Overview of Garcinia volkensii Engl.
Garcinia volkensii Engl. is a species of tropical tree in the family Clusiaceae. It is commonly known as African mangosteen, yellow mangosteen, or imbe. This plant is native to East Africa, specifically in Kenya and Tanzania, and is widely cultivated as an ornamental and fruit tree.
Appearance of Garcinia volkensii Engl.
The African mangosteen tree can grow up to 15 meters tall, with a trunk diameter of up to 45 cm. Its leaves are glossy, dark green, and oval-shaped, measuring up to 25 cm long and 15 cm wide. The plant produces small, white, and fragrant flowers that are followed by round or oval fruits that can grow up to 5 cm in diameter. The fruit’s flesh is yellow and juicy, with a sweet and sour taste. The fruit’s skin is thick and often reported to be tough and fibrous.
Uses of Garcinia volkensii Engl.
The fruit of G. volkensii is edible and is often consumed fresh, juiced, or processed into jams and jellies. The fruit is also thought to have medicinal properties and is used in traditional medicine to treat various ailments, including diarrhea, fever, and measles. The bark and roots of the tree are used to treat gastrointestinal disorders and venereal diseases. Additionally, the tree is known to have strong and durable wood, which is used in construction and furniture-making. The plant is also cultivated as an ornamental tree for its attractive foliage and fruit.
Growth Conditions for Garcinia Volkensii Engl.
Light Requirements: Garcinia volkensii Eng.l requires full sun to partial shade for proper growth and development.
Temperature Requirements: The plant can tolerate a wide range of temperatures, from 15°C to 35°C. However, it grows best in warm climates with temperatures between 20°C and 30°C.
Soil Requirements: The plant grows well in well-drained, fertile soils that are slightly acidic to neutral in nature. The pH should range from 5.0 to 7.5 for optimal growth. Sandy loam or loamy soils are ideal for the plant.
Water Requirements: The plant requires moderate watering during the first few months of growth, ensuring the soil is kept slightly moist. Once established, the plant can withstand periods of drought, but it is best to water it regularly.
Fertilizer Requirements: To ensure healthy growth and development, it is recommended to fertilize the plant with a balanced fertilizer regularly. Application of a nitrogen-rich fertilizer at the beginning of the growing season can benefit the plant.
Propagation: The plant can be propagated by seeds or cuttings. Seeds should be planted in well-drained soil during the rainy season. Cuttings should be taken from mature plants, ensuring there are enough leaves. Place the cuttings in a well-draining rooting medium and keep the soil slightly moist.
Pruning: Pruning should be done to remove dead or diseased leaves and branches. It is also used to promote bushier growth and desired shape.
Cultivation Methods
Garcinia volkensii Engl. is a drought-resistant plant that can grow well in a variety of soils, including sandy, loamy, and clay soils. The plant thrives best in warm and humid conditions with temperatures ranging between 20°C and 30°C. Ideally, it should be grown in areas that receive an average annual rainfall of about 800mm.
Propagation of Garcinia volkensii Engl. is usually done through seeds. The seeds are sown in a nursery bed or directly planted at a spacing of 3m x 3m. The plants should be kept weed-free, and the soil should be regularly cultivated to improve aeration and drainage.
Watering Needs
Garcinia volkensii Engl. is a drought-tolerant plant that can withstand long periods of dry spells. However, adequate irrigation is important during the first year of establishment, especially during the dry season. This helps the plant to develop deep roots, which in turn increases its drought resistance. Watering should be done deep and infrequently, preferably once every week.
Fertilization
The use of organic manure is highly recommended for optimal growth and yield of Garcinia volkensii Engl. Plants should be fertilized twice a year, preferably during the rainy season, with well-decomposed manure or compost. Nitrogen-rich fertilizers should be avoided as they may affect the quality of the fruit.
Pruning
Pruning is essential for healthy growth and disease management of Garcinia volkensii Engl. Pruning should be done immediately after fruit harvesting or during the dry season. Dead, diseased, or broken branches should be removed. The plant should also be pruned to maintain its desired shape and reduce its height for easy harvesting. The pruned branches should be disposed of far from the plantation.
Propagation of Garcinia volkensii Engl.
Garcinia volkensii Engl. is commonly propagated through seeds and vegetative propagation.
Propagation through seeds
The seeds of Garcinia volkensii Engl. are produced after the fruit has ripened. To propagate the plant through seeds, it is important to first extract the seeds from the fruit and clean them properly. After extraction and cleaning, the seeds should be sown in a well-prepared soil substrate. The soil pH should be between 5.5 and 6.5, and the temperature should be maintained at 25-30°C to facilitate germination. Germination typically occurs within two to three weeks.
Vegetative propagation
The vegetative propagation of Garcinia volkensii Engl. can be achieved through various methods such as cuttings, air layering, and grafting.
1. Stem cuttings: For stem cuttings, select a healthy branch and make a slanting cut below the node. The cutting should be about 15-20cm long and free of leaves. Treat the cutting with a rooting hormone and plant in a well-prepared soil substrate. The cutting should be kept in a humid environment until roots start to develop.
2. Air layering: Air layering involves making a small incision just below a node and wrapping the wound with moist sphagnum moss. After wrapping the wound, secure it with a plastic wrap and wait for roots to develop. When the roots are well-developed, the stem can be cut below the roots and transferred to a well-prepared soil substrate.
3. Grafting: Grafting involves joining two plant parts to create a new plant. It is done by joining a scion, which is a piece of selected plant material with desirable qualities, with a rootstock which provides a root system for support. Grafting is commonly used in Garcinia volkensii Engl. to produce improved cultivars with desirable qualities.
Disease Management of Garcinia volkensii Engl.
Garcinia volkensii Engl., commonly known as African mangosteen, is usually affected by various diseases which affect the yield and quality of fruits. Here are some common diseases of Garcinia volkensii and ways to manage them:
Fruit Rot
Fruit rot is a destructive disease of Garcinia volkensii in which fruits drop prematurely or rot on the tree. To control fruit rot, ensure that the planting site has well-draining soil and that there is adequate spacing between plants to allow airflow. Remove infected fruits, and prune the trees to allow better light penetration. Fungicides can also be used.
Leaf Spot
Leaf spot is a fungal disease that causes small, circular spots on the leaves of the plant. As the disease progresses, the leaves turn yellow and eventually fall off, causing defoliation. To manage leaf spot, remove and destroy infected leaves, and ensure that the planting site has good drainage and sufficient nutrients. Fungicides can also be applied to control the spread of the disease.
Pest Management of Garcinia volkensii Engl.
Garcinia volkensii is also susceptible to several types of pests. Here are some common pests of Garcinia volkensii and ways to manage them:
Fruit Flies
Fruit flies are one of the most damaging pests of Garcinia volkensii. These insects lay eggs in the fruit, and the larvae feed on the fruit pulp, causing it to rot. To control fruit flies, remove and destroy any infected fruit, use sticky traps, and apply insecticides.
Mealybugs
Mealybugs are small, white, cottony insects that suck sap from the leaves and stems of the plant, causing stunted growth. To manage mealybugs, remove and destroy infected plant material, improve the growing conditions of the plant, and apply insecticidal soap or horticultural oil.
