Overview of Striga hermonthica (Delile) Benth. subsp. senegalensis (Benth.) Maire
Striga hermonthica (Delile) Benth. subsp. senegalensis (Benth.) Maire is a parasitic plant found in Sub-Saharan Africa. It is commonly known as purple witchweed, witchweed, or purple Striga. The plant has a negative impact on cereal production in the region, making it a major agricultural concern for farmers.
Appearance of Striga hermonthica (Delile) Benth. subsp. senegalensis (Benth.) Maire
The plant has an underground network of roots that attach to the roots of host plants like cereals and grasses. Above the ground, Striga hermonthica (Delile) Benth. subsp. senegalensis (Benth.) Maire is composed of tall, slender stems that can range from 20 to 100 cm in height. The leaves are small and scale-like, while the flowers are small and purplish-pink in color.
Uses of Striga hermonthica (Delile) Benth. subsp. senegalensis (Benth.) Maire
Striga hermonthica (Delile) Benth. subsp. senegalensis (Benth.) Maire is not used for medicinal or culinary purposes due to its parasitic nature. However, researchers are studying the plant to find ways to mitigate its negative effects on cereal production in Sub-Saharan Africa.
Despite its status as a parasitic plant, Striga hermonthica (Delile) Benth. subsp. senegalensis (Benth.) Maire has cultural significance in some African countries. In parts of Mozambique, the plant is used in spiritual practices and considered to have protective powers.
Growth Conditions for Striga hermonthica (Delile) Benth. subsp. senegalensis (Benth.) Maire
Light: Striga hermonthica subsp. senegalensis requires full sun exposure for optimal growth. It is adapted to grow in areas with high levels of solar radiation.
Temperature: This plant thrives in warm temperatures and cannot tolerate frost or extreme cold. The ideal temperature range for growth is between 20 and 35 °C, but it can survive occasional spikes of up to 40°C if there is enough moisture in the soil.
Soil Requirements: Striga hermonthica subsp. senegalensis is adaptable to a range of soil types, but it prefers well-drained sandy or loamy soil with a slightly acidic to neutral pH ranging from 5.5-7.0. It grows best in soils with high organic matter content and good levels of nitrogen and phosphorous.
The seeds of Striga hermonthica subsp. senegalensis germinate in response to the presence of host plants such as sorghum, millet, and maize. The condition is known as striga "witchweed" parasitism. After germination, the plant invades the host roots and siphons off nutrients and water, leading to stunted growth and yield loss.
Crop rotation with non-host plants is an effective way to control the spread of Striga hermonthica subsp. senegalensis. Farmers can also use post-emergence herbicides such as Imazapyr and Glyphosate to control the parasitic plant's growth.
Cultivation of Striga hermonthica (Delile) Benth. subsp. senegalensis (Benth.) Maire
Striga hermonthica (Delile) Benth. subsp. senegalensis (Benth.) Maire is a parasitic plant that cannot survive without a host plant. Therefore, its cultivation involves planting a suitable host plant. It can grow on a variety of crops such as maize, sorghum, millet, rice, and sugarcane.
When planting, ensure that the host plant is healthy and has no signs of disease or pests as Striga hermonthica can quickly spread to other nearby plants. Additionally, it is essential to plant the host crop early in the season to avoid severe infestation by Striga hermonthica.
Watering Needs of Striga hermonthica (Delile) Benth. subsp. senegalensis (Benth.) Maire
This parasitic plant has no root system and cannot absorb water and nutrients from the soil. Instead, it attaches itself to the roots of its host plant and relies on it for water and nutrients. Therefore, watering Striga hermonthica is unnecessary as it feeds on the host plant.
Fertilization of Striga hermonthica (Delile) Benth. subsp. senegalensis (Benth.) Maire
As a parasitic plant, Striga hermonthica feeds on the nutrients provided by the host plant. Therefore, it does not require any additional fertilization. However, ensuring that the host plant has sufficient nutrients is essential in preventing the spread of Striga hermonthica. Test the soil to determine the type of fertilizer the host plant needs and apply it as required.
Pruning Striga hermonthica (Delile) Benth. subsp. senegalensis (Benth.) Maire
Pruning Striga hermonthica is not necessary as it is a parasitic plant that does not produce any leaves or branches. Instead, it attaches itself to the roots of the host plant and absorbs nutrients from it. However, it is essential to uproot and destroy any infected host plants to prevent the spread of the parasitic plant.
Propagation of Striga hermonthica subsp. senegalensis
Striga hermonthica subsp. senegalensis can be propagated both sexually and asexually. The most common propagation method is through the use of seed, but vegetative propagation can also be used.
Sexual Propagation
Seeds of Striga hermonthica subsp. senegalensis can be collected from mature plants and stored until ready for planting. They should be stored in a cool, dry place until the planting season. When planting, the seeds should be sown at a depth of 1 to 2 cm in well-draining soil. After sowing, the soil should be kept moist until germination occurs, which usually takes between 2 to 3 weeks.
Asexual Propagation
Striga hermonthica subsp. senegalensis can also be propagated vegetatively, although this method is less common. In this method, stem cuttings can be taken from mature plants and rooted in a well-draining soil. The cuttings should be approximately 10 cm long, and taken from the upper part of the stem. The leaves on the lower half of the cutting should be removed, and the cutting should be planted in a rooting hormone to encourage root growth. The rooted cuttings can then be transplanted to their final growing location.
Disease Management:
Striga hermonthica subsp. senegalensis is generally considered to be a hardy plant that can withstand a range of environmental stresses. However, there are several diseases that can affect the plant, including:
- Root Rot: This disease is caused by several fungi and occurs when the soil is too wet. To manage it, avoid overwatering the plant and ensure proper drainage.
- Leaf Spots: These are caused by various fungi and can lead to defoliation. Infected leaves should be removed and destroyed to prevent the spread of the disease.
- Powdery Mildew: This fungal disease appears as a white powdery substance on the leaves, stems, and flowers of the plant. To manage it, ensure adequate air circulation around the plant and apply a fungicide as needed.
Pest Management:
While Striga hermonthica subsp. senegalensis is largely considered resistant to pests, there are a few potential culprits to watch out for:
- Aphids: These small insects suck sap from the leaves and stems of the plant, causing distortion and yellowing. To manage them, remove infected portions of the plant and apply a horticultural oil or insecticidal soap.
- Caterpillars: These pests can devour the leaves of the plant, leading to defoliation. To manage them, manually remove as many caterpillars as possible and apply a biological or chemical insecticide if necessary.
- Spider Mites: These tiny pests feed on the plant's sap, causing yellowing and bronzing of the leaves. To manage them, regularly hose down the plant with water and apply a miticide as needed.
