Introduction
Grewia angolensis Welw. ex Mast. is a shrub or small tree that belongs to the family Malvaceae. It is commonly known as the Angolan raisin or the Rosy raisin.
Origin and Habitat
The plant is native to Angola and can also be found in other African countries such as Zimbabwe, Malawi, and Tanzania. It grows in open woodland, savannas, and rocky hillsides.
Appearance
Grewia angolensis can grow up to a height of 5 meters and has a spread of about 2 meters. The bark is greyish-brown and smooth while the young branches are hairy. The leaves are elliptic or oblong, measuring 3-12 cm long and 2-5 cm wide. The flowers are pink to mauve, with a diameter of about 1.5 cm and are borne on small axillary clusters.
The fruit is a small drupe that is red when ripe, with a diameter of about 0.5 cm. It is edible and has a sweet taste.
Uses
The plant has various uses. The leaves and bark are used in traditional medicine to treat ailments such as skin infections, dysentery, and diarrhea. The fruit is eaten fresh or made into jams and preserves. The wood is used to make utensils and is also used as fuel.
In addition, the plant is used for landscaping due to its attractive pink flowers and sweet-tasting fruit.
Conclusion
Grewia angolensis is a versatile plant that has various uses, from traditional medicine to landscaping. It is an important species in African countries and is valued for its medicinal properties and edible fruit.
Light Requirements
Grewia angolensis Welw. ex Mast. thrives in full sunlight but can also tolerate partial shade. A minimum of six hours of sunlight exposure is required for optimal growth and fruit production.
Temperature Requirements
Grewia angolensis is a plant species native to tropical regions and therefore requires warm temperatures for successful growth. It prefers an average temperature range of 20 - 30°C (68-86°F). This plant can tolerate high temperatures of up to 35°C without any adverse effects on growth.
Soil Requirements
Grewia angolensis can grow in a variety of soils, but it prefers loamy soils. The soil should be well-draining to avoid waterlogging and root rot. It can tolerate relatively dry soils, but it grows best in soils with moderate moisture content. This plant is also tolerant of acidic soils with a pH range of 5.5 - 7.5. However, soils that are rich in organic matter are the best for Grewia angolensis.
Cultivation Methods
Grewia angolensis Welw. ex Mast. thrives in tropical and sub-tropical regions, and it is typically grown outdoors in regions with warm climates. It requires full sunlight exposure, so it is essential to plant it in an area that gets ample sunlight. The plant does well in well-drained soils, and it is recommended to plant it in soil with a pH of 6.0-7.5. It is also crucial to ensure that the plant has enough space to grow, and it is typically recommended to plant it at least three to five feet apart.
Watering Needs
Grewia angolensis Welw. ex Mast. requires moderate watering. It is recommended to water the plant once or twice a week, depending on weather conditions. During hot and arid weather, the plant may need more watering to survive and thrive. Watering can be reduced during the winter season, as the plant undergoes dormancy during this time. It is crucial to ensure that the soil is well-drained to avoid root rot.
Fertilization
The plant benefits from regular fertilization to promote its growth and health. Fertilization should be done once per month during the growing season using a balanced, slow-release fertilizer. It is recommended to apply the fertilizer to the soil around the plant, making sure not to over-fertilize as this can lead to an excessive build-up of salts in the soil.
Pruning
Pruning the plant is essential to maintain its shape, and it also helps to promote new growth. It is typically recommended to prune the plant during the winter season when it is dormant. Pruning should be done to remove dead, diseased, and damaged branches. It can also be done to control the size of the plant, ensuring that it does not exceed the desired size. When pruning, it is important to use clean and sharp pruning tools to avoid causing any injury to the plant.
Propagation of Grewia angolensis Welw. ex Mast
Grewia angolensis Welw. ex Mast is a drought-resistant shrub or small tree that is indigenous to Angola, Botswana, Namibia, South Africa, Zambia, and Zimbabwe. It is a multipurpose plant with numerous uses, including medicinal, dietary, and industrial purposes.
To propagate Grewia angolensis Welw. ex Mast, farmers can use any of the following methods:
Seed Propagation
Grewia angolensis Welw. ex Mast can be propagated by seeds, which are readily available from the mature fruit. Collect the ripe fruits of the shrub/tree and remove their seeds. Clean the seeds and dry them to a moisture content of about 7%. Sow the seeds in germination trays or polybags containing a mixture of river sand, compost, and topsoil. The germination period is usually between 14 and 28 days, depending on the quality of the seeds and prevailing weather conditions.
Cuttings Propagation
Grewia angolensis Welw. ex Mast can also be propagated by cuttings. Take cuttings from semi-hardwood branches measuring 10-15 cm long and with a diameter of 5-10 mm. Dip the cuttings in rooting hormone powder and plant them in propagation trays or polybags containing a mixture of soil and compost. Keep the cuttings in a warm, humid, and shaded place and monitor their growth regularly. Root formation usually occurs within four weeks.
Grafting Propagation
Grafting is a relatively difficult method, but it can be effective in propagating Grewia angolensis Welw. ex Mast. It is primarily used for the production of improved clones with desirable traits, such as high yield, disease resistance, and drought tolerance. Scions are taken from mature trees with desirable traits and grafted onto rootstock obtained from seedling. The graft union should be protected from direct sunlight and kept moist until the union is established.
In conclusion, the propagation of Grewia angolensis Welw. ex Mast through seed, cuttings, or grafting can lead to improved yield, disease resistance, and drought resilience. Farmers should choose the propagation method that best suits their needs and resources.
Disease and Pest Management for Grewia angolensis Welw. ex Mast.
Grewia angolensis Welw. ex Mast., commonly known as the Angolan Crossberry, is a flowering plant that belongs to the family Malvaceae. It is native to Angola and can also be found in other African countries. This plant can be affected by various diseases and pests that can cause serious damage if not managed properly.
Common Diseases
One of the most common diseases that affect Grewia angolensis is powdery mildew. This fungal disease appears as a white or gray powdery coating on the leaves, stems, and flowers of the plant. To manage powdery mildew, it is important to remove and destroy any infected plant material. Fungicides can also be used to manage the disease.
Another common disease that affects Grewia angolensis is leaf spot. This disease manifests as circular or irregular spots on the leaves that can be yellow, brown, or black. The spots can merge, causing the leaves to turn yellow and eventually fall off. To manage leaf spot, it is important to remove and destroy any infected leaves. Fungicides can also be used to manage the disease.
Common Pests
Grewia angolensis can also be affected by various pests such as scales, mealybugs, and aphids. These pests suck the sap from the plant, causing stunted growth, yellowing of leaves, and eventual death. To manage these pests, it is important to regularly inspect the plant and remove any infested parts. Insecticidal soaps and horticultural oils can also be used to manage these pests.
Another common pest that affects Grewia angolensis is the spider mite. These pests cause damage by sucking the sap from the plant, causing the leaves to turn yellow or bronze. To manage spider mites, it is important to regularly inspect the plant and remove any infested parts. Insecticidal soaps and horticultural oils can also be used to manage these pests.
Proper care and maintenance can also help reduce the risk of diseases and pests in Grewia angolensis. This includes ensuring adequate sunlight and air circulation, proper irrigation, and fertilization.
