Overview
Rhus kirkii Oliv. var. polyneura (Engl. & Gilg) R.Fern. & A.Fern. is a woody plant species that belongs to the family of Anacardiaceae. It is a tree that can grow up to 25 m tall, and is commonly found in the savannah regions of East and Central Africa. The plant has several common names such as "African sumac," "velvet tamarind" or "nsuu" in Swahili.Appearance
The Rhus kirkii Oliv. var. polyneura (Engl. & Gilg) R.Fern. & A.Fern. has a distinct appearance characterized by slender, cylindrical trunks that can grow up to 30 cm in diameter. Its trunk and branches are covered with reddish-brown bark with a rough texture. The tree has a dense and dome-shaped canopy with pinnate leaves that have a velvety texture. The leaves are green on the upper side and pale green on the underside, measuring about 60 cm long. The tree blooms from November to February with small greenish flowers that develop into small dark-brown fruits.Uses
The Rhus kirkii Oliv. var. polyneura (Engl. & Gilg) R.Fern. & A.Fern. tree is of great importance to the local communities in Africa due to several uses. The leaves and bark of the tree have medicinal properties, and are used to treat dysentery, diarrhea, and hemorrhoids. The tree is also a source of tannin, which is used in leather making. The fruits of the tree are edible and are consumed raw or made into a drink similar to lemonade. The tree is also used as a shade tree and for ornamental purposes. In conclusion, the Rhus kirkii Oliv. var. polyneura (Engl. & Gilg) R.Fern. & A.Fern. is a valuable tree species that holds great cultural, ecological, and economic significance in Africa.Light Requirements for Rhus kirkii Oliv. var. polyneura
Rhus kirkii Oliv. var. polyneura requires a moderate amount of sunlight to thrive. The ideal light condition is partial shade, where the plant can receive 4-5 hours of direct sunlight every day. Excessive exposure to bright sunlight can cause sunscald on the leaves, while too little sunlight can hinder the plant's growth and development.
Temperature Requirements for Rhus kirkii Oliv. var. polyneura
The plant prefers warm and humid conditions. The ideal temperature range for Rhus kirkii Oliv. var. polyneura is between 20-30°C (68-86°F). Extreme temperatures can damage the leaves and cause the plant to wilt. The plant can tolerate occasional drops in temperature, but prolonged exposure to cold weather can be fatal. It is best to grow the plant in a greenhouse or indoors if the climate in your area is unpredictable.
Soil Requirements for Rhus kirkii Oliv. var. polyneura
The plant's soil should be well-draining and rich in nutrients. It thrives in loamy soil that is slightly acidic with a pH between 5.5-6.5. The plant is sensitive to waterlogging and can develop root rot if the soil is too moist. It is advisable to mix organic matter like compost or peat moss to improve the soil's structure. Rhus kirkii Oliv. var. polyneura also requires regular watering to maintain adequate soil moisture.
Cultivation
Rhus kirkii Oliv. var. polyneura is a hardy plant that can thrive in various soil and climate conditions. It can tolerate temperatures ranging from 10°C to 35°C and can grow in both full sun and partial shade. However, it prefers well-drained soil that is slightly acidic and enriched with organic matter.
Since the plant comes from areas with high humidity, adequate moisture is crucial for its growth. Regular watering can help the plant establish deep roots that can withstand drought periods better. During the growing season, the plant requires frequent watering, at least once a week. However, during winter, the watering frequency should be reduced to prevent root rot.
Fertilization
Fertilization is essential for Rhus kirkii Oliv. var. polyneura's proper growth and development. Since the plant prefers slightly acidic soil, using an acidic fertilizer can enhance its growth. The fertilizer should be applied during the growing season, mainly during spring and summer. Use a balanced fertilizer with a ratio of 10-10-10 and avoid over-fertilizing.
Pruning
Pruning Rhus kirkii Oliv. var. polyneura is not necessary, but it can help maintain its shape and size. The best time to prune the plant is during late winter or early spring before new growth begins. Prune out the dead, damaged, or diseased branches. Also, remove the older branches to promote new growth and ensure adequate air circulation in the plant's center.
Propagation of Rhus kirkii Oliv. var. polyneura (Engl. & Gilg) R.Fern. & A.Fern.
Rhus kirkii Oliv. var. polyneura can be propagated through various methods, including:
Seeds
Seeds can be collected from mature fruit capsules and kept in a dry, cool place until planting season. Soak the seeds in water for 24 hours before planting. Sow the seeds in well-draining soil and keep moist until germination. Germination time can vary from a few weeks to a few months.
Softwood cuttings
Softwood cuttings can be taken from the tender new growth in spring or early summer. Remove a 4- to 6-inch cutting from the terminal end of a stem and remove the lower leaves. Dip the cut end in rooting hormone and plant in a well-draining potting mixture. Keep the soil moist and provide bright, indirect light. Roots should form in 4 to 8 weeks.
Hardwood cuttings
In late fall or winter, take 8- to 10-inch hardwood cuttings from mature stems. Remove the lower leaves and dip the cut end in rooting hormone. Plant the cuttings in well-draining soil and keep them moist. Store the cuttings in a cool, dry place until spring. Once spring arrives, place the rooted cuttings in individual pots or in the ground.
Layering
Layering is a method of encouraging roots to form on a stem while it is still attached to the parent plant. In spring, bend a flexible stem of the plant to the ground and make a wound where the stem touches the soil. Anchor the stem to the ground with a U-shaped wire or a rock. Cover the wound with soil and keep moist. Roots should form within a few months and the new plant can be separated from the parent plant and transplanted to a new location.
Disease Management
Rhus kirkii Oliv. var. polyneura (Engl. & Gilg) R.Fern. & A.Fern. is susceptible to several fungal diseases such as leaf spot, anthracnose, and powdery mildew.
To manage these diseases, it is essential to maintain good cultural practices such as watering early in the day to ensure leaves dry quickly, pruning damaged or infected tissues, and proper plant spacing to increase air circulation. Fungicides can also be used to control the spread of these diseases. However, it is crucial to use them according to the manufacturer's instructions.
It is also important to note that preventing the spread of these diseases is easier than treating them. Therefore, routine inspections of the plant to check for signs of infection are highly recommended.
Pest Management
Several pests can affect Rhus kirkii Oliv. var. polyneura (Engl. & Gilg) R.Fern. & A.Fern., including spider mites, scale insects, and mealybugs. These pests can cause damage to the plant by sucking the sap from leaves and stems.
To manage these pests, it is essential to inspect the plant regularly and remove any visible pests by hand. In severe cases, insecticides can be used to control the infestation. It is crucial to use insecticides according to the instructions of the manufacturer.
It is also important to note that some pests are attracted to stressed or weak plants. Therefore, proper cultural practices such as watering appropriately, maintaining proper fertilization, and pruning damaged or infected tissues can help to reduce pest infestations.
In conclusion, preventing the spread of diseases and pests is key to maintaining a healthy Rhus kirkii Oliv. var. polyneura (Engl. & Gilg) R.Fern. & A.Fern. Plant. Routine inspection, proper cultural practices and the use of appropriate fungicides and insecticides can help to ensure that the plant stays healthy and productive.
