Overview of Dioscorea cayenensis Lam.
Dioscorea cayenensis Lam. is a perennial climbing vine that belongs to the family Dioscoreaceae. It is also commonly known as the Guinea yam, yellow yam, or Negro yam and is believed to have originated in West Africa. It is a popular crop in African nations and is also widely cultivated in the Caribbean and South America.
General Appearance of Dioscorea cayenensis Lam.
The Dioscorea cayenensis Lam. plant has a cylindrical and fleshy stem that can grow up to 5 meters in height. Its leaves are broad, heart-shaped, and have a glossy surface. The yam produced by this plant can grow up to 2 meters in length and weigh over 60 kg, making it one of the largest yams in the world. The yam itself has rough, scaly brown skin and yellowish-white flesh.
Uses of Dioscorea cayenensis Lam.
Dioscorea cayenensis Lam. is a highly nutritious tuber that is often used in many culinary dishes in West Africa, South America, and the Caribbean. The yam is boiled, roasted, fried, mashed, or grated, and is used in stews, soups, curries, and side dishes. It is rich in vitamins B and C, calcium, and potassium, and is also a good source of dietary fiber.
Aside from being a staple food, the plant has also been used in traditional medicine for its anti-inflammatory and anti-diabetic properties. The tuber's extract is believed to be a natural remedy for several health issues, including rheumatism, asthma, and high blood pressure.
In addition, the leaves of the plant have been utilized as livestock feed or food for farm animals. The tuber is also an important cash crop for small-scale farmers in Africa, providing them with a reliable source of income.
Conclusion
The Dioscorea cayenensis Lam. plant, also known as the Guinea yam, Negro yam, or yellow yam, is a versatile and valuable crop that is widely grown and consumed in West Africa, South America, and the Caribbean. Its highly nutritious yam, as well as its traditional medicinal properties, make it an essential food source for many nations. The plant's ability to thrive in various climatic and soil conditions also makes it an important crop for small-scale farmers.
Light Requirements
Dioscorea cayenensis Lam. requires full sunlight to grow. This means that the plant should be placed in an area in which it can receive at least 6 hours of direct sunlight. If grown indoors, supplemental lighting may be necessary to ensure the plant receives sufficient light.
Temperature Requirements
The optimal temperature range for Dioscorea cayenensis Lam. is between 25°C to 35°C, although it can tolerate temperatures outside of this range. The plant is sensitive to frost and cannot tolerate temperatures below 10°C. In colder regions, it is best to grow Dioscorea cayenensis Lam. in a greenhouse or other protected environment.
Soil Requirements
Dioscorea cayenensis Lam. prefers well-draining soils that are rich in organic matter. The ideal soil pH range is between 5.5 to 7.5. The plant can grow in a range of soil textures, from sandy to clay soils, as long as the soil is well-draining. It is important to ensure that the soil remains moist but not waterlogged, as waterlogged soils can lead to root rot and other fungal diseases.
Fertilizer Requirements
Dioscorea cayenensis Lam. benefits from regular applications of a balanced fertilizer with equal proportions of nitrogen, phosphorus, and potassium. It is recommended to apply the fertilizer at a rate of 1 to 2 pounds per 100 square feet every 6 to 8 weeks during the growing season. Over-fertilization should be avoided as it can lead to overly lush foliage and reduced tuber production.
Cultivation methods
Dioscorea cayenensis Lam., commonly known as the Yellow Guinea yam, is a tropical staple food crop. The plant can be propagated through the use of tubers and requires well-drained soil, with a pH range of 5.5 to 6.5 for optimal growth. Planting is best done during the wet season, and the yam should be planted in a hole around 10 cm deep and 30 to 50 cm apart.
Watering needs
The Dioscorea cayenensis Lam. plant requires a consistent supply of water to maintain optimal growth. Depending on soil quality and climatic conditions, the amount and frequency of watering may vary. It is essential to ensure that the plant's soil is moist but not waterlogged. In general, Yams should be watered at regular intervals to avoid over or under-watering.
Fertilization
Dioscorea cayenensis Lam. requires adequate nutrients to ensure healthy growth and development. Fertilization using organic and inorganic fertilizers is recommended to maintain healthy growth. Adding composted organic matter and other organic fertilizers helps improve soil fertility and promotes healthy root development. Additionally, adding inorganic fertilizers high in nitrogen, phosphorus, and potassium during planting and growth stages improves the plant's productivity.
Pruning
Pruning is an essential aspect of Dioscorea cayenensis Lam. cultivation that improves the plant's productivity. It involves removing dead and damaged branches to promote new growth and optimal development. Additionally, pruning helps control disease and pest infestation. It is essential to use sharp pruning tools to prevent damaging the plant and to sterilize the tools before and after use to prevent the spread of diseases. Pruning is best done when the plant has died back after harvesting.
Propagation of Dioscorea cayenensis Lam.
Dioscorea cayenensis Lam., also known as the yellow yam, can be propagated through various methods:
- Seed propagation: The most common method of propagation, but not recommended for commercial production as it results in variable offspring. The seeds should be harvested from fully mature yams and planted immediately in a well-draining seedbed. Germination can take up to 4 weeks.
- Cuttings: This method involves taking cutting from mature yam tubers and allowing them to propagate in soil. Cuttings should be taken from healthy, mature vines and should have 3 to 5 nodes. The cuttings should be planted in soil, and kept in a warm and humid environment. They should start sprouting in about 2 to 3 weeks.
- Tubers: The most common method for commercial propagations, tubers are vegetative propagules that are the underground portion of the stem. Harvesting of the tubers should be done carefully to prevent damaging them. The tubers can be planted immediately in a specifically prepared well-draining soil and given appropriate care.
- Tissue culture: This is a relatively new propagation technique that involves taking tissue segments from the yam plant and allowing them to grow in a nutrient-rich environment. This method is commonly used to produce virus-free planting material for commercial production. Though this method is becoming popular, it is still comparatively costly.
Propagation of Dioscorea cayenensis Lam. is moderately difficult, but with appropriate care, the plant can be propagated using any of the above-mentioned methods.
Disease and Pest Management for Dioscorea cayenensis Lam.
Dioscorea cayenensis Lam., commonly known as yellow yam, is a popular root crop grown in tropical regions. However, this crop is vulnerable to various pests and diseases that can cause significant losses if not properly managed. In this section, we will discuss some common diseases and pests affecting Dioscorea cayenensis Lam. and suggest some management strategies.
Common Diseases
1. Yam anthracnose: This is a fungal disease caused by Colletotrichum gloeosporioides that affects all aerial parts of the plant, including the leaves, stem, and fruits. Symptoms include circular brown spots on the leaves, stem cankers, and blackened dry rot on the tubers. To manage this disease, it is essential to maintain proper field hygiene, such as managing plant debris, avoiding planting yam after infected crops, and applying fungicides.
2. Yam mosaic virus: This viral disease is transmitted by aphids, mites, and other insects and affects the leaves, resulting in mottling, distortion, and yellowing. It reduces the quality and yield of the crop. Management strategies to prevent the spread of this virus include using virus-free seed tubers, controlling insect vectors, and roguing infected plants from the field.
3. Bacterial wilt: This disease is caused by Ralstonia solanacearum and affects the vascular system, leading to wilting, yellowing, and eventually death of the plant. It is spread through contaminated soil or water. To manage this disease, plants should be planted in well-draining soil with adequate water supply, and crop rotation should be practiced.
Common Pests
1. Yam beetle: This insect feeds on the leaves and stems, causing defoliation and stems' girdling. To manage this pest, farmers should regularly inspect their crops and handpick all beetles found on the plants. Pesticides may also be applied if the infestation becomes severe.
2. Yam nematode: This microscopic roundworm feeds on the roots and affects the growth and yield of the plant. Crop rotation, use of resistant cultivars, and soil fumigation are effective management strategies for this pest.
3. Yam tuber moth: This insect pest feeds on yam tubers and causes physical damage and rotting. To manage this, farmers should store their harvested tubers in a dry, well-ventilated area and treat with insecticides before storage.
In conclusion, proper management of pests and diseases is crucial to get maximum yield from the crop. Farmers should follow integrated pest and disease management practices to minimize the loss from these threats and sustain a healthy Dioscorea cayenensis Lam. crop.
