Origin and Common Names
Guarea ngounyensis Pellegr. is a tree species that belongs to the family Meliaceae. It is commonly known as African mahogany, Ako, Ako wusa, Bopel, or Yellow mahogany. This plant is native to West Africa, specifically to Guinea, Sierra Leone, Liberia, Ivory Coast, Ghana, Togo, Benin, Nigeria, Cameroon, Gabon, Congo, and the Democratic Republic of the Congo.
General Appearance
The African mahogany tree can grow up to 30 meters in height, with a trunk diameter of up to 80 centimeters. Its bark is grey to brown, with deep vertical fissures. The leaves are evergreen and alternate, consisting of 4 to 8 pairs of leaflets that are about 5 to 12 cm long. The leaflets are dark green and glossy on the upper surface, and pale green on the lower surface. The flowers are small, white to yellowish, and arranged in panicles at the ends of the branches. The fruits are ellipsoid to ovoid, about 4 to 5 cm long, green when young, and brown when mature.
Uses
Guarea ngounyensis Pellegr. has several uses in traditional medicine, particularly the bark, roots, and leaves. It is used to treat various illnesses, including fever, malaria, digestive disorders, and skin infections. The bark and roots have been found to contain several bioactive compounds, including alkaloids, flavonoids, and terpenoids, that may be responsible for its medicinal properties.
Aside from medicinal uses, African mahogany wood is highly valued for its hardness, durability, and attractive appearance. It is used to make furniture, cabinets, veneer, and other high-end wood products. The tree also provides shade, shelter, and food for wildlife, and helps regulate the local climate.
Light Requirements
Guarea ngounyensis Pellegr. typically grows in full sunlight in its natural habitat. However, it can also adapt to partial shade conditions.
Temperature Requirements
The plant is native to tropical regions and therefore requires warm temperatures in order to thrive. It cannot tolerate frost or temperatures below 10°C. The ideal temperature range for Guarea ngounyensis Pellegr. is between 20 and 30°C.
Soil Requirements
The plant can grow in a wide range of soils including loam, sandy loam, and clay soils. It prefers well-draining soils that are moderately fertile. It can tolerate soils that are slightly acidic to slightly alkaline. Soil pH in the range of 5.5 to 7.5 is optimal for Guarea ngounyensis Pellegr.
Cultivation Methods for Guarea ngounyensis Pellegr.
Guarea ngounyensis Pellegr is a slow-growing evergreen tree that is generally propagated by seeds. It grows best in tropical, humid environments with well-draining soil. The germination of seeds takes about six to eight weeks, and the young seedlings will become ready for transplantation after six to eight months.
The plant requires partial to full sunlight exposure for optimum growth, and it is recommended to plant it in the less windy regions to avoid damage to the foliage.
Watering Needs for Guarea ngounyensis Pellegr.
The tree prefers a moderate amount of watering. Mature trees can tolerate brief drought periods, but frequent watering during dry spells is necessary for young trees. It is essential to avoid waterlogging since it can lead to root rot and gradual wilting of the foliage.
A good watering schedule is to irrigate the plant frequently during the hot season and to reduce the watering frequency during the cold season.
Fertilization of Guarea ngounyensis Pellegr.
The tree requires adequate nutrients to maintain healthy growth. It is recommended to apply organic fertilizer twice every year to provide sufficient nutrients for the tree's development. It is best to spread the fertilizer around the tree's base and water it thoroughly afterward.
In addition, applying a balanced dose of nitrogen, potassium, and phosphorus-based fertilizers will improve the tree's overall health and enhance its growth.
Pruning of Guarea ngounyensis Pellegr.
Pruning is essential for the plant's health since it helps to remove the infected, damaged, or dead branches and leaves. It is advisable to prune the tree during the dormant season to enhance its productivity.
A good pruning practice is to cut branches that are growing towards the center of the tree. Cutting the branches at an angle that avoids leaving a stub ensures faster healing of the plant. Always use clean and sharp tools to avoid damaging the plant's tissues, which may expose it to infections.
Propagation of Guarea ngounyensis Pellegr.
Guarea ngounyensis Pellegr., commonly known as African whitewood, is a valuable timber species in tropical Africa. The plant can be propagated through several methods, both sexual and asexual.
Propagation by Seed
The most common method of propagating G. ngounyensis is through seed. Seeds are extracted from mature fruits, which ripen and split open around December to January. The seeds are then soaked in water for 24 hours to soften the hard seedcoat and enhance germination. They are then sown in nursery beds and covered lightly with soil.
The seedlings will emerge after about 3 weeks and can be transferred to polythene bags or individual pots after they have developed their first set of true leaves. The seedlings should be watered regularly to keep the soil moist and protected from direct sunlight for the first 4-6 weeks.
Asexual Propagation
African whitewood can also be propagated asexually through cuttings and air layering.
Cuttings are taken from young, actively growing branches in the rainy season. The cuttings are about 20cm long and 1cm in diameter and are treated with growth hormones before planting in rooting media. They should be kept in a moist environment and protected from direct sunlight until they have rooted, which takes about 6-8 weeks.
Air layering is another method of propagating G. ngounyensis. A branch is selected, and a 2-3cm section of bark is removed from the stem. The exposed tissue is treated with rooting hormone, and moist sphagnum moss is wrapped around the exposed area. After a few weeks, roots will have developed in the moss, and the new plant can be cut from the mother plant and potted in soil.
Propagation by grafting is possible but is not commonly used for African whitewood.
Disease Management
Guarea ngounyensis is a tropical plant that is susceptible to various diseases, including:
- Anthracnose: A fungal disease that causes brown spots on leaves and stems, leading to defoliation and stunted growth.
- Phytophthora Root Rot: A soil-borne fungal disease that attacks the roots, causing wilting and eventually death of the plant.
- Leaf Spot: A fungal disease that causes circular or irregular spots on the leaves, which turn yellow or brown and fall off.
- Powdery Mildew: A fungal disease that appears as white or gray powdery spots on the leaves, stems, and flowers.
To manage these diseases:
- Remove and destroy infected plant parts immediately to prevent the spread of disease.
- Ensure proper sanitation practices are in place, such as sterilizing tools before and after use.
- Avoid overhead watering and ensure proper drainage to reduce moisture on plant surfaces.
- Use fungicides or biocontrol agents, as directed by a professional, as a last resort.
Pest Management
Guarea ngounyensis is also susceptible to various pests, including:
- Aphids: Soft-bodied insects that suck the sap from leaves and stems, causing wilting and stunted growth.
- Scale Insects: Small, immobile insects that attach themselves to the plant and suck sap, leading to yellowing, wilting, and leaf drop.
- Mealybugs: Small, soft-bodied insects that produce a white, powdery substance on the surface of the plant, causing stunted growth and yellowing of leaves.
To manage these pests:
- Regularly inspect the plant for signs of infestation.
- Introduce natural predators, such as ladybugs or lacewings, to control pests.
- Use insecticidal soaps or oils, as directed by a professional, as a last resort.
- Practice good cultural practices, such as proper fertilization and watering, to keep plants healthy and resistant to pests.
