Overview
Stylosanthes viscosa Sw. is a species of legume that belongs to the Fabaceae family. It has multiple common names such as Sticky Stylo, Tanglehead, and Velvet Bean. It is known for its ability to improve soil fertility and is cultivated throughout the world for fodder, erosion control, and as a cover crop in agriculture.
Origin and Distribution
Stylosanthes viscosa Sw. is native to Central and South America, but it has been introduced in many other regions around the world, including Africa, Asia, Australia, and the Pacific. It grows well in tropical and subtropical regions and can tolerate a range of soils, including clay, limestone, and sandy soils.
Appearance
Stylosanthes viscosa Sw. is a perennial herb that can grow up to 80 cm tall. It has a deep taproot and a branching stem covered with fine hairs and sticky glandular hairs. The leaves are trifoliate, with elliptic leaflets up to 5 cm long. The flowers are small and yellow, clustered in compact heads that grow on long spikes at the end of the stems. The fruits are small pods that contain one to three seeds, which are light brown and kidney-shaped.
Uses
Stylosanthes viscosa Sw. has multiple uses, mainly as a forage crop and a cover crop. Its high protein content and digestibility make it a valuable fodder for livestock, particularly for cattle and sheep. Its ability to fix nitrogen in the soil makes it useful for improving soil fertility and reducing the need for fertilizers. It is also used for erosion control, particularly on steep slopes. Additionally, it has been reported to have medicinal properties, including antifungal, antibacterial, and anti-inflammatory effects.
Light Requirements
Stylosanthes viscosa Sw. requires full sun exposure to grow properly. It does not grow well under partial or complete shade conditions. Therefore, it is important to grow the plant in an open area that receives ample sunlight. It is also important to avoid planting the plant under trees or tall buildings that may cast shade on the plant.
Temperature Requirements
Stylosanthes viscosa Sw. is a tropical plant and requires warm temperatures to grow properly. The plant prefers a temperature range between 20°C and 35°C. The plant cannot tolerate frost or freezing temperatures, which can cause severe damage to the plant. Therefore, it is important to grow the plant in areas with a warm and consistent climate.
Soil Requirements
Stylosanthes viscosa Sw. requires well-draining soil that is rich in nutrients. The plant cannot tolerate waterlogged soil, which can cause root rot and other fungal diseases. The ideal soil pH range for the plant is between 6.0 and 7.5. The plant can grow in a wide range of soil types, including loamy, sandy, and clayey soils. However, it is important to ensure that the soil is well-draining and has good aeration.
Cultivation Methods
Stylosanthes viscosa Sw. is a tropical plant that requires warm temperatures and plenty of sunlight. It is best grown in well-drained soils that are rich in organic matter. The plant can be propagated from seeds or vegetative cuttings.
Seeds should be planted at a depth of 1-2 cm and spaced at least 10-15 cm apart. Vegetative cuttings should be taken from healthy plants, and the stems should be buried about 2-3 cm deep in the soil.
The plant should be irrigated regularly to maintain soil moisture. In areas with heavy rainfall, the plant may not require additional watering, but in dry areas, it should be watered every 10-14 days.
Watering Needs
Stylosanthes viscosa Sw. requires regular watering to ensure healthy growth. Irrigation should be done when the soil has dried out sufficiently. Overwatering may cause root rot and other problems.
The plant should be watered deeply and thoroughly to encourage root growth. It is best to water the plant in the early morning or late afternoon when temperatures are cooler and the water has a chance to soak into the soil before evaporating.
Fertilization
Stylosanthes viscosa Sw. requires moderate fertilization to maintain healthy growth. Balanced, slow-release fertilizers should be applied in small amounts every 2-3 months during the growing season.
Excessive fertilization can lead to soft growth and make the plant more susceptible to pests and diseases.
Pruning
Stylosanthes viscosa Sw. is a low-maintenance plant that requires only minimal pruning. Dead or damaged branches should be removed promptly to prevent the spread of disease.
The plant can be pruned to maintain a desired shape or to remove leggy growth. Pruning should be done after the flowering season to avoid reducing the plant's ability to produce flowers and seeds.
Propagation of Stylosanthes viscosa Sw.
Stylosanthes viscosa Sw. can be propagated by both sexual and asexual methods. The plant is primarily propagated through seeds, which are easily collected from mature fruits.
Sexual Propagation
Seeds should be collected when the pods turn brown and are dry. The seeds should then be planted at a depth of 1-2 cm in well-drained soil, which has been previously tilled to remove any weeds. Stylosanthes viscosa Sw. seeds take around 7-10 days to germinate, and the plants start flowering within 3-4 months of seedling emergence.
Asexual Propagation
Stylosanthes viscosa Sw. can be propagated asexually using stem cuttings or through layering. Stem cuttings can be taken from mature plants during the rainy season and should be cut from the top portion of the plant, measuring around 20-25 cm in length. The bottom end of the cutting should be trimmed to remove any leaves or flowers and treated with rooting hormone before inserting it into the planting medium. In around 2-3 weeks, the stem cuttings will root and eventually grow into a new plant.
The layering method involves burying the lower portion of a parent plant into the soil while still attached to the plant. Piled-up soil over the buried portion of the plant's stem encourages root growth, and eventually, a new plant will emerge. Once the new plant has sufficient roots, it can be separated from the parent plant and transplanted into the desired location.
Disease and Pest Management for Stylosanthes viscosa Sw.
Stylosanthes viscosa Sw. is a tropical legume that is commonly grown in pastures and forages for livestock feed. However, the plant is susceptible to various pests and diseases that can affect its growth and yield. Effective disease and pest management strategies are necessary to ensure a healthy and thriving crop. Here are some common diseases and pests that might affect Stylosanthes viscosa Sw. and ways to manage them:
Common Diseases:
1. Leaf spot: Leaf spot is a fungal disease that causes circular or oval spots on the leaves, which might turn yellow or brown with time. To manage this disease, remove and destroy infected plant parts, avoid overcrowding of plants, and water the plant early in the day to allow the leaves to dry. Fungicides can also be applied to manage severe cases of leaf spot.
2. Rust: Rust is a fungal disease that causes reddish-brown powdery spots on the leaves, stems, and flowers. Rust can be managed by removing and destroying infected plant parts, avoiding overhead irrigation, and applying fungicides, if necessary.
3. Root rot: Root rot is a soil-borne disease that causes the roots to decay, reducing the plant's ability to absorb water and nutrients. To manage this disease, ensure proper drainage, avoid overwatering, and plant in well-drained soils. Fungicides and soil fumigation can also be applied to manage severe cases of root rot.
Common Pests:
1. Aphids: Aphids are small insects that suck the sap from the leaves, causing them to wilt and curl. To manage this pest, introduce beneficial insects such as ladybugs or lacewings, use insecticidal soaps or oils, or spray water on the leaves to dislodge the aphids.
2. Spider mites: Spider mites are tiny pests that feed on the underside of leaves, causing them to turn yellow or brown. To manage this pest, increase humidity levels around the plant, introduce predatory mites, use insecticidal soaps or oils, or spray water on the leaves to dislodge the spider mites.
3. Caterpillars: Caterpillars are the larvae of butterflies and moths that feed on the leaves, causing irregular holes and damage. To manage this pest, handpick and remove the caterpillars, introduce natural enemies such as birds or parasitic wasps, or use insecticidal sprays.
Applying preventive measures, such as selecting disease-resistant cultivars and maintaining good plant hygiene, can also help prevent the spread of diseases and pests. Regular monitoring and early detection of diseases and pests can ensure effective management and reduce crop losses.
