Overview
Grewia dependens K.Schum. is a species of flowering plant in the family Malvaceae. It is a small tree or a large shrub that is native to East and Central Africa.
Common Names
Grewia dependens K.Schum. is commonly known as the River raisin, Nepalese crossberry, and Many-branched raisin.
Appearance
The plant typically grows up to 5 meters tall and has a dense, spreading crown. Its bark is brown and thin with light vertical fissures. The leaves are simple, alternate, and oval-shaped, measuring between 3-10 cm long. Its flowers are small and white, produced in clusters. The fruits are spherical, approximately 1 cm in diameter, and turn reddish-brown when ripe.
Uses
Various parts of the Grewia dependens K.Schum. plant are harvested and used for medicinal purposes. Its roots have been used as a traditional remedy for treating malaria. Its leaves can be crushed and applied topically to relieve pain. The fruit is edible and has a sweet taste, and is sometimes made into jam or used as a traditional medicine for treating diarrhea and dysentery.
Light Requirements
Grewia dependens K.Schum. thrives in full sun to partial shade. The plant will require about 6 hours of direct sunlight daily if grown indoors. If grown outdoors, the availability of natural light will determine the growth rate, size, and quality of the plant.
Soil Requirements
The plant can adapt to different types of soil, but it prefers well-drained, loamy soil. The soil should contain a mixture of sand, silt, and clay in equal proportions with a pH of 6.0 to 7.5. The soil should be fertile, with enough organic matter to enrich it. This plant can tolerate mildly alkaline soils, but acidic soils are unsuitable for it.
Water Requirements
Grewia dependens K.Schum. prefers moderate watering, meaning that the soil should not be too damp or too dry. Water the plant once a week during the growing season and reduce watering during the dormant period. Avoid overwatering as it can lead to root rot and other water-related problems.
Temperature Requirements
The plant can grow in a wide range of temperatures, as long as it is not exposed to extreme cold or heat. The ideal temperature range for Grewia dependens K.Schum. is 20-30°C (68-86°F). The plant can tolerate temperatures as low as 10°C (50°F) and as high as 40°C (104°F), but these extremes may slow down its growth rate or damage the plant.
Cultivation
Grewia dependens K.Schum. is a shrub that can be propagated by seeds, cuttings, or layering. It prefers well-drained soil with a neutral to slightly acidic pH and adequate sunlight for growth.
Watering Needs
Grewia dependens K.Schum. requires moderate water, especially during the growing season. Watering should be done when the soil is dry, but not overly dry. Too much water can lead to root rot, while insufficient water can result in stunted growth and lower yields.
Fertilization
The easiest way to fertilize Grewia dependens K.Schum. is by using organic compost. The shrub can also be fertilized with commercial fertilizers that are rich in nitrogen, phosphorus, and potassium. Fertilization should be done during the growing season and at least twice a year, or when necessary based on soil tests.
Pruning
Regular pruning is essential for Grewia dependens K.Schum. to maintain its shape and vigor. Pruning should be done during the dormant period to avoid the risk of damaging the plant. The broken, diseased, or damaged branches should be removed immediately to prevent the spread of infection to other parts of the plant.
Propagation of Grewia dependens K.Schum.
Grewia dependens K.Schum., commonly known as the Grey Buttonwood, is a species of shrub or small tree that grows in arid and semi-arid regions of Africa, from Ethiopia to South Africa. It is propagated both by seed and vegetatively.
Seed propagation
Seeds of Grewia dependens K.Schum. are usually collected from the tree during the dry season. The seeds are cleaned, dried, and stored in a cool and dry place until planting time. Seedlings can be raised in nursery beds or directly in the field.
When using nursery beds, the seeds are sown in raised beds filled with a well-draining mixture of soil and sand. The seeds are sown at a depth of about 1-2 cm, and the bed is watered regularly to maintain moisture. The seedlings are transplanted to individual pots after they develop 3-4 true leaves and kept in the nursery until they are large enough to be planted in the field.
If planting directly in the field, the seeds are sown in rows spaced about 50 cm apart and covered with a thin layer of soil. The field should be well-prepared with weed-free soil that is rich in organic matter. The seedlings are thinned out after they develop their first set of true leaves, leaving one seedling every 50 cm in the row.
Vegetative propagation
Grewia dependens K.Schum. can also be propagated vegetatively by stem cuttings or layering.
Stem cuttings are taken from mature trees during the dormant season. The cuttings should be about 20-25 cm long and have at least 2-3 nodes. The leaves from the lower one-third of the cutting should be removed, and the cutting is dipped into a rooting hormone before being planted in a well-drained potting mix. The pot is then covered with a plastic bag or a cloche to maintain high humidity and placed in a warm and bright location. The cuttings should root within 2-3 months and can then be transplanted to larger containers or directly in the field.
Layering involves bending a low-hanging branch of the tree to the ground and covering it with soil. The branch should be scraped lightly with a sharp knife at the point of contact with the soil to encourage root growth. The branch should be kept moist and well-ventilated until roots develop, usually within one growing season. The newly-rooted plant can then be separated from the parent tree and transplanted to its permanent location.
Disease and Pest Management for Grewia Dependens K.Schum.
Grewia dependens K.Schum. is a hardy shrub that is rarely affected by diseases and pests. However, like any other plant, it can be affected by certain pests and diseases under certain conditions. Proper management is required to ensure that the plant grows well and produces healthy flowers and fruits. Here are some common diseases and pests that might affect Grewia dependens K.Schum. and how to manage them:
Diseases
Leaf spot disease is a common problem that affects Grewia dependens K.Schum. The disease causes small, circular spots on the leaves that eventually turn brown and fall off. The disease is caused by a fungus and can be managed by removing the infected leaves and destroying them. Fungicides can also be used to control the spread of the disease. Powdery mildew is another fungal disease that affects the plant. The disease causes white, powdery patches on the leaves and stems and can be managed by pruning affected parts of the plant and applying fungicides.
Pests
Scale insects and mealybugs are common pests that affect Grewia dependens K.Schum. Scale insects attach themselves to the leaves, stems, and branches of the plant, and can be controlled by pruning affected parts of the plant and applying insecticides. Mealybugs, on the other hand, attach themselves to the stems and leaves and suck sap from the plant, causing damage to the plant. Management of mealybugs involves the use of insecticides and pruning of affected parts.
Caterpillars and aphids can also be a problem for Grewia dependens K.Schum. Caterpillars feed on the leaves of the plant, causing damage to the plant. They can be controlled by applying insecticides and picking them off by hand. Aphids, on the other hand, suck sap from the plant and can be managed by spraying the plant with a strong jet of water to dislodge them, or by applying insecticides.
In conclusion, while Grewia dependens K.Schum. is a hardy plant that rarely suffers from diseases and pests, it is important to be vigilant and to take appropriate measures when such issues arise. The management of diseases and pests involves a combination of cultural practices, such as pruning and removing infected parts, and the use of chemical control measures, such as fungicides and insecticides.
