Origin and Common Names
Abrus precatorius L. subsp. africanus Verdc. is a plant that is believed to have originated in Africa and is commonly found in tropical and subtropical regions of the world, including Asia, Australia, and the Americas. It is commonly known by various names like Jequirity bean, Rosary pea, Indian licorice, and Precatory bean.
Uses
The plant is highly valued for its medicinal properties and is widely used in traditional medicine to treat various ailments like fever, inflammation, bronchitis, and skin diseases. It is also used as a blood purifier and to increase sexual potency.
However, the plant is highly toxic and can be fatal if ingested in large quantities. Its seeds are among the most poisonous plant substances known and have been used in the past to create deadly poisons.
Despite its toxicity, the plant is also used in the manufacturing of jewelry, as the seeds are colorful and can be polished to a bright shine. The seeds are often strung together in bracelets, necklaces and rosaries which are sold as curios or souvenirs.
General Appearance
The Abrus precatorius L. subsp. africanus Verdc. is a perennial climber that grows up to 6 meters in height. Its leaves are compound, with 5-12 pairs of leaflets that are oblong to ovate in shape, with rounded tips and pointed bases.
The flowers are small and white, and are borne in racemes up to 10 cm long. The fruits are pods, which contain between 3 and 10 seeds, each of which is oblong, about 5 mm in size, and brightly colored in shades of red, black and white.
The plant is highly adaptable and can tolerate a wide range of soils, from sandy to heavy clay, and is drought tolerant.
Light Requirements
Abrus precatorius L. subsp. africanus Verdc. is a plant that tolerates full sunlight to partial shading. In shaded areas, the plant tends to grow taller and sprawl out more to reach for light.
Temperature Requirements
The plant can grow in a wide range of temperatures, but it prefers a warm, temperate climate. The ideal temperature range for growth is between 20-25°C. However, the plant can tolerate temperatures as low as 10°C and as high as 35°C. Frosty conditions are detrimental to the plant's growth.
Soil Requirements
The plant prefers well-drained soils with moderate to high fertility levels. Acidic to slightly alkaline soils, with a pH range of 5.5-7.5, are ideal for the plant. The soil should also be rich in organic matter, and the plant does not tolerate soils that are too waterlogged. In water-logged soils, the plant is prone to developing root rot.
Cultivation Methods
Abrus precatorius L. subsp. africanus Verdc. is a hardy, drought-tolerant plant that thrives in tropical regions. It can be grown from seeds, cuttings, or by division of roots.
Choose a well-drained location with full sunlight exposure and minimum shade. The plant can tolerate poor soil conditions but prefers a soil that is pH 6 to 7.5.
Sow the seeds in rows spaced 50 cm apart and cover them lightly with soil. Keep the soil moist and germination should occur within 2 to 3 weeks. Thin the seedlings to 30 cm apart when they reach a height of 10 cm. Alternatively, plant seedlings or cuttings at a spacing of 30 cm.
Watering Needs
Abrus precatorius L. subsp. africanus Verdc. requires moderate watering. Water the plants regularly during dry spells, especially when they are young. However, avoid overwatering as it can lead to root rot and cause the plant to wilt.
The plant can tolerate short periods of drought, but extended periods of dryness can cause it to drop leaves or flowers. The frequency of watering depends on the soil type, climate, and stage of growth of the plant.
Fertilization
The plant does not require much fertilization. However, to encourage growth and enhance blooming, you can apply a balanced fertilizer once or twice a year. Use an all-purpose granular fertilizer and apply it around the base of the plant, then water it well.
Alternatively, you can apply compost or organic manure in the same way. These will provide nutrients to the plant and improve soil structure and texture.
Pruning
Pruning is not required for Abrus precatorius L. subsp. africanus Verdc. However, you can trim the plant to maintain its shape and size. When pruning, remove dead, damaged, or diseased branches. Do not remove more than one-third of the plant in a single pruning session.
Trimming the plant can promote bushier growth and increase the number of flowers. You can also remove the spent flowers to encourage the plant to produce more blooms.
Propagation of Abrus Precatorius L. subsp. Africanus Verdc.
Abrus precatorius L. subsp. africanus Verdc. can be propagated through seeds, cuttings, and grafting.
Propagation through Seeds:
Seeds can be collected from mature pods and dried at room temperature. Before sowing, the seed coat of Abrus precatorius should be scarified to enhance germination rates. The scarification can be done by nicking the seed coat with a sharp blade or soaking the seeds in hot water for a few hours. Sow the scarified seeds in well-draining soil mix. Keep the soil moderately moist, and the seeds will sprout within 2 to 3 weeks.
Propagation through Cuttings:
Abrus precatorius can also be propagated through stem cuttings. Cut 6 to 8 inches long stems from the mother plant with at least two to three healthy leaves. Remove the leaves from the lower half of the cutting and dip the cut end in rooting hormone. Then, plant the cutting in a well-drained soil mix, water it thoroughly, and keep it in a shaded area until it forms new roots, which may take several weeks.
Propagation through Grafting:
Grafting is a more complicated method of propagation. It involves joining the stem of the Abrus precatorius plant with the root system of another related plant. The process requires some technical knowledge and skill and is usually not carried out by home gardeners.
Disease Management
Abrus precatorius L. subsp. africanus Verdc. is prone to a few diseases that can cause considerable damage to the plant if not managed effectively. Here are some common diseases that might affect the plant and ways to manage them:
Fungal Leaf Spot
Fungal leaf spot is a common disease that affects Abrus precatorius L. subsp. africanus Verdc. The symptoms of this disease are circular spots on the leaves with the center turning grayish-white and the edges becoming dark brown or black. The spots can merge together and cause the leaves to dry and fall off. To manage this disease, remove the infected leaves and destroy them. Maintain proper plant hygiene practices, ensure sufficient plant spacing, and avoid overwatering the plant, as it encourages the growth of fungal spores.
Bacterial Leaf Blight
Bacterial leaf blight is another common disease that affects Abrus precatorius L. subsp. africanus Verdc. This disease appears as water-soaked spots on the leaves that turn brown or black over time. The leaves eventually wilt and drop off. To manage this disease, remove and destroy the infected leaves and maintain proper plant hygiene. Practice crop rotation and avoid overwatering the plant to prevent the spread of bacterial spores. Use copper-based bactericides to control bacterial spread.
Pest Management
Abrus precatorius L. subsp. africanus Verdc. is also prone to pest attacks that can cause significant damage to the plant. Here are some common pests that might affect the plant and ways to manage them:
Mites
Mites are tiny pests that can cause considerable damage to the plant by sucking its sap and causing discoloration and curling of leaves. To manage mites, avoid overwatering the plant, as it creates a humid environment that favors mite growth and development. Isolate and treat infected areas with insecticidal soap or horticultural oils to kill mites.
Caterpillars
Caterpillars are another common pest that can cause significant damage to the plant by feeding on its leaves, resulting in defoliation. To manage caterpillar infestations, handpick and crush the larvae and apply biological pesticides to the affected areas to prevent further infestations.
Thrips
Thrips are small pests that feed on the plant's leaves, causing them to become distorted and discolored. To manage thrips, use sticky traps to trap the pests and apply insecticidal soaps or horticultural oils to kill them. Avoid overfertilizing the plant, as it promotes thrip infestations.
Conclusion
Regular monitoring and timely intervention are critical in managing disease and pest infestations in Abrus precatorius L. subsp. africanus Verdc. By following good plant hygiene practices, practicing crop rotation, using biological pesticides or insecticidal soaps or horticultural oils, and maintaining proper plant spacing and watering, you can prevent and manage disease and pest infestations and ensure healthy plant growth and development.
