Origin
Dioscorea smilacifolia De Wild. var. alternifolia De Wild., commonly known as "African yam" or "water yam," is a plant species that originated in West Africa. It can be found growing in a variety of habitats, including forest edges, savannas, and riverbanks.
Common Names
The plant is known by several common names in different regions of West Africa. In Nigeria, it is called "Ji akwukwo" in Igbo, "Efinrin" in Yoruba, and "Afia efere" in Efik. In Ghana, it is known as "Pona" in Twi and "Kpalu" in Ewe. It is also called "Kachilu" in Cameroon and "Agdéré" in Burkina Faso.
Uses
The edible tubers of the Dioscorea smilacifolia De Wild. var. alternifolia De Wild. are an important food source in many parts of West Africa. They can be boiled or roasted and eaten as a starchy vegetable. The leaves and stems are also sometimes used as a leafy vegetable, particularly in Nigeria and Ghana. Additionally, extracts from the plant have been traditionally used for medicinal purposes, including to treat fever, coughs, and skin conditions.
General Appearance
Dioscorea smilacifolia De Wild. var. alternifolia De Wild. is a climbing vine that can grow up to 15 meters in length. It has heart-shaped leaves that are glossy and dark green in color. The plant produces tubers that are elongated and cylindrical, with a rough, dark brown skin. The flesh of the tuber is white or cream-colored and has a starchy texture. The plant also produces small, greenish-white flowers that are arranged in clusters along the stem. The fruit is a capsule that contains several small seeds.
Light Requirements
Dioscorea smilacifolia De Wild. var. alternifolia De Wild. requires a moderate amount of sunlight to grow properly. It thrives in partially shaded to lightly shaded areas, but cannot tolerate total darkness. Direct sunlight for prolonged periods can damage the plant. Therefore, it is recommended to grow it under the shelter of larger trees or bushes.
Temperature Requirements
The ideal temperature range for the growth of Dioscorea smilacifolia De Wild. var. alternifolia De Wild. is between 18°C to 30°C. It prefers a warm and humid climate with a stable temperature. The plant can tolerate slight temperature fluctuations and occasional cold spells, but frost can be detrimental to its health.
Soil Requirements
The soil should be well-drained, moist, and rich in organic matter for proper growth of Dioscorea smilacifolia De Wild. var. alternifolia De Wild. The plant prefers slightly acidic to neutral soil with a pH range of 5.5 to 7.5. The presence of clay or loam in the soil can help retain moisture, but excessive waterlogging can cause rot and disease. Regular fertilization with nitrogen, phosphorus and potassium can also enhance the growth and yield of the plant.
Cultivation of Dioscorea smilacifolia De Wild. var. alternifolia De Wild.
Dioscorea smilacifolia De Wild. var. alternifolia De Wild. is a climbing plant that can grow to a height of 3-4 meters. It is mainly propagated through seed, tubers, or cuttings. For best results, it should be grown in well-drained soil that is rich in organic matter and has a pH of 6-7. The plant requires support for climbing, whether by providing trellis, fence or poles.
Watering Needs of Dioscorea smilacifolia De Wild. var. alternifolia De Wild.
The plant requires adequate watering, especially during the dry season. However, it does not tolerate waterlogging, which can cause the roots to rot. Therefore, it is important to ensure that the soil is well-drained to prevent waterlogging. The frequency of watering depends on the prevailing weather conditions, and one should avoid over-watering as this can lead to disease and pest infestations.
Fertilization of Dioscorea smilacifolia De Wild. var. alternifolia De Wild.
The plant requires regular fertilization to provide the necessary nutrients for growth and development. The best time to apply fertilizer is during the planting stage and at the beginning of the growing season. A balanced NPK fertilizer should be used, with a ratio of 10-10-10 or 14-14-14. Organic fertilizers such as compost can also be used to supplement the soil with organic matter and micronutrients.
Pruning of Dioscorea smilacifolia De Wild. var. alternifolia De Wild.
Pruning is necessary to control the growth of the plant and promote the development of lateral branches. It can also help to facilitate harvesting by making it easier to access the tubers. Pruning should be done during the dormant season, typically in the winter or early spring. It is recommended to remove old or diseased wood, as well as any crossing or rubbing branches. Cutting back the top growth can also encourage the development of new shoots and lateral branches.
Propagation of Dioscorea smilacifolia var. alternifolia
Dioscorea smilacifolia var. alternifolia De Wild. is a perennial plant that is mainly propagated vegetatively. There are different propagation methods that can be utilized to propagate this plant such as:
Tuber division
The most common method used to propagate Dioscorea smilacifolia var. alternifolia is through tuber division. Tuber division involves separating the tubers from the parent plant and planting them individually. This method is best done during the dormant period, which is usually in the winter months. The tubers should be carefully removed from the soil and any debris cleaned off. Then they can be divided into several sections, with each section containing a bud or sprout. These sections can then be planted in pots or directly in the ground.
Cuttings
Dioscorea smilacifolia var. alternifolia can also be propagated through cuttings. To propagate through cuttings, select healthy stems from the parent plant and cut them into sections with at least two nodes. These cuttings can be treated with rooting hormone and then planted in a mixture of sand and peat moss. It is important to keep the soil moist and the cuttings in a warm, humid place until they have developed roots and new shoots before transplanting them.
Air layering
Another propagation method that can be used for Dioscorea smilacifolia var. alternifolia is air layering. Air layering involves wounding a stem, applying rooting hormone, and then wrapping the wound with damp sphagnum moss and plastic wrap. The wound will eventually develop roots, and a new shoot will grow above the wound. After the new shoot has developed, the new plant can be carefully separated from the parent plant and potted in a well-draining potting mix.
Overall, Dioscorea smilacifolia var. alternifolia De Wild. can be propagated through tuber division, cuttings, or air layering. Each method has its advantages and disadvantages, and the selection of a propagation method depends on the grower's skills and resources.
Disease and Pest Management for Dioscorea smilacifolia var. alternifolia
Dioscorea smilacifolia var. alternifolia, commonly known as the water yam, can be affected by a variety of diseases and pests that can hamper its growth and yield. In order to ensure proper growth and adequate yield, it is necessary to manage these diseases and pests effectively.
Common Diseases
One of the most common diseases that can affect the water yam is anthracnose which causes leaf yellowing and brown spots on leaves and stems. Other common diseases include leaf blight, powdery mildew, and rust. Prevention is key to managing the spread of these diseases and using disease-resistant varieties is recommended. Application of fungicides can also help to control the diseases.
Common Pests
The water yam can also be affected by a variety of pests, including termites, nematodes, and yam beetles. Termites can cause significant damage to the roots and stems of the plant, while nematodes can cause root knot and stunted growth. Yam beetles can cause physical damage to the leaves and stems of the plant. To manage these pests, it is recommended to use natural predators, such as nematode-resistant crops and beneficial insects. Pesticides can also be used to control pest populations.
Integrated Pest Management and Cultural Practices
Integrated pest management practices aim to control the diseases and pests in an environmentally sustainable way. This includes the use of cultural practices such as crop rotation, maintaining proper soil moisture, and adequate drainage. Additionally, use of clean planting materials, proper sanitation, and regular monitoring are essential components of an integrated pest management plan. In the case of severe infestations, chemical control measures may be necessary; however, using non-chemical alternatives is always recommended to reduce negative effects on the environment.
By following these disease and pest management practices, it is possible to ensure proper growth and yield of Dioscorea smilacifolia var. alternifolia and prevent significant crop loss.
