Origin
Guizotia scabra (Vis.) Chiov. subsp. schimperi (Sch.Bip.) J.Baagoe, commonly known as Ethiopian Niger, is a flowering plant native to Africa. It is widely distributed in the tropical and subtropical regions of eastern and southern Africa, including Ethiopia, Kenya, Tanzania, Uganda, and Zambia.
Common Names
The plant has several common names such as Niger Seed, birdseed, Guizotia abyssinica, Ramtil, and Africa tea bush. In eastern Africa, it is known as “Mawingu” among the Kamba people, and “Katsar” in Ethiopia.
Uses
The Guizotia scabra plant has many uses. It is a source of edible oil, which is used for cooking, lamp lighting, and soap production. Niger seeds are also used for medicinal purposes - they have been traditionally used in the treatment of diabetes, atherosclerosis, and high blood pressure. The seeds are also used as birdseed, in the cosmetic industry, and in the manufacture of paints, varnishes, and resins. Moreover, the leaves of the plant can be powdered and used as a substitute for tea.
General Appearance
The Guizotia scabra plant is an annual herb that can grow up to 1.5 meters in height. It has a single stem that is usually covered in fine hairs. The leaves of the plant are alternate, simple, and serrated, with a dull green color. The flowers are yellow or orange in color and are arranged in small, compact inflorescences. The fruits are achenes that usually measure about 2.5 mm long and 1.5 mm wide, and they have a shiny, black color.
Light Requirements
Guizotia scabra subsp. schimperi prefers full sun exposure to grow well. This plant requires abundant bright light for photosynthesis and healthy growth, making it perfect for outdoor growth in areas with plenty of sunlight. Indoor growth is possible but requires constant and bright artificial lighting to mimic the sun's natural light.
Temperature Requirements
This plant is drought-tolerant and prefers hot temperatures to grow well. It thrives in warm weather with average daily temperatures ranging from 20 to 30 degrees Celsius. It can, however, tolerate temperatures as low as 10 degrees Celsius as long as it is winter dormant and well watered during that period. Temperatures above 35 degrees Celsius are too high for this plant to thrive and can result in wilting and even death.
Soil Requirements
Guizotia scabra subsp. schimperi prefers well-drained, sandy loam soil that has a neutral pH range of 6.5 to 7.5. The ideal soil for this plant should be rich in organic matter and nutrients. Poor drainage can lead to root rot and plant death, and heavy soils can cause poor root growth and development. This plant is moderately tolerant to salinity, making it suitable for growth in saline soil conditions.
Cultivation Methods
Guizotia scabra (Vis.) Chiov. subsp. schimperi (Sch.Bip.) J.Baagoe, commonly known as Niger, is a hardy and drought-tolerant plant species that is easy to grow. The plant prefers well-drained soil that is rich in organic matter and receives full sunlight. The seeds should be sown in rows and spaced 30-40 cm apart, with a depth of 2-3 cm. Niger plants can be grown in a variety of climates but are most commonly grown in tropical and subtropical regions.
Watering Needs
Proper watering is crucial for healthy Niger plants. The plant should be watered regularly, especially during the hot and dry summer months. Over-watering can lead to waterlogged soil and root rot, so it is important to ensure that the soil is well-drained and not too wet. As a general rule, the soil should be watered to a depth of 20-30 cm, and the frequency of watering should be adjusted according to the prevailing weather conditions.
Fertilization
Niger plants require regular fertilization to thrive. A balanced fertilizer that contains essential nutrients like nitrogen, phosphorus, and potassium should be applied to the soil during the growing season. The fertilizer should be spread evenly around the base of the plant and mixed with the soil. Compost or well-rotted manure can also be added to the soil to improve its fertility.
Pruning
Niger plants do not require extensive pruning, but occasional trimming can help to promote bushier growth and prevent the plant from becoming too leggy. The best time to prune Niger plants is after the flowering season has ended. Cut back any dead or damaged stems and remove any branches that are growing too close together. To keep the plant looking neat and tidy, any wild, straggly branches can also be cut back.
Propagation of Guizotia scabra subsp. schimperi
Guizotia scabra subsp. schimperi can be propagated by two main methods: seed propagation and vegetative propagation.
Seed Propagation
The most common method of propagating G. scabra subsp. schimperi is through seed propagation. The seeds can be either directly sown in the field or raised in a nursery before being transplanted. When sowing seeds in the field, it is recommended to do so during the rainy season to ensure adequate moisture for germination and establishment. In a nursery setup, the seeds can be sown in pots or trays filled with a suitable potting mix.
The seeds should be sown about 2 cm deep and spaced 5-10 cm apart. Germination usually occurs within 7-10 days, and the seedlings should be thinned out once they reach a height of 10-15 cm.
Vegetative Propagation
Vegetative propagation of G. scabra subsp. schimperi is not a common practice but can be used as a means of multiplying a particular selected genotype. The two methods of vegetative propagation commonly used for this purpose are stem cuttings and division of roots.
Stem cuttings should be taken from healthy, disease-free plants during the active growing season. The cuttings should be about 10-15 cm in length and have at least two nodes. The basal end of the cutting should be dipped in a rooting hormone before being planted in a suitable potting mix. Care should be taken to maintain high humidity around the cuttings until they establish roots.
Division of roots involves dividing the root system of a parent plant into smaller sections that can be replanted to form new individuals. This method is especially useful for plants that have a clumping growth habit.
Disease and Pest Management for Guizotia scabra (Vis.) Chiov. subsp. schimperi (Sch.Bip.) J.Baagoe
Like all plants, Guizotia scabra subsp. schimperi is also vulnerable to diseases and pests. Pests can cause extensive damage to the plant, while diseases can lead to reduced plant growth and yield. Hence, it is important to follow proper disease and pest management techniques to ensure healthy growth of the plant.
Common Pests
Guizotia scabra subsp. schimperi is highly susceptible to termite infestation. These pests can attack the roots of the plant, thereby hindering its growth. Additionally, aphids, whiteflies, and spider mites are also common pests that can cause damage to the plant.
Pest Management
The best way to control termite infestation is to apply a termiticide to the soil around the plant. Alternatively, one can also incorporate termiticide-treated wood shavings into the soil at the time of planting. To control aphids, whiteflies, and spider mites, one can spray neem oil or insecticidal soap on the plant. These measures will help control the pest population and prevent further damage to the plant.
Common Diseases
The most common disease that affects Guizotia scabra subsp. schimperi is leaf spot disease. This disease manifests itself as spots on the leaves of the plant and can reduce the yield significantly. In addition to leaf spot disease, powdery mildew and root rot are two other diseases that can afflict the plant.
Disease Management
To manage leaf spot disease, it is crucial to remove and destroy all infected parts of the plant. Avoid overhead irrigation, and instead, water the plant at the base to prevent water from getting splashed on the leaves. Powdery mildew can be controlled by spraying the plant with sulfur or a fungicide. To control root rot, it's essential to maintain well-drained soil and avoid overwatering the plant.
Overall, the key to ensuring a healthy plant is to implement proper disease and pest management techniques. Regular inspection of the plant and timely intervention are crucial in minimizing the damage caused by pests and diseases.
