickly, it should be stored in dry, cold, air tight conditions. After 1 year there is only 50% germination rate. Seed is best if used within 3 months.

Pretreatment is not necessary (RSCU 1992).

Seedling Management: Coppices and regenerates well. It is not a prolific seeder. Germination is usually quick and good. Attention must be given to seedlings against gall attack. Stumps (27 cm root length, 2 cm diameter) or striplings (2.4 m tall) are generally transplanted in the field (Forest Division 1984).

SILVICULTURE

Planting Types: Not suitable for close planting due to the incidence of leaf gall insect attack. Mixed or single tree planting is preferable.

Growth Factors: Relatively fast growing.

Growth Cycle: Rotation is 60 to 80 years.

Limitations to Planting: The need for special planting arrangements and management requires some technical advice.

Management Systems: Seedlings can be planted after 12 to 18 months in the nursery. M. excelsa generally requires special planting arrangements with wide spacing in order to reduce the incidence of gall attack (Forest Division 1984). Seedlings under shade in the forest are fairly free from gall as is a plant with a height of 4 m or more. A nurse tree is generally required, such as a fast growing tree like Trema orientalis or an agriculture crop like banana. The nurse crop should be spaced at about 2.7×2.7 m and M. excelsa at 9×9 m in groups of up to 4 stumps, 60 cm apart (Forest Division 1984). Vegetation should be removed around the stumps and the area weeded for 2 to 5 years. Thinning should be done over years 4 to 8, retaining the best trees in each group.

IMPORTANT USES

Use #1: TIMBER
The high quality timber is often used as a teak substitute. It is of significant commercial value and commands high prices internationally. Locally it is Used for furniture, boat building, and general purpose building timber. It resists termites well.

Use #2: MEDICINE
The bark, its ashes, the leaves, and the latex are all Used in local medicine. The latex is used to reduce tumours and obstructions of the throat and for stomach problems. The bark is used to treat coughs, dysentery, heart problems, and general tiredness.

Use #3: LAND IMPROVEMENT
It is often used as a shade tree and along streets as an ornamental. Its leaves are used as mulch and it is also nitrogen fixing.


Previous Page Top of Page Next Page