Overview
Lannea nigritana (Scott-Elliot) Keay var. nigritana is a versatile plant that can be found in many parts of Africa. It belongs to the Anacardiaceae family and is commonly known as the African mango or the bush mango. The plant is popular for its fruit, which is edible and highly nutritious. The Lannea nigritana tree is also used for its medicinal properties as many parts of the tree are believed to have healing properties.
Appearance
The Lannea nigritana tree is a medium-sized tree that grows up to 20 meters in height. The tree has a dense, rounded crown with a straight, cylindrical bole. Its leaves are compound, with an odd number of leaflets, and measure between 7 and 15 cm. The tree's bark is silvery-grey, smooth when young, and turns rough and brown as it matures.
Origin
The Lannea nigritana tree is native to West and Central Africa. It can be found in several countries, including Cameroon, Nigeria, Ghana, and Burkina Faso. The tree grows in a wide range of environmental conditions and can be found at various altitudes.
Uses
The Lannea nigritana tree is valued for its fruit, which is edible and highly nutritious. The fruit is used for making jams, jellies, and sauces, and is also eaten fresh. The tree's bark, leaves, and roots are used for medicinal purposes to treat a wide range of ailments, such as diarrhea, indigestion, and viral infections. The tree's wood is also used for making furniture and household items due to its durability and toughness.
In conclusion, the Lannea nigritana tree is an important plant in Africa due to its nutritional and medicinal value. Its attractive appearance also makes it valuable in horticulture, as it is often grown as an ornamental plant.
Growth Conditions for Lannea nigritana (Scott-Elliot) Keay var. nigritana
Light: Lannea nigritana requires full sun to partial shade for optimum growth. In its natural habitat, it is commonly found in savannas, open woodlands, and grasslands.
Temperature: This plant is tolerant of high temperatures and is well suited to hot, dry climates. However, it cannot survive temperatures below freezing. Lannea nigritana grows best in temperatures ranging from 20-40°C.
Soil: The plant can tolerate various soil types, but prefers well-drained, deep, fertile, and sandy soils. It can grow in soils with a pH range of 5.0 to 7.5 but it prefers soil pH between 6.0 and 7.0.
Moisture: Lannea nigritana requires a moderate amount of water. It can resist periodic drought, making it useful in dryland situations. However, it does not thrive in waterlogged or overly moist soil.
Nutrition: The plant requires a moderate amount of nutrients to grow well. A balanced fertilizer application before planting and annually can improve growth and yield. Lannea nigritana tolerates poor soil conditions and can grow in nutrient-depleted soils.
Cultivation Methods for Lannea nigritana
Lannea nigritana is a deciduous tree that grows in tropical and subtropical regions. It requires full sun exposure to grow well. The best soil for it is well-drained soil, rich in organic matter. The pH of the soil should range between 6-7.5. The tree can grow up to 10 meters, so it requires ample space for its growth. It is recommended to plant the tree during the rainy season to promote its growth.
Watering Needs for Lannea nigritana
Lannea nigritana requires regular watering during the growing season, especially during the dry season. The tree can tolerate short periods of drought, but prolonged drought can affect its growth adversely. It is recommended to water the plant deeply once a week, but the frequency may vary depending on the soil, climate, and season. Overwatering may lead to root rot, so it is necessary to maintain optimal moisture levels.
Fertilization for Lannea nigritana
Regular fertilization is necessary for the optimal growth and development of Lannea nigritana. The tree requires a balanced fertilizer with a nitrogen-phosphorus-potassium (NPK) ratio of 7-10-7. The fertilizer should be applied during the rainy season or early in the growing season. Over-fertilization can lead to the burning of roots, so it is essential to follow the recommended dosage rate. Organic compost can also be used as a natural fertilizer, which improves the soil quality and provides essential nutrients to the plants.
Pruning for Lannea nigritana
Pruning is necessary to maintain the shape and size of Lannea nigritana. It is recommended to prune the tree during the dormant season to promote its growth. The tree can be pruned to remove dead or diseased branches, crossing branches, or to promote more upright growth. It is advisable to avoid heavy pruning, which may weaken the tree. Pruned branches should be cut at the base, close to the trunk, using clean, sharp tools to prevent disease infection.
Propagation of Lannea Nigritana
Lannea nigritana is a commonly propagated plant species, found in the savannas and forests of Africa. The plant is commonly propagated by two main methods: sexual and asexual propagation.
Sexual Propagation
The sexual propagation method is achieved through the collection of seeds from mature plants. The seeds must be carefully harvested when they are mature, before they drop to the ground. To enhance germination, the fleshy coating of the seeds must be removed, washed, and then sown in good quality soil in a pot or container. The seeds take between two and nine months to germinate and should be kept moist and warm, in a well-ventilated environment. Once the seedlings are established, they can be transplanted to individual pots, cared for regularly and eventually transplanted to their final position in the garden when they reach maturity.
Asexual Propagation
Asexual propagation methods are used to ensure that the desirable traits of already mature plants are preserved in new plants. Asexual methods include the following:
Layering
Layering involves bending a mature branch or stem of the plant down to the ground and partially burying it with soil. Once the buried section develops roots, the branch can be separated from the parent plant and be dug to be replanted. This method can take up to a year for successful results.
Cuttings
Cuttings involve removing a stem or a leaf from a mature plant and encouraging it to produce roots of its own. The cut stem is then inserted into a rooting hormone powder and planted in a pot or container filled with good quality soil. The cutting needs to be kept moist and warm, with high humidity until the roots are established, usually within a few months. Once rooted, the young plant is then transplanted to its final growing site.
Grafting
Grafting is the process of combining two different plants to produce a single plant. The process involves making an incision in the stem of a mature plant, into which a compatible stem of another plant is attached. This method is typically used to introduce desired characteristics from one plant to another or to increase the vigor of a plant.
By using both sexual and asexual propagation methods, it is possible to rapidly establish many healthy plants in a relatively short period, both in controlled environments and in an open field.
Disease Management
Lannea nigritana is susceptible to several diseases, including leaf rust, anthracnose, and powdery mildew.
Leaf rust
Leaf rust, caused by the fungus Puccinia lanneae, results in small, yellow-orange spots on the leaves, which progress to red-brown, elongated pustules. The affected leaves will eventually turn brown and fall off the plant.
To manage leaf rust, remove and destroy the infected leaves as soon as possible. Also, keep the plant well-ventilated and avoid overhead watering.
Anthracnose
The fungus Colletotrichum gloeosporioides is the cause of anthracnose in Lannea nigritana. Symptoms include small, dark spots on leaves, stems, and fruit, which can turn into large, sunken lesions in humid weather. Severe infections can cause leaf drop and fruit rot.
To manage anthracnose, improve soil drainage and remove infected plant debris. Fungicides can also be used preventatively.
Powdery mildew
Powdery mildew, caused by the fungus Erysiphe cichoracearum, results in a white, powdery coating on all above-ground parts of the plant. Infected leaves may yellow and drop, and severely affected plants can be stunted.
To manage powdery mildew, keep the plant well-ventilated and avoid overhead watering. Fungicides can also be applied preventatively.
Pest Management
Lannea nigritana can also be attacked by several pests, including aphids, mealybugs, and spider mites.
Aphids
Aphids are small, pear-shaped insects that suck sap from the plant, causing distorted growth and yellowing leaves. They can also transmit plant viruses.
To manage aphids, remove them from the plant with a strong spray of water or insecticidal soap.
Mealybugs
Mealybugs are small, soft-bodied insects covered in a white, powdery wax. They feed on plant sap, causing yellowing leaves and stunted growth.
To manage mealybugs, remove them from the plant with a cotton swab dipped in rubbing alcohol or insecticidal soap.
Spider mites
Spider mites are tiny, eight-legged pests that feed on plant sap, causing yellowing leaves and webbing on the plant. They thrive in hot, dry conditions.
To manage spider mites, increase humidity around the plant with regular misting and remove heavily infested leaves. Insecticidal soaps and oils can also be used preventatively.
