Origin
Derris congolensis, also known as Common Derris or Congo Derris, is an African plant species belonging to the family Fabaceae. It is native to tropical and subtropical regions of Africa, including Cameroon, Congo, Gabon, Ghana, Guinea, Liberia, Nigeria, Sierra Leone, and Uganda.
Common Names
Common Derris may go by many local names in different countries and regions, including Eekin, Okpo, Ayin, Ehin, Enene, Aduruku, Nkwinkwin, Konkoli, Muzele, and Aduri among others.
Uses
Derris congolensis has many traditional medicinal uses in various African countries. The plant's bark, leaves, and roots are used for medicinal purposes to treat various ailments like fever, malaria, stomach ache, toothache, and rheumatism. The plant also contains rotenoids that possess insecticidal and piscicidal properties. The plant is also used for fishing by the locals. The root of the plant is chopped and placed in pools or rivers, and the rotenoids immobile or kill the fish, making them easy to catch.
General Appearance
Derris congolensis is a tall, deciduous tree, growing up to 30 meters tall in favorable conditions. The trunk is straight, and bark is smooth and grayish-brown. The leaves are pinnate, with 6-8 opposite pairs of leaflets and a terminal one. The leaflets are elliptical, 4-7 cm long, and 2-4 cm wide, with a pointed tip and a slightly wavy margin. The flowers are small and whitish-pink, borne in clusters at the end of the twigs. The fruit is a long, brown pod, 15-20 cm long, containing several seeds. The root of the plant is tuberous, enabling it to store nutrients and water during the dry season.
Light Requirements
The Derris congolensis De Wild. plant requires a moderate amount of sunlight to grow well. It grows optimally under partial shade but can also tolerate full sun exposure for some hours of the day. Excessive exposure to sunlight may lead to stunted growth and even death in severe cases.
Temperature Requirements
The Derris congolensis De Wild. plant can grow well in a wide range of temperatures. The ideal temperature range for the plant growth is between 20°C and 30°C. The plant can, however, tolerate temperatures as high as 35°C and as low as 5°C. Temperatures below 5°C may lead to frost stress, which may be detrimental to the plant's growth.
Soil Requirements
The Derris congolensis De Wild. plant prefers well-drained, slightly acidic soils with a pH in the range of 5.5 to 6.5. It is essential to maintain adequate soil moisture to support the plant's growth, but waterlogging should be avoided. Organic matter-rich soils are ideal for the plant's growth, and supplemental fertilization may be necessary to replenish soil nutrients.
Cultivation Methods
Derris congolensis De Wild. is a tropical plant species that requires a warm and humid environment for optimal growth. It is well suited to grow in containers or on the ground in warm regions with fertile soils. When planting on the ground, it is recommended to loosen the soil and add compost to enrich it.
To avoid overcrowding, ensure there is enough space between seedlings and mature plants. It is also crucial to protect it from strong winds and direct sunlight that can damage the leaves.
Watering Needs
The plant requires consistent moisture to thrive, and regular watering is necessary to maintain an adequate level of moisture in the soil. However, avoid overwatering, which can result in waterlogging and root rot.
A watering schedule of between 1 to 2 inches per week, depending on the weather, is suitable. It is also essential to water the plant on the root zone, avoiding sprinkling water directly on the leaves to prevent fungal diseases.
Fertilization
Regular fertilization is necessary to ensure healthy plant growth. Use a balanced fertilizer, which contains equal portions of nitrogen, phosphorus, and potassium. Apply the fertilizer during the growing season, which is typically in spring and summer.
The fertilizer can be added to the soil or as a foliar spray, depending on preference. It is also essential to follow the manufacturer's instructions on the packaging to avoid overfertilization, which can harm the plant.
Pruning
Pruning helps to control the growth and maintain the plant's shape. It is recommended to prune the plant during the dormant season, which is typically in winter.
Remove any dead or damaged branches and thin out any overcrowded areas. It is also necessary to remove any competing branches that can decrease sunlight penetration and hinder airflow in the plant's canopy. Prune the plant above a leaf node or bud to allow new growth to sprout.
Propagation of Derris congolensis De Wild.
Derris congolensis De Wild. is a plant species that is commonly propagated through cuttings and seedlings.
Cuttings
Cuttings from the stem of mature plants are an effective method of propagating Derris congolensis De Wild. The cuttings should be taken in the early morning when the plant's growth process is actively taking place. The cuttings should be about 15cm long and should be taken from the healthy stems of the parent plant.
The cuttings should be dipped in a rooting hormone solution before planting. The cutting should be planted in a well-draining potting mix and kept moist. The stem cuttings should root within 3 to 4 weeks and should be transplanted into individual pots when they develop at least 3 to 4 leaves. The transplanted cuttings should be kept in a shaded area and watered regularly until the roots are established.
Seedlings
Seedlings are another effective method of propagating Derris congolensis De Wild. The seeds are usually freshly harvested from mature plants and are planted in a well-prepared seedbed. The seeds should be sown thinly on the seedbed and covered with a thin layer of finely sieved soil.
The seedbed should be moist and placed in a shaded area. Germination should occur within 1 to 2 weeks. When the seedlings produce four leaves, they should be thinned out or transplanted into individual pots. The transplanted seedlings should be watered regularly and kept in a shaded area until the roots are established.
Overall, propagation of Derris congolensis De Wild. through cuttings and seedlings is relatively easy and straightforward. The plant has a high propagation success rate and can be an excellent addition to any tropical garden or medicinal plant collection.
Disease and Pest Management for Derris congolensis De Wild.
Derris congolensis De Wild., commonly known as African derris, is a perennial plant that is native to Africa. This plant is known for its multiple uses, including medicinal and pesticidal properties. However, it is susceptible to various diseases and pests that can negatively impact its growth and yield. Here are some common diseases and pests that might affect Derris congolensis and how to manage them.
Common Diseases
1. Leaf Spot: This disease is caused by fungi that attack the leaves, resulting in the formation of small brown spots. The disease can affect the plant's photosynthesis, leading to stunted growth. To manage leaf spot, proper sanitation practices should be observed, including removing infected leaves and avoiding overhead irrigation. Fungicides can also be used to control the spread of the disease.
2. Root Rot: Root rot is caused by soil-borne fungi that attack the roots of the plant. Symptoms of this disease include wilting, yellowing of leaves, and stunted growth. To manage root rot, it's vital to plant the derris congolensis in well-draining soil and avoid overwatering. Fungicides can also be used to control the spread of the disease.
Common Pests
1. Aphids: These are small insects that suck sap from the leaves, leading to curly, wilted leaves and stunted growth. To manage aphids, spraying insecticidal soap can be used to control the pest's population. Natural predators such as ladybugs and lacewings can also be introduced to eat the aphids.
2. Thrips: Thrips are tiny insects that feed on the plant's leaves, causing leaves to become discolored and deformed. To manage thrips, applying insecticidal soap or neem oil can help control their population. Sticky traps can also be used to capture thrips.
In conclusion, managing pests and diseases requires consistent monitoring through regular inspection of the plant. Early detection and prompt management practices are essential in ensuring the health and productivity of Derris congolensis De Wild.
