Overview
Lannea glaucescens Engl. is a tropical plant species that belongs to the family Anacardiaceae. It is a medium-sized deciduous tree that grows up to 30 meters in height and is native to Africa.
Common Names
The plant is commonly known as "African grape tree" in English and "Uchenjali" in Swahili. It is also referred to as "mutondo" in local languages in some African countries such as Zimbabwe and Zambia.
Appearance
Lannea glaucescens has a straight trunk and a rounded to spreading crown with drooping branches. Its bark is gray-brown and smooth when young, but becomes rough and fissured as the tree matures. The leaves are compound, and each leaflet is elliptical or oblong and measures 4-8 cm long and 2-3 cm wide. The tree produces cream-white to yellowish-green flowers that are about 5 mm in diameter. The fruit is a globose drupe that is about 2 cm in diameter and resembles a small grape. The fruit typically ripens from light green to yellow or pinkish-red, and contains a single seed.
Uses
Lannea glaucescens has many practical uses, both for food and medicinal purposes. The fruit is eaten fresh or dried and is known to be sweet and slightly acidic. The tree's bark and roots are used to make a decoction that is believed to have anti-inflammatory and analgesic effects and can be used to treat various ailments such as malaria, diarrhea, and stomach pain. The tree's leaves are also used to make a decoction that is believed to have antibacterial and anti-inflammatory properties and can be used to treat various skin ailments and wounds.
Light Requirements
Lannea glaucescens Engl. typically requires a lot of sunlight for optimal growth. It prefers to grow in open areas where it can receive direct sunlight for much of the day. In shady conditions, the plant may not grow as well and may even become stunted or develop leggy growth. Therefore, it is important to plant Lannea glaucescens in a location where it can receive full sunlight.
Temperature Requirements
The plant generally grows well in warm, tropical regions. It prefers temperatures between 20°C to 40°C and is not frost tolerant. When exposed to very low temperatures, the plant may experience damage and may even die. Therefore, it is important to plant Lannea glaucescens in an area with mild temperatures.
Soil Requirements
Lannea glaucescens can grow in a variety of soil types, including sandy, loamy, and clay soils. However, it typically prefers well-draining, fertile soil with a pH range of 5.5–7.5. The soil should be rich in organic matter and have good water retention capabilities to ensure optimal growth. To encourage healthy growth, it is recommended to provide nutrients such as phosphorus and nitrogen to the soil.
Cultivation:
Lannea glaucescens Engl. can be cultivated in a variety of soil types, including sandy and loamy soils. However, it grows best in well-drained soils with a neutral to slightly acidic pH level. It is recommended to plant the seedlings during the rainy season, which starts in May and lasts through August. The plant is relatively adaptable to different levels of rainfall but grows best with an annual rainfall range of 800-1300 mm.
Watering Needs:
The Lannea glaucescens Engl. plant has moderate water requirements. During the first year of growth, the plant should be watered regularly to establish the root system. After that, the plant can survive on the rainfall in the area. However, if the area experiences a prolonged drought, the plant needs to be watered regularly to survive. It is crucial to avoid overwatering since it can lead to root rot and other fungal diseases.
Fertilization:
The Lannea glaucescens Engl. plant is not a heavy feeder and can grow in nutrient-poor soils. It is recommended to add organic matter, such as compost or well-rotted manure, during planting. Fertilization can be done twice a year using a balanced fertilizer. The first application should be during the rainy season, and the second should be during the dry season. It is essential to follow the manufacturer's instructions when applying the fertilizer to avoid over-fertilization.
Pruning:
The Lannea glaucescens Engl. plant requires minimal pruning. However, it is recommended to remove any dead or diseased branches to maintain plant health. The best time to prune is during the dry season to avoid spreading fungal diseases. Pruning can also be done to shape the plant or control its size. It is crucial to use sterilized pruning tools to prevent the spread of diseases amongst plants.
Propagation of Lannea glaucescens Engl.
Lannea glaucescens Engl., a deciduous tree species commonly found in Southern Africa, is propagated vegetatively through stem cuttings, root suckers, and layering. The propagation of this plant species can also be done using seeds, but it is generally not preferred due to the high variability in seedling growth and quality.
Stem cuttings propagation
Using stem cuttings to propagate Lannea glaucescens is a reliable method. Cuttings are taken from mature and healthy trees during the growing period, and the basal leaves are removed to reduce water loss. The cuttings are then dipped in a rooting hormone to promote root formation before being planted in a well-draining rooting medium such as a mixture of sand and compost. The cuttings are kept in a humid environment with indirect sunlight until they have established roots, which typically takes about 2 to 3 months.
Root suckers propagation
Propagation through root suckers is another option for Lannea glaucescens. Root suckers are shoots that arise from the roots of the plant and can be separated from the parent tree once they have developed roots and leaves. The separated suckers are then replanted in a suitable soil mixture in a pot or directly in the field.
Layering propagation
Propagation through layering involves creating a wound in a low branch of the plant and then burying it in the soil to encourage rooting. The branch is held in place with a peg or rock to maintain contact with the soil. Once the branch has established roots, it can be cut off from the parent tree and transplanted to its desired location.
Overall, the propagation of Lannea glaucescens is accomplished through a combination of vegetative and seed propagation methods. With the suitable environmental conditions and proper management, these methods can produce high-quality plants that provide many benefits to the environment.
Disease and Pest Management for Lannea glaucescens Engl.
Lannea glaucescens Engl. is not a high-maintenance plant and is relatively resilient to pests and diseases. However, some common pests and diseases that might affect the plant include:
Pests
Spider Mites: Spider mites are common pests that typically appear on the underside of leaves. They suck the sap out of the plant which can cause severe damage or even death. To manage spider mites, regularly spray the plant with water to increase humidity levels and wipe the leaves with a cloth to remove spider mites. Additionally, you can also use insecticidal soap to control spider mites.
Caterpillars: Caterpillars can also be a problem for Lannea glaucescens Engl. They chew on the leaves, causing significant damage. To manage caterpillars, handpick them off the plant or spray with Bacillus thuringiensis (BT), a natural insecticide that targets caterpillars.
Diseases
Fungal Leaf Spot: Fungal leaf spot is a common disease that causes dark spots on leaves. To manage fungal leaf spot, remove the infected leaves and treat the plant with a fungicide. Additionally, avoid overwatering the plant and ensure good air circulation around the plant to prevent the disease from spreading.
Root Rot: Root rot is a fungal disease that affects the roots of plants and can cause them to die. To avoid root rot, ensure that the plant is not overwatered and that the soil drains well. If the plant does get root rot, remove the dead or mushy roots and repot the plant in fresh soil.
Regular watering and fertilization can help keep Lannea glaucescens Engl. healthy and less susceptible to pests and diseases. Overall, maintaining proper cultural practices is the best way to avoid any pest or disease problems with this plant.
