Overview of Dolichos volkensii Taub.
Dolichos volkensii Taub., also known as the Volkens' dolichos or wild banana bean, is an herbaceous climbing plant that belongs to the family Fabaceae, subfamily Faboideae. It is native to East Africa and is commonly found in countries such as Kenya, Tanzania, and Uganda. The plant is valued for its ornamental and medicinal properties as well as its hardy nature.
Description of Dolichos volkensii Taub.
The plant has long and slender twining stems that can grow up to 5 meters in length. The leaves are trifoliate, with each leaflet measuring between 6-15 cm in length and 4-10 cm in width. The flowers are borne in racemes, with each raceme containing several purple or pink-colored flowers that bloom from June to October. The fruits of the plant are long and cylindrical, with each pod measuring up to 15 cm in length and 1 cm in width. The pods are initially green, but they turn brown as they mature and split open to release the seeds.
Cultural and Medicinal Uses of Dolichos volkensii Taub.
The Volkens' dolichos is an important medicinal plant in traditional African medicine. The roots and leaves of the plant contain alkaloids, flavonoids, and tannins, which have antimicrobial, anti-inflammatory, and analgesic properties. The plant is used to treat various ailments such as skin diseases, stomach ailments, and respiratory infections. The roots are also used as a contraceptive and to induce labor.
The plant is also used for cultural and ornamental purposes. In Kenya, the plant is used during traditional wedding ceremonies where the groom's family presents the plant to the bride's family as a symbol of their intention to take care of their daughter. The plant is also used as an ornamental plant in gardens and landscapes due to its attractive flowers.
Light Requirements:
The plant Dolichos volkensii Taub. requires full sun or partial shade for optimal growth. It needs at least 6 hours of sunlight per day. Inadequate light can lead to poor growth and eventual death of the plant. Therefore, it should be grown in locations that receive adequate sunlight.
Temperature Requirements:
The plant Dolichos volkensii Taub. thrives in warm temperatures. It does best in temperatures ranging from 20-30°C. Temperatures below 10°C can lead to stunted growth and leaf yellowing. Extreme temperatures above 40°C can cause blossom drop, and the plant may become dormant. The plant is frost-sensitive; hence, it should be protected from harsh winter conditions.
Soil Requirements:
The plant Dolichos volkensii Taub. prefers well-draining, loamy soils with a pH ranging from 5.5-6.8. The soil should be rich in organic matter to support healthy growth. It does not tolerate waterlogged soils and may develop root rot if subjected to prolonged wet conditions. The recommended soil type for growing this plant is sandy or gravelly soil. Soil fertility can be improved by adding compost or any other organic matter.
Cultivation Methods of Dolichos volkensii Taub.
Dolichos volkensii Taub. grows best in warm, tropical climates with well-drained, loamy or sandy soil. It is typically propagated by seeds, which should be planted in warm soil at a depth of about 2 cm. The seeds should be watered immediately after planting and kept moist throughout the germination period, which typically takes 7 to 10 days.
Once the plants have emerged, they should be thinned to a spacing of about 20 cm to 30 cm to ensure that they have sufficient room to grow and develop. Dolichos volkensii Taub. requires full sun to thrive and should be grown in a location where it receives at least 6 to 8 hours of direct sunlight per day.
Watering Needs of Dolichos volkensii Taub.
Dolichos volkensii Taub. requires regular watering to maintain healthy growth, especially during dry spells. The plants should be watered once a week, providing enough water to saturate the soil to a depth of about 15 cm. Avoid excessive watering, as this can lead to root rot and other issues. The plant can tolerate short periods of drought, but prolonged drought can negatively affect its growth and yield.
Fertilization of Dolichos volkensii Taub.
Dolichos volkensii Taub. benefits from regular fertilization to promote healthy growth and maximum yield. A balanced, all-purpose fertilizer can be applied every two to three weeks during the growing season. Alternatively, a slow-release fertilizer can be applied at the beginning of the growing season and then once more halfway through the season.
Organic fertilizers, such as compost or well-rotted manure, can also be used to provide essential nutrients to the plant. These should be applied at the beginning of the growing season and then once more during midseason.
Pruning of Dolichos volkensii Taub.
Dolichos volkensii Taub. does not require extensive pruning. However, removing yellowed or damaged leaves can help to promote healthy growth and prevent the spread of disease. If the plant becomes too bushy, it can be lightly pruned to promote airflow and sunlight penetration.
The plant should be pruned in the early morning or late afternoon to avoid damaging the leaves due to sunburn or heat stress. Sterilize pruning tools before and after each use to prevent the spread of disease between plants.
Propagation of Dolichos volkensii Taub.
Dolichos volkensii Taub. can be propagated both by seeds and cuttings.
Seed Propagation
Propagation of Dolichos volkensii Taub. through seeds is the most common method used. The seeds are collected from mature pods and should be planted immediately to avoid losing viability. The seeds should be soaked overnight in warm water to help break their dormancy. The seeds should be sown in fertile soil in a well-drained container, and the depth of the sowing should be 1-2 centimeters. The container should be kept in a partially shaded area and watered regularly. The germination period for Dolichos volkensii Taub. is usually around 10-21 days.
Cutting Propagation
Dolichos volkensii Taub. can also be propagated through cutting. This method is usually used for the purpose of producing uniform plants. The cuttings should be taken from mature branches and should have at least two nodes. The bottom part of the cutting should be dipped in rooting hormone and then placed in a well-draining propagating mix. The container should be kept in a partially shaded area and watered regularly until the cutting roots. The rooting period for Dolichos volkensii Taub. is usually around 2-4 weeks.
Disease and Pest Management for Dolichos volkensii Taub.
Dolichos volkensii Taub., also known as the velvet bean, is a leguminous plant native to tropical Africa and widely distributed throughout the continent. The plant is known for its nitrogen-fixing capabilities, which make it an excellent choice for soil improvement and crop rotation. However, like all living organisms, the velvet bean is susceptible to diseases and pest attacks. Proper management is necessary to ensure healthy and vigorous growth and to prevent yield losses.
Common Diseases
Some of the common diseases that affect Dolichos volkensii Taub. include:
- Anthracnose: This fungal disease is characterized by dark and sunken lesions on the leaves, stems, and pods of the plant. It can cause premature defoliation and yield losses. Anthracnose can be managed by using resistant varieties, practicing crop rotation, and fungicide application.
- Bacterial blight: This disease is caused by the bacterium Xanthomonas axonopodis pv. vignicola. Symptoms include water-soaked lesions on the leaves and stems, which later turn brown or black and become necrotic. Severely affected plants can wilt and die. The disease can be managed by using disease-free seeds, avoiding overhead watering, and using copper-based fungicides.
- Mosaic virus: This virus is transmitted by insect vectors and causes mottled yellowing and distortion of the leaves. Affected plants may be stunted and produce fewer pods. Mosaic virus can be managed by using virus-free seeds, practicing good sanitation, and controlling insect vectors.
Common Pests
Dolichos volkensii Taub. is also susceptible to pest attacks. Some of the common pests that affect the plant include:
- Aphids: These small insects feed on the sap of the plant and can cause stunted growth, curling of leaves, and yield losses. Aphids can be managed by using natural enemies such as ladybugs and lacewings, or by using insecticidal soap or neem oil.
- Bean fly: The bean fly lays its eggs on the stem of the plant, and the larvae bore into the stem, causing wilting and eventual death of the plant. Bean fly can be managed by using insecticides or by covering the plants with insect-proof nets.
- Cutworms: Cutworms are nocturnal caterpillars that feed on the stem of the plant, causing wilting and death. Cutworms can be managed by handpicking, using biological control agents, or using insecticides.
Proper disease and pest management practices are critical for the health and vitality of Dolichos volkensii Taub. Using disease-resistant varieties, practicing good sanitation, and using biological and chemical control methods can help prevent disease and pest outbreaks and ensure a bountiful harvest.
