Overview
Dactyladenia pallescens (Baill.) Prance & F.White, also known as the African olive, is a tropical evergreen tree belonging to the family of Chrysobalanaceae. It is native to tropical Africa and grows in a wide range of soils at altitudes less than 1100 meters above sea level.
Description
The African olive tree can reach up to 15 meters high and has a distinct, rough, and dark-grey bark. The leaves of the tree are alternate, elliptic to oblong, and have an almost leathery texture. They are about 10-14cm in length and 2-4cm in width. The flowers are small and white or greenish-yellow in color, and arranged in racemes. The fruit that develops is an ovoid drupe, with a hard, woody shell, about 3-5cm long and 2-4cm wide, which splits into two parts at maturity, revealing the inner seed.
Common Names
The African olive is commonly referred to as Mfwelimbi (Shona); Òsàn òyìnbó in Yoruba; U-tree in English; Mfutubale in Bemba; and Munhimbili in Chichewa.
Uses
The fruit of the African olive, when ripe, has an edible pulp that tastes similar to the common olive and can be consumed raw or processed to make olive oil. The seed of the fruit also has a high oil content and is used to produce biofuels and traditional medicines. The stem bark and leaves of the tree are also used in traditional African medicine to treat various ailments such as diarrhea, dysentery, and fever.
The tree also has cultural significance in some African communities. It is believed to have spiritual powers and is used in various rituals and ceremonies. The timber of the African olive tree is strong, durable, and resistant to termites, making it ideal for construction and furniture-making.
Light Requirements
The Dactyladenia pallescens thrives in bright and partial sunlight. It prefers a bright but not direct light source for several hours a day. The plant cannot survive in complete shade and will become leggy and weak if exposed to too much sunlight. Therefore, it is best to grow it in a partially shaded area, such as under a tree canopy.
Temperature Requirements
The Dactyladenia pallescens grows best in warm and humid conditions. It prefers a temperature range of 20°C to 30°C. However, it can tolerate temperatures as low as 10°C and as high as 40°C. The plant cannot tolerate frost or freezing temperatures.
Soil Requirements
The Dactyladenia pallescens prefers well-draining, fertile soil that is rich in organic matter. It thrives in soils that are slightly acidic or neutral, with a pH range of 6.0 to 7.5. The plant can also tolerate slightly alkaline soils with a pH range of 7.5 to 8.0. It requires regular watering to maintain the soil's moisture level, but it cannot tolerate waterlogged soil.
Cultivation Method:
Dactyladenia pallescens (Baill.) Prance & F.White can be grown in both pots and as landscape plantings. The plant requires full sun to partial shade and grows well in well-drained soil. You can propagate the plant through seeds or stem cuttings. The best time to propagate is during late spring or early summer. Keep the soil moist until the new plant has established itself.
Watering Needs:
Dactyladenia pallescens requires regular watering during its growth period. However, you need to take care not to over-water the plant as it can lead to root rot. Water the plant deeply but infrequently to ensure that the soil is moist but not waterlogged. During winter, the plant may require less frequent watering.
Fertilization:
Dactyladenia pallescens needs regular fertilization to thrive. You can apply a balanced fertilizer during spring and summer to promote healthy growth. Use a fertilizer with a balanced N-P-K ratio of 10-10-10. Apply the fertilizer at half-strength monthly during the growing season.
Pruning:
Dactyladenia pallescens requires light pruning to maintain its shape and promote healthy growth. You can prune the plant during the spring or early summer. Remove the dead leaves and trim back any long or unwanted shoots. Make sure to use clean, sharp pruning shears to avoid tearing the plant's delicate tissues.
Propagation of Dactyladenia pallescens
Dactyladenia pallescens, also known as "Kotigondu" or "Mpapuro" in local dialects, is a plant species belonging to the family Chrysobalanaceae. It is a slow-growing tree, native to the African countries of Angola, Cameroon, Congo, Gabon, and Zaire. This plant has a unique and intricate propagation process.
Seed Propagation
The easiest and most common method for propagating Dactyladenia pallescens is through seeds. The tree produces round, dark-brown seeds with a diameter of about 20mm. The seeds must be collected when they are fully mature, during late August or early September. These seeds have a very hard outer shell, so it is best to soak them in water for 3-4 days before planting. The seeded pots should be covered with polythene bags and stored in a warm place or under partial shade. The germination process takes about 1-3 months, and the seedlings are transplanted to their permanent position after they reach 6-8cm height.
Cuttings Propagation
Another propagation method that can be used for Dactyladenia pallescens is through stem cuttings. Hardwood cuttings, between 20-30 cm long, taken in winter, root readily under mist. The cuttings should be dipped in rooting hormone (IBA) and inserted into pots containing a mix of sand and potting soil. The cutting's bottom end should be wounded to stimulate callus formation, which accelerates root initiation. The pots should be covered with polythene bags to maintain the required humidity level, and the tissue roots usually appear after about six weeks.
Air Layering Propagation
Air layering is another propagation method that can be used for Dactyladenia pallescens. This method is more time-consuming and complicated than the previous ones, but it can produce larger plants quickly. Select a healthy branch about one year old, remove the bark in a small area (10-12 cm), and cover the wound area with sphagnum moss. Cover the plant part with a plastic sheet and tie both ends with a thread. The moss should be kept moist with water or a hormone solution. After 4-6 months, roots will grow from the wound area. Then, the air-layered stem is cut off from the parent stem and planted in a pot containing a standard potting mix.
Overall, Dactyladenia pallescens is an amazing tree with many unique characteristics, and propagating it can be very rewarding, especially when you succeed in producing beautiful specimens that can be enjoyed by generations to come.
Disease Management
Dactyladenia pallescens can be commonly affected by fungal diseases, such as powdery mildew, leaf spot, and root rot. To control powdery mildew, it is recommended to remove and destroy infected plant parts, increase air circulation through pruning, and apply fungicides with active ingredients such as sulfur, neem oil, or potassium bicarbonate. Leaf spot can be controlled through regular sanitation measures, including removing fallen leaves, pruning infected branches, and applying fungicides such as chlorothalonil or copper-based products. Root rot can be prevented by avoiding overwatering, keeping the soil well-drained, and using fungicides containing active ingredients like azoxystrobin, thiophanate-methyl, or mefenoxam.
Pest Management
Dactyladenia pallescens can also be attacked by pests, including mites, scales, and aphids. Mites can be controlled through regular hosing down of the plant to remove them, using insecticidal soap or neem oil, or introducing predatory mites such as Phytoseiulus persimilis. Scales can be effectively managed through pruning of affected plant parts, using rubbing alcohol or horticultural oil to suffocate them, or introducing natural enemies like ladybugs or parasitic wasps. Aphids can be kept at bay through the application of insecticidal soaps or neem oil, introducing predatory insects like ladybugs or lacewings, or spraying plants with a solution of water and dish soap.
