Origin
Dioscorea angustiflora Rendle is a climbing perennial plant species that belongs to the family Dioscoreaceae. The plant is native to West and Central Africa, where it primarily grows in forests at an altitude of 300-600 meters above sea level.
Common Names
The plant is commonly known as "Bush Yam" or "Wild Yam" due to the fact that it grows in the wild and produces edible tubers that resemble yams. In some African countries, it is called "Adui" in Kenya, "Akasanua" in Ghana, "Fumbwa" in the Democratic Republic of Congo, and "Mfumbwa" in Zambia.
Uses
The tubers of Dioscorea angustiflora Rendle are a source of food and income for many people in West and Central Africa. The tubers are boiled, roasted, or fried and eaten as a staple food or used as a thickener in soups and stews. The plant has also been used in traditional medicine to treat a variety of ailments, including malaria, stomach problems, and skin diseases. In addition, the plant has significant potential as a source of bioactive compounds that may have therapeutic or industrial applications.
General Appearance
Dioscorea angustiflora Rendle is a climbing plant that can reach heights of up to 10 meters. The leaves of the plant are heart-shaped and can grow up to 20 cm long and 14 cm wide. The plant produces small greenish-yellow flowers that are arranged in clusters at the ends of the branches. The tubers of the plant are oblong or cylindrical and can measure up to 60 cm in length and 10 cm in diameter. The skin of the tubers is rough and brown, and the flesh is white or yellowish.
Light Requirements
Dioscorea angustiflora grows best in areas that receive a lot of light. It requires full sunlight or partial shade to thrive. It is not recommended to plant it in areas that are heavily shaded. The plant benefits from at least 6 hours of direct sunlight each day.
Temperature Requirements
The optimal temperature range for Dioscorea angustiflora growth is between 21°C to 29°C. However, it can tolerate temperatures up to 35°C, but growth will be slower. The plant cannot withstand frost or temperatures below 10°C. In general, the plant prefers warm temperatures and requires a warm climate for optimal growth.
Soil Requirements
The plant prefers well-drained soils that are slightly acidic and high in organic matter. It thrives in soils that are rich in nutrients. Clay soils are not recommended as they hold water and can cause the root system to rot. Sandy loam and loamy soils are ideal for plant growth. The soil should be loose to encourage root growth. Adding organic matter, such as compost or manure, will help improve the soil's fertility and drainage.
Cultivation Methods
Dioscorea angustiflora Rendle is a vine that can be grown outdoors in warm tropical and subtropical climates. This plant requires full sun to partial shade for proper growth and should be grown in well-draining, fertile soil. The soil pH level should range from 6.0-6.5. Planting should ideally take place during the rainy season, as the plant requires sufficient moisture to establish well.
Watering Needs
Dioscorea angustiflora Rendle requires regular watering to keep the soil moist, especially during the dry season. However, it is necessary to avoid overwatering as it can lead to root rot. The water requirement may be lower during the rainy season, but careful checking of the soil moisture levels is necessary to ensure that the plant does not get too dry in between rainfall.
Fertilization
Dioscorea angustiflora Rendle can benefit from periodic application of fertilizers to encourage healthy growth and improve yield. Fertilizers should be applied at the start of the growing season and at midseason during the plant's most active growth period. The fertilizer should be rich in nitrogen, potassium, phosphorus, and other essential trace elements. Use of an organic fertilizer is most appropriate for this type of plant.
Pruning
Dioscorea angustiflora Rendle requires minimal pruning as it tends to spread out on its own. However, some limited pruning can be done to manage the size and shape of the plant. Pruning should be done during winter after the plant has gone dormant. It is best to remove any dead or damaged branches and to trim the plant to maintain its size and shape within the available trellis or support structure.
Propagation of Dioscorea angustiflora Rendle
Dioscorea angustiflora Rendle, also known as the Narrow-flowered yam, is propagated by several methods, including:
Seed propagation
The Narrow-flowered yam can be propagated by seed. The seeds of this plant are small and dark. They should be sown in a well-draining potting mix, covered with a thin layer of soil and kept in a warm and moist environment. Germination can take several weeks to several months. The young seedlings should be transplanted to individual pots once they develop their first set of true leaves.
Division propagation
Dioscorea angustiflora Rendle can also be propagated by dividing its rhizomes. This is typically done when the plant becomes crowded in a pot or when it has outgrown its space in the garden. The rhizomes should be carefully separated to ensure that each division has enough roots and shoots to grow. They should be replanted immediately in a well-draining potting mix or a prepared garden bed.
Cutting propagation
Dioscorea angustiflora Rendle can be propagated by stem cuttings, but this method is less common. Stem cuttings should be taken from healthy and mature plants, ideally in the spring or summer. The cuttings should be at least 6 inches long and should have several leaves. They should be planted in a well-draining potting mix and kept in a warm and humid environment until they develop roots.
Regardless of the propagation method, the Narrow-flowered yam requires regular watering, fertilization and pruning to ensure optimal growth and health.
Disease and Pest Management for Dioscorea angustiflora Rendle
Dioscorea angustiflora Rendle is a species of yam that originates from Nigeria and Cameroon. Like other crops, this plant can be subjected to various diseases and pests. Therefore, it's crucial to implement effective disease and pest management strategies to ensure a healthy yield.
Common diseases that affect Dioscorea angustiflora Rendle
One of the most common diseases that can affect Dioscorea angustiflora Rendle is anthracnose, which is caused by the Colletotrichum gloeosporioides fungi. This disease normally affects leaves and can cause dark spots, dead tissue, and stem rot. The best management strategy for anthracnose is to remove and destroy all infected plants and avoid planting yams in the same area for at least two years.
Another disease that can affect Dioscorea angustiflora Rendle is powdery mildew. Powdery mildew is caused by various fungi that can create a white powdery film on the leaves and stems of the plant. To manage powdery mildew, use fungicides, and remove all infected plants.
Common pests that affect Dioscorea angustiflora Rendle
One of the most common pests that can affect Dioscorea angustiflora Rendle is the yam beetle, Heteroligus meles. The beetle larvae can cause serious damage to the plant's leaves and stems. The best way to control yam beetle larvae is to remove any adult beetles that are visible and spray a pesticide to control the larvae.
The mealybug is another pest that can attack Dioscorea angustiflora Rendle. The mealybug feeds on the sap of the plant, which causes the leaves to wilt and brown. To control mealybugs, use insecticidal soap or neem oil, and remove heavily infested plants.
Conclusion
Effective disease and pest management strategies are essential for cultivating healthy and productive Dioscorea angustiflora Rendle crops. To maintain a healthy yield, it is necessary to identify and respond to signs of pests and diseases as early as possible, by taking the measures discussed above.
