Albizia Angolensis Welw. Ex Oliv.

Origin

Albizia angolensis Welw. ex Oliv., commonly known as the African feather tree or the Chivu tree, is a deciduous tree native to tropical and southern Africa. It grows naturally in Angola, Botswana, Mozambique, Namibia, South Africa, Tanzania, Zambia, and Zimbabwe.

Common Names

Aside from African feather tree and Chivu tree, Albizia angolensis has several other common names such as Cape red albizzia, pod mahogany, red acacia, and sausage tree.

Uses

Albizia angolensis is a multi-purpose tree and has several uses in traditional medicine, agriculture, and the timber industry. In traditional African medicine, the bark, leaves, and roots of the tree have been used to treat various ailments such as chest pains, stomach ulcers, and dysentery. The bark is also used as a natural insecticide.

The tree is also used in agroforestry as it fixes nitrogen in the soil, provides shade for crops, and the leaves and pods serve as fodder for livestock. In the timber industry, the wood of Albizia angolensis is used for furniture making, flooring, and veneer. The tree's attractive flower clusters make it a popular ornamental plant.

General Appearance

The Albizia angolensis tree grows up to 20 meters in height and has a dense, spreading crown. The trunk is thick and gnarled, with a rough and dark grey-brown bark that peels off in strips. The leaves are alternate, feathery and bipinnate with multiple leaflets that are bright green in color.

The tree produces showy clusters of fragrant, pink to white flowers that bloom in the summer and are followed by long, flattened, and twisted pods that contain seeds. The shape of the pods resembles a sausage, which is where the tree also gets its common name, 'sausage tree'.

Typical Growth Conditions of Albizia Angolensis Welw. Ex Oliv.

Albizia angolensis Welw. ex Oliv., commonly known as the African albizia or East African albizia, is a species of flowering plant belonging to the Fabaceae family. It is native to a wide range of habitats across Sub-Saharan Africa, including savannas, woodlands, and dry forests.

Light Requirements

This plant requires full sun to partial shade to grow. As a sapling, it can tolerate shade, but for optimal growth, it requires more sunlight once it reaches maturity.

Temperature Requirements

The African albizia plant grows best in areas with a warm, subtropical climate. It can withstand temperatures as low as 15°C and as high as 38°C. It prefers growing in areas with an average temperature of 26°C.

Soil Requirements

The soil required for the growth of Albizia angolensis Welw. ex Oliv. should be well-draining. The plant is tolerant of various soil types, including sand, loam, and clay. However, it thrives best in well-drained soils that are rich in nutrients and have a pH range of 5.5–7.5. The plant is usually not tolerant of acidic soils below pH 5.0.

The African albizia plant is also drought-tolerant and can survive in areas with a rainfall range of 500-900 mm per year. However, the plant can grow taller with a greater amount of rainfall. Additionally, the plant is susceptible to frost damage and may not survive in areas with prolonged frost duration.

Cultivation Methods

Albizia angolensis Welw. ex Oliv. is a relatively easy plant to cultivate. It is adaptable to a variety of soil types, including sandy, loamy, and clay soils, and can even tolerate slightly acidic or alkaline conditions. The plant grows well in full sun to partial shade and typically reaches heights of 4 to 8 meters.

The best time to plant Albizia angolensis Welw. ex Oliv. is usually in the spring or fall. When planting, it is important to ensure that the hole is at least twice as wide as the root ball and just as deep. Amending the soil with compost or organic matter can help improve the soil fertility and drainage, which is especially important for heavy clay soils.

Watering Needs

Albizia angolensis Welw. ex Oliv. prefers moderate moisture levels and regular watering. It should be watered deeply once or twice per week depending on the weather conditions. During the hot and dry summers, it may require additional watering to maintain the desired moisture levels. Adequate water supply is critical during the first year after planting to ensure proper establishment.

Fertilization

The plant is not overly dependent on fertilization. However, adding some balanced granular fertilizer during planting can help establish the plant. If additional fertilization is necessary, a slow-release fertilizer applied at the beginning of growing season can help improve the plant's growth and overall health.

Pruning

Pruning can help shape and control the size of the plant. Albizia angolensis Welw. ex Oliv. can be pruned during the late winter or early spring to remove any dead or damaged branches. It is important to use clean and sharp pruning tools to prevent any damage to the plant. It is advisable to avoid pruning too much or too frequently, as the plant's growth may be affected, and flower production reduced.

Propagation of Albizia angolensis Welw. ex Oliv.

Albizia angolensis Welw. ex Oliv. can be propagated through various methods such as seeds, cuttings, and grafting. Each method has its advantages and disadvantages and may have different success rates depending on the type of propagating material.

Propagation by seeds

Propagation by seeds is the most common method for Albizia angolensis. The seeds should be collected from mature pods when they are dry and brown. The seeds can then be dried and stored until ready for planting. The seeds have hard-outer coats that can be scarified before planting to increase germination rates. The seeds can be planted in seed trays or directly in the ground at a depth of 1-2 cm. Germination can take 3-4 weeks but can sometimes take up to 6 months. The success rate for seed propagation can vary depending on the quality of the seeds and planting conditions.

Propagation by cuttings

Propagation by cuttings is another method that can be used for Albizia angolensis. Hardwood cuttings (10-15 cm) should be taken during the dormant season. The cuttings can be dipped in rooting hormones and planted in well-draining soil or in a soil and sand mixture. The cuttings need to be kept moist and in a shaded area until they have rooted. The success rate for propagation by cuttings can vary depending on the type of cutting and rooting conditions.

Propagation by grafting

Propagation by grafting can also be used for Albizia angolensis. Grafting involves attaching a scion (shoot or bud) from a desired plant onto a rootstock from another plant. Grafting is often used to propagate desirable traits, such as disease resistance or faster growth. The success rate for propagation by grafting can vary depending on the compatibility of the scion and rootstock, as well as proper care during the healing period.

Disease Management for Albizia angolensis Welw. ex Oliv.

Albizia angolensis Welw. ex Oliv. is susceptible to various diseases, including fungal infections and virus attacks. Keeping the plant healthy and stress-free is the best way to manage diseases primarily. Timely detection and appropriate treatment are necessary to prevent the spread of any disease. Here are some of the common diseases of Albizia angolensis and ways to manage them:

Fungal Infections

Fungal infections such as root rot, stem canker, and leaf spots are prevalent in Albizia angolensis. To manage fungal infections:

• Remove and dispose of infected plant parts immediately to prevent the spread of the infection.
• Ensure proper drainage to avoid waterlogging and reduce humidity levels to discourage fungal growth.
• Apply fungicides as per the manufacturer's instructions to control the spread of the infection.
• Ensure the plant is well-ventilated and receives adequate sunlight, which can help prevent fungal growth.

Virus Attacks

Virus attacks can cause mosaics, yellowing, and stunted plant growth in Albizia angolensis. They can spread from plant to plant and through infected soil or pests. To manage virus attacks:

• Remove and dispose of infected plant parts immediately to prevent the spread of the virus.
• Practice proper weed control to prevent the transmission of viruses by vectors such as aphids and other insects.
• Use virus-tested seeds and planting materials.
• If the plant is severely infected, uproot and dispose of it to prevent further spread.

Pest Management for Albizia angolensis Welw. ex Oliv.

Albizia angolensis is susceptible to pest attacks, which can cause stunted growth, premature defoliation, and death. Early detection and proper management are necessary to control pest infestations and prevent damage. Here are some of the common pests that attack Albizia angolensis and ways to manage them:

Leaf-Eating Insects

Caterpillars, beetles, and other leaf-eating insects can defoliate the plant, causing a loss of foliage and a reduction in photosynthesis. To manage leaf-eating insects:

• Remove and dispose of any infested leaves and plant parts.
• Use insecticides, pesticides, or other control methods such as biological control to manage the infestation.
• Practice proper sanitation measures, including maintaining a clean and weed-free environment and regularly inspecting the plant for insect activity.
• Attract beneficial insects such as lady beetles and lacewings that prey on the leaf-eating insects.

Sucking Insects

Sucking insects such as aphids, mites, and scale insects can attach themselves to the plant's leaves and suck essential plant juices, weakening the plant over time. To manage sucking insects:

• Prune and dispose of any infested plant parts.
• Use insecticidal soap or neem oil to control the infestation.
• Attract beneficial insects such as lady beetles and parasitic wasps that prey on the sucking insects.
• Practice proper sanitation measures, including maintaining a weed-free environment and regularly inspecting the plant for insect activity.

By preventing diseases and pest infestations from the start and managing them quickly and appropriately when they arise, you can help keep Albizia angolensis healthy and thriving.