Origin
Carissa bispinosa (L.) Desf. ex Brenan subsp. bispinosa is a plant species that belongs to the Apocynaceae family. It is native to Africa and can be found in several countries such as Tanzania, Malawi, and Zimbabwe.
Common Names
Carissa bispinosa is known by different names depending on the country or region. Some of its common names include red ivory, coastal redwood, and Natal plum. In Swahili, it is called Mpenda Harufu or Msupa Harufu.
Uses
The plant has medicinal properties and its fruits are edible. The leaves, fruits, and bark have been used to treat various ailments such as diarrhea, toothache, and constipation. In Zimbabwe, the roots are used to make a concoction that is believed to cure syphilis. In addition to its medicinal properties, Carissa bispinosa is also a popular ornamental plant because of its attractive flowers and shiny leaves.
General Appearance
Carissa bispinosa is a small, evergreen tree that can grow up to 8 meters in height. It has a dense, bushy crown and a single or multi-stemmed trunk that can have a diameter of up to 30 centimeters. The leaves are glossy, dark green, and oval-shaped with a pointed tip. The plant produces white to pinkish, sweet-smelling flowers that are about 2 cm in diameter. The fruits are round and red in color, and they are edible when ripe.
Light Requirements
The Carissa bispinosa (L.) Desf. ex Brenan subsp. bispinosa plant grows well in full sun to partial shade. It requires a minimum of 6 hours of direct sunlight daily for optimal growth. If the plant does not receive enough sun exposure, it may not produce flowers or fruit as it should.
Temperature Requirements
The plant is tolerant of high temperatures and can withstand hot and dry conditions. It prefers a warm climate with a minimum temperature above 10°C (50°F) and thrives in temperatures ranging from 20-30°C (68-86°F). Temperatures below this range may cause the plant to die off or stunt growth.
Soil Requirements
The Carissa bispinosa (L.) Desf. ex Brenan subsp. bispinosa plant prefers a well-drained soil that is fertile and rich in organic matter. It can tolerate a wide range of soil types, from sandy to loamy. The pH level of the soil should be slightly acidic to neutral and falls in the range of 6.0-7.5. The plant is also tolerant of slightly salty soils.
Cultivation Methods
Carissa bispinosa (L.) Desf. ex Brenan subsp. bispinosa is a relatively hardy plant species that can grow in a wide range of soil types and climatic conditions. However, it thrives best in well-draining soils that are loamy or sandy, with a pH range of 6.0-7.5.
This plant prefers full sun or partial shade, and it can grow up to 4 meters in height under favorable conditions. The best time to plant Carissa bispinosa is during the rainy season or after rains. The planting hole should be about twice the size of the root ball, and the root collar should be slightly above the soil level to prevent waterlogging.
Watering Needs
Carissa bispinosa requires moderate watering depending on the season. During the dry season, the plant needs regular watering twice a week. However, during the rainy season, it may require very little watering.
Over-watering can cause root rot, which may inhibit growth, and in severe cases, it may lead to plant death. On the other hand, under-watering leads to water stress, resulting in wilting and leaf loss.
The best way to water Carissa bispinosa is by a drip irrigation system that delivers water slowly and directly to the root zone. Alternatively, a handheld hose with a regulated nozzle can be used to water at the base of the plant.
Fertilization
To promote growth and flowering, Carissa bispinosa requires moderate fertilization. A balanced fertilizer with an NPK ratio of 10-10-10 is suitable, and it should be applied every three months during the growing season.
Organic compost or manure can also be added to the soil around the plant to improve soil fertility. However, caution should be taken not to over-fertilize the plant as this can lead to excessive growth and a reduced lifespan.
Pruning
Pruning is not necessary for Carissa bispinosa, but it can be done to control its size and shape. It is best done during the plant's dormant season, which is after the flowering period.
The dead or damaged branches should be removed to promote growth, and the weak or leggy branches should be cut back to encourage bushy growth. The pruning tools used should be sharp and sanitized to prevent the spread of diseases.
Propagation Methods for Carissa bispinosa (L.) Desf. ex Brenan subsp. bispinosa
Carissa bispinosa (L.) Desf. ex Brenan subsp. bispinosa can be propagated by various methods. Some of the common methods include:
1. Seed Propagation
Seeds are the most commonly used method of propagation for Carissa bispinosa (L.) Desf. ex Brenan subsp. bispinosa. The seeds should be collected from mature fruit, cleaned and sown in a well-drained substrate. The substrate should be kept moist but not waterlogged. The seeds will germinate within 3-4 weeks. Once the seedlings are about 10 cm tall, they can be transplanted into individual pots.
2. Stem Cuttings
Carissa bispinosa (L.) Desf. ex Brenan subsp. bispinosa can also be propagated by stem cuttings. The stem cuttings should be collected from healthy plants, and cuttings of about 10 to 15 cm in length are taken, and the lower leaves are removed. The cuttings should be planted in a well-drained substrate and kept moist until the roots are formed. This typically takes around 2-3 weeks.
3. Air Layering
Air layering is another method of propagation for Carissa bispinosa (L.) Desf. ex Brenan subsp. bispinosa. In this method, a branch of the plant is chosen, and a ring of the bark is removed. The exposed area is then treated with rooting hormone and wrapped with moist sphagnum moss and covered with plastic wrap. Once roots have formed in the moss, the branch can be cut off and planted in a well-draining substrate.
4. Grafting
Grafting is a more advanced method of propagation that can be used for Carissa bispinosa (L.) Desf. ex Brenan subsp. bispinosa. In this method, a cutting from the plant is attached to a rootstock from a related plant. The two are then joined and wrapped with grafting tape. This method can be more difficult and requires more skill but can result in a stronger and more robust plant.
Disease and Pest Management for Carissa bispinosa (L.) Desf. ex Brenan subsp. bispinosa
Carissa bispinosa (L.) Desf. ex Brenan subsp. bispinosa, commonly known as "Num-Num," is a hardy and drought-resistant plant. However, it is not immune to diseases and pests. Here are some of the common diseases and pests that can affect the plant:
Diseases
1. Leaf Spot - This disease is caused by a fungus and can manifest as small spots on the leaves. If left untreated, it can spread quickly and cause defoliation. To manage this disease, affected leaves should be removed and destroyed, and the plant should be treated with a fungicide.
2. Powdery Mildew - This disease is caused by a fungus and can manifest as white powdery patches on the leaves. It can reduce the plant's ability to photosynthesize and weaken the plant. To manage this disease, the plant should be sprayed with a fungicide and kept dry.
3. Root Rot - This disease is caused by waterlogging and can affect the roots of the plant. It can cause the plant to wilt, yellow, and eventually die. To manage this disease, the plant should be removed from the waterlogged area and transplanted into well-draining soil. Also, watering should be done carefully to avoid waterlogging.
Pests
1. Spider mites - These tiny insects can cause discoloration and distortion of the leaves. They thrive in dry and dusty conditions and can multiply quickly. To manage these pests, the plant should be sprayed with insecticidal soap or neem oil.
2. Mealybugs - These pests can cause wilting and discoloration of the leaves, and their presence can be seen as cottony masses on the plant. To manage these pests, they can be removed by hand, and the plant can be treated with insecticidal soap or neem oil.
3. Scale Insects - These pests can cause yellowing and dropping of the leaves, and their presence can be seen as hard and waxy bumps on the stems and leaves. To manage these pests, they can be removed by hand, and the plant can be treated with insecticidal soap or neem oil.
