Origin
Dioscorea dregeana (Kunth) T.Durand & Schinz var. hutchinsonii Burkill is a species of yam that is native to southern Africa. It can be found in countries such as Zimbabwe, Mozambique, and South Africa.
Common Names
This plant has a few different common names, including Hutchinson's Yam and Doma Yam. It is often referred to simply as Dioscorea dregeana as well.
Uses
Hutchinson's Yam is primarily used as a food source. The starchy tubers are a staple crop in many parts of southern Africa. It is also used in traditional medicine to treat a variety of ailments such as fever, and stomach issues.
General Appearance
Dioscorea dregeana (Kunth) T.Durand & Schinz var. hutchinsonii Burkill is a climbing vine with heart-shaped leaves that are bright green in color. The plant produces small, green flowers that grow in spike-like clusters. The yams themselves are cylindrical in shape and can range in color from white to reddish-brown. They are typically around 30-40cm in length and 10-15cm in diameter.
Light Requirements
The Dioscorea dregeana var. hutchinsonii requires partial shade to full sunlight for optimal growth. However, excessive sunlight can cause damage to the leaves, reducing the plant's growth rate. Therefore, providing partial shade during the hottest parts of the day may be necessary in regions with high temperatures.
Temperature Requirements
The plant is native to sub-tropical to tropical regions and thus prefers temperatures between 16°C to 25°C. It can tolerate a minimum temperature of 10°C and a maximum temperature of 35°C. However, if temperatures are persistently outside of these parameters, the growth and development of the plant may be negatively affected, and in extreme cases, the plant may die.
Soil Requirements
The Dioscorea dregeana var. hutchinsonii grows well in well-drained, fertile, and humus-rich soils with a pH range of 5.5 to 6.5. It is highly adapted to sandy and loamy soils with high organic content. The plant also prefers soils rich in nutrients such as potassium, phosphorus, and nitrogen. Adequate soil moisture levels are also crucial for the plant's growth and development.
Cultivation Methods for Dioscorea dregeana (Kunth) T.Durand & Schinz var. hutchinsonii Burkill
Dioscorea dregeana (Kunth) T.Durand & Schinz var. hutchinsonii Burkill, commonly known as the Hutchinson's Yam, is a woody climbing plant native to South Africa. Growing this plant requires specific cultivation methods that must be followed cautiously to achieve optimal results.
Propagation should be done through stem cuttings, air layering, or through seed planting. The plant requires a well-draining and fertile soil mix with good aeration, pH between 5.5-7.0, and plentiful organic matter.
The plant thrives in direct sunlight, but it can grow under partial shade. The use of trellises or support systems will aid the plants to climb moderately and prevent them from spreading on the ground, which may reduce their yield.
Watering Needs of Dioscorea dregeana (Kunth) T.Durand & Schinz var. hutchinsonii Burkill
Watering must be done reasonably and consistently to optimize the growth of this plant. The plants don't thrive well in waterlogged soil, and therefore proper drainage must be ensured. The soil should be adequately moist but not wet, and the plant must never be allowed to wilt.
The timing and frequency of watering should be controlled in response to the weather conditions prevailing in the area. In drier conditions, the number of watering sessions may need to be increased, and the watering needs to be done earlier in the morning or late afternoon when the foliage is cooler.
Fertilization of Dioscorea dregeana (Kunth) T.Durand & Schinz var. hutchinsonii Burkill
Dioscorea dregeana (Kunth) T.Durand & Schinz var. hutchinsonii Burkill plants require a balanced and complete soluble fertilizer every two weeks in the growing season and spring. The use of organic matter like compost and mulch may be done to improve the soil's richness and fertility.
Overfertilization may lead to salt buildup in the soil, causing harmful conditions that may be damaging to the plant. Therefore, it is wise to use the recommended fertilizer in the right amounts and at the appropriate intervals.
Pruning of Dioscorea dregeana (Kunth) T.Durand & Schinz var. hutchinsonii Burkill
Pruning of the plant should be done to remove dead, diseased, or damaged branches. Regular pruning and training can be done to establish a strong branching structure and provide adequate support to the vines.
While pruning, it's important to sterilize the pruning tools to prevent the spread of plant diseases.
Propagation of Dioscorea dregeana (Kunth) T.Durand & Schinz var. hutchinsonii Burkill
Dioscorea dregeana (Kunth) T.Durand & Schinz var. hutchinsonii Burkill is generally propagated through vegetative means. The following are the methods that can be used to propagate this plant:
Tuber division
Propagation of Dioscorea dregeana (Kunth) T.Durand & Schinz var. hutchinsonii Burkill can be achieved by dividing the tuber of a mature plant. The tuber should be carefully cut into sections, ensuring that each section has at least one bud and a few roots attached. The sections can then be planted in pots filled with well-draining soil and kept in a warm and humid location until new growth emerges.
Tissue culture
Dioscorea dregeana (Kunth) T.Durand & Schinz var. hutchinsonii Burkill can also be propagated through tissue culture. This involves taking a small piece of the plant, such as a leaf or stem, and placing it on a nutrient-rich medium in sterile conditions. The plant tissue is then encouraged to grow in a controlled environment until it forms plantlets that can be transplanted into soil.
Cuttings
A stem cutting can also be used for propagation. Cut a healthy stem at a slight angle, ensuring that it is at least 10cm long and has a few leaves. Remove the leaves from the lower two-thirds of the cutting and plant it in well-draining soil. Keep the soil moist until the cutting has rooted, which usually takes about 2-3 weeks.
Air layering
Air layering can also be employed to propagate Dioscorea dregeana (Kunth) T.Durand & Schinz var. hutchinsonii Burkill. In air layering, a branch of the plant is selected and a section of the bark is removed, exposing the inner tissue. The exposed stem is then wrapped with a moist material, such as sphagnum moss, and kept moist. After several weeks, roots will start to form at the exposed portion of the stem. At this point, the rooted stem can be cut from the parent plant and planted in soil.
Disease Management
Dioscorea dregeana (Kunth) T.Durand & Schinz var. hutchinsonii Burkill is susceptible to several diseases that can hamper its growth and yield potential. The following are some common diseases that affect this plant:
- Bacterial Soft Rot: This disease is caused by the bacterium Erwinia carotovora subsp. carotovora. It leads to the rotting of the stem and tubers. To manage this disease, it is advisable to remove and destroy the infected plants. Crop rotation and avoiding overwatering and damage to the tubers can also reduce the incidence of this disease.
- Fungal Diseases: Several fungal diseases such as anthracnose, fusarium wilt, and cercospora leaf spot can affect Dioscorea dregeana. These diseases can be managed by practicing proper sanitation, removing diseased plant parts, and using disease-resistant cultivars. Fungicides can also be used, but their efficacy varies depending on the type of disease and the stage of infection.
Pest Management
Several pests can attack Dioscorea dregeana (Kunth) T.Durand & Schinz var. hutchinsonii Burkill. Here are some common pests that can affect this plant:
- Yam Beetle: This pest feeds on the foliage of the plant and can cause severe defoliation. At early stages of infection, affected leaves can be pruned and destroyed. To prevent infestation, traps can be set up around the farm, or insecticides can be used. Predators such as birds and ants can also help to control the population of this pest.
- Root-Knot Nematodes: These pests can cause stunted growth and poor tuber development. Crop rotation and the use of resistant cultivars can help to prevent infestation. Soil fumigation with methyl bromide can also be effective in managing root-knot nematodes, but it is not an environmentally friendly option.
In conclusion, the effective management of diseases and pests in Dioscorea dregeana (Kunth) T.Durand & Schinz var. hutchinsonii Burkill is crucial to ensure a healthy and profitable yield. The above measures can help to prevent and manage disease and pest infestations for this plant.
