Overview
Dioscorea hockii De Wild. is a rare species of yam that belongs to the Dioscoreaceae family. It is known for its large edible tubers which have a sweet taste and are rich in nutrients. The plant is native to Central Africa and is widely cultivated in Cameroon, Gabon, and Congo.
Common Names
The plant is commonly known as "Hock's yam" in English, "Alodoh" in the Bantu language, and "Kpelekou" in the Mwele language.
Appearance
The Dioscorea hockii plant is a woody climbing vine that can grow up to 6 meters long. It has a thick stem with a diameter of about 5 cm, and its leaves are alternately arranged and heart-shaped. The plant produces small greenish flowers that are arranged in spikes. The tubers of the plant can reach up to 1 meter in length and 20 cm in diameter, and they are light brown in color.
Uses
The tubers of the Dioscorea hockii plant are a valuable food source for many people in Central Africa. They can be cooked in a variety of ways, such as boiling, frying, or roasting. The tubers are also used in traditional medicine to treat various ailments such as fever, diarrhea, and stomach problems. Additionally, the plant has great potential as a source of natural starch, which has numerous industrial applications such as in the production of paper and textiles.
Growth Conditions for Dioscorea hockii De Wild.
Light Requirements: Dioscorea hockii De Wild. requires moderate to bright light. Insufficient light can cause stunted growth and poor root development. It is recommended to place the plant where it can receive at least 4-5 hours of direct sunlight each day.
Temperature: This plant prefers a warm and humid environment, with temperatures ranging between 20-25°C (68-77°F) during the day and around 16-20°C (60-68°F) at night. Exposure to temperatures outside this range can cause the plant to grow poorly or die.
Soil Requirements: Dioscorea hockii De Wild. prefers a well-draining and fertile soil. The soil should be rich in organic matter to provide the necessary nutrients for growth. The pH of the soil should be neutral to slightly acidic, with a pH range of 6.0-7.0. A soil with poor drainage can lead to root rot, which can severely damage the plant.
Watering: This plant requires regular watering, especially during the growing season. However, it is important not to overwater the plant, as it can lead to waterlogging and root rot. The soil should be allowed to dry out slightly before the next watering.
Fertilization: Dioscorea hockii De Wild. benefits from regular fertilization during the growing season, especially with a fertilizer high in nitrogen. However, it is important not to over-fertilize the plant, as this can cause excessive growth at the expense of root development, making the plant susceptible to disease and pests.
Propagation: The plant can be propagated through stem cuttings or by dividing the rhizomes. The cuttings or rhizomes should be placed in a well-draining soil and kept at a warm temperature with sufficient light until they develop roots.
Cultivation of Dioscorea Hockii De Wild.
Dioscorea Hockii De Wild. is an edible tuber crop that's grown in tropical regions of Africa. It requires proper cultivation techniques to attain optimal growth and quality yields.
Planting and Watering Needs
Planting is done using tubers, which are first soaked in water to stimulate sprouting. The planting period coincides with the beginning of the rainy season. The soil should be well-drained, loamy, and rich in organic matter.
Dioscorea Hockii De Wild. requires a lot of water, mainly during the vegetative stage. Irrigation can be done using drip or sprinkler systems. Ensure the soil remains evenly moist throughout the growing season, as the plant may not tolerate dry spells.
Fertilization
Application of organic manure or compost before planting provides the necessary nutrients that initiate healthy growth. Top-dressing with NPK fertilizer can be done at the onset of the rainy season and then repeated at the full-bloom stage. Avoid excessive application of fertilizers since it may cause tuber splitting.
Pruning
Pruning helps optimize the number of tubers and ensures their quality. The vines that show no signs of new growth or molding should be pruned and discarded. This increases the availability of nutrients to the remaining vines, thus promoting better tuber growth.
Pruning can also be used to control diseased vines. Avoid over-pruning since the leaves are responsible for providing nutrition to the tubers. Prune the vines shortly before harvest, such that they don't interfere with the digging process.
Propagation of Dioscorea hockii De Wild.
Dioscorea hockii De Wild., commonly known as Hock's yam, is a perennial tuberous plant native to tropical Africa. Propagation of this plant is primarily through vegetative means.
Vegetative propagation
The most common method of propagating Dioscorea hockii De Wild. is through vegetative propagation. The plant's tubers can be used as seed material for propagation. Once the mature vine dies back and the tubers have developed, they can be dug up, cleaned, and cut into sections, each containing at least one node. These sections are then planted in soil with the nodes facing up, and kept moist.
Another method of vegetative propagation is through vine cuttings. Cuttings of the plant can be taken from the vine, dipped in rooting hormone, and planted in a soil mixture of peat and perlite. The cuttings should be kept moist and out of direct sunlight until they develop roots and can be transplanted.
In vitro propagation
In vitro propagation or tissue culture can also be used to propagate Dioscorea hockii De Wild. In vitro propagation involves taking small pieces of plant tissue, such as a leaf or stem, and placing them on a nutrient-rich agar gel. Over time, the cells will divide and form new plantlets. These plantlets can then be transferred to soil and grown into mature plants.
While in vitro propagation can be an effective means of propagating many plant species, it is typically more time-consuming and expensive than traditional vegetative propagation methods.
Disease Management for Dioscorea hockii De Wild.
Common diseases that might affect the plant include:
- Anthracnose: This is a fungal disease that causes leaf spotting, stem blight and fruit rot. It can be managed by using fungicides such as copper-based products, and by ensuring proper air flow and drainage to prevent the development and spread of the fungus.
- Yellow vein mosaic virus: This is a virus that causes yellowing and crinkling of the leaves, stunting of the plant and poor tuber development. It can be managed by using virus-resistant planting material, avoiding the use of infected seeds and control of the whitefly vector.
Pest Management for Dioscorea hockii De Wild.
Common pests that might affect the plant include:
- Yam beetle: This is a beetle that feeds on the leaves and stems of the plant, leading to defoliation and stunted growth. It can be managed by handpicking the beetles and by using insecticides such as carbaryl and chlorpyrifos.
- Root-knot nematodes: These are parasites that infest the roots of the plant, causing yellowing, stunted growth and poor tuber development. They can be managed by using resistant varieties, crop rotation and soil fumigation.
