Plant Description
Dovyalis macrocalyx, also known as wild orange, is a spiny, small to medium-sized tree that belongs to the Salicaceae family. It can grow up to a height of 10 meters with a trunk diameter of up to 30 cm. The leaves are ovate, glossy, and dark green, while the flowers are small, green, and inconspicuous.
Origin and Common Names
The species is native to tropical Africa and Madagascar and can be found in countries such as Cameroon, Nigeria, Tanzania, and Kenya. The plant is commonly known as jembirri in Nigeria, mbari in Cameroon, and kiwi in Swahili-speaking countries.
Uses
The fruits of Dovyalis macrocalyx are the main economic products of the plant. The fruits are orange in colour and have a sour taste. They are edible and can be consumed fresh or used in the preparation of juices, jams, curries, and sauces. The fruit is also rich in vitamin C and other nutrients and is used in traditional medicine to treat various ailments such as fever, diarrhea, and stomach disorders. In addition, the plant is also used for fencing, making canes, and in reforestation programs.
General Appearance
Dovyalis macrocalyx has a thorny stem and branches, which are characteristic of the Salicaceae family. The tree has a dense foliage cover with a rounded or conical shape. The bark is grey or dark brown and has shallow indentations. The roots of the plant are shallow and widespread and are adapted to grow in sandy soils. The plant is mainly propagated through seeds and cuttings and is easy to cultivate.
Growth conditions for Dovyalis macrocalyx
Dovyalis macrocalyx is a plant species that is mostly found in Africa, specifically in the eastern parts. The plant is known for its edible fruits and is therefore of economic and nutritional importance. Here is a detailed discussion of the typical growth conditions of Dovyalis macrocalyx:
Light requirements
For optimal growth, Dovyalis macrocalyx requires full sunlight. The plant can tolerate some shade, but failure to provide sufficient light may result in reduced fruit production, and the quality of the produced fruits may also be inferior.
Temperature requirements
The plant can grow in a wide range of temperatures, but it requires warm/hot temperatures for flower initiation and fruit development stages. Dovyalis macrocalyx can survive drought seasons and can tolerate temperatures as high as 35°C. However, the plant cannot tolerate frost and temperatures below 10°C.
Soil requirements
Dovyalis macrocalyx requires well-drained and fertile soils for optimal growth. The ideal soils are moderately acidic with pH ranging from 5.5 to 6.5. The plant can also tolerate a wide range of soil types, including sandy, loam, and clay soils. It is important to note that the plant is sensitive to waterlogging; therefore, it is crucial to avoid soils that hold too much water.
Cultivation Methods
Dovyalis macrocalyx (Oliv.) Warb. is a tropical plant native to East Africa and Southern Africa. It is a small, evergreen tree or shrub that grows up to 7 meters in height. The plant requires a warm, humid environment and prefers well-drained soil with a pH between 6.0 and 7.5. The plant can be grown from seed or cuttings and should be transplanted into a well-prepared soil mixture with plenty of organic matter.
Watering Needs
The plant requires moderate watering during the growing season, which is from spring to autumn. The soil should be kept moist but not waterlogged. It is important to avoid overwatering the plant, as this can lead to root rot and other diseases. The plant should be allowed to dry out slightly before watering. During the dormant season, the plant requires less water, and the soil should be kept slightly dry.
Fertilization
Fertilization should be done during the growing season to promote healthy growth and fruiting. A balanced fertilizer with a higher nitrogen content, such as a 10-10-10 NPK blend, is ideal for the plant. The fertilizer should be applied every 2-3 months at a rate of 1/4 to 1/2 cup per plant, depending on the size of the plant. It is important to follow the manufacturer's instructions when applying fertilizers. Over-fertilization can lead to excessive growth, poor fruit quality, and other issues.
Pruning
Pruning is essential for maintaining the shape and size of the plant and promoting healthy growth and fruiting. The plant should be pruned after harvesting, in late winter or early spring. Dead or diseased branches should be removed first. Then, any crossing branches, water sprouts, and weak growth should be pruned back to the main stem or a healthy branch. The plant should be pruned to maintain an open canopy, as this allows for better air circulation and sunlight penetration. It is important to use clean, sharp pruning tools to avoid damaging the plant or spreading diseases.
Propagation of Dovyalis Macrocalyx
Dovyalis macrocalyx (Oliv.) Warb. can be propagated through different methods. These include:
Seed Propagation
The plant produces seeds that can be used for propagation. The seeds should be collected when they are mature. This can be determined by the change in color from green to yellow or orange. The seeds should be cleaned, then sown in a well-draining medium. The medium should be kept moist, and the seeds should germinate in 2-4 weeks. For optimal germination, the seeds require a temperature range of 20-25°C.
Cuttings
The plant can be propagated through cuttings. Softwood cuttings can be taken from the plant in early summer. The cuttings should be 8-10 cm long, and the leaves on the lower half should be removed. The cuttings should be dipped in rooting hormone and planted in a well-draining medium. The cuttings should be kept in a warm, humid environment. Roots should start to develop in about 2-4 weeks.
Grafting
Grafting is another method of propagation for Dovyalis macrocalyx. Grafting involves joining a scion (the desired cultivar that will produce the fruit) onto a rootstock (the plant that will provide the root system). This method is often used to ensure that the desired cultivar is reproduced. The rootstock used should be compatible with the scion used. The process is delicate and requires the correct timing and technique.
Disease Management for Dovyalis macrocalyx
Dovyalis macrocalyx is generally resistant to most diseases, but it can still suffer from a few fungal infections and viral diseases that can affect its growth and yield. One of the most common diseases that affect this plant is anthracnose.
Anthracnose is a fungal disease that causes leaf spots, necrosis, and eventually defoliation if left untreated. To manage this disease, it's advisable to ensure the plant is well-spaced to promote good air circulation, avoid overhead watering, and remove and dispose of any infected debris around the plant immediately. Fungicides can also be applied preventively to protect the plant from infection.
Bacterial leaf spot is another disease that affects Dovyalis macrocalyx. This disease causes small, water-soaked spots on the leaves, which later turn brown and fall off. It can be managed by ensuring the plant is well-watered and not stressed, avoiding overhead watering, and promptly removing and destroying any infected plant parts. Copper-based fungicides may also be applied to prevent the spread of the disease.
Pest Management for Dovyalis macrocalyx
Dovyalis macrocalyx can also be affected by several pests that can cause significant damage to the plant. One of the most common pests is the fruit fly.
The fruit fly lays its eggs on the fruit, and the larvae feed on the fruit pulp. To manage this pest, it's essential to ensure good sanitation practices by removing and destroying infected fruit and harvest the fruit promptly. Insecticidal sprays can also be applied during the fruiting season to protect the fruit from infestation.
The plant can also be affected by mealybugs, aphids, and scale insects. These pests typically feed on the leaves and stems, causing stunted growth, yellowing leaves, and evident signs of stress. Infected plants can be treated with insecticidal soap or neem oil to control and manage these infestations.
In conclusion, a proper understanding of the common diseases and pests that affect Dovyalis macrocalyx and their management practices can help maintain healthy plant growth and maximize yields. Early detection and prompt management are crucial in preventing the spread of diseases and pests.
