Markhamia Zanzibarica (bojer Ex Dc.) K.schum.

Overview: Markhamia zanzibarica (Bojer ex DC.) K.Schum.

Markhamia zanzibarica (Bojer ex DC.) K.Schum. is a perennial and deciduous tree from the family of Bignoniaceae. It is commonly known as the bell bean tree and is native to tropical African countries such as Tanzania, Uganda, Kenya, Mozambique, Malawi, and Zimbabwe.

Appearance:

The bell bean tree can grow up to 25 m tall and can have a trunk diameter of up to 60 cm. It has a grey-brownish bark which is rough and corky, and the young branches are greenish-brown with tiny hairs. The leaves are compound, with five to seven leaflets, measuring 15-25 cm in length and 7-13 cm in width. During the flowering period, the tree produces clusters of up to 15 trumpet-shaped flowers, which are fragrant and range in color from pale yellow to pink or creamy white. The fruit is a long and slender capsule, measuring up to 30 cm in length.

Uses:

The bark, leaves, and roots of the bell bean tree have various medicinal properties and are used to treat a variety of ailments such as malaria, coughs, and digestive problems. In traditional African medicine, the plant is used as an arrow poison. The wood of the tree is used for carving and lighter constructions such as boats and boxes.

Furthermore, the tree has ornamental value, and it is planted in many tropical regions as a shade tree or as a flowering tree in parks and gardens. The bell bean tree is also known to have soil-improving qualities, and it is used in agroforestry systems to prevent soil erosion and improve soil fertility.

In conclusion, the Markhamia zanzibarica (Bojer ex DC.) K.Schum. is an attractive and highly valued plant in many tropical countries. Its medicinal properties, ornamental value, and positive impact on the environment make it an excellent choice for sustainable agriculture and landscaping.

Light Requirements

Markhamia zanzibarica is a tropical plant which prefers bright and direct sunlight. It requires at least 6 hours of sunlight daily for optimal growth. The plant can tolerate partial shade, but inadequate light can cause it to grow slowly or not at all.

Temperature Requirements

The ideal temperature for Markhamia zanzibarica growth ranges from 18°C to 35°C. The plant cannot withstand temperatures below 10°C, which can cause frost damage. In general, this plant thrives best in a warm and humid environment, typical of most tropical regions.

Soil Requirements

Markhamia zanzibarica requires well-draining soil that is rich in organic matter. The pH of the soil should be neutral to slightly acidic, ranging between 6.0 and 7.5. Soil that is too compact or too wet can cause root rot. Therefore, the soil's drainage must be adequate to allow the water to seep through it easily. The plant prefers a soil depth of at least 1.5 meters to allow healthy root development.

Cultivation of Markhamia zanzibarica

Markhamia zanzibarica is an evergreen tree that grows well in tropical and subtropical climates. It can grow up to 20 meters in height and is commonly found in East Africa. The following are some guidelines for cultivating Markhamia zanzibarica:

• Choose a sunny location: Markhamia zanzibarica requires plenty of sunlight to grow well.
• Suitable soil: The tree grows well in well-draining soil with a pH range between 6 and 7.5.
• Seedlings: Seedlings should be planted during the rainy season to give them enough time to establish themselves before the onset of the dry season.
• Spacing: Markhamia zanzibarica trees should be spaced at least 6 meters apart to allow for adequate growth.

Watering Needs

Markhamia zanzibarica requires regular watering, especially during the dry season. The following are some guidelines for watering:

• Water frequently during the first year after planting to ensure the tree's establishment.
• After the tree has become established, water only when necessary, and avoid overwatering, as this can cause root rot.
• It is best to water the tree early in the morning or late in the evening to minimize water loss due to evaporation.

Fertilization

Fertilization is essential for the proper growth of Markhamia zanzibarica. The following are some guidelines for fertilization:

• Apply a balanced fertilizer with a 3:1:2 or 4:1:2 ratio to the soil around the tree's base.
• Fertilization should be done during the rainy season to allow for proper absorption.
• Fertilize the tree twice a year, once during the rainy season and once during the dry season.

Pruning

Pruning is necessary for the healthy growth of Markhamia zanzibarica. The following are some guidelines for pruning:

• Pruning should be done during the dry season, as this is when the tree is dormant.
• Remove any dead or damaged branches to promote healthy growth.
• Trim the lower branches of the tree to a height of 2 meters to allow for ease of movement.
• Trim the upper branches to allow for proper light penetration.

Propagation of Markhamia zanzibarica

Markhamia zanzibarica (Bojer ex DC.) K.Schum. can be propagated through two major methods, namely:

1. Seed Propagation

The easiest and most popular way to propagate Markhamia zanzibarica (Bojer ex DC.) K.Schum. is by using its seeds. The seeds of this plant are readily available and easy to collect. Here are the steps to follow when propagating this plant through seeds:

1. Collect the seeds when the plant is shedding off its capsules.
2. Remove the seed coat to allow easy germination.
3. Sow the seeds in well-drained soil in a nursery bed.
4. Cover the seeds with a thin layer of soil and keep the soil moist but not waterlogged.
5. Germination of the seeds should occur within 2 to 3 weeks.
6. Transplant the seedlings into individual pots when they have developed two pairs of true leaves.
7. After 6 to 8 months, the seedlings should be tall enough to transplant into their permanent position.

2. Vegetative Propagation

Vegetative propagation is another way of propagating Markhamia zanzibarica (Bojer ex DC.) K.Schum. This method requires cutting a stem from the plant and rooting it to form a new plant. Here are the steps to follow when using vegetative propagation:

1. Select a healthy branch of about 1 to 2 meters long from the plant.
2. Cut the branch into segments of about 20cm long.
3. Remove the leaves from the lower part of the cutting till only 3 to 4 leaves are left at the top.
4. Apply rooting hormone powder on the lower part of the cutting to enhance rooting.
5. Plant the cuttings vertically in a nursery bed filled with moist soil mixed with sand.
6. Water the cuttings regularly to keep the soil moist.
7. The cuttings will start developing new shoots in about 3 weeks, indicating that rooting has taken place.
8. After 6 to 8 weeks, transplant the cuttings into individual pots.
9. After another 6 to 8 months, the plants can be transplanted into their permanent position.

Disease Management

Markhamia zanzibarica is a relatively resilient plant, but some diseases can affect it. One common fungal disease that affects the plant is powdery mildew. This disease manifests as a white powdery growth on the leaves, and it can stunt the plant's growth if not controlled.

To manage powdery mildew, you should remove all infected leaves and dispose of them immediately. You can also use a fungicide to control the spread of the disease. However, you should always follow the instructions on the fungicide's label, as excessive use can damage the plant.

Another disease that affects Markhamia zanzibarica is root rot. This disease is caused by waterlogged soil or poor drainage, and it can cause the plant's leaves to wilt and its stem to become discolored. To manage root rot, you should improve soil drainage and avoid overwatering the plant.

Pest Management

Markhamia zanzibarica is also vulnerable to pest infestations. One common pest that affects the plant is the mealybug. Mealybugs are small, white insects that feed on the plant's sap, causing its leaves to yellow and wilt.

To manage mealybugs, you should spray the plant with a mixture of water and insecticidal soap. You can also remove any visible mealybugs manually with a cotton swab dipped in rubbing alcohol. However, you should be careful not to damage the plant while doing so.

Another pest that affects Markhamia zanzibarica is the spider mite. Spider mites are tiny pests that suck on the plant's sap, causing its leaves to turn yellow and become speckled. To manage spider mites, you should increase the plant's humidity levels by misting it with water regularly. You can also spray the plant with a mixture of water and neem oil to control the infestation.

Overall, managing diseases and pests in Markhamia zanzibarica requires a proactive approach. Regularly monitoring the plant and taking steps to prevent and control infestations can help ensure the plant's health and longevity.