Origin
Dolichos eriocaulus Harms, commonly known as the "velvet bean," is a tropical legume that originates from Africa and Asia. It is widely distributed throughout tropical and subtropical regions of the world, including India, Sri Lanka, Thailand, Papua New Guinea, and several African countries.
Common Names
Aside from "velvet bean," Dolichos eriocaulus Harms is known by various common names depending on the region. In India, it is called "kaunch," while in Sri Lanka it is known as "imbiri." In Africa, it is called "néré" or "dawa-dawa," and in Thailand, it is known as "hua ceng ki."
Uses
Dolichos eriocaulus Harms has been used for various purposes throughout history. Its ripe seeds are commonly used in traditional medicine to treat a wide range of conditions, such as infertility, Parkinson's disease, and diabetes. In some regions, the seeds are also used to make a traditional tonic drink believed to have aphrodisiac properties.
Aside from its medicinal uses, Dolichos eriocaulus Harms is also an important crop plant. Its young leaves and pods are used as a vegetable in several African and Asian countries. The dried seeds of the plant are used as a source of protein, and the plant is sometimes grown as a forage crop for livestock.
General Appearance
Dolichos eriocaulus Harms is a climbing vine that can grow up to two meters in height. The plant has trifoliate leaves that are dark green in color, with a leathery texture. Its flowers are small and pea-like, with purple or white petals. The plant's fruits are large pods that are covered in soft, velvety hairs, giving rise to its common name, "velvet bean."
The pods contain several seeds that are oval-shaped and covered in a hard, smooth seed coat. The seeds are usually black but may sometimes be brown or white. The plant's root system includes a taproot and numerous lateral roots that anchor the plant to the ground.
Light Requirements
Dolichos eriocaulus Harms is a plant that requires full sun exposure for optimal growth. It prefers bright, direct sunlight and must be placed in a location that receives at least six hours of full sun daily.
Temperature Requirements
Dolichos eriocaulus Harms is a tropical plant that requires warm temperatures to thrive. It grows best in temperatures between 65-85°F (18-29°C). Temperatures below 50°F (10°C) can be fatal to the plant.
Soil Requirements
The soil for Dolichos eriocaulus Harms needs to have good drainage. It prefers a slightly acidic to neutral soil pH level (6.0-7.0). It can grow in a variety of soil types, including sandy, loamy, or clay soils. However, the soil should be rich in nutrients and organic matter.
Cultivation of Dolichos eriocaulus Harms
Dolichos eriocaulus Harms, commonly known as the woollypod dolichos, is a wild legume plant found in East Africa, mostly in Kenya and Tanzania. The plant thrives in well-draining soils, rich in organic matter. Dolichos eriocaulus grows best in warm climates and can tolerate mild drought conditions.
To grow Dolichos eriocaulus Harms, prepare your planting site by loosening the soil to a depth of at least 8 inches. Then, plant the seeds in rows, leaving a spacing of about 18 inches between the rows. Cover the seeds with a thin layer of soil and water well.
Watering Needs of Dolichos eriocaulus Harms
To keep the plants healthy, regular watering is necessary, especially during the germination and flowering stages. Water the plant frequently, at least twice a week, to maintain the moisture level in the soil.
However, avoid watering excessively as it can lead to the development of diseases like root rot. Reduce the watering frequency during periods of prolonged rainfall to avoid waterlogging the area around the plants.
Fertilization of Dolichos eriocaulus Harms
Dolichos eriocaulus Harms requires a rich soil with sufficient nutrients to grow. To boost the soil's fertility, apply a slow-release fertilizer, like a balanced 10-10-10 NPK fertilizer, before planting the seeds.
You can also apply a topdressing of compost during the plant's active growth periods to provide the necessary nutrients. Avoid over-fertilizing the plants as it can harm their growth and development.
Pruning of Dolichos eriocaulus Harms
Pruning is not necessary for Dolichos eriocaulus Harms, unless you want to manage its height or improve plant shape. You can pinch back the growing tips of the plant to encourage bushier growth or remove any dead or diseased branches.
Pruning should be done during the plant's dormant season or after flowering to avoid interrupting the plant's natural growth cycle.
Propagation Methods of Dolichos eriocaulus Harms
Dolichos eriocaulus Harms is propagated through sexual and asexual means. Sexual propagation involves the use of seeds while asexual propagation involves the use of cuttings and root divisions.
Propagation by Seed
The seeds of Dolichos eriocaulus Harms are collected when mature pods are harvested from the plant. The seeds are then cleaned, dried, and sown in a well-prepared seedbed. The seedbed should be moist, and the seeds should be pressed firmly into the soil to ensure good seed-to-soil contact. Germination should start within 7 to 14 days after sowing. As the seedlings grow, they should be thinned to allow for proper spacing.
Propagation by Cuttings
Dolichos eriocaulus Harms can be propagated by taking cuttings from a mature plant. These cuttings should be taken from the plant's softwood, which is a growth that is not too old and not too young. The cuttings should be about 8 to 12 cm long and preferably from the branches at the lower part of the plant. After cutting, the leaves should be removed, and the cuttings should be dipped in rooting hormone before planting in a rooting medium. The rooting medium should be kept moist, and the cuttings should be placed in bright, indirect sunlight until they are well-rooted.
Propagation by Root Division
Another way to propagate Dolichos eriocaulus Harms is by dividing the plant's roots. This method is suitable for plants that have grown too large for their container or garden space. The plant should be carefully removed from its pot or garden bed and the root system divided into smaller sections. Each division should have at least one healthy shoot. The divided sections should be immediately planted in pots or other garden sites with a well-draining soil mix, watered well, and placed in a shaded area until they are established.
Disease and Pest Management for Dolichos eriocaulus Harms
Dolichos eriocaulus Harms, also known as hairy-stemmed horse gram, is a legume crop that is mainly grown in Asia and Africa. This plant is versatile and has various uses, including soil conservation, animal feed, and food for human consumption. However, like any other crop, Dolichos eriocaulus is prone to diseases and pests that can affect its production. Here are some of the common diseases and pests that might affect Dolichos eriocaulus and how to manage them:
Common Diseases
Anthracnose: This is a fungal disease that affects the leaves, stems, and pods of Dolichos eriocaulus. The infected plant parts develop circular, brown, or black lesions with a reddish-brown border. The disease is more prevalent in wet and warm weather conditions. To manage anthracnose, use crop rotation and avoid planting infected seeds or plant parts. Apply fungicides to the affected plants and remove any infected plant debris from the field.
Bacterial leaf spot: This is a bacterial disease that causes angular brown or black spots on the leaves of Dolichos eriocaulus. The leaves may turn yellow or wilt, leading to stunted growth and reduced yield. The disease spreads quickly in wet and humid conditions. To manage bacterial leaf spot, plant resistant varieties and avoid overhead irrigation. Apply copper-based fungicides to control the disease.
Common Pests
Aphids: Aphids are small, pear-shaped insects that suck sap from the leaves and stems of Dolichos eriocaulus. They cause stunted growth, yellowing of leaves, and distortion of plant parts. To manage aphids, use insecticidal soaps or oils, prune heavily infested parts, and encourage natural predators like ladybugs and lacewings.
Pod borers: These are moth larvae that bore into the pods of Dolichos eriocaulus, leading to reduced yield and quality of the harvest. The infested pods have holes, tunnels, and frass. To manage pod borers, practice crop rotation, handpick and destroy the infested pods, and use insecticidal sprays before the pods develop.
Bean fly: Bean fly larvae feed on the roots of Dolichos eriocaulus, causing wilting, stunting, and reduced yield. The adults are brown flies that lay eggs at the base of the plant. To manage bean fly, use resistant varieties, drench the soil with insecticides before planting, and avoid planting infested seeds.
In conclusion, Dolichos eriocaulus Harms is prone to diseases and pests that can affect its production. Therefore, farmers must be vigilant and use the appropriate management practices, including crop rotation, use of resistant varieties, and timely application of insecticides and fungicides to control pests and diseases.
