Overview
Guizotia scabra (Vis.) Chiov. var. sotikensis (S.Moore) Robyns is a plant species in the Asteraceae family. This plant is commonly known as the Kenyan black seed or simply, black seed. It is an annual flowering plant native to tropical and subtropical regions of Africa and is widely cultivated for its high-quality oil-rich seeds.
Appearance
The Guizotia scabra var. sotikensis usually grows up to a height of 1-2 meters, with yellow flowers that sprout in clusters at the top of the stem. Its leaves are dark green and have small serrations on the edges. The plant's fruit is a small black seed that is compressed and elongated, measuring about 2-3 mm in length.
Uses
The main use of Guizotia scabra var. sotikensis is for its oil-rich seeds. The seeds are rich in essential fatty acids, protein, and minerals, making them valuable in the production of cooking oil, animal feed, and health supplements. The oil from the seeds is also used in the production of soap, cosmetics, and lubricants.
Moreover, the seeds are used in traditional medicine to cure ailments such as asthma, respiratory problems, and parasitic infections. The leaves of the plant also have medicinal uses for treating gastrointestinal ailments, fever, and headaches.
The plant is also used as an ornamental plant in gardens and parks due to its attractive flowers and foliage.
Conclusion
The Guizotia scabra var. sotikensis is a valuable plant with various uses ranging from oil extraction to medicinal purposes. The plant's striking appearance makes it a great choice for ornamental gardening. Its popularity in Africa and global cultivation is a testament to its vast utility.
Light Requirements:
Guizotia scabra var. sotikensis requires full sun to grow. It can adapt to partial shade but it may cause decreased flowering and fruit production, as well as thin and weak stems.
Temperature Requirements:
This plant species thrives in warm weather conditions. The ideal temperature range for Guizotia scabra var. sotikensis to grow is between 20°C to 25°C. Temperatures above 35°C or below 10°C can affect its growth and development.
Soil Requirements:
Guizotia scabra var. sotikensis prefers well-draining soils that are rich in organic matter. The soil pH range should be between 5.5 to 7.5. It can tolerate low soil fertility and the soil texture can range from sandy to clayey. However, it cannot tolerate waterlogging or poorly drained soils.
Cultivation Methods
Guizotia scabra (Vis.) Chiov. var. sotikensis (S.Moore) Robyns is a relatively easy plant to cultivate. It thrives in well-draining soil with a pH of 6.0-7.5 and requires full sun exposure. The ideal temperature range for its growth is between 12°C and 27°C. The plant is propagated through seeds, and it takes about four months from germination to maturity.
Watering Needs
The plant requires regular watering, especially during its growth stage. However, it can also tolerate moderate drought conditions. Over watering can lead to root rot, so it is best to maintain soil moisture at a consistent level and not let it become water-logged.
Fertilization
Guizotia scabra (Vis.) Chiov. var. sotikensis (S.Moore) Robyns plants respond well to balanced fertilizers such as a 10-10-10 or 20-20-20 blend. Apply fertilizer during the vegetative stages, and reduce or withhold it during the flowering phase. Over-fertilization can lead to excess foliage growth and fewer flowers.
Pruning
The plant requires minimal pruning, mainly to control its shape or size. Prune away any dead or damaged stems and leaves. If the plant appears leggy, pinch back its tips to encourage bushier growth, which results in more flowers. Regularly removing spent flowers can also extend the blooming period.
Propagation of Guizotia Scabra Var. Sotikensis
Guizotia scabra (Vis.) Chiov. var. sotikensis (S.Moore) Robyns, commonly known as Kenyan black oilseed, belongs to the Asteraceae (sunflower) family and is indigenous to Kenya. This plant is an annual herbaceous plant that grows up to 1.5 meters in height. The plant has short internodes, long leaves, and yellow flowers that sport a dark center.
Propagation Methods
The propagation of Guizotia scabra var. sotikensis can be done in several methods. The following are the primary propagation methods:
- Seeds: The easiest and primary method of propagation for Guizotia scabra var. sotikensis is through seeds. Harvested seeds can be directly sown into the soil or raised in a greenhouse. It is advisable to sow seeds after the last frost has passed.
- Cuttings: Guizotia scabra var. sotikensis can be propagated via stem cuttings. Stem cuttings are taken from healthy stems with no flowers or buds. The cuttings are then transplanted into pots and placed in a greenhouse until roots have formed.
- Division: Guizotia scabra var. sotikensis can also be propagated via division. This method involves separating clumps of the plant's root systems and replanting them in pots. The divided portion must have at least three stems and require greenhouse conditions until the roots form.
These are the primary means of propagating Guizotia scabra var. sotikensis. Proper handling of the plant and ensuring ideal growing conditions is necessary to increase the success rate of propagation.
Disease Management
Guizotia scabra var. sotikensis is susceptible to various diseases that can severely impact its growth and yield. Below are some of the common diseases that affect this plant and ways to manage them:
Downy Mildew
Downy mildew is a fungal disease that affects the leaves of Guizotia scabra var. sotikensis. Symptoms include yellowish spots on the upper surface of leaves, along with a greyish-white growth on the underside. The leaves may also curl and curl up.
To manage downy mildew, it is important to maintain good air circulation around the plants and to avoid overhead watering. Fungicides such as copper-based products can also be used, but they should be applied before the disease becomes too severe.
Rust
Rust is a fungal disease that causes small yellowish-orange or reddish-brown spots on the leaves of Guizotia scabra var. sotikensis. Severe infections can cause defoliation and decrease yield.
To manage rust, remove infected leaves and dispose of them properly. Fungicides may also be used, but as with downy mildew, they should be applied preventatively.
Pest Management
Guizotia scabra var. sotikensis can also be affected by various pests that can damage the plant and reduce yield. Below are some of the common pests that affect this plant and ways to manage them:
Aphids
Aphids are small, soft-bodied insects that feed on the sap of the plant. They can cause yellowing and deformation of leaves, and can transmit plant viruses.
To manage aphids, it is important to remove weeds around the plants that may harbor them. Beneficial insects such as ladybugs can also be introduced, as they feed on aphids. Insecticidal soaps and oils may also be effective.
Cutworms
Cutworms are the larvae of various species of nocturnal moths. They can cut through the stems of young Guizotia scabra var. sotikensis plants, causing them to topple over.
To manage cutworms, it is important to keep the area around the plants free of weeds and debris, which can provide hiding places for them. Physical barriers such as collars made of cardboard or plastic can also be placed around the stems of young plants to prevent cutworms from reaching them.
