Overview
Strychnos nigrovillosa De Wild., also known as the black hairy-fruited monkey orange, is a small tree species that belongs to the Strychnaceae family. It is native to the tropical regions of Africa, particularly in Cameroon, Gabon, and Congo, where it grows in the rainforest understory.
Appearance
The black hairy-fruited monkey orange is a slow-growing tree that can reach a height of up to 5 meters. The bark is grayish-brown and rough, while the leaves are dark green, shiny, and oblong. The tree produces small, greenish-yellow flowers that bloom from January to February and give way to fleshy round fruits that are about 3-4 cm in diameter. The fruits are covered in black hairs and contain several seeds.
Common Names
Apart from black hairy-fruited monkey orange, the plant has other common names such as Akwa tree, Egbongbo, Mbwe, Mponplo, among others, depending on the region where it is found.
Uses
The black hairy-fruited monkey orange tree has various traditional medicinal uses. The bark, leaves, and roots are used to treat various ailments such as fever, toothache, and stomach problems. In Gabon, the bark is used to make a stimulant to treat impotence, while in Congo, the roots are used to treat diarrhea. The fruit pulp is edible and is consumed locally, although it is not widely known. Additionally, the plant has a strong, durable wood that is used for making tools and handles.
Despite its various uses, the black hairy-fruited monkey orange is not cultivated commercially and is mostly found in the wild. However, with more research on the medicinal properties of the plant, it could be a potential source of new drugs.
Light Requirements
Strychnos nigrovillosa De Wild. thrives in full sunlight to partial shade conditions. In its natural habitat, the plant receives direct sunlight for a considerable part of the day, but it can also grow under the shade of trees or in partial shade conditions. However, the more sunlight it receives, the more vigorous its growth and the better flowering and fruiting it produces.
Temperature Requirements
The plant grows best in warm temperatures, with an average temperature range between 20°C and 35°C. Strychnos nigrovillosa De Wild. can tolerate occasional drops in temperature, but it is sensitive to frost or extended periods of cold weather. It is, therefore, best suited to tropical or subtropical conditions and grows well in USDA hardiness zones 10 and 11.
Soil Requirements
Strychnos nigrovillosa De Wild. is adaptable to a range of soils but prefers well-drained, sandy or loamy soils. The soil pH should be slightly acidic to neutral, between 5.5 and 7.5. The plant does not do well in waterlogged soils or those with poor drainage, which can cause root rot. Adding organic matter to the soil can improve fertility, nutrient retention, and water-holding capacity. Moreover, drought-tolerant and moderately fertile soils in low to medium elevations are the best growth conditions for the plant.
Cultivation of Strychnos nigrovillosa De Wild.
Strychnos nigrovillosa De Wild., commonly known as Black hairy-seed, is a tropical tree found in the African rainforest. It is typically grown from seed and should be planted in well-draining soil that is fertile and nutrient-rich. The tree grows best in a balanced shade and full sunlight environment, which helps to control the growth rate. If the plant is to be grown indoors, ensure that it has sufficient light exposure and a warm and humid environment to support healthy growth.
Watering Needs of Strychnos nigrovillosa De Wild.
Strychnos nigrovillosa De Wild. requires adequate watering to ensure that the soil remains moist but not waterlogged. Water the plant deeply once a week and adjust watering frequency based on the temperature and humidity levels in the environment. In times of heavy rainfall, adjust watering patterns to prevent the roots from becoming waterlogged. Proper watering is essential to promote healthy growth and prevent the plant from drying out.
Fertilization of Strychnos nigrovillosa De Wild.
Strychnos nigrovillosa De Wild. requires regular fertilization to ensure that it receives adequate nutrients. Fertilize the plant every three months using a balanced formulation of nitrogen, phosphorus, and potassium. You can also add compost to the soil to provide additional nutrients. Slow-release fertilizers can also be applied to ensure a steady supply of nutrients to the plant as it grows.
Pruning of Strychnos nigrovillosa De Wild.
Strychnos nigrovillosa De Wild. should be pruned as needed to control its growth and promote healthy branching. Pruning should be done during the dormant season to prevent excessive bleeding. Prune suckers and water shoots to promote the growth of the main trunk. Thin out overcrowded branches to promote better light penetration and air circulation. Care should be taken when pruning to prevent damage to the tree, as wounds can lead to disease and insect infestation.
Propagation of Strychnos nigrovillosa De Wild.
Strychnos nigrovillosa De Wild. can be propagated through two different methods: seeds or vegetative cuttings.
Propagation through seeds:
Seeds should be harvested when the fruit is ripe. Before sowing, the seeds must be extracted from the fruit, cleaned, and dried in the shade. Once dry, the seeds can be stored for approximately one year.
For successful germination, the seeds must be scarified; this means that the seed's coat must be broken, allowing water to penetrate the seed. One common method is with hot water. The seeds need to be soaked in hot water (approximately 80°C) for 5-10 minutes and then soaked in cold water for another 24 hours before sowing.
The seeds should be planted in a well-drained, sandy soil mix and kept in a warm, humid area with indirect light for approximately 30-45 days after sowing. Germination is typically low, ranging from 10-25%.
Propagation through vegetative cuttings:
Vegetative propagation of S. nigrovillosa should be done during the growth period. The parent plant should be approximately two years old and have at least one healthy branch.
Cuttings should be taken from the parent plant and dipped into a rooting hormone solution before planting. The cuttings should be planted in a well-draining mix and kept in a warm, humid area with indirect light. It is recommended to use a rooting hormone gel or powder to enhance the cutting's success rate.
The cuttings will start to develop roots after approximately 30-60 days, and they can be transplanted to a bigger container or directly into the ground after approximately six months.
Disease Management
Strychnos nigrovillosa De Wild. is prone to several diseases, which can damage the plant and affect its growth. The following are the common diseases affecting this plant:
- Anthracnose: Anthracnose is a fungal disease that can cause brown patches on leaves, which can expand and eventually lead to defoliation. The best way to manage this disease is to maintain proper sanitation practices, including removing the affected leaves and pruning the plant to improve air circulation.
- Canker: Canker is a bacterial or fungal disease that causes the bark to crack and peel away from the stems. This can weaken the plant and cause dieback. To manage canker, prune the affected areas and sterilize pruning tools between cuts to prevent the spread of the disease.
- Powdery mildew: Powdery mildew is a fungal disease that can cause a white, powdery coating on leaves. This can reduce photosynthesis and cause stunted growth. To manage powdery mildew, increase air circulation around the plant and reduce humidity levels. Fungicides may also be effective in controlling the disease.
Pest Management
Strychnos nigrovillosa De Wild. is also prone to pest infestations, which can damage the plant and reduce its yield. The following are the common pests affecting this plant:
- Spider mites: Spider mites are small pests that can feed on the leaves of the plant, which can cause yellowing and stunted growth. To manage spider mites, spray the plant with water to dislodge the pests and introduce natural predators like ladybugs or predatory mites.
- Caterpillars: Caterpillars are the larvae of moths or butterflies and can feed on the leaves of the plant, which can cause defoliation. To manage caterpillars, remove and destroy the affected leaves and manually remove the caterpillars from the plant.
- Mealybugs: Mealybugs are small, soft-bodied insects that can feed on the sap of the plant, which can cause yellowing and stunted growth. To manage mealybugs, prune the affected areas and spray the plant with a solution of water and soap. In severe cases, an insecticide may be necessary to control the infestation.
