Origin
Albizia glaberrima (Schumach. & Thonn.) Benth. var. glabrescens (Oliv.) Brenan is a tree species that belongs to the genus Albizia and the family Fabaceae. Its origins can be traced back to tropical and subtropical Africa, where it is native to various countries including Ghana, Kenya, Nigeria, and Uganda.
Common Names
The plant Albizia glaberrima (Schumach. & Thonn.) Benth. var. glabrescens (Oliv.) Brenan is commonly referred to as the Flat Crowned Albizia or Smooth Albizia in English. In Africa, it is known by various local names such as 'Naam' in Ghana, 'Omukega' in Kenya, 'Anwo-Akpa' in Nigeria, and 'Mugavu' in Uganda.
Uses
The Flat Crowned Albizia is a versatile tree species that is highly prized for its numerous uses. The bark and sap of the tree have been used in traditional medicine to treat various ailments such as fever, coughs, and skin diseases. The leaves and pods of the tree are an important source of fodder for livestock. The wood of Albizia glaberrima is light in weight and easy to work with, making it perfect for constructing lightweight furniture, plywood, and particleboard. The tree also provides shade and shelter for humans, animals, and other plants.
General Appearance
The Albizia glaberrima (Schumach. & Thonn.) Benth. var. glabrescens (Oliv.) Brenan tree can grow up to 25 meters in height, with a crown that is often flat or rounded. The leaves are bipinnately compound, with 4-10 pairs of pinnae, each with 10-20 pairs of leaflets. The flowers are small, white or cream-colored, and are arranged in spherical or cylindrical clusters that are approximately 2-8 cm in length. The fruit of the tree is a flat, papery pod that can be up to 25 cm in length. The bark of the tree is smooth and greyish-brown.
Light Requirements
Albizia glaberrima var. glabrescens thrives in full sunlight and requires at least six hours of direct sunlight each day for optimal growth. Insufficient light could result in stunted growth or leaf loss.
Temperature Requirements
The optimal temperature range for Albizia glaberrima var. glabrescens growth is between 18°C to 30°C. The species is quite adaptable and could tolerate temperatures as low as 10°C, although prolonged exposure to this temperature will slow its growth rate. Similarly, temperatures above 35°C could be detrimental to its growth and development.
Soil Requirements
Albizia glaberrima var. glabrescens grows best in well-draining soil with a pH range of 6.0 to 7.5. It prefers soil that is slightly acidic to neutral. The plant will not tolerate waterlogged or poorly-draining soils, so proper drainage is crucial. Organic matter can be added to the soil to enhance its fertility, but too much can be detrimental to the plant's root system. The species also thrives in soils with moderate fertility and could tolerate some drought conditions.
Cultivation methods
Albizia glaberrima (Schumach. & Thonn.) Benth. var. glabrescens (Oliv.) Brenan is a fast-growing tree that is easy to cultivate. It can be grown from seeds or cuttings and can tolerate a wide range of soil types, including poor soils. The tree requires full sun and can be grown in a variety of climates.
Watering needs
When young, Albizia glaberrima (Schumach. & Thonn.) Benth. var. glabrescens (Oliv.) Brenan requires regular watering. Once the tree is established, it can survive on natural rainfall alone as it is tolerant to drought conditions. However, during prolonged dry spells, watering can be done once a week to keep the soil moist.
Fertilization
Albizia glaberrima (Schumach. & Thonn.) Benth. var. glabrescens (Oliv.) Brenan does not require frequent fertilization. However, fertilization can be done once a year in early spring using a balanced fertilizer. The application should be done at the base of the tree under the canopy, then watered immediately after applying the fertilizer.
Pruning
Pruning Albizia glaberrima (Schumach. & Thonn.) Benth. var. glabrescens (Oliv.) Brenan is necessary to promote the growth of new, healthy branches. Pruning can be done in the late winter or early spring before new growth begins. Any dead, diseased, or damaged branches should be removed. Additionally, any branches that cross or rub against each other should be cut.
Propagation of Albizia glaberrima var. glabrescens
Albizia glaberrima var. glabrescens can be propagated both sexually and asexually. However, sexual propagation through seeds is the most common method used in nurseries.
Seed Propagation
Seeds of Albizia glaberrima var. glabrescens can be collected from mature pods which turn brownish-black when ripe. The collected seeds should be cleaned, sun-dried, and stored in a cool place. Prior to sowing, the seeds can be soaked in boiling water for 24 hours to help break the seed coat dormancy.
The preferred type of seedbed for germination is raised seedbeds. A mixture of topsoil, sand, and compost in a ratio of 2:2:1 is recommended as the planting medium. The planting medium should be thoroughly sterilized before planting to avoid fungal infections. Germination usually occurs within 10 to 15 days. Seedlings should be transplanted into individual container bags or polyethylene bags and placed under shade.
Asexual Propagation
Albizia glaberrima var. glabrescens can be propagated asexually through patch budding, air layering, and softwood cuttings.
Patch budding involves the removal of a small rectangular patch of bark from the rootstock and inserting a bud from a desired cultivar into the patch. This method is useful in creating clones of a superior cultivar.
Air layering involves girdling a mature stem and covering the wound with a rooting hormone and soil mixture before wrapping with a plastic sheet. Roots will start to form at the wound and can be removed and planted separately.
Softwood cuttings should be collected during the dormancy period. The cuttings should be stripped of leaves and placed in a rooting hormone before being planted in a prepared rooting bed. Rooting usually occurs in about 3 to 4 weeks.
Disease Management
Some of the common diseases that can affect Albizia glaberrima var. glabrescens include anthracnose, powdery mildew, and leaf spot diseases. These diseases can cause significant damage to the plant, leading to a reduction in growth and yield. Therefore, it is essential to implement effective disease management strategies to protect the plant from these diseases.
One of the most effective strategies for managing diseases is to maintain proper hygiene. This involves regularly removing the dead and infected plant parts and disposing of them far away from the plant. It is also crucial to keep the plant well-aerated and to avoid overwatering, as excess moisture can create a conducive environment for disease development.
Another effective strategy for managing diseases is the use of fungicides. Fungicides can be applied preventively or curatively to control active diseases. It is important to use the appropriate fungicide and to follow the manufacturer's guidelines for the rate of application and timing to achieve optimum results.
Pest Management
Albizia glaberrima var. glabrescens can also be attacked by various pests, including spider mites, aphids, and thrips. These pests can cause significant damage to the plant, leading to stunted growth, yellowing of leaves, and even death. Therefore, it is essential to implement effective pest management strategies to prevent and control infestations.
One effective strategy for managing pests is the use of biological control agents such as predatory mites and parasitic wasps that feed on the pests. This method is environmentally friendly and can be cost-effective in the long term. However, its success depends on several factors, including the timing of the application, the type of pests present, and the level of infestation.
The use of insecticides is another effective strategy for managing pests. However, it is crucial to use the appropriate insecticide and to follow the manufacturer's guidelines for the rate of application and timing to avoid toxicity to both the plant and beneficial organisms such as pollinators and natural enemies of the pests.
Regular monitoring of the plant is also essential for effective pest management. Early detection of pests can lead to timely intervention, minimizing damage to the plant. Therefore, it is important to inspect the plant regularly to detect any signs of pest infestation such as webbing, honeydew, and curled or distorted leaves.
