Guizotia discoidea Sch.Bip. - Overview
Guizotia discoidea Sch.Bip. is a plant species belonging to the family Asteraceae. It is native to various parts of Africa and is commonly known as niger or ramtil. This plant is an annual crop whose seeds are high in oil content, making it a valuable oilseed crop.
Appearance
Guizotia discoidea Sch.Bip. typically grows to a height of 1-2 meters and has a branched stem. The leaves are alternate and lanceolate, with serrated edges. The plant produces small, bright yellow flowers which are arranged in heads. The fruit is a small, compressed achene that is oval in shape and measures approximately 0.5 cm in length.
Common Names
Guizotia discoidea Sch.Bip. is known by various common names, such as niger, blackseed, ramtil, and nyjer. The name niger (meaning black) is derived from the plant's characteristic dark color seeds.
Uses
The seeds of Guizotia discoidea Sch.Bip. are commonly used for oil extraction, and the oil is used for cooking and as a biofuel. The plant is also used for medicinal purposes in traditional medicine to treat various ailments, including diarrhea, fever, and respiratory infections. Additionally, the seeds are a popular source of food for birds, and are often used in bird feeders for songbirds such as finches.
In conclusion, Guizotia discoidea Sch.Bip. is a valuable plant species for its oilseed and medicinal properties. Its bright yellow flowers and dark colored seeds make it a visually stunning addition to any garden or landscape.
Light Requirements
The plant Guizotia discoidea Sch.Bip. requires full sunlight to grow and flourish. The plant should receive at least six to eight hours of sunlight per day for optimal growth. If the plant does not receive adequate sunlight, it may become leggy and weak.
Temperature Requirements
The plant Guizotia discoidea Sch.Bip. prefers a warm and mild climate. It is a tropical plant that grows best in temperatures between 20-30°C (68-86°F). Temperatures below 15°C (59°F) can harm the growth of the plant. The plant is sensitive to frost and cannot tolerate freezing temperatures.
Soil Requirements
The plant Guizotia discoidea Sch.Bip. prefers well-drained soils that are rich in organic matter. The soil should have a pH range of 6.0-7.5. The plant can tolerate a wide range of soil types, including loam, clay, and sandy soils. The plant requires regular water but cannot tolerate waterlogged or poorly-drained soils.
Cultivation method for Guizotia discoidea Sch.Bip.
Guizotia discoidea Sch.Bip., also known as niger or ramtil, is a plant grown for its oilseed, which is used in cooking and soap production. The plant is an annual and thrives in hot, dry, and semi-arid regions. The following tips will help in cultivating Guizotia discoidea Sch.Bip:
- Planting season: The best time to plant Guizotia discoidea Sch.Bip is in the rainy season when soil moisture is high.
- Soil requirements: The plant prefers well-drained, sandy, or loamy soils with a pH range of 6.5 to 7.5.
- Spacing: Plant Guizotia discoidea Sch.Bip 20 to 30cm apart to allow for proper growth and airflow.
- Seed treatment: Before planting, treat the seeds with fungicides to protect them from soil-borne diseases.
- Sowing method: The seeds can be sown by broadcasting or drilling at a depth of 1.0 to 1.5cm.
Watering needs for Guizotia discoidea Sch.Bip.
Water is vital in the growth of Guizotia discoidea Sch.Bip. The following tips will help in watering the plant:
- Irrigation: The plant requires moderate irrigation of about 400 to 500mm of water during the growing period. Over-irrigation may lead to waterlogging and root rot.
- Rainfall: Guizotia discoidea Sch.Bip. can tolerate low rainfall ranging from 400 to 600mm but thrives in areas with higher rainfall.
- Watering schedule: Water the plant twice a week during the dry season and once a week in areas with high rainfall.
Fertilization of Guizotia discoidea Sch.Bip.
Fertilization is crucial in promoting the growth and productivity of Guizotia discoidea Sch.Bip. Here are some tips:
- Soil testing: Test the soil to determine the nutrient levels and pH and adjust accordingly.
- Nutrient requirement: The plant requires a balanced application of NPK fertilizer at a ratio of 50:60:50kg/ha or 20:50:20kg/ha of diammonium phosphate (DAP) at planting.
- Application: Apply the fertilizer at planting and incorporate in the soil to prevent surface runoff during irrigation.
Pruning Guizotia discoidea Sch.Bip.
Pruning is not necessary for Guizotia discoidea Sch.Bip. unless the plant becomes too bushy, which may limit airflow and sunlight penetration, leading to reduced yields.
- Reasons for pruning: Prune to reduce the bushy nature of the plant and promote branching.
- Pruning time: Prune the plant four to six weeks after planting.
- Tools used: Use sharp pruning shears to make quick and clean cuts.
Propagation of Guizotia discoidea Sch.Bip.
Guizotia discoidea Sch.Bip. is propagated by two primary methods: seed propagation and vegetative propagation.
Seed Propagation
Seed propagation is the most common method of propagation in Guizotia discoidea Sch.Bip. The seeds are collected from the mature plants once the flower heads are dry. The collected seeds are then cleaned, treated with fungicide and stored in a cool and dry place for future use. The seeds are sown in the early spring season in well-prepared beds with fine soil. The seeds are sown 5 to 10 cm apart and 1 to 2 cm deep in the soil. The seeds are then covered with soil and watered immediately. The germination usually starts within 3 to 5 days, and the seedlings appear within one week of sowing. The seedlings are thinned to a distance of 20 to 30 cm apart, depending on the variety and soil fertility.
Vegetative Propagation
Vegetative propagation is the second method of propagation commonly used in Guizotia discoidea Sch.Bip. The plant can be propagated by stem cuttings or root cuttings. The cuttings are taken from mature plants during the growing season. The cuttings should be 6 to 8 cm long, each having two leaves, and treated with rooting hormone. The cuttings are then planted in the well-prepared soil in a nursery bed. They should be watered regularly to maintain the moisture content in the soil. The cuttings usually take 3 to 4 weeks to develop roots. Once the roots are developed, they can be transplanted into the main field.
Disease and pest management for Guizotia discoidea Sch.Bip.
Guizotia discoidea Sch.Bip., commonly known as niger, is a hardy plant that is relatively resistant to most pests and diseases. However, some pests and diseases can still attack the plant and reduce its yield. Here are some common pests and diseases that are known to affect Guizotia discoidea Sch.Bip. and the methods that can be used to manage them:
Diseases
Anthracnose: This is a fungal disease that can affect the stems, leaves, and seeds of the Guizotia discoidea Sch.Bip. plant. It is characterized by the appearance of dark brown or black splotches or lesions on the affected parts. The disease can be controlled by using fungicides, pruning and destroying the infected parts of the plant, and ensuring proper plant hygiene.
Leaf spot: This is another fungal disease that affects the leaves of Guizotia discoidea Sch.Bip. The disease is characterized by the appearance of small, brownish-grey circular spots on the leaves. The spots may coalesce and form larger patches that can cause the leaves to wither and die. The disease can be controlled by using fungicides, ensuring proper plant hygiene, and avoiding overcrowding of plants to enhance adequate air circulation.
Pests
Aphids: These are tiny, sap-sucking insects that commonly attack Guizotia discoidea Sch.Bip. plants. The insects cause stunted growth, yellowing of leaves, and distorted flowers. The pest can be controlled by using insecticides, introducing beneficial insects such as ladybugs, and ensuring that the plants are grown in favorable conditions.
Cutworms: These are the larvae of nocturnal moths that feed on the leaves and stems of Guizotia discoidea Sch.Bip. plants. The insects can cause defoliation and hamper plant growth. The pest can be controlled by handpicking the insects, using insecticides, and practicing crop rotation.
Whiteflies: These are tiny, winged insects that commonly infest Guizotia discoidea Sch.Bip. plants. The insects feed on the sap of the plant, causing yellowing of leaves, stunted growth, and the development of mold on the leaves. The pest can be controlled by using insecticides, introducing beneficial insects such as ladybugs, and ensuring that the plants are grown in favorable conditions.
While Guizotia discoidea Sch.Bip. is relatively resistant to most pests and diseases, it is essential to regularly monitor the plants for any signs of infestation or disease. Early detection can help prevent the spread of pests and diseases and minimize damage to the crop. Adopting good agricultural practices such as proper fertilization, watering, and crop rotation can also help promote the growth of healthy plants that are more resistant to pests and diseases.
