Overview
Dioscorea esculenta (Lour.) Burkill, also known as air potato or winged yam, is a species of root vegetable native to Southeast Asia and the Pacific. This plant is widely cultivated in tropical and subtropical regions and is popular for its edible tubers, which are consumed as a staple food by many indigenous communities.
Appearance
Air potato is a fast-growing perennial vine that can reach up to 20 meters in length. The leaves are large, heart-shaped, and glossy, with long petioles that attach to the stem. The stem of the plant is thick, twining, and can grow up to 10 centimeters in diameter, making it stand out from other vines in the area. The most characteristic feature of the air potato is its aerial tubers, which hang from the stem and look like small potatoes. These tubers can be up to 20 centimeters in diameter and are covered in a dark, scaly skin.
Common Names
Air potato is known by many names in different regions around the world. Some of the common names include winged yam, aerial yam, air potato, hilaha, and ñame volador. These names reflect the plant's unique appearance and its ability to produce tubers that grow in the air.
Uses
The tubers of Dioscorea esculenta are an important source of food for many communities in Southeast Asia and the Pacific. The tubers are rich in carbohydrates, fiber, and essential nutrients, such as vitamin C and potassium. They can be cooked in a variety of ways, including boiling, roasting, and frying, and are often used as a substitute for potatoes or taro. In addition to its culinary uses, air potato is also valued for its medicinal properties. The plant has been used to treat a range of ailments, including fevers, coughs, and digestive disorders. Its leaves and stems are also used to make traditional remedies for skin irritations and wounds. Finally, air potato is also used in ornamental horticulture, as its large leaves and aerial tubers make it an attractive addition to gardens and parks.
Light Requirements
Dioscorea esculenta typically requires full sun to grow and produce tubers. In areas with extremely hot climates, partial shade may be necessary to mitigate heat stress.
Temperature Requirements
The ideal temperature range for Dioscorea esculenta growth is between 20°C and 30°C. Temperatures below 15°C or above 35°C may adversely affect growth and tuber production.
Soil Requirements
Dioscorea esculenta prefers well-draining, sandy or loamy soil with a pH range of 5.0-6.5. It does not tolerate waterlogged conditions or heavy clay soils.
The plant also benefits from soil with high organic matter content, which enhances soil fertility and provides essential nutrients for growth.
In areas with poor soil quality, adding compost or manure can help to improve soil structure and fertility.
Cultivation Methods
The Dioscorea esculenta (Lour.) Burkill, also known as the lesser yam, is a root crop that is widely cultivated in tropical regions. It is a hardy crop that is well adapted to different soil types, but it thrives best in loamy and well-drained soils.
Plant the tubers in a shallow trench or hole, with a spacing of about 1.5 meters between the rows and 50 to 75 centimeters between plants. The planting depth should be about 5 to 8 centimeters deep.
The crop requires a warm and humid environment, with temperatures ranging between 20 to 30 degrees Celsius. It also requires a lot of sunlight, and therefore should be grown in an open area where it can receive enough sunlight.
Watering Needs
The Dioscorea esculenta requires adequate water supply, especially during the early stages of growth. The crop should be irrigated regularly, especially during the dry season, to ensure that the soil does not dry out.
The best time to irrigate the crop is during the late afternoon or early morning, to reduce water loss due to evaporation.
However, care should be taken not to overwater the crop, as this may lead to water-logging, which can cause root rot and other diseases.
Fertilization
The Dioscorea esculenta requires regular fertilization to ensure optimal growth and yield. Organic manure or compost should be applied before planting to improve soil fertility and texture.
During the growing season, the crop should be fertilized with nitrogen, phosphorus, and potassium fertilizers. The application rate and frequency of fertilization should be determined by a soil analysis and may vary depending on the nutrient requirements of the crop.
Pruning
Pruning is not necessary for the Dioscorea esculenta. However, removing diseased and damaged leaves and stems can help to reduce the spread of diseases and pests.
The crop should also be trained to climb on trellises or stakes to prevent it from sprawling on the ground, which can make it vulnerable to pests and diseases.
Propagation Methods of Dioscorea Esculenta (Lour.) Burkill
Dioscorea esculenta (Lour.) Burkill, commonly known as lesser yam, is a perennial climber and belongs to the family Dioscoreaceae. The plant is widely cultivated in Southeast Asia, particularly in Indonesia, Malaysia, and the Philippines, as a food and medicinal crop.
Vegetative Propagation
The most common method of propagating Dioscorea esculenta is through the use of vine cuttings. The vines should be cut into pieces about 30-40 centimeters long, with at least 2-3 nodes. The nodes should be planted horizontally, about 5-10 centimeters deep in well-draining soils. The vines can be planted directly in the field or raised in a nursery and then transplanted to the field after 1-2 months.
Seed Propagation
Propagation of Dioscorea esculenta through seeds is less common because the plant does not produce seeds frequently. However, seeds can be collected from the mature fruits when they ripen and fall to the ground. The seeds should be sown in a nursery and kept under shade until they germinate. The seedlings can be transplanted to the field after about 3 months.
Tissue Culture Propagation
Another method of propagating Dioscorea esculenta is through tissue culture. Tissue culture involves growing the plant in vitro, which means in a laboratory under controlled conditions. Tissue culture propagation is useful when there is a need to produce a large number of plants with desirable characteristics. However, tissue culture propagation requires specialized equipment and expertise.
Disease and Pest Management for Dioscorea esculenta (Lour.) Burkill
Dioscorea esculenta (Lour.) Burkill, commonly known as Chinese yam, is an important food crop, especially in Asia. However, the plant can be affected by a number of diseases and pests, which can significantly reduce the yield. Here are some common diseases and pests that affect Dioscorea esculenta and ways to manage them.
Diseases
Anthracnose: This is a fungal disease that affects the leaves and stems of the plant. Symptoms include brown, circular spots on the leaves, which can expand and cause defoliation. The fungus can also cause cankers on the stems, leading to stem necrosis. To manage anthracnose, remove and destroy infected plant parts and apply fungicides, such as copper-based products.
Bacterial soft rot: This bacterial disease can occur during the storage of the tubers, causing them to become soft and eventually rot. To prevent bacterial soft rot, store the tubers in a cool, dry place and ensure that they are not damaged during harvest and storage.
Yam mosaic virus: This viral disease is transmitted by aphids, and symptoms include chlorotic mottling, yellowing, and distortion of the leaves, as well as stunting of the plant. To manage Yam mosaic virus, control aphid populations using insecticides and remove and destroy infected plants.
Pests
Yam tuber beetles: These are the most common pests of Dioscorea esculenta. The adult beetles feed on the leaves, while the larvae bore into the tubers, causing significant damage. To manage yam tuber beetles, remove and destroy infested plant parts and apply insecticides, such as neem oil or pyrethroids.
Yam nematodes: These microscopic roundworms feed on the roots of the plant, causing stunted growth and reduced yields. To manage yam nematodes, use resistant cultivars and apply nematicides, such as carbofuran or fenamiphos, to the soil.
Yam moth: The larvae of this moth bore into the tubers, causing them to become hollow and lose weight. To manage yam moth, use pheromone traps to monitor and control adult populations and store the tubers in a cool, dry place.
In conclusion, Dioscorea esculenta is a valuable crop that can be affected by a range of diseases and pests. However, by implementing preventative measures and using appropriate management strategies, it is possible to minimize the damage caused by these threats and ensure a healthy crop yield.
