Origin
The plant Dioscorea quartiniana A.Rich. var. latifolia R.Knuth is native to Madagascar, an island in the Indian Ocean off the coast of Southeast Africa. It is found in the eastern part of the island, in the regions of Analanjirofo, Atsinanana, and Vatovavy-Fitovinany.
Common Names
The common name of Dioscorea quartiniana A.Rich. var. latifolia R.Knuth is "Vatsimbina" in the local Malagasy language. It is also known as "Madagascar yam" or "bitter yam" in English.
Uses
Dioscorea quartiniana A.Rich. var. latifolia R.Knuth is an important crop in Madagascar, where it is cultivated for its starchy tubers. The tubers are boiled, roasted or fried, and are a staple food for many people in the region. They are also used to make a type of porridge or soup. The plant has traditional medicinal uses as well, with the tubers used to treat various ailments such as rheumatism, joint pain, and snake bites.
General Appearance
Dioscorea quartiniana A.Rich. var. latifolia R.Knuth is a climbing vine that can grow up to 8 meters in length. It has a thick stem and branches out extensively, often covering large areas. The leaves are heart-shaped and dark green in color, and can grow up to 15 cm in length. The plant produces small, greenish-yellow flowers that bloom in clusters. The tubers of the plant are irregularly shaped and can grow up to 25 cm in length and 10 cm in diameter. They are covered in a brown or grayish-yellow skin that is rough to the touch.
Light Requirements
Dioscorea quartiniana A.Rich. var. latifolia R.Knuth is a tropical plant that thrives in partial to full sun exposure. Therefore, it is best to place it in an area where it can receive adequate sunlight for at least six hours each day.
Temperature Preferences
The plant prefers a warm and humid environment, with temperatures ranging from 25°C to 35°C. It cannot survive in areas with temperatures below 15°C or above 40°C.
Soil Requirements
The ideal soil for Dioscorea quartiniana A.Rich. var. latifolia R.Knuth is well-draining, nutrient-rich, and loamy. This type of soil allows for root growth, water retention, and aeration. The plant requires consistent moisture but does not tolerate waterlogged soil. To achieve this, mix organic matter into the soil before planting and ensure that the soil does not dry out completely while maintaining adequate drainage.
Other Growing Conditions
Aside from the elements mentioned above, this plant does not have any other significant growing requirements. However, it is important to note that it is a climbing plant and will require support structures as it grows over time.
Cultivation Methods
Dioscorea quartiniana A.Rich. var. latifolia R.Knuth, also known as Urera, is a tropical plant that is commonly found in South America. It can grow up to 15 meters, and its vines can be trained to climb on a trellis or a supportive structure. The plant prefers rich, well-drained soil, and partial shade to full sun exposure.
It can be propagated by seeds or cuttings. The germination of seeds requires at least six hours of sunlight and constant humidity. The cuttings should be taken from new-growth branches and planted in a well-draining soil mixture. It is advisable to treat the cuttings with rooting hormone to promote growth.
Watering Needs
Urera requires moderate watering, and the soil should be kept moist but not soggy. Overwatering can lead to root rot, and under-watering can cause the plant to dry out. The frequency of watering depends on the climate, humidity, and soil type. However, it is advisable to water the plant deeply once or twice a week, especially during dry seasons.
Fertilization
The plant can be fertilized with organic or inorganic fertilizers. It is advisable to fertilize the plant during the growing season with a balanced fertilizer that contains nitrogen, phosphorus, and potassium. The fertilizer should be applied at the base of the plant, and it should be watered immediately to prevent root burning. However, over-fertilizing can lead to excessive growth and poor flowering.
Pruning
Pruning is essential in maintaining the plant's health and shape. The plant should be pruned during the dormant season to remove dead, damaged, or diseased parts. The pruning should be done using sharp, sterile tools, and the wounds should be treated with a fungicide to prevent infection. The vines should be trained to climb on a trellis or supportive structure to prevent entanglement and decrease the risk of breakage.
Propagation of Dioscorea quartiniana A.Rich. var. latifolia R.Knuth
Dioscorea quartiniana A.Rich. var. latifolia R.Knuth, commonly known as the "Giant Yam," is a vine that belongs to the Dioscoreaceae family. It is endemic to Madagascar and is known for its large edible tubers that are used as a source of food. The plant is propagated through various methods, which are discussed below.
Propagation by Cuttings
Propagating Dioscorea quartiniana A.Rich. var. latifolia R.Knuth by cuttings is easy and is one of the most common methods used to increase the plant's population. The best time to take cuttings is in the spring when new growth appears. Cuttings should be taken from healthy plants that are free from any diseases or infections. The cuttings should be about 30 cm in length and should consist of a tip with few leaves. The cutting should be planted in a potting mixture of equal parts of sand, loam, and compost and placed in a warm and humid place. The cutting will begin to develop roots in about 3-4 weeks, and once the roots have developed, the plant can be transplanted into the ground or a larger pot.
Propagation by Tubers
Dioscorea quartiniana A.Rich. var. latifolia R.Knuth is primarily propagated through tubers. The tubers should be harvested when the plant is dormant, usually during the winter months. The tubers are washed and soaked in water for about 24 hours to soften them. The tubers are then planted about 10-15 cm deep in a potting mixture of equal parts of sand, loam, and compost. The pot should be placed in a warm and humid place, and the tuber will start developing roots in about 3-4 weeks. Once the roots have developed, the plant can be transplanted into a larger pot or the ground.
Propagation by Seeds
Dioscorea quartiniana A.Rich. var. latifolia R.Knuth can also be propagated by seeds. The seeds should be collected when the fruit is ripe, usually during the fall. The seeds should be soaked in water for about 24 hours to soften the seed coat, and then planted in a potting mixture of equal parts of sand, loam, and compost. The pot should be placed in a warm and humid place, and the seeds will germinate in about 2-3 weeks. Once the seedlings have grown to a suitable size, they can be transplanted into larger pots or directly into the ground.
Disease Management
Dioscorea quartiniana A.Rich. var. latifolia R.Knuth are susceptible to various diseases that affect their growth and productivity. The common diseases affecting the plant include:
- Anthracnose: This disease is caused by a fungus and leads to the appearance of brown or black spots on the leaves, stems, and tubers of the plant. To manage anthracnose, farmers can apply fungicides and practicing crop rotation to avoid the buildup of pathogens in the soil.
- Root rot: Root rot is caused by soil-borne pathogens that thrive in wet and poorly drained soils. Overwatering of the plant can also lead to root rot. Farmers can manage root rot by improving drainage, reducing irrigation frequency, and applying bio-fungicides.
- Scab: This disease is caused by a bacteria that affects the leaves and tubers of the plant, causing small lesions. Applying fungicides can help manage scab.
- Viral diseases: These diseases are transmitted through infected planting materials and sucking insects. Viral diseases cause stunted growth and yield loss in plants. Farmers can avoid viral diseases by using certified planting materials, practicing good farm hygiene, and controlling insect vectors.
Pest Management
Pests pose a significant threat to Dioscorea quartiniana A.Rich. var. latifolia R.Knuth. Common pests that affect the plant include:
- Yam beetles: These are insects that bore into the plant stems and tubers, causing wilting of leaves and reduction in yield. Farm practices such as crop rotation and timely planting can help manage yam beetles. Farmers can also use botanical insecticides such as neem seed extracts and pyrethrum to control yam beetles.
- Mites: Mites feed on plant sap causing damage, which appears as yellowing of leaves and stunted growth. Farmers can manage mites by practicing good farm hygiene, using biological control agents like predatory mites, and applying acaricides.
- Termites: Termites are soil-borne insects that feed on roots, stems, and tubers of Dioscorea quartiniana A.Rich. var. latifolia R.Knuth. The use of resistant cultivars can help manage termites. Farmers can also control termites by practicing good farm hygiene, application of bio-pesticides, and soil treatment with pesticides.
- Mealybugs: These insects suck sap from leaves and stems of the plant resulting in stunted growth and reduced yield. Farmers can manage mealybug infestations by using insecticides and practicing good field hygiene.
