Acacia nilotica (L.) Willd. ex Delile subsp. kraussiana (Benth.) Brenan
Acacia nilotica (L.) Willd. ex Delile subsp. kraussiana (Benth.) Brenan, also known as the Krauss's acacia, is a plant species belonging to the Fabaceae family. The plant is native to Africa, including Sudan, Kenya, Somalia, Ethiopia, Tanzania, Zimbabwe, South Africa, and Botswana.
Common Names
Acacia nilotica (L.) Willd. ex Delile subsp. kraussiana (Benth.) Brenan is commonly known as Krauss's acacia, gum arabic acacia, and Egyptian thorn. The plant is also identified by other common names, including prickle acacia, thorny acacia, and babul.
General Appearance
Acacia nilotica (L.) Willd. ex Delile subsp. kraussiana (Benth.) Brenan is a deciduous tree or shrub that grows up to 15 meters in height. The bark of the tree is dark grey or brown and rough with vertical fissures. The leaves are bipinnate and pale-green in color, with 2-5 pairs of pinnae and 10-20 pairs of leaflets. The tree produces fragrant yellow flowers that form clusters. The fruit is a legume pod that is about 10-20 cm long, dark brown to black in color and contains numerous seeds.
Uses
Acacia nilotica (L.) Willd. ex Delile subsp. kraussiana (Benth.) Brenan is widely used for medicinal purposes. It has antimicrobial, antioxidant, anti-inflammatory, analgesic, and antipyretic properties. The bark, leaves, and pods of the plant are used to treat various ailments, including diarrhea, dysentery, cough, fever, and skin infections. The tree's gum is also used in the preparation of adhesives, textiles, inks, and pharmaceuticals. Additionally, the tree is a source of fodder for livestock and is used for erosion control, fuelwood and charcoal.
Light Requirements
Acacia nilotica subsp. kraussiana is a plant species that grows well in bright, direct sunlight conditions. In its native range, it often grows along floodplains, riverbanks, and other open, sunny areas. In general, this plant needs a light intensity of at least 6000-7000 lux for optimal growth. If grown indoors, the plant requires exposure to direct sunlight for at least 4-6 hours per day.
Temperature Requirements
This plant is well adapted to hot, arid environments and can tolerate considerable temperature fluctuations. The ideal temperature range for growth and development of Acacia nilotica subsp. kraussiana is between 20-45 °C (68-113 °F). The species can withstand short periods of freezing temperatures, but extended exposure to frost or low temperatures below -3°C (27°F) can damage or kill the plant.
Soil Requirements
Acacia nilotica subsp. kraussiana can grow in a variety of soil types, but thrives in well-drained, sandy soils. The plant prefers slightly alkaline soils with pH ranging between 7.2-8.5. These soils should be rich in nutrients, especially nitrogen, phosphorus, and potassium, for optimal growth and development. The plant can tolerate periodic flooding and drought, but prolonged waterlogged conditions can lead to root rot and eventual death of the plant.
Cultivation methods
Acacia nilotica subsp. kraussiana can be grown in a range of soils but prefers those that are well-draining and slightly acidic. The plant grows best in full sun and is tolerant of drought and moderate frost, making it suitable for semi-arid and arid regions. The seeds can be sown directly in the ground or in pots.
Watering needs
The plant requires moderate watering during the growing season to establish itself, but thereafter can be left on its own to survive without regular watering. Overwatering can cause root rot, so it is important not to water the plant excessively.
Fertilization
Acacia nilotica subsp. kraussiana is a nitrogen-fixing plant and therefore does not require regular fertilization. However, a balanced fertilizer may be applied in the early stages of growth to support root growth.
Pruning
Pruning should be done in the early stages of growth to shape the plant and promote bushy growth. Regular pruning is not necessary, but the removal of dead or damaged branches is beneficial. It is also important to remove any weak growth near the base of the plant to promote stronger growth at the top. Use clean, sharp pruning shears and disinfect them after use to prevent the spread of disease.
Propagation of Acacia nilotica (L.) Willd. ex Delile subsp. kraussiana (Benth.) Brenan
Acacia nilotica (L.) Willd. ex Delile subsp. kraussiana (Benth.) Brenan can be propagated by various methods which include seed propagation, vegetative propagation, and tissue culture.
Seed Propagation
Seed propagation is the most common method of propagating Acacia nilotica subsp. kraussiana. The seeds are collected from ripe pods and cleaned to remove any debris. The cleaned seeds can be sown directly in the field or in a nursery bed. The seeds are first soaked in water for 24 hours to improve their germination rate. The seeds are then sown in rows spaced approximately 50cm apart and covered with soil to a depth of 2-3 cm. The seedlings should start to emerge within 7-14 days and can be transplanted to their permanent location after 8-12 weeks.
Vegetative Propagation
Acacia nilotica subsp. kraussiana can also be propagated by vegetative means which involve the use of stem cuttings or root suckers. Stem cuttings are taken from the parent plant and are usually 10-15 cm long. The cuttings should be taken from young and healthy shoots and should have at least 3 nodes. The lower leaves are removed, and the cuttings are dipped in a rooting hormone before being planted in a rooting medium. The cuttings are placed in a moist and shady area and should start producing roots in 4-6 weeks. Root suckers can also be used for propagation. Root suckers are removed from the parent plant and planted in a nursery bed until they are strong enough to be transplanted.
Tissue Culture
Tissue culture is a more advanced method of propagation that involves the use of plant tissues to produce new plants. The tissues are sterilized and then grown in a nutrient medium in a laboratory. The resulting plantlets are then transplanted to a nursery bed until they are strong enough to be transplanted to their permanent location. Tissue culture is a useful method for propagating large numbers of plants in a short period.
Disease Management
Acacia nilotica subsp. kraussiana is a hardy plant that is relatively resistant to diseases. However, like all living organisms, it may occasionally fall prey to some diseases. One of the most common diseases affecting this plant is gummosis.
Gummosis is a fungal disease that causes the formation of gummy exudates on the bark of trees. This disease may result in the death of the plant if left untreated. To manage gummosis, the diseased area must be cut and destroyed. Preventive measures include ensuring the plant is well-watered and fertilized, and avoiding crowding the tree.
Pest Management
Acacia nilotica subsp. kraussiana is also relatively resistant to pests. However, some pests may still attack the plant, causing damage and reducing its yield. One of the most common pests affecting this plant is the scale insect.
The scale insect is an insect that feeds on the sap of the plant, weakening it and reducing its productivity. To manage scale insects, they can be treated with neem oil or insecticidal soap. Additionally, removing the scales from the plant with a soft-bristled brush and soapy water also works. Regularly pruning and removing affected leaves and branches can prevent infestation.
