Overview
Strychnos usambarensis Gilg, also known as the "African Poison Strainer," is a plant species that belongs to the family Loganiaceae. It is native to the African continent and can be found in various countries such as Uganda, Tanzania, and Kenya. The plant is widely known for its poisonous properties and has been used in traditional medicine for centuries.
Common Names
The plant is known by several common names, including the "African Poison Strainer," "East African Orange," "Muvumu," and "M'vumu." The name "Muvumu" is derived from Swahili, a Bantu language widely spoken in East Africa, meaning "that which strengthens the body."
Uses
The plant is highly toxic and contains strychnine, a potent alkaloid that affects the nervous system. Despite its toxicity, the plant has been used in traditional medicine for various ailments, including malaria, convulsions, and snake bites. The plant's bark is also used as a fish poison in some parts of Africa. Additionally, the plant has cultural significance and is used in various rituals and ceremonies among some African communities.
General Appearance
The Strychnos usambarensis Gilg plant is a small to medium-sized tree that can grow up to 20 meters in height. The bark is gray and rough, while the leaves are dark green, glossy, and leathery. The plant produces beautiful, cream-colored flowers that are about 4cm in diameter. The fruits are large, orange, and berry-like, with a diameter of about 6cm. The plant's seeds are small and flat, with a hard outer coat that protects the poisonous kernel inside.
Light Requirements
Strychnos usambarensis Gilg thrives in moderate to high light conditions. It requires a minimum of six hours of sunlight daily, and it generally grows best in full sun with some shade in the afternoon.
Temperature Requirements
Native to East Africa, Strychnos usambarensis Gilg prefers warm and humid climates. It grows in temperatures between 10°C to 40°C.
Soil Requirements
Strychnos usambarensis Gilg requires well-draining soil with good fertility. It primarily grows on rocky, well-drained slopes with sandy and/or loamy soil. It needs soil with a pH of 5.5-6.5 and can tolerate soil with a pH of 7.5.
Cultivation Methods
Strychnos usambarensis Gilg is a tropical plant that requires warm temperatures to grow well. It should be planted in well-drained soil that is rich in organic matter. The plant prefers full sun but can also tolerate partial shade.
Propagation can be done either through seeds or stem cuttings. The seeds should be soaked in water overnight before planting in a seedbed. The stem cuttings should be taken from healthy plants during the growing season, preferably in the morning hours, and should be treated with rooting hormone before being planted in well-prepared soil.
Watering Needs
The watering needs of Strychnos usambarensis Gilg vary depending on the growth phase of the plant. During the planting phase or establishment phase, the plant needs to be watered regularly to encourage root growth. Once established, the plant can tolerate some drought and should be watered only when the soil is dry to the touch. Overwatering the plant can lead to root rot and other water-related problems.
Fertilization
Strychnos usambarensis Gilg responds well to regular fertilization during the growing season. The best time to fertilize the plant is in the early spring or fall when the plant is actively growing. Use a balanced fertilizer that contains all the essential nutrients required for plant growth. Organic fertilizers such as compost or manure can also be used to improve the soil structure and nutrient content.
Pruning
Pruning is an essential practice in maintaining the shape and health of Strychnos usambarensis Gilg. The best time to prune the plant is during the dormant season, preferably in winter or early spring before the plant starts growing. The aim of pruning is to remove any dead or diseased branches, improve air circulation, and control the size and shape of the plant. Care should be taken not to remove too many branches as this can weaken the plant.
Propagation of Strychnos usambarensis Gilg
Strychnos usambarensis Gilg can be propagated through different methods such as seeds, cuttings, and through root suckers.
Propagation through Seeds
The easiest and most common method of propagation for Strychnos usambarensis Gilg is through seeds. The seeds should be collected from ripe fruits and sowed immediately. It is recommended to sow the seeds at a depth of 1–2 cm in a nursery bed or pots filled with rich, well-draining soil. Keep the nursery bed or pots moist and free from weeds. Germination can be expected between 2-6 weeks and seedlings will be ready for transplanting after 6 months to 1 year.
Propagation through Cuttings
Propagation through stem-cuttings is possible but difficult due to the plant's strong apical dominance. It is recommended to select semi-hardwood stem cuttings from the previous season's growth. Cuttings should be about 10-15 cm long and should be treated with rooting hormones and kept in humid conditions. Cuttings can then be inserted into a well-drained soil mix and kept moist until they form roots. Transplanting of cuttings can be done after 6 months.
Propagation through Root Suckers
The sprouting of new shoots from an established plant's roots is known as root suckering. This method of propagation is usually utilized when there is a need to propagate a specific variety or maintain the same characteristics as the parent plant. Root suckers should be dug out carefully and should have sufficient root development before being transplanted to a well-prepared soil bed.
Disease and Pest Management for Strychnos usambarensis Gilg Plant
Strychnos usambarensis Gilg, commonly known as the green monkey orange, is an evergreen tree that belongs to the Loganiaceae family. The tree is commonly found in East Africa, particularly in Tanzania, Uganda, and Kenya. Like any other plant, the green monkey orange is susceptible to diseases and pests that can significantly reduce its yield if not appropriately managed. In this write-up, we will discuss some of the common pests and diseases that affect the plant and suggest ways of managing them.
Common Pests
The Strychnos usambarensis Gilg plant is prone to attack by several pests, including:
- Monkey beetles: The beetles are major pests to the plant, especially during the flowering period, where they cause significant damage to the flowers and fruits.
- Caterpillars: Caterpillars cause damage to the leaves, leading to reduced photosynthesis and subsequent stunted growth and decreased productivity.
- Fruit flies: The fruit flies lay their eggs on ripening fruits, causing them to rot and eventually yield low quality or no yield at all.
Pest Management
To manage pests, it is essential to adopt an integrated pest management approach, which involves the following actions:
- Cultural control practices: Such practices involve maintaining clean farming practices and improving the general plant's health by weeding and pruning when necessary.
- Biological control: Involves the use of natural enemies, such as parasitoids, predators, and pathogens, to control the pest population.
- Chemical control: Can be used as a last resort when the pest population becomes uncontrollable. It involves the use of recommended pesticides, taking into account safety and environmental concerns.
Common Diseases
Strychnos usambarensis Gilg plant can also be affected by several diseases that include:
- Fungal leaf spot: Caused by several fungal pathogens that cause spots on the foliage.
- Dieback: Caused by several factors, including fungi such as Fusarium solani and Phytophthora cinnamomi.
- Root rot: Caused by Phytophthora spp. and Pythium spp., common soil-borne pathogens.
Disease Management
The following are some of the control measures for plant diseases:
- Cultural control practices: These include maintaining overall plant health, proper sanitation practices, and field management practices like crop rotation, inter-cropping, and weed control.
- Biological control: Biocontrol agents can be used to manage plant diseases. For example, Trichoderma spp., a beneficial fungus, can be used to control root pathogens by outcompeting them for nutrients and space.
- Chemical control: This should be the last resort. Pesticides should not be used unless necessary, and the recommended ones used while adhering to safety and environmental concerns.
In conclusion, the Strychnos usambarensis Gilg plant is susceptible to pests and diseases that can significantly reduce its yield. Effective management practices, including the adoption of an integrated pest and disease management approach, are necessary to mitigate the effects and improve the plant's productivity, leading to significant economic gains.
