Origin
Sphenostylis erecta (Baker f.) Hutch. ex Baker f. subsp. obtusifolia (Harms) Potter & Doyle, commonly known as African Yam Bean, is a legume plant species native to tropical Africa. It is a hardy perennial plant that grows well in warm climates and can be found in countries such as Nigeria, Ghana, Ivory Coast, and Cameroon.
Common Names
African Yam Bean is known by various names depending on the region it is found in. Some of its common names include Jicama de Africa, Okpodudu, Ugba, and Aki awusa.
Uses
African Yam Bean has both culinary and medicinal uses. In African cuisine, the seeds and tubers of this plant are consumed as a nutritious food source. The seeds can be boiled, roasted, or cooked in stews and soups. The tubers, which are similar in appearance to yams, can be peeled, sliced, and fried. The leaves of the plant are also edible and can be used as a vegetable.
In traditional medicine, African Yam Bean is used to treat various ailments such as diarrhea, dysentery, and stomachaches. The plant is also believed to have anti-inflammatory and antioxidant properties and is used to boost the immune system.
General Appearance
African Yam Bean is a climbing plant that can grow up to 3 meters long. It has a woody base and a slender stem with tendrils that help it climb. The leaves are trifoliate, with each leaflet measuring up to 15 cm long and 8 cm wide. The plant produces white, pink, or purple flowers that are about 2 cm long and borne in clusters. The fruits are oblong pods that measure about 10 cm long and contain up to 20 seeds per pod. The seeds are brown, black or white and are similar in size and shape to kidney beans.
Growth Conditions for Sphenostylis erecta subsp. obtusifolia
Light: Sphenostylis erecta subsp. obtusifolia grows best in full sun. It requires at least six hours of direct sunlight each day. If the plant is grown in partial shade, it may produce fewer flowers and less fruit than plants grown in full sun.
Temperature: Sphenostylis erecta subsp. obtusifolia is a warm-season crop that requires a minimum temperature of 18°C (65°F) for successful growth. It grows best in temperatures between 25°C (77°F) and 30°C (86°F). Temperatures above 35°C (95°F) can decrease fruit production and quality. The plant is sensitive to frost and cannot tolerate temperatures below 5°C (41°F).
Soil: Sphenostylis erecta subsp. obtusifolia prefers well-drained soil with a pH between 6.0 and 7.5. It can tolerate relatively poor soil, but will not grow well in heavy clay or waterlogged soil. The plant requires good drainage to prevent root rot, especially during the rainy season. The addition of organic matter such as compost or well-rotted manure can improve soil structure and fertility.
Cultivation Methods
Sphenostylis erecta (Baker f.) Hutch. ex Baker f. subsp. obtusifolia (Harms) Potter & Doyle is a plant that can be grown in tropical and subtropical regions. It requires a well-draining soil mix with a pH range of 6.0 to 7.0. The plant prefers full sunlight, but it can also grow in partially shaded areas. Propagation can be done by seed or vegetative means. Seeds should be soaked for 24 hours to enhance germination. After germination, the seedlings can be transplanted into small pots or directly into the ground.Watering Needs
Sphenostylis erecta (Baker f.) Hutch. ex Baker f. subsp. obtusifolia (Harms) Potter & Doyle requires adequate watering, especially during the growing season. The plant does not tolerate waterlogging, so it is essential to ensure that the soil drains well. Watering should be done deeply and less frequently than light watering, which can lead to shallow roots and poor growth.Fertilization
Sphenostylis erecta (Baker f.) Hutch. ex Baker f. subsp. obtusifolia (Harms) Potter & Doyle requires regular fertilization to ensure that it grows and matures optimally. Fertilization should be done every six to eight weeks using a balanced fertilizer.Pruning
Sphenostylis erecta (Baker f.) Hutch. ex Baker f. subsp. obtusifolia (Harms) Potter & Doyle requires minimal pruning. However, removing the dead or damaged parts of the plant can help to promote new growth. If the plant becomes too bushy, thinning it out by removing some branches can help to enhance air circulation and light penetration, leading to better growth.Propagation of Sphenostylis erecta subsp. obtusifolia
Sphenostylis erecta subsp. obtusifolia can be propagated by various methods. The following are the most commonly used:
Seed Propagation
Seeds of Sphenostylis erecta subsp. obtusifolia can be sown directly into the ground, or into seed trays filled with well-draining potting mix. The seeds should be sown at a depth of 2-3 cm and kept moist until germination. Germination usually occurs within 7-14 days. Seed propagation is the most common method used for the propagation of this plant.
Cuttings Propagation
Softwood or semi-hardwood cuttings taken from Sphenostylis erecta subsp. obtusifolia can be used for propagation. Cuttings should be taken from the plant during the growing season, usually in the spring or early summer. Cuttings should be about 10-15 cm long and should have a couple of nodes. The cuttings should be dipped in rooting hormone and placed in a well-draining potting mix. Cuttings should be kept moist and warm until roots develop, usually within 6-8 weeks.
Division Propagation
Sphenostylis erecta subsp. obtusifolia can be propagated by division. The plant should be dug up, and the root ball should be divided into separate plants. Each plant should have a few stems and a good root system. The separated plants can be re-potted into well-draining potting mix and kept in a warm, shady area until they become established.
Disease Management
Sphenostylis erecta subsp. obtusifolia is susceptible to some diseases such as:
- Anthracnose: a fungal disease that causes dark spots, wilting, and defoliation. Anthracnose can be managed by removing infected plant parts and spraying the plant with fungicides.
- Rust: a fungal disease that causes reddish-brown spots on leaves and stems. Rust can be managed by removing infected plant parts and spraying the plant with fungicides.
- Root rot: a fungal disease that causes the plant to wither and die. Root rot can be managed by avoiding overwatering and using well-drained soil.
Pest Management
Sphenostylis erecta subsp. obtusifolia is also susceptible to pests such as:
- Aphids: small insects that feed on the plant sap, causing stunted growth and yellowing leaves. Aphids can be managed by spraying the plant with insecticidal soap or neem oil.
- Spider mites: tiny arachnids that feed on the plant sap, causing yellowing and dry leaves. Spider mites can be managed by spraying the plant with neem oil or horticultural oil.
- Cutworms: caterpillars that feed on the stem of the plant, causing the plant to wilt and die. Cutworms can be managed by handpicking them or using insecticides containing Bacillus thuringiensis.
Regular monitoring of the plant for signs of disease and pests can help prevent their spread and minimize the damage to the plant. Using organic and chemical control methods can effectively manage disease and pest problems in Sphenostylis erecta subsp. obtusifolia.
