Origin
Vernonia calvoana (Hook.f.) Hook.f. var. mokaensis (Mildbr. & Mattf.) C.Jeffrey is a species of flowering plant from the family Asteraceae that is native to West and Central Africa. It is found in countries such as Cameroon, Gabon, Congo and the Democratic Republic of Congo.
Common Names
Vernonia calvoana (Hook.f.) Hook.f. var. mokaensis (Mildbr. & Mattf.) C.Jeffrey is known by several common names. In Cameroon, it is commonly known as Mokabi or Mokabi-mokolo, while in Gabon, it is called Ekwala or Tchibanga. In Congo and the Democratic Republic of Congo, it is known as Kalalou or Kandzedi.
Uses
The leaves, stems and roots of Vernonia calvoana (Hook.f.) Hook.f. var. mokaensis (Mildbr. & Mattf.) C.Jeffrey have a variety of uses. In traditional medicine, it is used to treat various ailments such as diarrhea, fever, malaria, and respiratory infections. Its anti-inflammatory and analgesic properties make it effective in relieving pain and inflammation.
The plant is also used in agroforestry. Its deep root system and high biomass make it an excellent soil stabilizer, preventing soil erosion. It can also be used for reforestation, as it grows quickly and easily in degraded areas. Additionally, its leaves and stems are used as livestock feed, particularly for goats and cattle.
General Appearance
Vernonia calvoana (Hook.f.) Hook.f. var. mokaensis (Mildbr. & Mattf.) C.Jeffrey is a large shrub or small tree that can grow up to 15 meters tall. Its leaves are dark green, glossy and leathery, with a length of about 10-20 cm and a width of 3-5 cm. The flowers are purple or pinkish-purple and are arranged in terminal clusters. The fruit is a small, brown, dry achene with a length of about 3-4 mm.
Light Requirements
Vernonia calvoana var. mokaensis typically grows best in areas with moderate sunlight to partial shade. Direct sunlight for prolonged periods can cause the leaves to scorch, while insufficient light may affect the plant's growth and cause it to become leggy. Therefore, it is essential to place the plant in a location where it can receive moderate sunlight or partial shade.
Temperature Requirements
This plant thrives in warm and humid conditions. The ideal temperature range for growing Vernonia calvoana var. mokaensis is between 22-28°C (71-82°F). Temperatures above or below this range may cause the plant to experience stunted growth, leaf drop, or even death. Additionally, it is important to protect the plant from frost and extreme fluctuations in temperature.
Soil Requirements
Vernonia calvoana var. mokaensis prefers well-draining soils rich in organic matter. The soil pH should be slightly acidic to neutral, with a range between 5.5 to 7.0. The plant can also be grown in sandy or loamy soil, provided that it is well-draining. Soil that is too wet can cause root rot, so it is important to ensure that the soil is well-drained. Adding compost or other organic matter to the soil can help improve soil quality and enhance the plant's growth.
Cultivation Methods
Vernonia calvoana var. mokaensis is a woody plant that can be propagated through seeds, stem cuttings or grafting. It thrives well in well-drained soil with a pH range of 5.5-6.5 and prefers a sunny location. The plant needs adequate spacing to facilitate proper growth and prevent overcrowding. Regular weeding, mulching and application of organic matter is necessary to support optimal growth.
Watering Needs
Vernonia calvoana var. mokaensis requires moderate watering, and its watering schedule will depend on the prevailing climatic conditions. It is drought tolerant and can survive in periods of low rainfall. However, for optimal growth and development, regular watering is crucial, especially during the flowering period and fruit development phase.
Fertilization
The plant needs regular fertilization to enhance growth, yield and overall health. Organic fertilizers such as compost, well-rotted animal manure, and bone meal are preferred. Application of chemical fertilizers should be done sparingly as they have a negative impact on soil health. Fertilization should be done during the growing season, and the recommended dose should be based on soil fertility tests.
Pruning
Pruning is essential to control the plant's shape, stimulate growth and enhance the overall aesthetics. Pruning should be done early in the growing season to encourage new growth. The plant can be trained to achieve different shapes such as a single stem, a bush or hedge. Dead or diseased branches should be removed to prevent the spread of diseases. Pruning should be done using sterilized tools to prevent the spread of plant diseases.
Propagation of Vernonia Calvoana var. Mokaensis
Vernonia Calvoana var. Mokaensis can be propagated through various methods including:
Seed Propagation
Seeds can be collected from the plant once they are fully matured which typically happens in the fall. Once the seeds are collected, they can be planted directly into a seedbed or container with adequate soil mix and moisture levels. The seeds can take up to three weeks to germinate and will need to be monitored and cared for until they are large enough to be transplanted. It is important to note that this method can result in genetic variation of the plant.
Cuttings Propagation
Cuttings can be taken from the plant during the growing season. The cuttings should be semi-hardwood, around 10-15cm in length, and taken from healthy and disease-free plants. Once the cuttings are taken, remove the leaves from the lower two-thirds of the stem and dip the end in rooting hormone. Place the cutting in a well-aerated rooting medium, mist with water, and cover with a plastic dome to retain moisture. The cutting should be kept in an area with bright, indirect sunlight and the rooting medium should be kept moist. The cuttings should begin to root within 4-6 weeks.
Division Propagation
Vernonia Calvoana var. Mokaensis can be divided during the growing season. This method is best performed on older plants that have developed multiple shoots and a strong root system. Carefully dig up the plant and use a clean and sharp knife to divide the plant into sections, ensuring that each section has viable roots and shoots. Plant each divided section in a new container or area in the garden with adequate soil mix, and water well.
Disease and Pest Management for Vernonia calvoana var. mokaensis
Vernonia calvoana var. mokaensis is prone to several diseases and pests that could affect its growth and yield. Here are some of the common ones and how to manage them:
Diseases
Leaf spot: This is a fungal disease that affects the leaves, causing circular or irregular spots of different colors, mostly brown or gray. To manage this disease, remove the infected leaves and destroy them or use fungicides. Make sure to water the plant at the base and avoid wetting the foliage.
Root rot: Root rot is caused by fungi in the soil. It affects the roots, causing discoloration, rotting or decay, and stunted growth. To prevent root rot, avoid overwatering the plant and ensure good drainage. If the plant is infected, remove it and replant in a new location with fresh soil. Use fungicides to treat the soil.
Bacterial wilt: This is a bacterial disease that affects the stem, causing wilting, yellowing, and eventually death. There is no known cure for bacterial wilt, so prevention is the key. Plant resistant cultivars, rotate crops, and use disease-free planting materials. Remove and destroy infected plants and avoid working in the garden when it is wet.
Pests
Mealybugs: These are small white insects that gather in clusters on the foliage, causing yellowing and stunted growth. To manage mealybugs, use insecticidal soap or neem oil or wipe them off with a cotton swab dipped in alcohol.
Aphids: Aphids are small insects that suck sap from the leaves, causing distortion and yellowing. To manage aphids, use insecticidal soap or neem oil or spray them with a strong jet of water.
Caterpillars: Caterpillars are the larvae of moths and butterflies. They eat the leaves, causing large holes and defoliation. To manage caterpillars, remove them by hand or use Bacillus thuringiensis (Bt) insecticide.
By following these disease and pest management practices, you can ensure the healthy growth and yield of your Vernonia calvoana var. mokaensis plant.
