Origin
Crotalaria polysperma Kotschy subsp. stewartii (Baker) Baker f. is a native plant of Africa, particularly found in Kenya and Tanzania.
Common Names
This plant is commonly known as Stewart's rattlepod, while locally it can be called as 'Mbelele' in Swahili, due to the rattling sound the seeds make.
Uses
Crotalaria polysperma Kotschy subsp. stewartii (Baker) Baker f. is a multipurpose plant utilized in various ways. The leaves and young stems are consumed as a vegetable by some communities, while the plant also serves as a medicinal herb, especially to aid in treating liver disorders. The seeds of Stewart's rattlepod are used as a source of natural dye while the stems have been used to make fiber and rope.
General Appearance
This perennial herbaceous plant has rigid, thin stems that can grow up to a height of 2 meters. The plant's leaves are dark green, alternate, about 5 cm to 8 cm long, and narrowly oblong in shape. Its flowers are yellow, pealike, and are produced abundantly, forming into inflorescences in axillary and terminal racemes. This plant's fruit is a cylindrical legume, containing about 15-20 seeds that are black, small, and highly compressed, producing a rattling noise when shaken.
Light requirements
Crotalaria polysperma Kotschy subsp. stewartii requires full sun to partial shade for its optimal growth. The plant can tolerate direct sunlight for a few hours every day, but prolonged exposure to the sun can damage its leaves.
Temperature requirements
The plant thrives in warm to hot temperatures and can tolerate temperatures as high as 40°C. The minimum temperature required for growth is about 15°C. Frost can damage the plant, so it is not suitable for areas where the temperature drops below freezing.
Soil requirements
Crotalaria polysperma Kotschy subsp. stewartii prefers well-draining, loamy soils that are slightly acidic to neutral. The soil should be fertile, with a pH range of 5.5 to 7.0. The plant can tolerate poor soils, but it grows best in soils that are rich in organic matter. It is not suitable for waterlogged or heavy clay soils.
Cultivation
Crotalaria polysperma Kotschy subsp. stewartii (Baker) Baker f. is a plant species that can be grown both indoors and outdoors. When grown indoors, it requires a lot of sunlight as it is a full-sun plant. The plant can be grown in a pot or a hanging basket, but it is crucial to ensure that the pot or basket is deep enough to accommodate the root system.
When grown outdoors, Crotalaria prefers well-drained soil and a warm climate. It can grow well in sandy and loamy soils, but it does not tolerate waterlogged soils. The plant should be grown in an open area where it can receive direct sunlight.
Watering Needs
The watering needs of Crotalaria polysperma Kotschy subsp. stewartii (Baker) Baker f. are moderate. The plant should be watered regularly. It requires watering when the soil is dry to the touch, but care should be taken not to over-water the plant, as the roots can rot in waterlogged soil. It is advisable to water the plant in the morning or evening when the temperatures are cool to avoid wilting.
Fertilization
Regular fertilization is essential for the growth and blooming of Crotalaria polysperma Kotschy subsp. stewartii (Baker) Baker f. The plant can be fertilized with a balanced fertilizer every two weeks during the growing season. It is advisable to reduce fertilization during the winter months when the plant is dormant.
Pruning
Pruning is necessary to maintain the shape and size of Crotalaria polysperma Kotschy subsp. stewartii (Baker) Baker f. When grown indoors, it is beneficial to pinch off the tips of the plant to encourage branching and fullness. When grown outdoors, the plant can be pruned after the blooming season to maintain its shape and size.
Propagation of Crotalaria polysperma Kotschy subsp. stewartii (Baker) Baker f.
Crotalaria polysperma Kotschy subsp. stewartii (Baker) Baker f., also known as Stewart’s Rattlepod, is a flowering plant that belongs to the family Fabaceae. This plant species is native to tropical and southern Africa and can grow up to 2 meters tall. Propagating C. polysperma can be done through various methods such as seeding, stem cuttings, and layering.
Seeding
The easiest and most common method of propagating C. polysperma is through seed propagation. The seeds can be sowed directly into the soil or raised in seed trays. The ideal time for seeding is during the spring season. The seeds need to be pressed firmly into the soil and covered lightly with soil or a thin layer of sand. It’s important to water the seeds regularly, keeping the soil moist but not wet. Germination of the seeds occurs within two weeks, and the seedlings should be transplanted once they have grown to a height of 10cm.
Stem cuttings
Propagating C. polysperma through stem cuttings involves the removal of a stem from a mature plant and planting it in soil until roots grow. The stem cuttings should be taken from the mother plant during the active growth period in summer. The cuttings need to be 8-10cm long and cut just below the node. Remove the lower leaves and place the cutting into soil, keeping it moist throughout. Roots may form in as little as 5 days.
Layering
Layering is a propagation method where a portion of the main stem is buried under the soil. The buried portion will then form roots and can be cut and transplanted once a sufficient number of roots have developed. To do this, choose a healthy branch with a node close to the ground or at a point where the stem touches the ground without burying a lot of the stem. Make a shallow cut at the node and bury it in soil, watering it regularly. The new plant can be separated and transplanted once roots have formed.
Disease and Pest Management for Crotalaria polysperma Kotschy subsp. stewartii (Baker) Baker f.
Crotalaria polysperma Kotschy subsp. stewartii (Baker) Baker f. is a leguminous plant that is susceptible to several pests and diseases. Here are some common diseases and pests that can affect the plant and ways to manage them.
Diseases
Root Rot: This is a fungal disease that affects the roots of the plant, leading to wilting and eventual death. To manage root rot, it is essential to plant the crop on well-drained soil. Avoid over-watering the plants and ensure that the drainage system is functional. Fungicides can be used to control the spread of the disease. Also, remove and destroy any infected plants to prevent the spread of the disease to other plants.
Bacterial Wilt: Bacterial wilt affects the stem of the plant, causing it to wilt and eventually die. The bacteria that cause this disease can survive in soil for several years, making it essential to practice crop rotation. Remove and destroy any infected plants, and avoid planting new crops in areas where infected plants were harvested. Using healthy seeds and transplants can also help prevent the spread of the disease.
Anthracnose: This is a fungal disease that causes dark, sunken lesions on the leaves and pods of the plant. To manage anthracnose, it is essential to practice good crop hygiene by removing and destroying any infected plant material. Ensure that the plants have proper spacing to increase air circulation, which helps reduce the humidity levels that promote fungal growth. Fungicides can also be used to control the spread of the disease.
Pests
Cutworms: These are moth larvae that cut the stem of the plant at its base, causing the plant to die. To manage cutworms, it is essential to remove debris from the field, which serves as a shelter for the larvae. Check the plants regularly for signs of damage and install collars around the seedlings to prevent cutworms from accessing them. Biological control methods can also be employed, such as introducing predators or parasites that feed on the cutworms.
Aphids: These are small, soft-bodied insects that can cause significant plant damage. They pierce the plant and suck the sap, leading to stunted growth and wilting. To manage aphids, it is essential to scout the plants regularly and remove any heavily infested areas. Insecticides can also be used to control the spread of the pest.
Thrips: These are small, slender insects that feed on the plant's sap, causing scarring and deformities on the leaves. To manage thrips, it is essential to improve hygiene by removing plant debris regularly. Insecticides and beneficial insects, such as predatory mites and wasps, can also be used to control the pest.
