Guizotia ringoetii De Wild.
Guizotia ringoetii De Wild. is a plant species in the family Asteraceae. This species is commonly known as the black seed or Njugu Mawe in Swahili. The plant is native to Africa and is historically an important crop in Ethiopia, Nigeria, Sudan and other African countries.
Appearance
The Guizotia ringoetii De Wild. plant is an annual herb which grows up to a height of 1-2 meters. The plant has a long taproot and stems that are erect, branching and hairy. The leaves are alternate, sessile or petiolate, and are ovate to lanceolate in shape, with a serrated margin. The flowers of the plant are yellow and grow in clusters at the top of the branches. The fruit is a small, blackish, achene.
Uses
The Guizotia ringoetii De Wild. plant is grown for its oil-rich seeds, which are used for food and non-food purposes. The seeds contain high levels of oil, which is rich in polyunsaturated fatty acids and has a good balance of omega-3 and omega-6 fatty acids. The oil is used for cooking, in cosmetics, and in the production of soap and biodiesel. The plant also has medicinal properties and is used to treat various ailments such as diarrhea, fever, and skin infections.
The plant is also an important source of forage for livestock, as it produces a high-quality feed that is rich in protein and minerals. The leaves and stems of the plant are used as animal feed, while the seed cake left over from oil extraction is used as a fertilizer or feed.
In addition, the plant is used for soil conservation and as an intercrop in agroforestry systems. Its deep root system helps to improve soil structure and water retention, and its ability to tolerate drought makes it a valuable crop in areas with limited rainfall.
In conclusion, Guizotia ringoetii De Wild. is a plant with diverse uses and benefits. Its oil-rich seeds, medicinal properties, and value as animal feed and soil conservation crop make it an important crop in many African countries.
Growth Conditions for Guizotia ringoetii De Wild.
Light: Guizotia ringoetii De Wild. requires full sun exposure for optimal growth and development. It cannot tolerate shade and requires a minimum of 6-8 hours of direct sunlight daily.
Temperature: This plant is adapted to warm temperatures and cannot tolerate frost. It grows best in temperatures between 20-30°C ( 68-86°F) during the day and 15-20°C (59-68°F) at night. Temperatures below 10°C (50°F) or above 40°C (104°F) can negatively affect the growth and yield of the plant.
Soil: Guizotia ringoetii De Wild. prefers well-drained soils with a pH range of 6.0-7.5. The plant can withstand moderately saline soils but does not grow well in waterlogged or poorly drained soils. The soil should be rich in organic matter and nutrient content for optimal growth, and regular fertilization is necessary.
Cultivation of Guizotia ringoetii De Wild.
Before cultivating Guizotia ringoetii De Wild., ensure that the soil is well-drained and fertile. The plant prefers full sun but can tolerate partial shade. It thrives in warm tropical to subtropical regions and does not tolerate frost.
Prepare the land by cultivating to a reasonable depth and removing any weeds. Sow the seeds directly into the soil, preferably at the onset of the rainy season. Planting depth should be approximately one inch, and the spacing should be at least six inches apart. Cover the seeds with soil and water sufficiently to keep it moist until germination.
Watering Needs
Guizotia ringoetii De Wild. requires moderate watering. Irrigate the plants at least once a week during dry weather conditions to maintain optimal growth. However, ensure that the soil does not become waterlogged as it can lead to root rot, which may eventually kill the plant. During the rainy season, reduce watering frequency, as rainfall can be sufficient to meet the plant’s water needs.
Fertilization
Guizotia ringoetii De Wild. benefits from regular fertilization to promote maximum yield. Apply fertilizer when planting to ensure that the plant has sufficient nutrients to establish itself. Thereafter, apply nitrogenous fertilizer once every four weeks to ensure continuous growth. Additionally, apply a balanced slow-release fertilizer during the active growth stage to guarantee that the plant has the necessary nutrients to produce healthy shoots.
Pruning Guidelines
Pruning Guizotia ringoetii De Wild. is not a mandatory practice. However, pruning can facilitate better growth and higher yield by removing damaged leaves and branches, allowing sufficient sunlight, and ensuring aeration. Perform pruning during the first six months of growth, preferably every two weeks, to promote bushy growth. Cut off any diseased or affected areas to prevent the spread of diseases to the healthy parts.
Propagation of Guizotia ringoetii De Wild.
Guizotia ringoetii De Wild., also known as the Ethiopian Niger or Ramtil, is a flowering plant commonly grown for its oil-rich seeds that are used in cooking and bird feed production.
The following are the propagation methods of Guizotia ringoetii De Wild.:
seeding
Guizotia ringoetii De Wild. can be propagated through seed sowing. The seeds are sown in seedbeds filled with well-drained soil during the rainy season. The seeds should be placed 1-2 cm deep in the soil at a spacing of 10-15 cm between rows.
The seeds take about 7-10 days to germinate, after which they can be transplanted to their permanent location. Guizotia ringoetii De Wild. seeds can also be directly sown in the field at a spacing of 20-30 cm between rows.
vegetative propagation
Guizotia ringoetii De Wild. can also be propagated vegetatively through stem cuttings. The stem cuttings are taken from healthy and mature plants during the rainy season when the plant is actively growing.
The cuttings should be about 10-15 cm long and should have 2-3 leaves. The cuttings are then planted in well-prepared soil in a greenhouse or shade house until they establish roots. The rooted cuttings are then transplanted into the field.
division
Guizotia ringoetii De Wild. can also be propagated through division. The plant is dug up, and the older outer parts are carefully separated into smaller plants with their own root systems.
The smaller plants can then be transplanted in well-prepared soil in the field during the rainy season. This method should be done during the cool months to prevent the newly transplanted plants from drying out.
Overall, Guizotia ringoetii De Wild. can be propagated through seed sowing, stem cuttings, and division. These propagation methods can help farmers and gardeners increase their yield and ensure the genetic characteristics of the plant are preserved.
Disease Management for Guizotia Ringoetii De Wild.
Several diseases can affect Guizotia Ringoetii De Wild., including:
- Leaf spot disease: This disease is caused by the fungi Alternaria and Cercospora. Symptoms include dark brown or black spots on leaves, which may enlarge and coalesce, leading to defoliation. The management of this disease involves the use of fungicides that contain Copper or Chlorothalonil. Also, practicing crop rotation can help control the spread of the disease.
- Powdery mildew: A fungal disease that appears as white powdery growth on the leaf surface. In severe cases, it can cause defoliation, and yield losses. To control powdery mildew, you can use a combination of cultural practices and fungicides, including sulfur and potassium bicarbonate. Early detection and regular field monitoring are also essential to manage the spread of the disease.
- Root and stem rot: Resulting from different soil-borne fungi such as Rhizoctonia, Pythium, and Fusarium, this disease can cause sudden wilting and death of the plant. Prevention measures include planting disease-free seeds and avoiding low-lying, poorly drained areas with a history of the disease. Management also includes the use of biofungicides and fungicides that contain metalaxyl or thiophanate methyl.
Pest Management for Guizotia Ringoetii De Wild.
Several pests that attack Guizotia Ringoetii De Wild. include:
- Flea beetle: Small beetles that jump when disturbed. They cause feeding injury to young plants, and severe infestation can lead to stunted growth and yield loss. Row covers and insecticides such as neem oil, pyrethrin, and spinosad can be used to control flea beetles.
- Aphids: Small sap-sucking insects that colonize leaves and stems leading to leaf curl, stunted growth, and reduced yield. They can be controlled with insecticidal soaps and horticultural oils, or by introducing natural predators such as ladybird beetles and lacewings into the field.
- Cutworms: Larvae of various moth species that cut through the stem at the soil level, causing plants to wilt and die. Control measures include the use of sex pheromone traps, crop rotation, the use of resistant varieties, and the application of Bacillus thuringiensis (Bt).
