General Description
Dioscorea cayenensis Lam. subsp. cayenensis, also known as Guinea yam or Yellow yam, is a perennial climbing vine that belongs to the Dioscoreaceae family. It is native to West Africa but is now widely cultivated in many tropical and subtropical regions of the world including the Caribbean, Central and South America, and India.
Appearance
The Guinea yam plant has a tuberous root that is typically large, cylindrical, and often curved with a rough, scaly texture on the outside. The leaves are heart-shaped and large, with secondary veins originating from a central vein. The stem of the plant is twining and climbs over supports using tendrils that arise from the leaf axils. The flowers are small, greenish-yellow, and occur in clusters that arise from the leaf axils, while the fruit is a capsule that contains many small seeds.
Common Names
The plant is commonly known as Guinea yam, Yellow yam, Bwa-debout, Igname de Guinée, Igname jaune, Ñame amarillo, and many other local names depending on the region or country where it is grown.
Uses of Dioscorea cayenensis
The Guinea yam plant is highly valued for its nutritious tubers, which are a rich source of carbohydrates, dietary fiber, protein, and various micronutrients. The yam is an important staple food in West Africa and other parts of the world, where it is boiled, roasted, fried, or mashed and used in various traditional dishes. It is also used in the production of flour and in the preparation of various types of confectionery, such as cakes, bread, biscuits, and noodles. Additionally, the plant has various medicinal properties and is used in traditional medicine to treat a range of ailments including, asthma, bronchitis, arthritis, and stomach problems.
Overall, the Dioscorea cayenensis Lam. subsp. cayenensis is a versatile and highly valued plant that has a significant impact on the economic, nutritional, and cultural well-being of many communities around the world.
Light Requirements
Dioscorea cayenensis Lam. subsp. cayenensis requires a minimum of 6-8 hours of direct sunlight for optimal growth. This plant tends to thrive in bright and sunny locations, and any shading could lead to stunted growth or decreased yields.
Temperature Requirements
The ideal temperature range for the growth of Dioscorea cayenensis Lam. subsp. cayenensis is between 25-30°C. The plant cannot survive in extremely hot or cold temperatures. If the temperature exceeds 35°C, the plant may show signs of stress, such as wilting or shedding of leaves. Under cooler temperatures, the plant growth may slow down or become dormant.
Soil Requirements
The soil type and quality are vital elements for the growth of Dioscorea cayenensis Lam. subsp. cayenensis. The ideal soil for this plant should be well-draining, fertile, and rich in organic matter. The plant prefer slightly acidic soil with a pH range of 5.8-6.5. The presence of excessive moisture or waterlogging in the soil can lead to poor yield and root rot.
Cultivation methods for Dioscorea cayenensis Lam. subsp. cayenensis
Dioscorea cayenensis Lam. subsp. cayenensis, commonly referred to as the yellow yam, is a tropical tuber crop that is grown for its edible underground tubers. This plant is best grown in warm, humid climates with well-drained soils and abundant sunshine. Planting should be done during the rainy season, and the bed should be well-prepared with organic matter such as compost or manure.
The tubers should be planted about 5-10cm deep, and the spacing between plants and rows should be about 40-60cm apart. After planting, the bed should be kept moist until the plants germinate and establish themselves.
Watering Needs
Dioscorea cayenensis Lam. subsp. cayenensis requires consistent moisture during the growing period, and it is important to ensure that the soil does not dry out. The plants should be watered regularly, at least once a week in dry weather, to maintain adequate soil moisture levels. However, excessive moisture can lead to root rot and other fungal diseases, so care should be taken to avoid waterlogging the soil.
Fertilization
Dioscorea cayenensis Lam. subsp. cayenensis benefits from regular fertilization during the growing season to encourage healthy growth and maximize yields. A balanced fertilizer should be applied at the beginning of the rainy season, and again at mid-growth stage. Organic fertilizers such as compost or farmyard manure can also be applied to improve soil fertility and to provide additional nutrients that the plant requires.
Pruning
Dioscorea cayenensis Lam. subsp. cayenensis does not require much pruning, but it is important to remove any dead or diseased leaves as soon as possible to prevent the spread of disease. Staking and trellising can be used to support the plants, especially when they have heavy tubers. These practices also help to reduce the spread of fungal diseases that can occur when the plants are in contact with the ground.
Propagation of Dioscorea cayenensis Lam. subsp. cayenensis:
Dioscorea cayenensis Lam. subsp. cayenensis, commonly known as 'Yellow yam', is propagated through different methods, including:
Tubers:
The most common method of propagation of Dioscorea cayenensis Lam. subsp. cayenensis is through planting tubers. Tubers are the underground stem of the plant. While planting, tubers should be planted horizontally, with the buds pointing upwards. The tubers should be planted in soil that is rich in nutrients. The best time to plant tubers is at the beginning of the rainy season when the soil is moist and warm.
Mini-setts:
Mini-setts are small pieces of tubers that are cut into small sections, each containing at least one bud. These mini-setts are usually 2-3 cm in length. They are planted directly in the soil at a depth of about 5 cm. Mini-setts should also be planted at the beginning of the rainy season. This method of propagation is beneficial as it increases the yield of the crop.
Cuttings:
Dioscorea cayenensis Lam. subsp. cayenensis can also be propagated through cuttings. Stem cuttings that are about 30-40 cm in length, with a few nodes, can be used for propagation. These cuttings are then planted horizontally in the soil, with the uppermost nodes exposed to the sun. This method is advantageous as it allows for the production of more crops in a small space.
Vine cuttings:
The propagation of Dioscorea cayenensis Lam. subsp. cayenensis can also be done through vine cuttings. The vines are cut into pieces that are about 20-30 cm in length, with at least two nodes. These vine cuttings are then planted in soil that is rich in nutrients. This method is beneficial as it ensures the production of disease-free plants.
In conclusion, Dioscorea cayenensis Lam. subsp. cayenensis can be propagated through different methods like tubers, mini-setts, cuttings, and vine cuttings. Proper research and understanding of each propagation method are essential in ensuring maximum yield of the plant.
Disease and Pest Management for Dioscorea Cayenensis Lam. subsp. Cayenensis
When it comes to pest and disease management for Dioscorea cayenensis Lam. subsp. cayenensis, it is important to identify the warning signs early on to prevent the spread of pests or diseases. Regular inspection and maintenance of the plants can help control and prevent outbreaks.
Common Pests
The most common pests that can affect Dioscorea cayenensis Lam. subsp. cayenensis are aphids, mites, and caterpillars. These insects can infest the plant and cause damage to the leaves and stems. Aphids can be easily controlled through the application of insecticidal soap, pyrethrin, or neem oil. Mites can be controlled with horticultural oil or insecticidal soap. Caterpillars can be controlled manually by hand-picking them off the plant.
Common Diseases
Dioscorea cayenensis Lam. subsp. cayenensis is susceptible to several diseases, including fungal infections, bacterial infections, and viral diseases. The most common fungal infection is powdery mildew, which appears as a white powdery substance on the leaves and stems. This can be controlled through the application of fungicides such as sulfur or copper-based sprays.
Bacterial infections can cause leaf spot or blight on Dioscorea cayenensis Lam. subsp. cayenensis. This can be prevented by applying copper-based fungicides before symptoms appear. Additionally, removing infected plant parts and practicing good sanitation measures can prevent the spread of infection.
Viral diseases can cause mottled leaves, yellowing, and stunted growth of the plant. Unfortunately, there is no cure for viral diseases, and infected plants should be removed and destroyed to prevent the spread of infection to healthy plants.
Preventative Measures
Preventing pests and diseases requires a combination of good cultural practices, proper maintenance, and early detection. Dioscorea cayenensis Lam. subsp. cayenensis should be planted in well-draining soil and watered appropriately to prevent the spread of fungal diseases. Additionally, pruning infected plant parts and removing dead plant material can prevent pests and diseases from taking hold in the plant. Using organic matter, such as compost, can also help improve soil health and provide nutrients to the plant, which can make it more resistant to pests and diseases.
In conclusion, Dioscorea cayenensis Lam. subsp. cayenensis can be susceptible to several pests and diseases. However, with proper maintenance, regular inspection, and early detection, these issues can be managed and prevented from spreading.
