Introduction
Dioscorea pynaertioides De Wild. is a unique plant that belongs to the family Dioscoreaceae. It is a climbing vine that grows up to 15 meters in length and is native to Africa.
Common Names
The plant is known by several common names in Africa. In Ghana, it is known as "Asatia," while in Nigeria, it is referred to as "Isu Baka." In Cameroon, it is known as "Namah Namah" or "Pena Pena."
Appearance
Dioscorea pynaertioides De Wild. is a climbing vine that has a cylindrical stem with a diameter of about 3 cm. The leaves are heart-shaped and are about 10-15 cm long and 7-12 cm wide. The plant produces tubers that are fusiform and can grow up to 40 cm in length and 5 cm in diameter.
The plant produces greenish-white flowers on short stalks that arise from the leaf axils. The fruit is a capsule that contains numerous winged seeds.
Uses
Dioscorea pynaertioides De Wild. is an important plant in African traditional medicine. The tubers are used to treat several diseases, including cough, malaria, and diarrhea. The tubers are also used as a source of food in many African countries.
The plant is also used as an ornamental plant in some parts of Africa. The climbing habit of the plant makes it an ideal plant to cover fences and walls. Additionally, the greenish-white flowers of the plant are attractive and add beauty to landscapes and gardens.
Light Requirements
Dioscorea pynaertioides De Wild. typically prefers partial to full sunlight exposure. The plant will grow well if exposed to bright, indirect sunlight for most of the day. Direct sunlight can burn the leaves and cause the plant to wilt. In shaded areas, the plant will grow slowly and may become spindly.
Temperature Requirements
The ideal temperature range for Dioscorea pynaertioides De Wild. is between 20°C to 30°C. The plant can tolerate a broader range of temperatures but may experience slower growth or damage if the temperature falls below 10°C or exceeds 35°C. During the winter months, the plant may require extra protection from cold drafts.
Soil Requirements
Dioscorea pynaertioides De Wild. prefers well-draining soil with high organic matter content. The pH level of the soil should be between 6.5 and 7.5, which is slightly acidic to neutral. The plant will thrive in soils that are rich in nutrients, with a good balance of nitrogen, phosphorus, and potassium. It is best to avoid waterlogged or compacted soil, as these conditions can cause the roots to rot.
Regular watering is essential to maintain the health of Dioscorea pynaertioides De Wild. The soil should be kept moist but not overly wet. Depending upon the environment, it is recommended to check the soil moisture levels and provide water accordingly.
Cultivation methods
Dioscorea pynaertioides De Wild. is a perennial plant that can be cultivated either through vegetative propagation or through seeds. The plant requires well-drained soil with a pH range of 5.5 to 7.5. It thrives in warm temperatures between 20°C to 30°C and requires partial shade, as it cannot tolerate full sun. It can be grown in both pots and in the ground and typically reaches a height of 2-3 meters with a spread of 1-2 meters.
Watering needs
The plant requires regular watering, especially during the growing season. It does not tolerate waterlogging, so it is necessary to ensure proper drainage to prevent the roots from rotting. The amount of water required depends on factors such as the temperature and humidity levels of the environment where the plant is growing.
Fertilization
The plant requires regular fertilization to thrive. Nitrogen-rich fertilizers are recommended during the growing season to enhance vegetative growth. Phosphorus and potassium fertilizers can be applied during the flowering and fruiting stages to improve the yield. Organic fertilizers can also be used to enrich the soil and improve its fertility.
Pruning
Pruning the plant is essential to maintain its shape and prevent it from becoming too bushy. Dead or decaying leaves should be removed to prevent the spread of diseases. Pruning should be done during the dormant season or after harvesting the tubers. It is advisable to sterilize the pruning tools before use to prevent the spread of diseases and infections.
Propagation of Dioscorea pynaertioides De Wild
Dioscorea pynaertioides De Wild., also called the guinea yam, is a tropical tuber crop that belongs to the family Dioscoreaceae. Propagation of this plant can be done through both sexual and vegetative methods.
Propagation through sexual means
The sexual propagation of D. pynaertioides is done through seed production. The plant has both male and female flowers on separate plants, and bees help in pollination. The female plant produces a three-winged fruit that contains several small oval seeds. The seeds must be sown as soon as possible, not allowing them to dry out or go dormant. The optimum germination temperature is 30°C, and the seedlings emerge in 4-6 weeks.
Propagation through vegetative means
The vegetative propagation of D. pynaertioides is done through the use of tubers or stem cuttings. The yam tubers are cut into small pieces, each with at least one bud in it, and planted in well-drained soil during the rainy season. The ideal time to plant is between March and April. The tubers start sprouting after 6-8 weeks, and they need to be weeded and protected from pests and diseases.
Propagation through stem cuttings involves taking stem cuttings from young plants with at least two nodes. The cuttings are planted in a rooting medium after dipping them in rooting hormones, and covered with a plastic film or kept in a propagator for 5-6 weeks. After rooting, the cuttings are transplanted into pots or directly into the field, taking care of the soil moisture and fertility.
Both the seed and vegetative propagation methods of Dioscorea pynaertioides De Wild. require proper care and attention to ensure that the plants grow well and provide good yields. Proper soil preparation, watering, and pest control are essential for successful propagation and cultivation of this crop.
Disease and Pest Management for Dioscorea pynaertioides De Wild.
Dioscorea pynaertioides De Wild. is a climbing plant that is prone to various diseases and pests, which can hinder its growth and productivity. Therefore, it is essential to understand the common diseases and pests that might affect this plant and ways to manage them effectively.
Common Diseases
Anthracnose: This is a fungal disease that causes the leaves to turn brown and die. It also causes stem lesions, which can lead to wilting and plant death. To manage this disease, affected plant parts should be removed and destroyed, and the surrounding soil should be treated with fungicides.
Leaf spot: This is another fungal disease that causes small, circular spots on the leaves, which later become brown and necrotic. It can cause substantial yield losses if not adequately managed. Regular application of fungicides can prevent and control this disease.
Viral diseases: Dioscorea pynaertioides De Wild. is susceptible to various viral diseases, such as the mosaic virus and the yellow vein virus. These diseases can cause stunted growth, yellowing of leaves, and reduced yields. There are no effective treatments for viral diseases, and the best prevention strategy is to use healthy planting materials and control the vectors, such as insects.
Common Pests
Mealybugs: These are tiny, white, and soft-bodied insects that suck sap from the plant, reducing its vigor. They also produce a sticky substance that attracts ants and promotes the growth of sooty mold. Mealybugs can be managed by using insecticides and introducing natural enemies such as ladybugs and lacewings.
Spider mites: These are small, red or yellow, and oval-shaped insects that live on the underside of leaves, causing yellowing and stippling of the foliage. They reproduce quickly under hot and dry conditions and can be controlled by using insecticides or introducing predatory mites.
Root-knot nematodes: These are microscopic worms that feed on the roots of the plant, causing galls and reducing the plant's ability to absorb water and nutrients. Crop rotation, using resistant cultivars, and soil fumigation with nematicides are effective ways of managing this pest.
Conclusion
In conclusion, the management of diseases and pests in Dioscorea pynaertioides De Wild. is critical to ensuring its proper growth and productivity. It is essential to take preventive measures such as using healthy planting materials, regular crop monitoring, and applying appropriate chemical treatments to manage these issues effectively.
