Origin
Dioscorea gillettii Milne-Redh., commonly known as Gillett's yam, is a species of perennial herbaceous vine that belongs to the family Dioscoreaceae. It is native to West and Central Africa, particularly in Cameroon, Gabon, Congo, and Nigeria.
Common Names
In addition to Gillett's yam, Dioscorea gillettii Milne-Redh. is also referred to by other common names such as Arikpo, Agbenurugbu, Awudi, and Iborun.
Uses
The tubers of Dioscorea gillettii Milne-Redh. are used as a food source in many parts of West and Central Africa. The yams are usually boiled or roasted and can be eaten with soup or as a porridge. The plant is also used in traditional medicine to treat several ailments such as dysentery and malaria. The roots are believed to have antidiabetic properties, and recent studies have shown that they may have potential as a treatment for diabetes.
General Appearance
The plant typically grows to a height of about two meters and has heart-shaped leaves that are up to 15 centimeters long and 12 centimeters wide. The flowers of Dioscorea gillettii Milne-Redh. are greenish-yellow and grow in clusters. The tubers are usually cylindrical or oval-shaped, and can range in size from small to very large, with some weighing up to 6 kilograms. The skin of the tubers is generally brown or black, while the flesh can be white, pale yellow, or pale pink.
Growth Conditions for Dioscorea gillettii Milne-Redh.
Dioscorea gillettii Milne-Redh., commonly known as Gillett's yam, is a perennial climbing vine that thrives in tropical and subtropical regions of Africa. It is an important food crop due to its high nutritional value and is often cultivated in home gardens and small farms. The following are the typical growth conditions for this plant:
Light Requirements
Dioscorea gillettii requires full sunlight to grow and produce tubers. The plant prefers at least 6 hours of direct sunlight each day. It is best to plant the yam in an open area that receives ample sunlight.
Temperature Requirements
Temperature is a crucial factor in the growth and development of Dioscorea gillettii. The plant thrives in warm temperatures ranging from 25-30°C (77-86°F) during the day and 20-25°C (68-77°F) at night. The yam cannot tolerate frost or low temperatures, and extreme heat may cause wilting or damage to the leaves.
Soil Requirements
The yam plant requires well-drained soil that is rich in organic matter for optimal growth and development. It is best to plant the yam in soil that has a pH range between 5.5-6.5. The soil should be loose and well-aerated to allow proper root development. Additionally, the yam vine should be supported by trellises or poles to prevent the tubers from coming into contact with the ground and minimize soil-borne diseases.
Cultivation methods
Dioscorea gillettii Milne-Redh. is a tropical plant that requires warm temperatures, a moderate amount of rainfall, and good drainage for optimal growth. It thrives in well-draining, loamy soils with a pH range of 5.0 to 6.5. The plant can grow up to several meters in height and needs a strong support structure to climb.
The planting space should be prepared by tilling the soil to a depth of at least 25 cm, incorporating organic matter, and breaking up any clumps or rocks. The planting holes should be dug 20 cm deep and 30 cm wide, and the seedlings should be transplanted during the rainy season, as it favors faster growth.
Watering needs
Dioscorea gillettii Milne-Redh. requires regular watering to maintain optimal growth. Water should be applied consistently during the growing season, especially during periods of hot or dry weather. Overwatering should be avoided to prevent waterlogging, which can affect root development and lead to diseases.
Watering should be done early in the morning or late in the evening to reduce evaporation and increase absorption and distribution to the plant's roots. During the dormant season, watering should be reduced, allowing the plant to rest.
Fertilization
To thrive, Dioscorea gillettii Milne-Redh. requires regular fertilization. Fertilizers should be applied every three months, starting from the plant's second year, to ensure healthy growth, increased productivity, and disease resistance.
The type of fertilizer used should contain nitrogen, phosphorus, and potassium in equal proportions. Organic manure, such as compost, can also be applied to enhance soil fertility and improve nutrient absorption and retention. Fertilizers should be applied evenly and worked into the soil around the plant's roots.
Pruning
Dioscorea gillettii Milne-Redh. requires minimal pruning. Pruning should be done to manage the plant's growth and prevent it from spreading uncontrollably. Pruning can include removing any dead or diseased foliage and cutting back any branches that have grown beyond the support structure.
Pruning can also be done to increase the plant's yield and encourage new growth. This can be achieved by removing any lateral shoots from the vine's main stem and reducing the vine's length.
Propagation of Dioscorea gillettii Milne-Redh.
Dioscorea gillettii Milne-Redh., also known as Guinea yam, is a climbing vine of the family Dioscoreaceae. It is native to tropical Africa, particularly in Guinea and Ivory Coast.
Propagation Methods
Dioscorea gillettii Milne-Redh. can be propagated through both vegetative and seed methods.
Vegetative Propagation
One of the most common methods of propagating Dioscorea gillettii Milne-Redh. is through the use of cuttings or tubers. Cuttings can be taken from the stem of the vine and planted in well-drained soil. They should be kept moist and in a warm, humid environment until they establish roots. Tubers can also be planted directly into the soil. If using tubers, make sure they have at least one bud or eye that will sprout new growth.
Seed Propagation
To propagate Dioscorea gillettii Milne-Redh. through seeds, it is necessary to wait for the fruits to ripen and harvest the seeds. Once harvested, they should be cleaned and soaked in water for 24 hours to soften the seed coat. Sow the seeds in a well-drained soil mix and keep moist until they germinate. Seed propagation is generally less successful than vegetative propagation.
Propagation of Dioscorea gillettii Milne-Redh. can be challenging, but with proper care and attention, it is possible to grow healthy, productive plants.
Disease and Pest Management for Dioscorea Gillettii Milne-Redh.
Dioscorea gillettii Milne-Redh., also known as Guinea yam, is a popular tropical crop that is highly susceptible to various diseases and pests. Effective management of these challenges is paramount in ensuring high quality and quantity yields. Here are some common diseases and pests that affect Dioscorea gillettii and ways to manage them:
Pests
1. Yam beetle - Yam beetle is a major pest of Dioscorea gillettii, and it can cause significant damage to the leaves and stem of the plant. To manage yam beetle infestation, farmers can use insecticides such as carbaryl, dimethoate, and deltamethrin. Crop rotation can also help in reducing yam beetle populations.
2. Leafhoppers - Leafhoppers are responsible for the transmission of viruses that can infect Dioscorea gillettii. Farmers can use insecticides such as pyrethrins and neem oil to manage leafhopper infestations.
Diseases
1. Yam mosaic virus - Yam mosaic virus is spread by infected seeds, and it causes yellowing and distortion of leaves. There is no known cure for yam mosaic virus, so farmers should focus on selecting disease-free planting material.
2. Anthracnose - Anthracnose is a fungal disease that causes rotting of the yam tubers. To prevent anthracnose, farmers can use fungicides such as chlorothalonil and copper-based fungicides. Proper storage of yam tubers can also help in preventing infestation by anthracnose fungi.
3. Yam nematode - Yam nematodes are microscopic worms that infect the roots of Dioscorea gillettii. Farmers can use nematicides such as oxamyl and carbofuran to manage nematode infestations. Crop rotation with non-host plants can also help in controlling nematode populations.
Effective management of diseases and pests is crucial for successful Dioscorea gillettii production. Farmers should adopt integrated pest and disease management strategies that involve the use of resistant varieties, crop rotations, cultural practices, and chemical controls. Regular monitoring of the crop for signs of diseases and pests is critical in early detection and control.
