Overview
Ochthocosmus calothyrsus (Mildbr.) Hutch. & Dalziel is a species of flowering plant in the family Rubiaceae. It is native to tropical Africa and can be found in countries such as Cameroon, Congo, and Gabon. Common names for this plant include "Mbogni", "Ntabo", and "Mpokpo".
Appearance
The Ochthocosmus calothyrsus plant typically grows to a height of 3-6 meters. It has a straight trunk with a diameter of up to 30 cm and a smooth grayish bark. The leaves are large, about 15-40 cm long and 10-15 cm wide, with a shiny, dark green upper surface and a lighter underside. The flowers are small, yellowish-white, and grow in clusters at the ends of branches. The fruit is a small, fleshy drupe that turns black when ripe.
Uses
In traditional African medicine, various parts of the Ochthocosmus calothyrsus plant are used to treat a variety of ailments. The bark of the tree is used to treat malaria, fever, and diarrhea, while the roots and leaves are used to treat coughs, skin infections, and wounds. The fruit is edible and is sometimes used to make a type of jam. In addition, the wood of the Ochthocosmus calothyrsus plant is used for construction, furniture, and fuel.
Overall, the Ochthocosmus calothyrsus plant is an important natural resource in many parts of Africa due to its medicinal properties, edible fruit, and various uses in construction and furniture-making.
Light Requirements
Ochthocosmus calothyrsus is a shade-loving plant and requires filtered light instead of direct sunlight. It cannot tolerate full sun exposure, and excessive sunlight exposure may cause leaf burn, yellowing, and wilting.
Temperature Requirements
The ideal temperature range for the growth and development of Ochthocosmus calothyrsus is moderate to warm. The plant can tolerate temperatures between 15°C to 30°C. However, it cannot withstand frost or extreme temperatures. Temperatures below 10°C can cause leaves to drop, while temperatures above 35°C may lead to scorching and leaf damage.
Soil Requirements
Ochthocosmus calothyrsus requires well-draining soil with a moderate amount of organic matter. The soil pH must be neutral to slightly acidic, ranging from 6.5 to 7.5. The plant prefers soils rich in nutrients and can tolerate sandy, loamy, or clay soils. However, excessively wet or waterlogged soil can lead to root rot, which may stunt plant growth and cause yellowing of leaves.
Cultivation methods
Ochthocosmus calothyrsus is an evergreen shrub that can grow up to 3 meters tall. It is best grown in tropical and subtropical regions with warm temperatures and high humidity. This plant thrives in well-draining soils with a pH of 5.5 to 6.5. Ensure that the planting area also has access to partial to full sunlight.
When propagating Ochthocosmus calothyrsus, use cuttings or seeds. Cuttings should be taken in the early summer and planted into a mix of perlite and peat moss. Sow seeds in the spring and lightly cover them with soil. Water them regularly to keep the soil evenly moist. This plant can also be propagated through air layering, where select branches are wrapped in sphagnum moss to encourage root growth.
Watering needs
Ochthocosmus calothyrsus requires regular watering to keep the soil moist. Water more frequently during periods of growth and less during the winter months. Do not let the soil dry out completely as this will cause stress to the plant and affect its growth.
Overwatering should also be avoided, as it can lead to root rot. It is best to water the plant early in the morning or late in the afternoon to avoid scorching the leaves during the hottest parts of the day.
Fertilization
To encourage growth and maintain the health of Ochthocosmus calothyrsus, the plant should be fertilized during the growing season. Use a balanced fertilizer with equal amounts of nitrogen, phosphorus, and potassium. Avoid using fertilizers that are high in nitrogen as this can lead to excessive leaf growth at the expense of flower production.
Fertilize the plant every three weeks during the growing season, and reduce frequency during the winter months when the plant is dormant. Follow the manufacturer's instructions regarding the amount and frequency of application.
Pruning
Pruning is essential to maintain the shape and size of Ochthocosmus calothyrsus. It is best to prune the plant immediately after flowering, in the early summer months, to encourage new growth.
Prune back any dead, diseased, or damaged branches to prevent the spread of disease. Remove any branches that are crossing over each other to prevent rubbing and encourage air circulation.
Always use sharp, clean tools when pruning to prevent injury to the plant and to prevent the spread of disease.
Propagation of Ochthocosmus calothyrsus
Ochthocosmus calothyrsus can be propagated through both sexual and asexual means. Sexual propagation is primarily through the use of seeds while asexual propagation can be achieved through stem cuttings, air layering, and grafting.
Propagation by seeds
The seeds of Ochthocosmus calothyrsus can be collected from mature fruits and sown in well-draining soil. The seeds should be sown at a shallow depth and covered with a thin layer of soil. The soil should be kept moist but not waterlogged and placed in a warm and well-lit area. The seeds will germinate within two to three weeks.
Propagation by stem cuttings
Stem cuttings are taken from the parent plant and rooted in a well-draining soil mix. The cuttings should be taken from the current year's growth and should be around 6 inches in length. The leaves at the bottom of the cutting should be removed, and the cutting should be dipped into rooting hormone powder. The cutting should be planted into the soil mix up to the first node and watered well. The cutting should be kept in a warm and well-lit area and misted regularly to maintain humidity. The cutting should root within 4 to 6 weeks.
Propagation by air layering
Air layering involves creating a small wound on a stem and encouraging it to produce roots where the injury occurred. This method is best used for older, woody stems. A section of bark is removed from around the stem, and rooting hormone is applied to the wound. A bag is then placed around the wound, and a moist soil mix is packed into the bag. The bag is secured with a tie, and the stem is left to root. Once roots have formed, the stem can be cut below the new root system and potted up.
Propagation by grafting
Grafting involves joining a scion of the desired plant to a rootstock of a related plant. This is a common method in the commercial production of Ochthocosmus calothyrsus. The scion is selected from a healthy parent plant and joined to a rootstock using a grafting technique. The two parts are held together until the graft has successfully taken and the new plant is established.
Disease Management
Ochthocosmus calothyrsus is susceptible to a few fungal and bacterial diseases that can cause significant damage to the plant if not managed properly. The common diseases that might affect the plant include:
- Anthracnose: It is a fungal disease that causes leaf spots, defoliation, and twig dieback. To manage this disease, infected plant parts should be removed and destroyed, and a fungicide application is recommended.
- Powdery Mildew: It is a fungal disease that appears as a white powdery layer on the leaves. To manage this disease, avoid overhead watering and ensure good air circulation around the plant. Applying a fungicide can also be helpful.
- Bacterial Blight: It causes leaf spots, wilting, and branch dieback. Removal of infected plant parts and use of copper-based bactericides can help manage this disease.
Pest Management
Ochthocosmus calothyrsus is also vulnerable to a few pests that can damage the plant's leaves and flowers. The common pests that might affect the plant include:
- Spider Mites: They are small mites that feed on the plant, causing leaf yellowing and bronzing. Use of insecticidal soap or horticultural oil can help control spider mites.
- Scale Insects: They are small, immobile insects that suck on the plant's sap, causing leaves to yellow and drop. Use of horticultural oil or a systemic insecticide can help manage scale insects.
- Thrips: They are tiny insects that feed on the plant's leaves and flowers, causing damage and discoloration. Use of insecticidal soap, spinosad, or a systemic insecticide can control thrips.
Regular scouting of the plants for any signs of diseases or pests is important for early detection and prompt management. Cultural practices such as proper irrigation, fertilization, and pruning can also help prevent diseases and pests in Ochthocosmus calothyrsus. In case of severe infestation, it is recommended to seek professional advice from a local cooperative extension service or a certified arborist.
