Overview
Lablab purpureus (L.) Sweet var. uncinatus is a plant species commonly known as the bonavist bean. It is a type of legume that is native to Africa but widely cultivated in many other parts of the world. It is an annual climbing plant with numerous uses, both as a food and forage crop.
General Appearance
The bonavist bean plant is a slender climbing vine that can reach heights of up to 6 meters. It has trifoliate leaves, consisting of three ovate leaflets, and the flowers are creamy white or light purple. The fruit of the plant is a long and narrow pod, which contains numerous seeds.
Common Names
The plant is also known by several other common names, including hyacinth bean, lablab bean, Indian bean, Egyptian bean, and dolichos bean. The bonavist bean is also referred to by its scientific name, Lablab purpureus var. uncinatus.
Uses
The bonavist bean has many uses, both as a food and forage crop. Its seeds can be consumed either raw or cooked, and are rich in protein, fiber, and micronutrients. The plant is also used as a forage crop for animals due to its high protein content. In addition, the bonavist bean is also used for medicinal purposes, particularly in traditional African medicine for treating diabetes, asthma, and hypertension.
Light
Lablab purpureus var. uncinatus prefers full sunlight exposure for at least 6-8 hours every day. It can tolerate partial shade but this can reduce fruit and seed yield.
Temperature
This plant grows well in tropical and subtropical regions where temperatures range from 20°C to 35°C. The ideal temperature for Lablab purpureus var. uncinatus to grow and produce fruit and seeds is between 25°C and 30°C. Frost or extremely cold temperatures are not suitable for this plant, and it cannot tolerate temperatures below 15°C.
Soil Requirements
The plant grows well in fertile, well-drained and loamy soils with a pH range of 6.5 to 7.5. Soil should be rich in nitrogen and phosphorus. It performs well in soils that are slightly acidic or neutral, but it does not tolerate soils that are too salty or contain too much clay. Proper drainage is necessary to avoid waterlogging, which can limit the plant's growth and yield.
Cultivation Methods
Lablab purpureus var. uncinatus, also known as Hyacinth Bean, is primarily grown as a vegetable crop in tropical and subtropical regions. It is a vine-like plant that requires support such as trellis, teepee or fence for proper growth.
The plant prefers well-drained and fertile soil, enriched with organic matter. It can grow in both acid and alkaline soils, with a pH range of 5.5-7.5. The optimal temperature for the growth of Lablab purpureus is between 20-30°C, with a minimum temperature of 15°C.
The seeds of Lablab purpureus should be soaked in water overnight before sowing. It is advisable to sow the seeds directly in the field or container as transplanting disturbs the roots and may lead to stunted growth. The ideal spacing between the plants is 25-30cm with rows spaced 60-75cm apart.
Watering Needs
Hyacinth Bean is a heat-loving plant that requires adequate water for optimal growth and productivity. The plant should be watered regularly to keep the soil moist, especially during the flowering and pod formation stage.
A lack of water can lead to stunted growth, yellowing of leaves, and drop-off of flowers and fruits. It is important to avoid overwatering as it can lead to waterlogging, root rot, and other fungal diseases.
Fertilization
To promote the growth and yield of Lablab purpureus, the plant requires regular fertilization with a balanced NPK fertilizer. Adding organic matter to the soil also helps to improve soil fertility and structure.
The plant should be fertilized twice a month during the vegetative stage, and once a week during flowering and fruiting stage. Foliar applications of fertilizer can also be done to provide essential micronutrients.
Pruning
Pruning is important for maintaining the vigour and productivity of the Hyacinth Bean plant. The plant should be pruned regularly to remove diseased, damaged, or dead branches. It also helps to control the growth of the plant and increase air circulation.
It is advisable to prune the plant when it reaches a height of 20-30cm, leaving only the strongest stems to grow and trellising them for support. Pruning should be done early in the morning or late afternoon to avoid sunburn damage.
Propagation of Lablab purpureus (L.) Sweet var. uncinatus Plant
Propagation is a crucial process in the cultivation of Lablab purpureus (L.) Sweet var. uncinatus. There are several methods of propagating this plant. These include:
Seed Propagation
Seed propagation is the most common method of propagating Lablab purpureus (L.) Sweet var. uncinatus. The seeds are sown directly into the soil. Before sowing, the seeds are soaked in water for 12-24 hours to soften the seed coat. This helps the seeds germinate faster. The seeds should be planted at a depth of 2-3 cm. Seed germination usually takes 7-14 days.
Cuttings Propagation
Cuttings can also be used to propagate Lablab purpureus (L.) Sweet var. uncinatus. Softwood cuttings or semi-hardwood cuttings should be used for best results. Cuttings should be taken from healthy, disease-free plants. Cuttings should be 10-15 cm in length and should have 2-3 nodes. The cuttings should be planted in a rooting hormone and then placed in a mixture of sand and peat moss. Cuttings should be kept in a warm, humid place until they form roots. This usually takes 2-3 weeks.
Division Propagation
Division propagations are carried out by dividing the rhizomes of mature plants. The rhizomes should be divided into smaller sections. Each section should have at least one growing point. The divided rhizomes should be planted immediately in well-drained soil.
Conclusion
Propagation of Lablab purpureus (L.) Sweet var. uncinatus is important for the expansion of the plant population. Seed propagation, cuttings propagation and division propagation are all effective methods for propagating this plant. Growers can choose the most suitable method depending on their needs and preferences.
Disease management
Lablab purpureus (L.) Sweet var. uncinatus is susceptible to various diseases that can affect the yield and quality of the crop. Some of the common diseases that can affect Lablab plants include anthracnose, bacterial wilt, powdery mildew, and leaf blight. To manage anthracnose, it is advisable to plant disease-free seeds, rotate crops, and prune infected plants. For bacterial wilt, which is caused by bacteria, it is important to control the vector that spreads the bacteria, avoid plant stress, and practice crop rotation. Powdery mildew can be managed by keeping the plants well-spaced to encourage air circulation and applying fungicides as necessary. Leaf blight can be controlled by removing infected leaves and maintaining proper field hygiene.
Pest management
Lablab purpureus (L.) Sweet var. uncinatus is also affected by various pests, which can reduce the yield and quality of the crop. Some common pests that might affect Lablab plants include aphids, mites, thrips, and caterpillars. To control aphids, it is advisable to introduce beneficial insects such as ladybugs, maintain proper field hygiene, and apply insecticides as necessary. Mites can be controlled by spraying the plants with water or applying acaricides. Thrips can be managed through the use of sticky traps and insecticides. Caterpillars can be controlled through handpicking, introducing natural predators such as birds, and applying Bacillus thuringiensis (BT) insecticide. It is important to monitor the plants regularly for pest infestations and take swift action to prevent extensive damage.
