Overview of Dolichos lablab L.
Dolichos lablab L., also known as lablab bean, hyacinth bean, dolichos bean, or simply lablab in different parts of the world, is a leguminous plant that belongs to the family Fabaceae. It is widely cultivated for its edible seeds, pods, leaves, and roots, which have numerous nutritional and medicinal benefits. This plant is native to Africa but now it is grown in several countries across the world for culinary, fodder, ornamental, and soil enhancement purposes.
Appearance of Dolichos lablab L.
Dolichos lablab L. is a fast-growing and climbing perennial vine that can reach up to 10 meters in height. It has a deep taproot system and produces several branched stems that are covered with dense and hairy foliage. The leaves are trifoliate, alternate, and oval-shaped with serrated edges. The flowers are showy and attractive, having a range of colors such as white, pink, purple, or blue-violet. They are borne in clusters or racemes and have a sweet fragrance.
The fruit of Dolichos lablab L. is a long and thick pod that is cylindrical or crescent-shaped and has a hard and smooth surface. The pod can grow up to 30 cm in length depending on the variety and maturity stage. Inside the pod, there are some oval-shaped seeds that can be white, green, brown, black, or mottled. The seeds have a characteristic sweet and nutty flavor and are used in various cuisines.
Uses of Dolichos lablab L.
Dolichos lablab L. has various uses that have been recognized for centuries. The plant is a rich source of protein, carbohydrates, dietary fiber, vitamins, and minerals, making it an important food crop for many communities. The seeds and pods can be eaten raw, boiled, steamed, fried, or roasted, and are used as ingredients in soups, stews, curries, salads, or snacks.
The leaves of Dolichos lablab L. are also edible and can be cooked like spinach or used as a vegetable in traditional dishes. Moreover, the plant has medicinal properties that have been used to treat various ailments such as diabetes, hypertension, fever, inflammation, diarrhea, and skin disorders. The roots of Dolichos lablab L. are also used for fodder, and the plant is often grown as a cover crop or intercrop to improve soil fertility and control pests and diseases.
Furthermore, Dolichos lablab L. is valued for its ornamental qualities and is grown in gardens, parks, and landscapes to provide shade, privacy, and beauty. The plant is easy to propagate and requires minimal care, making it an ideal option for home gardening and landscaping.
Growth Conditions of Dolichos Lablab L.
Dolichos lablab L. is a warm-season annual climbing plant that thrives well in tropical and subtropical regions across the world. It is commonly referred to as hyacinth bean, lablab bean, and Indian bean among others. The following are the typical growth conditions required for optimal growth and productivity of dolichos lablab L:
Light Requirements
Dolichos lablab L. requires a minimum of 6 to 8 hours of full sun exposure per day to thrive and produce a good yield. Insufficient sunlight may lead to stunted growth, poor flowering, and low yields. However, extreme heat and direct sunlight can cause leaf scorching, wilting, and sunburn in young plants. Therefore, partial shade during the hottest part of the day is recommended in extremely hot regions.
Temperature Requirements
The optimal temperature range for the growth and development of dolichos lablab L. is between 20 to 32°C (68 to 90°F). Temperatures above 35°C (95°F) may cause heat stress and lead to rapid moisture loss, wilting, and death of the plant. Cool temperatures below 10°C (50°F) can also stunt growth and cause leaf yellowing, and eventually, death of the plant.
Soil Requirements
The ideal soil for dolichos lablab L. should be well-drained, fertile, and rich in organic matter. The plant grows well in soils with a pH range of 6.0 to 7.5. It is tolerant to a wide range of soil types, including sandy, loamy, and clay soils, as long as they are well-drained. Waterlogged soils are not suitable for the growth of dolichos lablab L. as they cause root rot and limit nutrient uptake.
Cultivation Methods of Dolichos lablab L.
Dolichos lablab L. is a warm-season crop that thrives in well-draining soils. The plant can grow up to 6 feet in height, requires plenty of sunlight, and should be planted in an area sheltered from strong winds. For optimum growth, the soil pH should be between 6.0-7.5. The seeds should be planted 1-1.5 inches deep and 3-4 feet apart in rows. It's advisable to add compost and organic manure to the soil before planting.
Watering Needs
Dolichos lablab L. requires consistent moisture throughout the growing season. Regular and frequent watering is crucial during germination and early growth. However, overwatering should be avoided, as it could lead to fungal and bacterial diseases. Once established, the plant can tolerate drought, but it's advisable to water the plant deeply once a week.
Fertilization
The plant requires adequate nutrition to thrive. Organic fertilizers such as compost and well-rotted manure can be applied before planting. During the growing season, nitrogen-rich fertilizers such as blood meal and fish emulsion fertilizer can be applied. It's advisable to avoid excessive nitrogen fertilization as it could lead to excessive leaf growth at the expense of pod growth.
Pruning
Pruning is not necessary for Dolichos lablab L. However, it's advisable to remove any dry, dead, or diseased parts of the plant to prevent the spread of diseases. Pinching the tips of young plants can help promote bushier growth.
Propagation of Dolichos lablab L.
The Dolichos lablab L., commonly known as lablab bean or hyacinth bean, can be propagated by several methods such as seeds, cuttings, and division.
Propagation by Seeds
Propagation by seeds is the most common way to grow Dolichos lablab L. This is because the seeds are easily available, low-cost and have a high germination rate. To start with, the seeds must be soaked in water for at least 12 hours to soften and imbibe water before planting. Sow the seeds in well-prepared soil at a depth of 2-3 cm and cover with soil. It is best to do this after the danger of frost has passed and the soil temperature is at least 15°C. Water the seeds regularly, ensuring they receive enough sunlight, and the seedlings should emerge within a week or two.
Propagation by Cuttings
Dolichos lablab L. can also be propagated by cuttings. Cuttings should be collected from healthy, disease-free plants during the active growing season. Select stem that is 5-7 cm long, snip it off using a sharp knife or scissors, and remove the leaves from the lower half of the stem to expose the nodes. Dip the cut end of the stem in rooting hormone powder and plant in well-draining soil. Keep the soil moist and provide indirect light. The cuttings should start rooting within 2-3 weeks.
Propagation by Division
Dolichos lablab L. can be divided three years or more after planting. To divide a plant, gently dig up the root ball and separate it into sections with a shovel or sharp knife. Each section should have a healthy shoot and a good root system. Replant each section in well-draining soil with the crown at soil level and water regularly.
Disease and Pest Management for Dolichos lablab L.
The Dolichos lablab L. plant, also known as lablab bean, is prone to various diseases and pest infestations. Proper management of these issues can result in a healthy and productive harvest. Here are some of the most common diseases and pests that affect this plant, along with suggestions for how to manage them:
Common Diseases
Anthracnose: This fungal disease causes dark, sunken lesions on leaves, stems, and pods. To manage anthracnose, remove infected plant parts and destroy them. Applying a fungicide can also help prevent its spread.
Fusarium wilt: This soil-borne fungal disease causes wilting, yellowing, and stunting of the plant. To manage fusarium wilt, practice crop rotation, use disease-free seeds, and avoid overwatering the plant.
Rust: This fungal disease causes rusty, orange-colored spots on leaves, stems, and pods. To manage rust, remove infected plant parts and destroy them. Applying a fungicide and providing good air circulation can also help prevent its spread.
Common Pests
Aphids: These small insects suck the sap from the plant and excrete a sticky substance, attracting other pests like ants. To manage aphids, use an insecticidal soap or spray them off with a strong jet of water.
Cutworms: These caterpillars feed on the young shoots and can cut the plant at the soil surface. To manage cutworms, use a physical barrier around the plant base or apply a biological insecticide.
Bean beetle: This pest feeds on the leaves, flowers, and pods of the plant. To manage bean beetles, handpick and remove them from the plant or apply a botanical insecticide.
By implementing these disease and pest management techniques, you can ensure a healthy and productive harvest of your Dolichos lablab L. plant.
