Origin
Oncoba tettensis is commonly known as the African wild olive and belongs to the family of Salicaceae. This plant is primarily found in Sub-Saharan Africa where it is distributed in tropical and subtropical regions of Kenya, Tanzania, and Zambia.
Common Names
Oncoba tettensis is commonly known by several different names in the regions where it is grown such as the wild butter tree, sand olive, or wild yellow coconut.
Uses
Oncoba tettensis has various medicinal and economic uses. The bark, leaves, and roots of the plant are used in traditional medicine to treat different ailments such as headache, fever, and stomach-related problems. The plant is also used for agroforestry as it can grow on degraded soils and is commonly used as a shade tree in coffee, tea, and banana plantations.
General Appearance
Oncoba tettensis is a small to medium-sized tree which can grow up to 20 meters in height. The tree has a straight trunk with a grey-brown bark that is rough and fissured. The leaves are simple, alternate and ovate to elliptical in shape measuring 5 - 14 cm long and 2 - 8 cm wide. The flowers of Oncoba tettensis are yellow to cream in color, fragrant and appear in clusters towards the end of branches. The fruit of this plant is a fleshy berry, yellow-orange when ripe, and contains up to three seeds.
Light Requirements
Oncoba tettensis requires full to partial sunlight to grow. It thrives well in bright light conditions but can also survive in partial shade. Direct sunlight exposure of more than six hours per day can harm the plant and stunt its growth. Hence, it is best to grow Oncoba tettensis in places with filtered light or partial shade.
Temperature Requirements
Oncoba tettensis prefers tropical and subtropical weather conditions. It thrives best in temperatures ranging from 20°C to 30°C (68°F to 86°F). Young plants usually find it difficult to tolerate temperatures below 15°C (59°F). Oncoba tettensis is not very frost tolerant, so it should be grown in areas with mild winter conditions.
Soil Requirements
Oncoba tettensis is not very specific in terms of soil requirements. It can grow in various soil types, but it prefers fertile, well-draining soils with a slightly acidic to alkaline pH ranging from 6.0 to 7.5. The presence of compost or organic matter in the soil can improve its growth rate and enhance the quality of foliage and flowers. It can grow in sandy, loamy or clayey soils, but it is important to ensure good drainage to avoid waterlogging, which can harm the roots and damage the plant.
Cultivation
Oncoba tettensis is a relatively low-maintenance plant that thrives in most soil types. It can tolerate partial shade, but full sun is preferable for optimal growth. When planting Oncoba tettensis, ensure that the soil is well-draining and rich in organic matter.
The plant can be propagated through seeds or cuttings. However, seed propagation can be a bit challenging, and cuttings would be a better option. Mature shrubs can be propagated by taking hardwood cuttings from the plant's base during the dormant season.
Watering Needs
Watering during the growing season is crucial, but ensure not to overwater the plant as it may cause root rot. The plant needs enough moisture to thrive, but the soil should not be waterlogged. It is recommended to water the plant thoroughly once a week, especially during the dry season.
Fertilization
The Oncoba tettensis plant requires regular fertilization to promote growth and maintain proper health. Use a well-balanced fertilizer in the ratio of 10:10:10 every four to six weeks during the growing season. However, it is best to avoid fertilizing the plant during the dormant season.
Pruning
Pruning is essential in maintaining the shape and health of Oncoba tettensis. The plant generally requires minimal pruning, which involves removing diseased, damaged, or dead branches. Pruning should be done during the dormant season to minimize the risk of stress or reduced flowering.
Propagation of Oncoba tettensis (Klotzsch) Harv. var. tettensis
Oncoba tettensis (Klotzsch) Harv. var. tettensis can be propagated through seeds, stem cuttings, and root cuttings.
Propagation through seeds
The best time to collect the seeds is during the dry season. Once the fruits are mature and dry, the seeds can be easily separated from the fruit pulp. The seeds can be sown directly in the soil or nursery beds. They should be sown at a depth of 1-2 cm and watered regularly to keep the soil moist. Germination usually occurs within 2-3 weeks.
Propagation through stem cuttings
Stem cuttings can be taken during the rainy season when the plant is actively growing. Select well-matured stems with a diameter of 0.5-1 cm and a length of 10-15 cm. Remove the leaves from the lower half of the stem and dip the cut end in rooting hormone powder. Plant the cutting in a well-draining potting mix and keep the soil moist. Rooting usually occurs within 4-6 weeks.
Propagation through root cuttings
Root cuttings can be taken during the dormant season. Select well-developed roots with a diameter of 0.5-1 cm and a length of 10-15 cm. Cut the roots into smaller pieces with 2-3 buds each. Plant the cuttings horizontally in a well-draining potting mix and keep the soil moist. Shoots will emerge from the buds and rooting will occur within a few months.
Disease and Pest Management for Oncoba tettensis (Klotzsch) Harv. var. tettensis
Oncoba tettensis (Klotzsch) Harv. var. tettensis is a hardy plant that can grow in a range of environmental conditions. However, like any other plant species, it is susceptible to diseases and pests that can cause significant damage to the plant if left uncontrolled. This section provides valuable information on common diseases and pests that may affect Oncoba tettensis and ways to manage them effectively.
Common diseases
There are several diseases that can affect Oncoba tettensis. The most common ones include:
- Powdery mildew: This disease presents itself as a gray-white powdery substance on leaves and stems, leading to wilting and death of the plant if not treated. To manage powdery mildew, ensure the plant has good air circulation and check humidity levels in the surroundings. Fungicides can also be used to control the disease.
- Leaf spot: This disease presents itself as brown or black spots on leaves and can spread to other parts of the plant, causing defoliation and weakening the plant. To manage leaf spot, remove infected leaves and destroy them. Fungicides can also be used to control the disease.
- Root rot: This disease is caused by fungi that thrive in wet and poorly drained soil. It can cause stunted growth, yellowing of leaves, and rotting of the root system. To manage root rot, improve drainage around the plant, avoid over-watering, and use fungicides to control the disease.
Common pests
Oncoba tettensis is also susceptible to attack by pests, including:
- Mealybugs: These pests suck sap from the plant's foliage, causing yellowing, stunted growth, and wilting. To manage mealybugs, use insecticidal soap or horticultural oil to control the population.
- Aphids: These pests also suck sap from the plant's foliage, leading to wilting and stunted growth. They also produce honeydew that attracts ants and sooty mold. To manage aphids, use insecticidal soap or horticultural oil to control the population.
- Spider mites: These pests can rapidly reproduce and cause leaf yellowing, stippling, and bronzing. They thrive in hot and dry conditions. To manage spider mites, increase humidity around the plant, and use insecticidal soap or horticultural oil to control the population.
It's essential to detect and manage pests and diseases early before they spread and cause significant damage to the plant.
