Overview of Desmodium purpureum
Desmodium purpureum (P. Mill.) Fawcett & Rendle is a perennial plant that belongs to the family Fabaceae, also known as the legume family. The plant is native to tropical and subtropical regions of Africa and South America. The plant is also called purple bush-bean, tick clover, and purple desmodium.
Appearance of Desmodium purpureum
Desmodium purpureum is an erect plant that can grow up to 2.5 meters in height. The stem is woody and can be brown or black in color. The leaves of the plant are alternate and trifoliate, with each leaflet measuring up to 10 centimeters long and 5 centimeters wide. The leaflets have a purple tinge and are slightly hairy on both sides. The flowers are small and purple, and are arranged in dense, elongated clusters that can be up to 20 centimeters long.
Uses of Desmodium purpureum
Desmodium purpureum has several medicinal properties, and is used in traditional medicine to treat various ailments such as coughs, fever, and stomach disorders. The plant is also used for its anti-inflammatory and antioxidant properties. In addition, the plant is used as a forage crop for livestock, as it is highly nutritious and palatable.
The roots of Desmodium purpureum are known to increase soil fertility and improve the soil structure by fixing atmospheric nitrogen. As a result, the plant is used in agroforestry systems to enhance soil fertility and improve crop yield.
Cultivation of Desmodium purpureum
Desmodium purpureum requires a warm and humid climate to grow, and can thrive in a range of soil types. The plant can be propagated by seeds or cuttings, and requires regular watering and fertilization for optimal growth. The plant can also be intercropped with other crops such as bananas, maize, and beans to enhance soil fertility.
In conclusion, Desmodium purpureum is a valuable plant that has various medicinal and agricultural uses. The plant's ability to improve soil fertility makes it an important crop in agroforestry systems, and its medicinal properties make it a valuable natural remedy for a variety of ailments.
Light Requirements
Desmodium purpureum requires full sun to thrive and produce abundant growth. It cannot tolerate shade for prolonged periods and will quickly wither under such conditions. Therefore, it is crucial to plant this species in well-lit areas with no obstructions to sunlight.
Temperature Requirements
The preferred temperature range for Desmodium purpureum growth is between 20°C and 35°C. The species can tolerate a broad range of temperatures, making it ideal for different regions worldwide. However, it requires warm soil temperatures for optimal germination. Therefore, it is best to plant this species during the warm months of the year or when the soil is warm.
Soil Requirements
Desmodium purpureum requires well-drained, fertile soils to develop healthy growth. It prefers neutral to slightly acidic soils with a pH range of 5.5–7.5. The species cannot tolerate salty soils or waterlogged conditions, which can lead to root disease and stunted growth. Therefore, it is essential to cultivate the soil well before planting with organic matter such as compost or manure to increase soil fertility and drainage.
Cultivation Methods
Desmodium purpureum thrives in a warm and humid climate and can be grown in both tropical and subtropical regions. The plant prefers well-drained soils and can tolerate a range of soil types, including sandy soils and loamy soils.
The plant can be propagated through seeds, cuttings, and by dividing the rootstock. For best results, it is recommended to propagate the plant during the rainy season when the moisture content in the soil is high. After propagation, the plant should be placed in a partially shaded area.
Watering Needs
Desmodium purpureum requires regular watering to maintain healthy growth. The plant should be watered frequently during the dry season and less frequently during the rainy season. Overwatering can cause root rot and damage the plant, so it is important to monitor the amount of water the plant receives.
Watering can be done using a hose, watering can, or sprinkler system. It is recommended to water the plant early in the morning or late in the evening when the sun is not intense to avoid evaporation.
Fertilization
Fertilization is essential to promote the growth and health of Desmodium purpureum. The plant responds well to organic fertilizers, such as compost and manure. Fertilizers should be applied during the rainy season when the soil is moist.
It is important not to over-fertilize the plant as this can cause excessive vegetative growth and reduce seed production. A balanced fertilizer with an N-P-K ratio of 4-3-2 is ideal for promoting healthy growth and seed production.
Pruning
Pruning is important to maintain the shape and size of Desmodium purpureum and to promote healthy growth. Pruning should be done during the dry season when the plant is not actively growing.
The pruning process involves cutting back the stems and branches to the desired length. It is important to use sharp pruning shears to avoid damaging the plant.
Dead or damaged branches should be removed immediately to prevent the spread of disease and to promote healthy growth. Regular pruning will also improve air circulation and reduce the risk of pest infestations.
Propagation of Desmodium purpureum
Desmodium purpureum can be propagated by two main methods: seed propagation and vegetative propagation.
Seed Propagation
Propagation by seeds is a relatively simple and inexpensive method. Seeds can be collected from the plant when the pods are fully mature and starting to dry out. The collected seeds should be stored in a cool, dry place until they are ready for use.
Before sowing, the seeds should be soaked in water for about 24 hours to soften the hard seed coat and improve the germination rate. The planting bed should be well prepared and free of weeds and other debris. The seeds can then be sown directly in the planting bed, covered with a thin layer of soil and watered regularly. The seedlings will emerge after 7-10 days.
Vegetative Propagation
Vegetative propagation is a more advanced method of propagation and it involves taking cuttings from healthy plants to create new plants. This method is useful for maintaining the genetic characteristics of a specific plant variety.
The best time to take cuttings is during the growing season when the plant is actively growing. The cuttings should be taken from the top of the plant and should be about 10-15 cm long. The lower leaves should be removed leaving only a few leaves at the top of the stem. The cuttings should be dipped in rooting powder and inserted in a potting mix made from equal parts of sand and peat moss.
The cuttings should be watered regularly and kept in a shaded area until they root. Rooting should occur within 2-3 weeks. Once the cuttings have rooted, they can be transplanted to their final planting location.
Disease Management
Desmodium purpureum is susceptible to a range of diseases, including leaf spots, root rot, and stem blight. Leaf spots are caused by fungi, and they appear as yellow or brown spots on the leaves. Root rot is caused by waterlogging and poor drainage, leading to the decay of the roots. Stem blight is caused by bacteria, and it causes wilting and death of the plant.
Preventive measures include planting resistant cultivars, keeping the soil well-drained, and avoiding overcrowding of plants. Fungicides can be used to manage leaf spots, while bactericides are effective against stem blight. In severe cases of root rot, affected plants should be removed and the soil sterilized before replanting.
Pest Management
Desmodium purpureum can also suffer from various pests such as aphids, mites, and nematodes. Aphids are small, soft-bodied insects that suck sap from the plant, causing distortion and yellowing of the leaves. Mites are tiny arthropods that feed on the undersides of the leaves, causing yellowing and eventual death of the affected parts of the plant. Nematodes are microscopic worms that live in the soil and attack the roots of the plant.
Preventive measures include regular inspection of the plants to detect and control the pests before they become a major problem. Various chemical and non-chemical control methods can be employed, such as the use of insecticides and acaricides to manage aphids and mites, respectively. Biocontrol agents such as ladybird beetles and parasitic wasps can be introduced to control aphids. Soil solarization is an effective method for controlling nematodes in the soil.
Cultural practices such as crop rotation, proper sanitation, and good weed control can also help to prevent the build-up and spread of pests and diseases in the field. Regular watering and fertilization of the plants can also help to improve their resistance to pests and diseases.
