Physostigma Balf. Description
Physostigma Balf., also known as Calabar bean, is a perennial plant native to West Africa, specifically Nigeria and Cameroon. It belongs to the Fabaceae family and has an almond-like shape that can grow up to 15-20 cm in length. The plant has a unique appearance with its dark green color and white striations.
Physostigma Balf. Common Names
Calabar bean is the most common name used for Physostigma Balf. due to its origin from Calabar, Nigeria. Other common names for this plant include esere, esere-ndi, and arimu.
Physostigma Balf. Uses
The leaves, seeds, and roots of the Calabar bean have been used for medicinal purposes for centuries. The plant contains alkaloids, notably physostigmine, which is a potent cholinesterase inhibitor that has been used to treat glaucoma, Alzheimer's disease, and myasthenia gravis. Besides, it has been used for traditional practices such as treating snake bites and stomach disorders. In some areas of West Africa, the plant has also been used as a hunting tool by poisoning insects and rodents for easy hunting.
Physostigma Balf. General Appearance
Physostigma Balf. is a woody vine or shrub that can grow up to 3 meters in height. The plant has a dark green color with white striations and has large, beautiful flowers that can be pink or purple in color. The leaves are pinnate and have elliptical leaflets that are pointed at the base. The seeds are the most notable feature of the plant, as they have a unique shape and are used for medicinal purposes.
Light Requirements
Physostigma Balf. requires bright indirect sunlight. Direct sunlight can scorch the leaves of the plant. Therefore, it should be placed in a location where it can receive bright light but is protected from direct sunlight.
Temperature Requirements
Physostigma Balf. requires warm temperatures to grow well. The ideal temperature range for this plant is between 16-24°C. It cannot tolerate temperatures below 13°C or above 30°C. To maintain optimal growth, protect it from cold drafts and avoid exposing it to extreme temperatures.
Soil Requirements
Physostigma Balf. prefers a well-draining soil that is rich in organic matter. The soil must be kept moist but not waterlogged, as excessive moisture can cause root rot. A soil mix that contains peat moss, perlite, and vermiculite can be used. Ensure that the pot has proper drainage to avoid waterlogging and root rot.
Cultivation Method
The Physostigma Balf. plant is typically grown as a perennial plant in warm, tropical climates. It prefers well-draining soil, rich in nutrients and organic matter, and a mildly acidic pH range of 6.0 to 6.5. The plant is usually propagated through seeds or stem cuttings, and planting should be done during the warm season when temperatures are around 30°C. For best results, the plant should be grown in full sun to partial shade and sheltered from strong winds.
Watering Needs
Physostigma Balf. plant requires adequate watering, especially during the growth period. The plant should be watered deeply, but not too frequently, to avoid waterlogging, which can lead to root rot. One should ensure that the soil remains moist, but not soaked, in between watering. In the dry season, the plant should be watered regularly and deeply, preferably in the early morning or late evening, to prevent water loss through evaporation. Watering should be reduced during the winter season when the plant becomes dormant.
Fertilization
The Physostigma Balf. plant requires regular fertilization for healthy growth and optimal yields. A balanced fertilizer with an NPK ratio of 20:20:20 is recommended during the growing season, which should be applied every two to three weeks. During the flowering period, a fertilizer high in phosphorus, such as a 10:30:10 ratio, is recommended every three weeks to boost flower production and quality. Slow-release fertilizers can also be used to provide long-term nutrient supply.
Pruning
The Physostigma Balf. plant requires regular pruning to control its size, shape, and encourage healthy growth and flower production. Pruning should be done in the early spring before the growing season begins and after the flowering period. The plant can be pruned by removing any dead or damaged leaves, stems, or branches, as well as any weak or crossing branches. The top and sides of the plant should be trimmed to promote bushiness and flowering. Pruning should be done using a sharp and sterilized pruning saw or shears. Suckers or offshoots from the base of the plant can be removed to prevent overcrowding and maintain the plant's shape.
Propagation of Physostigma Balf.
The plant Physostigma Balf., commonly known as the Calabar bean, can be propagated in several ways. It is important to note that the plant contains toxic alkaloids and should be handled with care.
Seed Propagation
The plant produces pods containing seeds. The seeds must be harvested when they are mature and dry. The seeds need scarification before planting, which is the process of breaking or weakening the seed coat to assist with germination. Scarification can be accomplished by soaking the seeds in hot water or by nicking the seed coat with a file or knife. The seeds should be planted in containers filled with a well-draining soil mix. Keep the soil moist but not overly wet. Germination generally takes between 14 and 21 days.
Vegetative Propagation
Physostigma Balf. can also be propagated vegetatively through stem cuttings. Take cuttings from the plant in the spring or summer. Cut a healthy stem with a sharp, sterile knife just below a leaf node. Remove the lower leaves from the cutting and dip the cut end in rooting hormone. Place the cutting in a container filled with a well-draining soil mix and keep the soil moist. The cutting should root within a few weeks. Once the cutting has rooted, transplant it to a larger container or directly into the garden.
Division Propagation
Another way to propagate Physostigma Balf. is through division. Carefully dig up an established plant, being mindful of the toxic alkaloids. Using a sharp, sterile knife, divide the plant into several sections, with each section containing at least one stem and several roots. Replant the divided sections in a well-draining soil mix, keeping the soil moist until new growth appears.
Disease Management for Physostigma Balf.
Physostigma Balf. can be affected by various diseases, including fungal and viral diseases. However, the most common disease that affects this plant is root rot.
Root rot is caused by waterlogging of the soil that leads to the growth of fungi, which thrive in wet conditions. Symptoms of root rot include yellowing of leaves, wilting, and stunted growth.
To manage root rot, you should get rid of any standing water around the plant and ensure that the soil is well-draining. If the roots are already affected, you can use fungal treatments, such as copper or sulfur-based fungicides to control the infection. Pruning the infected roots might also help save the plant from further damage.
Pest Management for Physostigma Balf.
Physostigma Balf. can also be affected by several pests, including spider mites, mealybugs, and aphids.
Spider mites are the most common pest that infests this plant. They suck sap from the leaves, causing wilting, yellowing, and drying out of the plant. To manage spider mites, you can spray the plant's leaves with insecticidal soap or neem oil. You can also increase humidity around the plant to repel spider mites.
Mealybugs and aphids are other pests that can infest Physostigma Balf. and cause damage. They can be controlled by wiping off the insects with a damp cloth and using insecticidal soap to prevent future infestations. You can also introduce natural predators, such as ladybugs or lacewings, to feed on the pests and keep their population under control.
To prevent the onset of pests and diseases, you should ensure that the plant is grown in a well-drained soil, watered adequately, and provided with enough sunlight. Additionally, ensure to keep the plant clean by regularly wiping off the leaves with a damp cloth and checking the leaves' undersides for any pests.
