Overview
Dioscorea sylvatica (Kunth) Eckl. subsp. lydenbergensis Blunden & Hardman & Hind is a plant with a tuberous rootstock that belongs to the family Dioscoreaceae. It is a climbing plant that is commonly found in South Africa and Swaziland.
Common Names
The plant is commonly known as the forest yam, wild yam, or mountain yam.
Appearance
The forest yam has a climbing habit, and its stems can grow up to 6 meters long. The leaves are heart-shaped and glossy, with a length of up to 10 centimeters and a width of 8 centimeters. The plant produces tubers that can grow up to 15 centimeters long and weigh up to 1 kilogram.
Uses
Traditionally, the tubers of Dioscorea sylvatica have been used by the indigenous people of South Africa and Swaziland for medicinal purposes. The tubers are believed to have anti-inflammatory and analgesic properties and have been used to treat various ailments such as rheumatism, arthritis, and headaches. The tubers are also a source of food and are consumed after being boiled or roasted.
Today, the plant is of increasing interest to researchers due to the presence of various phytochemicals in the tubers, including diosgenin, a compound used in the production of steroids such as progesterone. Diosgenin is also used in the production of pharmaceuticals for the treatment of various health conditions such as osteoporosis and menopausal symptoms.
Light Requirements
Dioscorea sylvatica (Kunth) Eckl. subsp. lydenbergensis Blunden & Hardman & Hind requires bright, indirect light to flourish. The plant thrives under partially shaded conditions, receiving a minimum of four hours of sunlight per day. Direct sun exposure should be avoided as it may cause leaf scorching.
Temperature Requirements
The plant grows best in warm temperature conditions ranging from 20°C to 30°C. It does not tolerate temperature fluctuations, and cold drafts should be avoided. Temperatures below 10°C or above 35°C may cause damage to the plant and impede its growth.
Soil Requirements
The plant prefers well-draining, moist soils rich in organic matter. A pH range of 5.5 to 6.5 is ideal for optimal growth. The soil should be kept consistently moist but not waterlogged. Overwatering and underwatering can both be detrimental to the plant's growth, so it's crucial to maintain adequate moisture levels.
Cultivation methods
Dioscorea sylvatica (Kunth) Eckl. subsp. lydenbergensis Blunden & Hardman & Hind, commonly known as forest yam, is a perennial plant that thrives in tropical and subtropical regions. The first step towards cultivating this plant is to select a location with well-draining soil and partial shade. The plant prefers loamy soil with a pH between 6.0 and 7.0.
Propagation by planting tubers is the most common cultivation method. The tubers should be planted at a depth of 10-15 cm and spaced at a distance of 50 cm between each plant. Seed propagation can also be done, but it takes longer for the plant to mature.
Watering needs
Forest yam requires regular watering, especially during the dry season. The plant requires moderate soil moisture levels. Water should be applied at the base of the plant to avoid wetting the leaves, which can lead to fungal diseases. Overwatering can lead to root rot and should be avoided.
Fertilization
The forest yam plant requires regular fertilization to thrive. A balanced fertilizer with nitrogen, phosphorus, and potassium should be applied every two months during the growing season. The application of organic matter, such as compost or manure, can also be beneficial.
When applying fertilizer, care should be taken not to apply too much fertilizer, as this can lead to leaf burn and an increase in pest and disease problems.
Pruning
Pruning is not required for forest yam plants. However, removing the dead foliage and any damaged or diseased leaves can help to prevent the spread of pests and diseases. It is also important to remove any weeds from around the plant to prevent competition for nutrients.
Propagation of Dioscorea sylvatica (Kunth) Eckl. subsp. lydenbergensis Blunden & Hardman & Hind
Dioscorea sylvatica (Kunth) Eckl. subsp. lydenbergensis Blunden & Hardman & Hind is propagated both by seed and vegetatively. However, the propagation of the plant through seeds is a relatively slow process, often taking up to a year before germination occurs. Instead, vegetative propagation methods such as stem cuttings and tissue culture are more commonly used to propagate the plant.
Stem Cuttings
Stem cuttings of Dioscorea sylvatica (Kunth) Eckl. subsp. lydenbergensis Blunden & Hardman & Hind are taken from mature stems during the dormant season. The cuttings should be about 10-15 cm long and should include at least one node. The cuttings are then placed in a rooting hormone before being planted in a suitable growing medium. It is important to keep the cuttings moist while they establish roots and begin to grow.
Tissue Culture
Tissue culture is another effective method of propagating Dioscorea sylvatica (Kunth) Eckl. subsp. lydenbergensis Blunden & Hardman & Hind. Tissue culture involves the growth of plant cells or small plant pieces in a sterile environment. This method of propagation allows for rapid propagation of large numbers of plants in a small space. Additionally, tissue culture can be used to produce disease-free plants.
Disease Management
Dioscorea sylvatica (Kunth) Eckl. subsp. lydenbergensis Blunden & Hardman & Hind, commonly known as the Wild Yam plant, is susceptible to various fungal, bacterial, and viral diseases. The following are some common diseases that can affect the plant and suggested ways to manage them:
Anthracnose
Anthracnose is a fungal disease that causes leaf spots, stem cankers, and root rot, ultimately leading to plant death. The disease spreads through wind, rain, and infected tools. To manage anthracnose, remove infected plant parts and destroy them. Use a copper-based fungicide to prevent further spread of the disease.
Black Rot
Black rot is a bacterial disease that causes dark lesions on leaves, stems, and tubers. The disease spreads through infected soil, water, and tools. To manage black rot, remove infected plant parts and destroy them. Apply a copper-based fungicide to prevent further spread of the disease. Additionally, avoid overcrowding the plant and practice crop rotation to prevent the recurrence of the disease.
Leaf Spot
Leaf spot is a fungal disease that causes brown or black spots on the leaves, leading to defoliation and reduced yield. The disease spreads through infected water and tools. To manage leaf spot, remove infected plant parts and destroy them. Apply a copper-based fungicide to prevent further spread of the disease. Avoid overhead watering, and water the plant at the base.
Pest Management
The Wild Yam plant is susceptible to various pests such as aphids, mealybugs, and scales. The following are some common pests that can affect the plant and suggested ways to manage them:
Aphids
Aphids are small, soft-bodied insects that suck the sap from the plant, causing leaf curling and deformities. To manage aphids, physically remove them from the plant or use insecticidal soap. Additionally, attract ladybugs and lacewings to the garden, as they are natural predators of aphids.
Mealybugs
Mealybugs are small, white insects that also suck the sap from the plant, causing leaf yellowing and stunted growth. To manage mealybugs, physically remove them from the plant or use insecticidal soap. Additionally, attract ladybugs and lacewings to the garden, as they are natural predators of mealybugs.
Scales
Scales are small, flat insects that attach themselves to the stems and leaves of the plant, sucking the sap and causing yellowing and dropping of the leaves. To manage scales, physically remove them from the plant or use insecticidal soap. Additionally, attract parasitic wasps to the garden, as they are natural predators of scales.
