Origin and Common Names
Vangueria nigrescens Scott-Elliot ex Oliv. is a plant species that belongs to the family Rubiaceae. It is commonly known as African medlar, wild medlar, or velvet seed.
The plant is native to tropical and subtropical regions of Africa, from Senegal in the west to Tanzania in the east, and south to Angola and Zambia.
Appearance
Vangueria nigrescens is a short, evergreen tree that grows up to 6 meters in height. Its bark is smooth and grey, with large, round, and dark green leaves that are approximately 7-8 cm wide and 10-16 cm long.
The tree produces small, white, fragrant flowers that bloom from November to January. The fruit of Vangueria nigrescens is a round, orange to red berry, about 2-3 cm in diameter and has a velvet-like surface. Each berry contains one to four hard, black seeds that are shiny and slightly pointed at one end.
Uses
The fruit of Vangueria nigrescens is edible and has a sweet and sour taste. It is used for making jam, jellies, and juice drinks. The fruit is also used in traditional medicine to treat various ailments such as fever, diarrhea, and stomach ache.
The leaves, bark, and roots of the tree have medicinal properties and are used to cure conditions such as malaria, toothache, and snake bites. The wood of the tree is used to make furniture, tool handles, and construction materials.
In addition, the tree is used for reforestation and erosion control in some areas of Africa. The plant is easy to grow and is suitable for cultivation in warm, humid climates.
Light Requirements
Vangueria nigrescens requires full sun exposure for optimal growth and fruit production. The plant can tolerate partial shade, but yields may be reduced if it does not receive enough sunlight. Therefore, it is recommended to plant the species in a location that receives at least 6 hours of direct sunlight daily.
Temperature Requirements
The plant thrives in warm to hot temperatures, preferably between 22°C and 35°C. Vangueria nigrescens can tolerate temperatures as low as 10°C, but growth will be stunted. Extreme cold temperatures may cause damage to the plant tissue and reduce the chances of fruit production. It is ideal to avoid planting Vangueria nigrescens in areas that experience frost or chilling temperatures.
Soil Requirements
Well-draining soil with a pH range of 5.5 to 7 is the most suitable for Vangueria nigrescens growth. The plant can grow in a variety of soils, including sandy loams, clay soils, and sandy soils. However, it is critical to avoid soils with poor drainage because this can lead to waterlogging and root rot. Additionally, Vangueria nigrescens requires regular watering, so planting in water-retentive soils that hold moisture well is recommended.
Cultivation Methods:
Vangueria nigrescens Scott-Elliot ex Oliv is a shrub that can grow up to 5 meters tall. It thrives in warm to hot temperatures with plenty of sunlight. It is best to plant the shrub in well-draining soils that are slightly acidic to neutral. The plant can also grow in sandy, loamy, or clay soils.
Depending on the size of the plant, allow 2-3 meters of space between each one to provide enough room for growth. Vangueria nigrescens Scott-Elliot ex Oliv can grow in tropical regions and withstand periods of drought. Young plants may require some shade until they grow a little more robust.
Watering Needs:
Vangueria nigrescens Scott-Elliot ex Oliv is not a water-loving shrub, though it requires some watering to promote growth. Water the plant thoroughly but avoid overwatering, which may lead to root rot. The shrub can tolerate dry conditions and a lack of rainfall, but it is essential to water weekly in the first year of planting. Reduce watering during the wet season and increase it during dry periods.
Fertilization:
Fertilization is essential for optimal growth and fruit production. Vangueria nigrescens Scott-Elliot ex Oliv requires balanced fertilization, usually three times a year - at the start of the rainy season, at the end of the dry season, and in June or July. Fertilize with a mixture of nitrogen, potassium, and phosphorus, and avoid using heavy nitrogen fertilizers. Add the fertilizer granules to the soil around the plant's base; do not apply it too close to the trunk.
Pruning:
Vangueria nigrescens Scott-Elliot ex Oliv requires pruning to remove weak, dead, or diseased branches. This will promote growth and produce strong, healthy branches. Prune after the fruiting season and during the dormant season. Ensure that the pruning shears are sharp, clean, and disinfected to prevent the spread of diseases. Cut the branches just above the node or bud.
Propagation of Vangueria nigrescens Scott-Elliot ex Oliv.
Vangueria nigrescens Scott-Elliot ex Oliv. can be propagated by seeds, cuttings, and grafting.
Seed Propagation
The seeds of Vangueria nigrescens Scott-Elliot ex Oliv. are usually collected when the fruit is mature and ripe. The fruit must be crushed to remove the seeds, which are then washed and dried in the shade. The seeds can be sown immediately in a seedbed or stored in a cool dry place for up to six months before sowing.
Before sowing, the seeds must be soaked in cold water for 24 hours. The seedbed must be well prepared, free of weeds and with good drainage. The soil should be moistened, and the seeds sown at a depth of 1-2 cm. The seedbed should be kept moist and in shade, and the seedlings should germinate within 3-4 weeks.
Cutting Propagation
Cuttings of Vangueria nigrescens Scott-Elliot ex Oliv. can be taken from mature branches in the late spring or early summer. The cuttings should be about 30 cm long and have at least three nodes. The leaves on the lower half of the cutting should be removed, and the remaining leaves should be halved to reduce water loss.
The cuttings should be treated with rooting hormone powder and inserted in a rooting medium consisting of peat moss, perlite, and sand. The cuttings should be kept in a warm, humid place with bright indirect light and should be watered regularly. The cuttings should root within 3-4 weeks and can be transplanted to individual pots after 2-3 months.
Grafting
Grafting can be used to propagate Vangueria nigrescens Scott-Elliot ex Oliv. onto rootstocks of related species such as Vangueria infausta or Chrysophyllum viridifolium. The scions are collected from healthy, disease-free trees and should be about 10 cm long with a diameter of 5 mm.
The rootstocks should be at least one year old and have a diameter of 1 cm. The rootstocks should be cut, and the scions inserted into the cut, making sure the cambium layers match. The graft union should be wrapped with plastic tape, and the grafted plants should be kept in a warm, humid place and protected from direct sunlight until the graft takes, which can take about 4-6 weeks.
Disease and Pest Management for Vangueria nigrescens Scott-Elliot ex Oliv.
Vangueria nigrescens Scott-Elliot ex Oliv., commonly known as African medlar, is a plant species native to Africa that is commonly grown as an ornamental tree. It is relatively hardy and disease-resistant, but it may still be affected by certain pests and diseases.
Common Pests
The African medlar can be affected by a range of pests, including aphids, spider mites, and scale insects. These pests can cause harm to the leaves, stems, and fruit of the plant.
To manage these pests, regularly inspect the plant and remove any infected portions using pruning shears. Additionally, you may use insecticidal soap or horticultural oil to control pests.
Common Diseases
Although resistant to many diseases, Vangueria nigrescens Scott-Elliot ex Oliv. can be infected with fungal diseases such as leaf spot and root rot. Leaf spot is characterized by brown spots that appear on the leaves, while root rot is caused by overwatering and results in the plant becoming weak, yellowing and leaf dropping.
To manage these diseases, prune affected leaves and affected parts of the plant. Additionally, avoid overwatering the plant, making sure the soil is well-drained and watering only when necessary. Fungicides may also be used preventively to keep the diseases at bay.
Conclusion
Vangueria nigrescens Scott-Elliot ex Oliv. is a hardy plant that is not prone to many diseases and pests. However, it is still important to regularly inspect the plant and take preventive measures to keep pests and diseases at bay. This will ensure the plant remains healthy and vibrant.
