Overview of Dolichos saponarius De Wild.
Dolichos saponarius De Wild., also known as African yam bean, is a climbing legume plant that is native to Africa and widely cultivated in tropical regions. The yam bean is relatively unknown and underutilized in many countries, but it has great potential as a food and forage crop.
Appearance of Dolichos saponarius De Wild.
The plant is a long-lived perennial vine that can grow up to 2 meters tall. The leaves are pinnate and can be up to 30 cm long, with each leaf having 7 to 11 leaflets. The flowers are clustered in racemes and are usually purple or white in color. The pods are thick and elongated, measuring up to 15 cm in length, and contain 3 to 5 seeds.
Common Names of Dolichos saponarius De Wild.
Dolichos saponarius De Wild. is known by several common names in different locations including African yam bean, Sego bean, Atili, Jicama bean, and Awusa bean.
Uses of Dolichos saponarius De Wild.
The yam bean is a valuable food and forage crop in some African countries due to its high protein and nutrient content. The seeds can be cooked, roasted, or processed into flour and used in a variety of dishes such as stews, soups, and porridges. The tubers can be eaten raw or cooked and are also used in the production of local alcoholic beverages. The leaves and pods of the plant can be used as animal feed.
In addition, Dolichos saponarius De Wild. is useful in soil improvement due to its nitrogen-fixing properties.
Growth Conditions for Dolichos saponarius De Wild.
Dolichos saponarius De Wild. requires specific growth conditions to thrive. Below are the three primary growth conditions that this plant needs to grow successfully.
Light
Dolichos saponarius De Wild. requires full sunlight to grow. The plant needs approximately six hours of sunlight daily to receive the necessary amount of energy to synthesize food through photosynthesis.
Temperature
The plant grows best in areas with hot temperatures ranging between 21°C to 33°C (73.4°F to 91.4°F). Dolichos saponarius De Wild. is intolerant to frost and freezing temperatures. The plant can withstand temperatures down to 10°C (50°F) at night.
Soil Requirements
The ideal soil for Dolichos saponarius De Wild. to grow is well-drained, moist soil with a neutral pH range of 6.0 to 7.5. The plant can also grow in slightly acidic or alkaline soils. It prefers soils that are rich in organic matter, such as loam and sandy loam. The soil should have a good nutrient profile for the plant to acquire enough nutrients for growth.
Cultivation Methods
Dolichos saponarius De Wild., also known as the soap bean plant, is native to tropical West Africa. It thrives in warm climates with temperatures ranging from 20 to 30 degrees Celsius. It can be cultivated in a wide range of soils, although it prefers loamy or sandy soil that is well-drained. It requires full sun exposure for optimal growth and must be protected from strong winds as it has weak stems. The soap bean plant can be propagated through seeds and should be planted during the rainy season.
Watering Needs
The soap bean plant has moderate water needs and requires regular watering during the growing season. It is important to ensure that the soil is well-drained to prevent waterlogging, which can lead to root rot.
Fertilization
The soap bean plant requires regular fertilization to ensure optimal growth. A balanced fertilizer with a 10-10-10 nutrient ratio can be used during the growing season. It is also beneficial to incorporate organic matter such as compost into the soil.
Pruning
The soap bean plant has a sprawling growth habit and may require staking or trellising to support its weak stems. Regular pruning is necessary to control its growth and shape. Dead and diseased branches must be removed promptly to prevent the spread of diseases. Pruning also encourages the growth of new branches, which promotes a denser foliage. It is important to use sharp pruning tools to avoid damaging the plant.
Propagation of Dolichos saponarius De Wild.
Dolichos saponarius De Wild., commonly known as the "soap bean" or "african yam bean," can be propagated by various methods.
Seed Propagation
The plant can be propagated by sowing the seeds in well-drained soil. The seeds should be soaked in water for 24 hours prior to sowing to increase germination rates. The recommended soil temperature for germination is between 25-30°C. The seedlings will emerge within 7-10 days after sowing depending on soil temperature and moisture.
Vegetative Propagation
Dolichos saponarius De Wild. can be propagated vegetatively by stem cuttings, root cuttings, or layering.
Stem Cuttings: Stem cuttings should be taken from lateral branches and inserted into the soil media. The cuttings should be about 10-15cm long, and the lower leaves should be removed to reduce water loss. The cuttings should be lightly watered, and then covered with a plastic bag or placed in a propagator to maintain high humidity. The cuttings will root within 4-6 weeks.
Root Cuttings: Root cuttings should be taken from healthy roots and planted in well-drained soil. The cuttings should be about 5-8cm in length and placed vertically with the cut side facing downwards. The soil should be kept consistently moist, and the cuttings will develop roots within 3-4 weeks.
Layering: Layering is a method in which a branch is bent down to the ground and covered with soil, leaving the tip exposed. After some time, roots will form from the exposed part of the branch. The new plant can then be separated from the parent plant once the roots have developed sufficiently.
Disease and Pest Management for Dolichos saponarius De Wild.
Dolichos saponarius De Wild. is generally a low-maintenance plant that grows well in hot and dry environments, making it resistant to many pests and diseases. However, the following are some of the common diseases and pests that can affect the plant and suggestions to manage them:
Diseases
Anthracnose: This fungal disease causes circular, water-soaked lesions on the leaves, stems, and pods. As the disease progresses, the lesions become large and dark. Anthracnose can be prevented by planting disease-resistant varieties, applying fungicides, and avoiding excessive watering which can create a moist environment that encourages the development of the disease.
Bean rust: A fungal disease that causes yellow or orange-brown pustules to form on the underside of leaves. This disease can be managed by using rust-resistant varieties, avoiding overhead watering, and removing any infected leaves on the plant. Fungicides can also be used preventatively.
Mosaic virus: This viral disease causes leaves to develop mottled or streaked patterns. Unfortunately, there is no cure for mosaic virus, so infected plants should be removed immediately and destroyed to prevent the spread of the disease.
Pests
Aphids: These small, pear-shaped insects cluster on the undersides of leaves and suck sap from the plant. They can be managed by using insecticidal soaps, neem oil, or spraying the plant with a forceful stream of water to dislodge them.
Leaf miners: These insects cause tiny tunnels to appear on the surface of leaves. They can be prevented by maintaining a healthy garden by removing any infected or diseased plants, using sticky traps, and applying insecticides if necessary.
Cutworms: These caterpillars feed on the stems of young plants, causing the plant to fall over and die. Cutworms can be managed by tilling the soil in the fall to expose any overwintering larvae and using protective collars around young plants to prevent them from getting damaged.
By following these simple pest and disease management tips, Dolichos saponarius De Wild. can be kept healthy and thriving, providing beautiful foliage and flowers to enjoy.
