Overview
Picralima nitida (Stapf) T.Durand & H.Durand is a small, evergreen tree native to West and Central Africa. The plant is known for its medicinal properties and has been used traditionally for centuries by local tribes. The tree is commonly referred to by several names, including akuamma, vincamajoridine, and Picralima nitida.
General Appearance
The Picralima nitida tree grows up to 12 meters high with a short trunk and branched crown. The leaves of the tree are elliptical, about 10 to 20 cm long and 5 to 10 cm wide with a glossy green surface. The tree bears small, yellowish-white flowers, that appear in clusters from October to December. Afterward, the fruits are pear-shaped and contain up to 10 seeds that are about 1.5 cm in diameter.
Uses
The seeds of Picralima nitida are the most important parts of the plant because of their medicinal values. The seeds contain a variety of alkaloids such as akuammine, akuammicine, akuammiline, and akuammigine, which have been used for their pain-relieving and anti-inflammatory properties. The powdered seeds are usually consumed by the local tribes for their analgesic effects. The seeds can also be used to treat malaria, diarrhea, and bronchitis. Additionally, the plant has been used for its sedative and anxiolytic effects, treating hypertension, and improving cognitive function.
Aside from medicinal purposes, the plant's wood is used for making furniture, canoes, and other household items. The seeds are also used as a source of dye. They contain a red-colored resin used to create a bright, reddish-brown color.
Conclusion
Picralima nitida is a valuable plant, with medicinal and economic significance. The tree's seeds have been used traditionally for many years to treat various ailments and offer analgesic effects. Its wood is also extensively used for various purposes. However, the plant is endangered due to overexploitation for commercial and medicinal purposes. Conservation efforts must be employed to save this important plant species.
Light Requirements
The Picralima nitida plant prefers partial shade to full sun exposure. It can grow well in areas where it gets exposed to indirect sunlight. However, exposure to direct sunlight for long periods can harm the plant.
Temperature Requirements
The plant grows well in a warm and humid environment. The optimal temperature ranges between 20°C to 30°C. Temperatures below 15°C can damage the plant, causing slow growth and discoloration of leaves.
Soil Requirements
The Picralima nitida plant requires well-draining, fertile, and acidic soil with a pH between 5 to 6.5. The soil should be rich in organic matter, and it should retain enough moisture. However, waterlogged soil can cause root rot and damage the plant. It can grow well in loamy soils with a high quantity of organic matter.
Cultivation Methods:
Picralima nitida, commonly known as Akuamma, is a tropical tree that requires a warm and humid climate to thrive. The ideal temperature range for cultivation is between 20 to 35°C with a relative humidity of 70-80%. It grows best in well-draining sandy loam soil that is rich in organic matter.
The plant can be propagated through seeds, which should be sown in a well-prepared seedbed. Once the seeds have germinated, the young plants should be transplanted to individual bags or containers. It is recommended to keep the plants in a shaded area for the first few weeks after transplantation.
Watering Needs:
Akuamma plants require regular watering, especially during the early stages of growth. It is recommended to water the plant when the topsoil feels slightly dry to the touch. However, overwatering should be avoided, as it can lead to root rot and other fungal diseases.
During the dry season, the plant may require more frequent watering, depending on the soil condition and humidity levels. In general, it is essential to maintain a consistent level of moisture in the soil.
Fertilization:
Regular fertilization is essential for the healthy growth of Akuamma plants. In general, a balanced fertilizer with an NPK ratio of 10:10:10 is suitable for the plant. The fertilizer should be applied every 2-3 months during the growing season.
The fertilizer should be applied at the base of the plant, and care should be taken not to allow the fertilizer to come into contact with the leaves or stem, as it can cause burning or scorching.
Pruning:
Pruning is essential for the healthy growth of Akuamma plants. It is recommended to prune the plant regularly to remove dead or damaged branches and to promote new growth.
The best time to prune the plant is during the early stages of growth, before the flowering season. Care should be taken not to over-prune the plant, as it can lead to stunted growth and reduced yield.
It is also essential to maintain a balanced shape of the plant by trimming leaves and branches that are growing unevenly or too close to the ground.
Propagation of Picralima nitida
Picralima nitida (Stapf) T.Durand & H.Durand, commonly known as akuamma, is a small evergreen tree native to tropical Africa. It is widely cultivated for its medicinal properties and seeds, which contain alkaloids such as akuammine, which are used to manage pain, anxiety, and inflammation.
Propagation Methods
The propagation of Picralima nitida can be done in several ways, including seed propagation, stem cuttings, and air-layering.
Seed Propagation
The most common method of propagating Picralima nitida is through the use of seeds. The seeds of this plant are viable for up to two years from the time of harvest. To propagate through seed, the seeds should be extracted from the fruit, washed thoroughly, and then planted in a well-drained soil mix in flats or trays.
The seeds should be planted at a depth of about 1 cm, and then watered sparingly until seedlings emerge. Once the seedlings are large enough, they can be transplanted into individual pots or planted directly into the ground.
Stem Cuttings
Picralima nitida can also be propagated through stem cuttings. This method requires the use of healthy stems from a parent plant. The stem should be about 10-15 cm long and should have several sets of leaves.
The bottom of the stem should be cut at a 45-degree angle and then dipped in rooting hormone. The stem should then be planted in a well-draining soil mix and kept moist until roots develop. Once the roots have developed and the cutting has started to grow, it can be transplanted into a larger pot or planted directly into the ground.
Air-Layering
Air-layering is a propagation method that involves the rooting of stems while still attached to the parent plant. This method is best done during the growing season when the plant is actively producing new growth.
To propagate via air-layering, a healthy stem should be identified, and a 2-3 cm section of bark should be removed from below a node. The exposed stem should be treated with rooting hormone, and then wrapped with sphagnum moss or other moist material. The wrapped section should then be covered with plastic to retain moisture.
Roots should start to form in about 4-6 weeks. At this point, the rooted section can be cut from the parent plant and transplanted into soil.
Overall, the propagation of Picralima nitida can be done easily through the use of any of the methods described above, depending on the available resources and in consideration of the species growth paterns.
Disease Management:
Picralima nitida (Stapf) T.Durand & H.Durand is prone to various diseases that can affect its appearance and productivity. The most common diseases that affect this plant include anthracnose, Fusarium wilt, and root rot. These diseases can be managed through the following ways:
Anthracnose:
This disease is caused by the fungus Colletotrichum gloeosporioides. It causes leaf spots and blights, stem lesions, and fruit rot. To manage anthracnose, it is advisable to prune infected plant parts and remove them from the garden to prevent further spread. The use of fungicides such as copper-based sprays, mancozeb, tebuconazole, and carbendazim can also be effective in controlling this disease.
Fusarium wilt:
This is a soil-borne disease caused by the fungus Fusarium oxysporum. It causes wilting, yellowing, stunting, and death of the plant. To manage this disease, it is advisable to rotate crops, practice soil solarization, and use resistant varieties. The use of fungicides such as azoxystrobin, propiconazole, and thiophanate-methyl can also be effective in controlling this disease.
Root Rot:
This disease is caused by fungi such as Pythium, Rhizoctonia, and Fusarium. It causes root decay, stunted growth, yellowing, and wilting. To manage root rot, it is advisable to avoid overwatering, practice good drainage, and use well-drained soils. The use of fungicides such as fosetyl-aluminum, mefenoxam, and fluazinam can also be effective in controlling this disease.
Pest Management:
Picralima nitida (Stapf) T.Durand & H.Durand is also prone to various pests that can affect its growth and productivity. The most common pests that affect this plant include aphids, spider mites, and mealybugs. These pests can be managed through the following ways:
Aphids:
Aphids suck sap from the leaves, stems, and flowers of the plant, causing yellowing, wilting, and stunting. To manage aphids, it is advisable to introduce natural predators such as ladybugs, lacewings, and parasitic wasps. The use of insecticidal soap, neem oil, and pyrethrin can also be effective in controlling aphids.
Spider Mites:
Spider mites feed on the undersides of the plant leaves, causing yellowing, stippling, and webbing. To manage spider mites, it is advisable to improve humidity, introduce natural predators such as predatory mites, and use insecticidal soap or neem oil. Spraying the plant with water can also be effective in controlling spider mites.
Mealybugs:
Mealybugs suck sap from the plant and secrete a waxy substance that covers their body, causing wilting and stunting. To manage mealybugs, it is advisable to prune infected plant parts and remove them from the garden. The use of insecticidal soap, neem oil, and rubbing alcohol can also be effective in controlling mealybugs.
