Description of Dalbergia melanoxylon Guill. & Perr.
Dalbergia melanoxylon Guill. & Perr. is a small to medium-sized deciduous tree that belongs to the family Fabaceae. It is commonly known as African blackwood, Mozambique ebony, and Grenadilla. The tree is native to the dry savanna regions of southern Africa, including Mozambique, Zimbabwe, South Africa, and Tanzania.
General Appearance
The African blackwood tree has a height of about 4-15 meters and a trunk diameter of up to 60 centimeters. The bark is smooth and grey-brown in color. The leaves are pinnately compound and measures approximately 8-15 cm long. The flowers are small, white, and fragrant, and the fruit is a pod that is about 3-7 cm long. The wood of the tree is considered one of the world's hardest woods, making it a valuable resource for various purposes.
Uses and Significance
The African blackwood tree is famous for its dense, dark heartwood, which is used for fine woodworking, carving, musical instruments, and sculptures. The wood's color ranges from dark brown to purple-black, and it has a fine, even texture. Its durability and lustrous sheen make it a popular choice for high-end furniture, knife handles, chess pieces, and other decorative items.
Apart from its commercial uses, the African blackwood tree is also known for its medicinal and cultural significance. In the traditional African medicine practices, the tree's bark and leaves are used to treat various ailments such as coughs, colds, and fever. The tree also holds cultural value as it plays a crucial role in various African communities' rites of passage and cultural practices.
However, the African blackwood tree is currently threatened by deforestation due to its high demand in the global market. To conserve the species, efforts are being made to regulate the harvesting and trade of African blackwood and promote sustainable forest management practices.
Light Requirements
The plant Dalbergia melanoxylon, commonly known as African blackwood, requires ample light to grow. It prefers bright, indirect light, but can tolerate partial shade. A lack of appropriate light can hinder its growth and development.
Temperature Range
The typical growth conditions for Dalbergia melanoxylon call for warm to hot temperatures. The plant thrives in temperatures ranging from 65°F to 85°F (18°C to 29°C). The lowest temperature it can tolerate is around 50°F (10°C) and it is generally not suited for the cooler climates of areas prone to frost.
Soil Requirements
African blackwood requires a well-draining, nutrient-rich soil for optimal growth. The ideal soil pH range is between 5.5 and 7.5. It grows best in soils with good drainage and ample aeration. It is also important to ensure that the soil is kept moist but not waterlogged.
Cultivation of Dalbergia melanoxylon Guill. & Perr.
Dalbergia melanoxylon, also known as African blackwood or mpingo, is a slow-growing tree that is native to central and southern Africa. It requires a tropical or subtropical climate with temperatures that range between 20°C and 30°C.
The tree prefers well-draining soils that are rich in organic matter. It can grow in a variety of soils, including sandy, loamy, and clay soils, as long as they are well-draining.
Dalbergia melanoxylon needs to be grown in an area with plenty of sunlight. Therefore, it is advisable to plant it in an open area with little or no shade. The tree is drought-tolerant and can survive long periods of drought, but it requires regular watering during the first few years of growth to establish its root system.
Watering Needs of Dalbergia melanoxylon Guill. & Perr.
The frequency of watering Dalbergia melanoxylon depends on the climate and the soil type. In general, the tree should be watered deeply once a week during the dry season. However, in sandy soils, it may require more frequent watering.
During the first year after planting, the tree should be watered more often, at least twice a week, to help establish its root system. Once established, the tree can withstand long periods of drought without damage.
It is essential to avoid waterlogging the plant as excessive moisture can result in root rot or other fungal diseases. Therefore, it is important to ensure that the soil is well-draining, and the water drains away from the roots.
Fertilization of Dalbergia melanoxylon Guill. & Perr.
Fertilization is crucial for the growth and overall health of the Dalbergia melanoxylon tree. The plant requires regular fertilization during its early growth stages.
A balanced fertilizer with a composition of 10-10-10 or 20-20-20 is ideal for the Dalbergia melanoxylon tree. Fertilization should be carried out every three months during the growing season (spring and summer).
It is important to avoid fertilizing the tree during the dormant season (winter) as it may result in damage to the roots.
Pruning of Dalbergia melanoxylon Guill. & Perr.
Pruning is essential for the proper growth and form of the Dalbergia melanoxylon tree. The best time to prune the tree is during the dormant season (winter) as the tree is less likely to experience stress.
To encourage upright growth, it is advisable to remove side branches that grow at low angles. It is also important to remove dead, diseased, or damaged branches as they can harbor pests and diseases.
Pruning should be done sparingly, and the tree should not be over-pruned as it can weaken the tree and reduce its overall health.
Propagation of Dalbergia melanoxylon
Dalbergia melanoxylon Guill. & Perr., commonly known as African blackwood, is a tree species known for its high-quality timber. Propagation of this plant species can be done through three methods: seed propagation, vegetative propagation, and air-layering.
Seed propagation
Seeds of Dalbergia melanoxylon are obtained from mature pods that have turned brown and dry. The seeds are cleaned and soaked in hot water for about 24 hours to break dormancy. After soaking, the seeds are sown in well-drained soil in a nursery bed or in polybags. The seedlings are transplanted to the field after one year.
Vegetative propagation
Vegetative propagation involves the use of cuttings or grafting. Cuttings are taken from the top of well-grown trees with a minimum diameter of 2cm. The cuttings are dipped in a rooting hormone solution and planted in well-drained soil. Grafting is done by joining a piece of a mature tree's stem with a seedling's rootstock. Vegetative propagation has a higher success rate compared to seed propagation.
Air-layering
Air-layering is done on mature trees of Dalbergia melanoxylon. The bark of the branch is removed and a rooting hormone is applied on the exposed surface. The exposed part of the branch is then wrapped with moist sphagnum moss covered with polythene film. Roots develop in the moss, and after about three months, the rooted branch is cut off and planted in the field.
Disease Management
Dalbergia melanoxylon is susceptible to various diseases, including leaf spot, stem cankers, powdery mildew and root rot. Preventive measures such as monitoring the growing environment and maintaining good cultural practices can help reduce the incidence of these diseases. Cultural practices that could be helpful include pruning the infected parts of the plant, keeping the soil moist but not waterlogged and avoiding overcrowding of plants.
Apart from cultural practices, the use of fungicides could be helpful in managing some diseases. Fungicides such as copper-based compounds and sulfur-based compounds could be used to prevent and control leaf spot and powdery mildew. Fungicides should be applied according to the manufacturer's instructions, and care should be taken to avoid direct contact with the plant.
Pest Management
Dalbergia melanoxylon is also susceptible to pest attacks. Common pests that could attack this plant include mealybugs, spider mites, and thrips. Mealybugs are small, scale-like insects found on the stems, leaves, or roots of the plant. They suck the sap out of the plant and produce a white, waxy covering that makes them difficult to remove. Spider mites and thrips are small insects that suck the juices from the plant, causing it to wilt and die.
Control of these pests can be achieved by spraying the plant with insecticides. Insecticides such as neem oil, spinosad, and pyrethroids could be used to control these pests. However, care should be taken when using insecticides. Follow the manufacturer's guidelines when using them, and avoid using them excessively as they can harm beneficial insects such as bees.
Proper care of the environment and regular monitoring of the plant can prevent pest and disease problems altogether. When problems do arise, however, early detection followed by prompt and appropriate management is essential to keep the plant healthy and productive.
