Origin
Dioscorea praehensilis Benth. is a plant species that belongs to the family Dioscoreaceae. It is native to western and central Africa, found in countries like Angola, Cameroon, Democratic Republic of Congo, Gabon, Ghana, Guinea, Ivory Coast, Nigeria, and Sierra Leone.
Common Names
The plant is commonly known as the "Guinea potato" or "Bitter yam" in English. It is also referred to as "Kokoro" in Nigeria, "Woho" in Ghana, and "Bakulutu" in Cameroon.
Uses
The Dioscorea praehensilis Benth. plant is an important staple food in many African countries. The tubers of the plant are cooked and consumed in various ways, including boiling, frying, baking, and pounding into flour for making porridges and bread. The taste of the tuber ranges from sweet to bitter, depending on the variety.
Aside from being a food source, the plant has also been used for medicinal purposes. Its roots, leaves, and stems contain compounds that have anti-inflammatory, analgesic, and antioxidant properties. In traditional African medicine, it has been used to treat snakebites, rheumatism, and other ailments.
General Appearance
Dioscorea praehensilis Benth. is a climbing vine that can grow up to 10 meters in length. The plant has heart-shaped leaves that are arranged in a spiral pattern around the stem. It has small, greenish-yellow flowers that grow in clusters. The tubers of the plant are elongated and can grow up to 1 meter in length. They are usually rough and dark brown in color.
Light Requirements
Dioscorea praehensilis Benth. requires moderate to bright indirect light. In their natural habitat, they can be found in shaded areas beneath taller vegetation. Too much direct sunlight can scorch their leaves, so it is best to place them near a window with a sheer curtain or in a bright room away from direct sunlight.
Temperature Requirements
These plants prefer warm temperatures between 65°F-85°F (18°C-29°C). They can tolerate slightly cooler temperatures, but it must not dip below 55°F (13°C). It is important to protect these plants from drafts or sudden temperature changes as it can shock the plant and affect its growth.
Soil Requirements
Dioscorea praehensilis Benth. prefers well-draining soil that is rich in organic matter. A mixture of potting soil, perlite, and vermiculite would be suitable. It is important to ensure that the soil is moist but not waterlogged. These plants do not tolerate sitting in wet soil as it can lead to root rot and ultimately kill the plant.
Cultivation
Dioscorea praehensilis Benth., commonly known as Guinea yam, is a herbaceous plant that grows in tropical and subtropical regions. It is a climbing plant and needs support to grow well. It prefers a well-draining soil that is rich in organic matter.
The ideal planting time for Dioscorea praehensilis Benth. is during the wet season. The plant is usually propagated by tubers. The tubers should be planted at a depth of 10 cm to 15 cm and spaced about 25 cm apart. They should be planted in mounds or ridges to ensure good drainage.
Watering Needs
Dioscorea praehensilis Benth. requires regular watering, especially during the dry season. The soil should be kept moist but not waterlogged, as this can lead to root rot. It is best to water the plant early in the morning or late in the evening to minimize evaporation.
However, excessive watering should be avoided, as this can lead to poor root development and stunted growth. It is important to monitor the soil moisture level and adjust the watering schedule accordingly.
Fertilization
Dioscorea praehensilis Benth. requires regular fertilization to promote healthy growth and improve yield. A balanced fertilizer with a ratio of 10-10-10 should be applied at a rate of 150 kg per hectare, two weeks after planting and again four weeks later.
In addition, organic fertilizers such as compost or manure can be applied to improve soil fertility and provide micronutrients that are essential for plant growth.
Pruning
Pruning is necessary to control the growth of Dioscorea praehensilis Benth. and to promote the formation of strong, healthy stems. The plant should be pruned after the vines have reached a height of about 90 cm.
To prune the plant, remove the lateral shoots that emerge from the axils of the leaves. This will encourage the plant to grow straight and strong, rather than sprawling in all directions.
Regular pruning also helps to reduce the incidence of pest and disease infestations, as it promotes better air circulation and reduces humidity around the plant.
Propagation of Dioscorea praehensilis Benth.
Dioscorea praehensilis Benth. can be propagated through both sexual and asexual means.
Sexual Propagation
Sexual propagation of Dioscorea praehensilis Benth. involves sowing seeds, which are usually produced in large numbers. The seeds should be harvested when they mature and become hard, and they should be sown immediately as they have a short viability period. The seeds can be sown into pots or seedbeds filled with loamy soil. After sowing, the containers should be kept under shaded conditions and watered regularly. The seeds usually germinate within 2-3 weeks, and the resulting seedlings can be transplanted into their permanent locations after they have developed enough roots.
Asexual Propagation
Asexual propagation of Dioscorea praehensilis Benth. is mainly accomplished through the use of tubers or bulbils. Tubers are the main propagules of the plant, and they are usually large, fleshy, and knotted. To propagate with tubers, the parent plant should be dug up during the dormant season and the tubers should be separated from the parent plant. The tubers should then be planted shallowly in soil, with the knotted side facing upwards. The tubers should be watered regularly and kept under shaded conditions until they sprout. Bulbils, which are small, ball-shaped structures produced on the stem of the plant, can also be used to propagate Dioscorea praehensilis Benth. To propagate with bulbils, they should be removed from the stem of the parent plant and planted in soil, as with tubers.
Disease Management for Dioscorea praehensilis Benth.
The most common fungal diseases affecting Dioscorea praehensilis Benth. include anthracnose, leaf spot, and Fusarium wilt. To manage these fungal diseases, it is essential to ensure proper sanitation practices, including pruning infected plant parts, removing and destroying any infected debris, and avoiding overhead irrigation. Other preventive measures include planting disease-resistant varieties, crop rotation, and the use of fungicides like copper-based sprays, depending on the severity of the infestation.
Pest Management for Dioscorea praehensilis Benth.
The Yam tuber beetle, Heteroligus meles, is a pest that can cause severe damage to Dioscorea praehensilis Benth. plants. This beetle larva feeds on the bulbous stem base and can bore into the tubers, causing them to rot. To manage these pests, regular monitoring through visual inspection is essential. Early detection and removal of the affected plant parts and the use of cultural control techniques such as crop rotation, plant spacing, and the use of organic mulches can significantly reduce the incidence and severity of the infestation. In severe cases, insecticides can be used as a last resort.
