Overview
Manilkara seretii, also known as De Wild. and H.J. Lam, is a flowering plant belonging to the family Sapotaceae. It is a tropical tree with a wide distribution in Africa, particularly in the Congo Basin, Cameroon, and Gabon. Commonly used for its medicinal and economic purposes, this plant has various local names depending on the region where it grows.
Appearance
Manilkara seretii is an evergreen tree that can grow up to 40 meters tall, with a trunk diameter of about 1.5 meters. The tree has a rounded or conical crown, and its bark is rough and flaky, with a gray-brown color. The branches are sturdy and upright, and its leaves are dark green, glossy, and leathery, measuring 5-20 cm in length and 2-10 cm in width.
Common Names
Manilkara seretii has several common names, depending on the language and region, such as "Omu," "Mimusops," "Sapotille," and "Wild Manilkara."
Uses
Manilkara seretii has multiple uses, particularly in traditional medicine and the timber industry. Its bark and leaves are used to treat various ailments, including fever, malaria, bronchitis, and diarrhea. The tree's extracts also possess anti-inflammatory and antioxidant properties. The timber from this tree is durable and resistant, making it ideal for construction and furniture. In addition, the fruits of this tree are edible, with a yellow or orange color when ripe, and sweetened flavor.
Light Requirements
Manilkara seretii (De Wild.) H.J.Lam requires plenty of light to grow properly. It's preferable to place it in an area where it can receive direct sunlight for at least a few hours per day. However, it's essential to prevent the plant from being exposed to direct sunlight for prolonged periods since this can stunt its growth.
Temperature Requirements
Manilkara seretii (De Wild.) H.J.Lam thrives under warm and humid conditions. The optimal temperature range for the plant is between 20 to 35°C. At temperatures below 15°C, growth is greatly reduced, which can delay its flowering and fruiting. Therefore, it's vital to maintain a warm temperature in the region where the plant is growing.
Soil Requirements
The soil must have a pH level ranging from 6.0 to 6.5 to provide ideal growing conditions for Manilkara seretii (De Wild.) H.J.Lam. It's also essential to ensure that the soil is well-draining and rich in organic matter. The plant's roots cannot tolerate standing water, and overly compact soil can lead to poor growth and root rot. A mix of sand, loam, and organic matter like peat moss or compost can provide the perfect growing medium.
Cultivation Methods
The Manilkara seretii (De Wild.) H.J.Lam plant is a slow-growing evergreen tree that can reach up to 20 meters high. It is native to Africa and is commonly found in countries like Cameroon, Gabon, and Congo. The tree thrives in tropical regions that receive high rainfall and is best grown in well-drained soils with high organic matter content.
The plant is usually propagated by seeds, but cuttings can also be used. The seeds should be soaked in water for at least 24 hours before planting to help break dormancy. The plant requires full sun and should be protected from strong winds.
Watering Needs
The Manilkara seretii (De Wild.) H.J.Lam plant has moderate water requirements and needs to be adequately watered to thrive. It should be watered regularly, but not excessively, especially during the dry season. Overwatering can lead to root rot, which can be fatal to the plant. The soil should be allowed to dry out slightly before the next watering.
Fertilization
The Manilkara seretii (De Wild.) H.J.Lam plant is a slow-growing tree and requires minimal fertilization. However, it should be fertilized once a year to help maintain its growth and health. A balanced fertilization regimen that contains equal parts of nitrogen, phosphorus, and potassium should be used. The fertilizer should be applied during the rainy season to help prevent leaching.
Pruning
Manilkara seretii (De Wild.) H.J.Lam requires minimal pruning. However, pruning can be done to shape the tree and remove any dead or diseased branches. Pruning should be done during the dry season to minimize damage to the tree. The tree should be pruned lightly to avoid causing stress to the plant.
Propagation of Manilkara seretii (De Wild.) H.J.Lam
Manilkara seretii propagation can be done through two main methods: seed germination and vegetative propagation.
Seed Germination
Fresh seeds of Manilkara seretii can be sown immediately after extraction. Before sowing, the seeds should be washed in water and surface-dried to prevent fungal infection. The germination rate of fresh seeds is around 70% - 90%.
To improve germination rates, pre-treatment methods can be employed. One such method is to break the seed coat to hasten water intake. This can be done through various techniques, such as nicking the seed coat with a scalpel or soaking the seeds in hot water for four hours before sowing.
The ideal germination medium for Manilkara seretii seeds is well-drained sandy loam soil. After sowing, the germination tray should be placed under partial shade conditions with good humidity. Germination begins around two weeks after sowing. Seedlings are transplanted to polybags or pots when they reach a height of 10-15 cm.
Vegetative Propagation
Manilkara seretii can also be propagated using vegetative methods, such as cuttings and air-layering.
Cuttings are taken from mature trees during the dormant season. The cuttings should be at least 1 cm in diameter and 20-30 cm long. The basal portion of the cutting should be dipped in rooting hormone powder before planting it in a rooting medium consisting of one part perlite and one part compost. After planting, cuttings should be placed in a humidity chamber or covered with a plastic bag to maintain moisture. Rooting can take up to three months.
Air-layering, on the other hand, involves inducing roots to grow on a branch while it is still attached to the parent plant. This can be done by removing a ring of bark 2-3 cm wide and 1 cm deep from the branch. The exposed portion should then be covered with a rooting hormone powder and moss wrapped with plastic. After 3-4 months, roots will have formed on the moss ball and can be removed for transplanting.
Disease Management
Manilkara seretii is susceptible to a variety of diseases that can negatively affect growth and reduce crop yield. Here are some of the most commonly occurring diseases in Manilkara seretii and the management strategies to prevent or manage them:
Leaf spot
Leaf spot is caused by fungi and can cause the Manilkara seretii's leaves to turn yellow and then brown. This disease spreads quickly under wet conditions, so it is vital to avoid watering the foliage of the plant. Applying a copper fungicide may help control leaf spot disease spread. If the disease is severe, removing the affected parts of the plant might help prevent further spread.
Anthracnose
Anthracnose is a fungal disease that infects all parts of the plant. It can lead to severe defoliation, shoot dieback, and fruit drop. Maintaining proper plant spacing to improve air circulation and applying fungicide sprays may help control this disease.
Phytophthora stem and root rot
This soil-borne fungal disease often thrives in wet soil conditions, leading to root and stem rot. To prevent root rot, avoid waterlogging the soil, and ensure well-drained soil. Additionally, planting disease-resistant plants and increasing the soil's organic matter content may help manage this disease. Infected plants must be removed and disposed of properly to prevent further spread.
Pest Management
Manilkara seretii is also susceptible to attacks from some pests such as thrips, mealybugs, and scale insects. Here are some measures to help prevent and manage these pest infestations:
Thrips
Thrips can cause significant damage to the foliage of Manilkara seretii. It can also transmit viruses from infected plants to healthy ones. Yellow sticky traps and insecticidal sprays can be effective in managing thrips infestations.
Mealybugs
Mealybugs are sap-sucking insects that prefer to settle in the leaf joints, undersides, and tender shoots of Manilkara seretii. They can cause yellowing, weakening, and fruit drop. A combination of mechanical control and insecticide spray may help manage mealybugs. Mealybugs can be removed physically with the use of specialized brushes, followed by the application of insecticidal soap or neem oil spray on affected plants.
Scale insects
These pests feed on the plant by sucking sap. This can lead to yellowing of the leaves, and eventually, death. Natural predators such as ladybirds and parasitic wasps can help manage a scale insect infestation, so it is essential to observe their presence. Sticky traps can also help in controlling scale insect populations or infested parts removed and destroyed.
