Origin and Common Names
Pentadesma excelliana Staner, also known as African walnut or Congowood, is a tropical tree native to West Africa. It belongs to the family Clusiaceae and is mainly found in the rainforests of Ivory Coast, Cameroon, Ghana, Liberia, and Sierra Leone.
Uses
The tree has various uses, and its bark, leaves, seeds, and roots are of great importance to traditional medicine. The seeds are edible and are used in making oils, chocolates, and butterlike spreads. The Pentadesma excelliana tree is also been used for timber production due to its dense, hard, and heavy nature. The wood is used for making furniture, poles, and durable construction materials. The bark and leaves of the plant have astringent and antiseptic qualities, making them useful in the treatment of skin diseases and wounds. The roots, on the other hand, possess diuretic properties and have been used in the treatment of bladder and kidney infections. The plant is a vital source of livelihood for many communities in West Africa, earning income through the sale of nuts and timber.
General Appearance
Pentadesma excelliana tree is an evergreen that can reach up to a height of 30 meters. It has a straight trunk with smooth greyish-brown bark. The leaves are thick and leathery, growing up to 10 cm long and 5 cm wide, and have wavy margins. The plant produces greenish-yellow flowers with five petals, which are self-pollinated by insects. The fruit is a large, woody, and spherical capsule, up to 10cm in diameter. The capsule contains five to seven seeds, which are oval-shaped and have a whitish-yellowish hue. The seeds are enclosed in a hard, brown seed coat that contains a fleshy kernel inside. The plant thrives well in tropical regions with an annual rainfall of 1500 to 2500 mm, with a temperature range of 21 to 27 degrees Celsius.
Light
Pentadesma excelliana Staner prefers bright but indirect sunlight. It can tolerate some shade, so it is best to avoid placing the plant in intense, direct sunlight, which can scorch the leaves. It is recommended to place the plant near a north or east-facing window in a room with ample natural light.
Temperature
The ideal temperature range for the growth of Pentadesma excelliana Staner is between 18°C and 27°C. Temperatures below 12°C may cause the leaves to wilt and discolor. Avoid placing the plant near heating and cooling vents that generate sudden temperature changes. A consistent and warm environment is great for optimal growth.
Soil Requirements
Pentadesma excelliana Staner grows best in acidic soils that are well-drained and nutrient-rich. A mixture of peat moss, perlite, and bark in most potting soils create the perfect environment for the plant’s growth. In the wild, Pentadesma excelliana Staner grows in dense tropical forests with soils that are constantly replenished with decomposing organic matter. Avoid overwatering the plant, as the roots can easily become waterlogged and lead to root rot.
Cultivation Methods
Pentadesma excelliana Staner, commonly known as Djansang or Essessang in Africa, is a tropical tree. It is highly esteemed in the African culture, especially in Cameroon, for its medicinal properties and edible seeds.
Since it is a tropical tree, it grows well in hot and humid conditions; hence, it needs enough sunlight and warmth to thrive. The plant can grow in various soil types: sandy, clay, or loamy soils. However, the soil must be well-draining to avoid waterlogging, which can be detrimental to the plant's growth.
The best way to propagate Pentadesma excelliana Staner is through seeds. Plant the seeds in prepared beds or directly in the ground, and ensure that the soil is warm enough. The seeds should germinate in two to three weeks, and the plant should begin to grow in about six weeks.
Watering Needs
Watering is essential, especially during the plant's early stages of growth. The plant requires regular watering, especially during the dry season when rainfall is minimal. However, avoid overwatering as it can lead to waterlogging and root rot, which are detrimental to the plant.
It's crucial to note that the plant doesn't tolerate drought well, so it's essential to water it regularly. Ensure that the plant receives enough water during flowering and fruiting seasons to facilitate the growth of the seeds.
Fertilization
Fertilizer application is necessary to ensure that the plant grows well and produces good quality fruits. Organic manure or a balanced fertilizer composition is suitable for Pentadesma excelliana Staner.
The tree requires the application of fertilizers three times a year, in February-March, June-July, and September-October. Apply the fertilizer around the base of the plant or spread it across the plantation.
Pruning
Pruning helps to maintain the tree's shape and promote good health. It is necessary to prune the tree before it begins to bear fruits and after harvesting the fruit. Pruning also helps to prevent the spread of pests and diseases that can damage the plant.
Begin by removing dead or diseased branches and limbs that may hinder the tree's growth. The next step involves pruning the branches that grow too low, blocking the light from reaching the tree's inner parts. Remember to disinfect your pruning tools to avoid transmitting diseases and pests to the tree.
Propagation of Pentadesma excelliana Staner
Pentadesma excelliana Staner can be propagated via seed or vegetative methods.
Propagation through Seed
The seeds of Pentadesma excelliana Staner should be sown in a well-draining soil mix. Prior to sowing, the seeds should be soaked in water for 24 hours to promote germination. The soil mix should be kept moist but not waterlogged. Germination occurs within 1-2 months.
Propagation through Vegetative Methods
Pentadesma excelliana Staner can also be propagated through vegetative methods like stem cuttings and air layering. Stem cuttings should be taken from mature, healthy plants and should be dipped in rooting hormone before being planted in a soil mix. The cutting should be kept in a warm and humid location until it roots.
Air layering involves making a cut in the middle of a parent plant's stem, and then wrapping the cut section in moist moss or soil. After roots form, the newly rooted section can be separated from the parent plant and potted in a well-draining soil mix.
Disease Management
There are several diseases that can affect the Pentadesma excelliana plant, such as:
- Anthracnose: characterized by the presence of small, sunken circular spots on the leaves; can be controlled by removing and destroying infected leaves and branches, and applying fungicides.
- Cercospora leaf spot: identified by grayish-white or brown spots on the leaves; can be prevented by practicing proper sanitation and applying fungicides.
- Phoma stem canker: causes moist, grayish lesions on the trunk and branches; can be controlled by removing and destroying infected branches and applying fungicides.
Preventive measures such as good sanitation, proper irrigation, and ensuring proper nutrient balance can go a long way in keeping the plant healthy and resistant to diseases.
Pest Management
The Pentadesma excelliana plant can be susceptible to a variety of insect pests, such as:
- Mealybugs: identified by the presence of a white, cotton-like substance on the leaves; can be controlled by removing and destroying infected plant parts and applying insecticidal soap.
- Scale insects: causes yellowing of leaves and a sticky substance on the plant; can be prevented by practicing good sanitation and applying neem oil or insecticidal soap.
- Caterpillars: causes holes in the leaves; can be controlled by handpicking or applying biological insecticides.
Regular inspection of the plant, the use of physical barriers such as nets, and practicing proper sanitation can also help prevent pest infestations. In case of severe infestations, chemical insecticides can be used as a last resort.
