Origin and Common Names
Desmodium huillensis (Welw. ex Hiern) K.Schum., commonly known as Huilla Tick-trefoil, is a plant species belonging to the family Fabaceae. This species is indigenous to Africa, specifically Southern, Central, and East Tropical Africa and is widely distributed in Angola, Congo, Gabon, Kenya, Malawi, Mozambique, Zambia, Zimbabwe, and Tanzania.
General Appearance
Desmodium huillensis is a perennial herb, growing up to 1.5 meters in height. The plant has a dense inflorescence, with many small flowers of pink and white or light lilac color. Each flower is about 8-10 millimeters long and has a hairy, bell-shaped calyx and a slender corolla tube. The plant also has a pod fruit that is straight or slightly curved, measuring about 2-3cm long, covered with fine, short hair, and is dehiscent. The stem and branches are green with small hairs, while the leaves are trifoliolate, elliptic to ovate-lanceolate in shape, about 5-12cm long, and has a blunt apex.
Uses
The plant has traditional medicinal uses and is used in treating various ailments such as coughs, chest congestion, and diarrhea. It is also used as a remedy for intestinal worms and is known to be effective against hookworms, roundworms, and whipworms. The leaves and roots of this plant are used for medicinal purposes.
Desmodium huillensis is also used in agroforestry practices as a valuable source of forage for livestock and is used in soil conservation and stabilization. It is also used as a green manure for restoring degraded soils in areas prone to erosion or with poor soil fertility.
Overall, Desmodium huillensis is a valuable plant species blessed with numerous uses and benefits, thus deserving the attention and protection of conservationists and policymakers.
Light Requirements
Desmodium huillensis requires a moderate amount of sunlight to thrive. It grows well in partial shade, but full sun exposure for a few hours in a day is highly recommended. Direct sunlight for long periods may damage the plant.
Temperature Requirements
The ideal temperature for the growth of Desmodium huillensis ranges between 20 to 25 degrees Celsius. The plant can tolerate temperatures up to 30 degrees Celsius but may wilt under extremely high temperatures. Frost or freezing temperature is harmful to the plant, and it cannot survive in such conditions.
Soil Requirements
Desmodium huillensis prefers well-drained soil that is rich in organic matter. The soil should be slightly acidic with a pH range of 5.5 to 6.5. The plant can tolerate slightly alkaline soil with a pH of up to 7.5. The soil should also be fertile, with a good balance of nitrogen, phosphorus, and potassium. It can grow in sandy, loamy, or clay soils as long as they are adequately drained and have a good water holding capacity.
Cultivation of Desmodium huillensis
Desmodium huillensis is a perennial plant that requires a proper planting process. The plant can be propagated through seeds or cuttings. While planting from the seeds, they should be soaked in water for 24 hours, and the hard seeds should be scarified to make them permeable to water. The best planting season for this plant is during the rainy season when the soil is moist, and the temperature is relatively warm. A well-drained soil with good organic matter content is ideal for the proper growth of Desmodium huillensis. The plant requires enough space to spread out and get enough sunlight and air circulation.
Watering Needs of Desmodium huillensis
Desmodium huillensis requires well-drained soil to allow for air circulation and the prevention of water-logging. This plant requires moderate watering, especially during the dry season, to prevent wilting and dehydration. Adequate watering should be done in the mornings or evenings to reduce the loss of water through evaporation. Overwatering should be avoided as it may cause root rot, which can be fatal to the plant.
Fertilization of Desmodium huillensis
Desmodium huillensis requires fertilizers rich in nitrogen and potassium, which are essential for the plant's growth and development. The recommended type of fertilizer is organic manure, which can be applied twice a year during the rainy season. Inorganic fertilizers can also be used, but caution is advised to avoid over-application, which may cause harm to the plant.
Pruning of Desmodium huillensis
Pruning is a vital practice in the cultivation of Desmodium huillensis, as it helps in shaping the plant, improving air circulation, and promoting flower and fruit production. It is recommended to prune the plant at the beginning of the rainy season to encourage new growth. Dead or damaged branches should be pruned immediately to prevent them from spreading pests and diseases to other parts of the plant. Regular maintenance pruning should be done to remove weak or excess branches and maintain the plant's shape and size.
Propagation of Desmodium huillensis
Desmodium huillensis can be propagated through various methods, including seed propagation and vegetative propagation techniques.
Seed propagation
Seeds of Desmodium huillensis can be harvested from mature pods. The seeds should be sown immediately after harvesting, as they lose viability quickly. Seeds can be sown directly in the field or in containers. When sowing in containers, use a well-draining seedling mix and keep the soil moist but not waterlogged. Germination usually occurs within 7-10 days after sowing.
Vegetative propagation
Desmodium huillensis can also be propagated vegetatively through stem cuttings and root cuttings.
Stem cuttings: Select a healthy stem and cut it into sections of about 10-15 cm with a clean, sharp knife. Remove the leaves from the bottom half of the stem and dip the cut end in rooting hormone. Insert the cut end into a well-draining rooting mix and keep it moist. After the roots develop, transplant the cutting to a pot or the field.
Root cuttings: Take root cuttings from a mature plant during the dormant season. Cut the roots into sections of about 5-8 cm and plant them horizontally in a well-draining mix. Keep the soil moist but not waterlogged. The roots will develop shoots, and the new plant can be transplanted to a pot or directly in the field.
Regardless of the propagation method used, it is important to keep the soil moist until the plants are well established. Young plants should also be protected from direct sunlight and strong winds.
Disease Management
Desmodium huillensis is generally a hardy plant and is not susceptible to many diseases. However, like any other plant, it can be affected by various diseases caused by fungi, bacteria, or viruses. The most common diseases that may affect D. huillensis are root rot, leaf spot, and powdery mildew.
To manage root rot, it's essential to avoid over-irrigation and ensure proper drainage to prevent waterlogging. Infected plants should be removed to prevent the spread of the disease. Leaf spot can be managed by proper sanitation, such as removing infected leaves and debris surrounding the plant. The use of fungicides may also help control the spread of the disease. Powdery mildew can be managed by planting resistant varieties or by applying fungicides as soon as symptoms appear.
Pest Management
D. huillensis is generally not prone to pest infestations but can be affected by a few pests. The most common pest that may affect D. huillensis is the aphids.
To manage aphids, pruning the affected parts of the plant is a crucial step. You can also introduce natural predators such as ladybugs and lacewings to help keep aphid populations under control. Insecticidal sprays can also be used to manage severe infestations, although care should be taken not to harm beneficial insects.
