Overview
Grewia coriacea Mast. is a flowering plant that is native to South and Central Africa. The plant belongs to the family Malvaceae and is commonly known as the Grey-leaved raisin or the Silver raisin.
Appearance
The plant is a densely branched shrub or small tree that can grow up to 5 meters in height. The leaves are oval-shaped, with a grey-green color and a velvety texture. The plant produces small, white to pink flowers that develop into small, edible fruits that resemble raisins. The stems of the plant are woody and have a rough texture.
Uses
The fruits of Grewia coriacea are edible and are used in traditional medicine to treat various illnesses including sore throats, coughs, and stomach problems. The leaves and bark of the plant are also used for medicinal purposes. The bark is used to make twine and rope, while the wood is used for fuel and in the construction of houses.
In addition to its medicinal uses, Grewia coriacea is also grown as an ornamental plant due to its attractive foliage and flowers. It is often used as a hedge, especially in dry and arid regions, as it is a drought-resistant plant.
The plant plays an important role in the ecosystem as it provides food and shelter for various insects, birds, and mammals. It is also used as a food source for livestock in some areas.
In conclusion, Grewia coriacea Mast. is a multi-purpose plant that is valued for its medicinal uses, ornamental value, and contribution to ecological balance.Light Requirements
Grewia coriacea requires full sun to partial shade to grow. It tends to tolerate partial shade, but growth will be slower compared to plants exposed to full sun.
Temperature Requirements
The plant prefers a warm and humid climate and grows best in regions with temperatures ranging from 20 to 30 °C. It is not frost tolerant, and temperatures below 10°C can cause harm to the plant.
Soil Requirements
The plant grows well in well-drained soils with a pH range of 6.0 - 7.0. It can tolerate a wide range of soil textures, including clay, sandy loam, and loamy soils. However, the best growth of Grewia coriacea occurs in soils with good organic matter and moisture holding capacity.
Cultivation Methods
Grewia coriacea Mast. is a small tree or shrub that generally grows well in tropical and subtropical climates. It can be grown in a wide range of soils, but it prefers well-draining soils with moderate fertility levels. The plant can be propagated from seeds or stem cuttings. When planting, ensure adequate space between the plants, and provide support to young trees if necessary.
Watering Needs
Grewia coriacea Mast. prefers moderate to frequent watering, especially during the hot and dry seasons. Although the plant can tolerate some degree of drought, extended periods of water scarcity can lead to stunted growth or even plant death. The best approach to watering is to apply water at the base of the plant, taking care not to wet the leaves or flowers.
Fertilization
Applying fertilizer to Grewia coriacea Mast. can improve plant growth and yield. A balanced fertilizer, with equal amounts of nitrogen, phosphorus and potassium, is appropriate for this plant. Fertilizer application should be done in small doses at regular intervals, rather than in large doses at once. Fertilizer should be applied close to the root zone and watered well.
Pruning
Regular pruning is important for maintaining the size and shape of Grewia coriacea Mast. Mature trees can be pruned annually to remove diseased or damaged branches, and to promote healthy growth. Pruning should be done during the late winter or early spring when the plant is in a dormant state. Ensure that all pruning tools are clean and sharp to minimize damage to the plant.
Propagation of Grewia coriacea Mast.
Grewia coriacea Mast., commonly known as a timber tree, is often propagated through vegetative means. However, it can also be propagated through seeds.
Propagation through Seeds
Seeds of Grewia coriacea are sown in nursery beds or polybags that are filled with a mixture of sand and compost. The sowing is done during spring or rainy seasons. Before sowing, the seeds are soaked overnight in tepid water to enhance germination.
The beds are kept moist by sprinkling water over them regularly. The seeds take around 14-28 days to germinate. Once the seedlings have four to six leaves, they can be transplanted to individual bags.
Propagation through Cuttings
Grewia coriacea can be propagated through hardwood or softwood cuttings. Hardwood cuttings are taken during the dormant season, and softwood cuttings are taken during the growing season.
The cuttings are taken from healthy and mature trees that are disease-free. The cuttings are usually 15-20 cm long, with at least two nodes. Before planting, the cuttings are treated with rooting hormone to enhance the rooting process.
The cuttings are then planted in a mixture of sand and compost. The planting depth should be around 2-3 cm. The cuttings are then kept in a shaded area and regularly misted to maintain moisture.
In a few weeks, the roots start to develop, and the cuttings can then be shifted to individual bags or containers. The survival rate of hardwood cuttings can be increased by keeping them in a polythene bag to promote humidity around the cuttings.
Disease Management for Grewia coriacea Mast.
Grewia coriacea Mast. is susceptible to several diseases that can negatively affect its growth and productivity. Some of the most common diseases include:
Anthracnose
Anthracnose is a fungal disease that is characterized by the presence of small, circular lesions on the leaves and stems of the plant. These lesions gradually enlarge and can cause the leaves to wilt and fall off. To manage anthracnose, farmers are advised to maintain proper hygiene around the farm by clearing any fallen leaves or debris around the plant. Additionally, farmers can apply fungicides on the plant to control the fungal spread.
Bacterial Blight
Bacterial blight is another common disease that affects Grewia coriacea Mast. The disease is characterized by the presence of yellowish lesions on the leaves and stems of the plant. The leaves eventually curl, wilt, and fall off. To manage bacterial blight, farmers are advised to implement crop rotation as the primary control measure. Additionally, farmers can apply copper-based fungicides to prevent the spread of bacterial blight.
Pest Management for Grewia coriacea Mast.
Grewia coriacea Mast. is also susceptible to several pests that can cause significant damage to the plant. Some of the most common pests that affect Grewia coriacea Mast. include:
Aphids
Aphids are characterized by their small, pear-shaped bodies and are usually found on the underside of leaves. These pests can cause considerable damage to the plant by sucking the sap from the leaves. To manage aphid infestations on your Grewia coriacea Mast. plants, farmers are advised to release natural predators such as ladybugs and lacewings. Another management strategy is to use insecticidal soap, which effectively kills the pests.
Spider Mites
Spider mites are tiny, eight-legged pests that suck sap from the plant, causing severe damage to the leaves. These pests usually thrive in hot, dry conditions and can infest your Grewia coriacea Mast. plants during the dry season. To manage spider mites, farmers can use miticides, which are chemicals that are specifically designed to target spider mites. Additionally, farmers can also maintain proper irrigation practices to prevent the buildup of hot, dry conditions that promote spider mite infestations.
