Overview
Sorghum bicolor var. drummondii, also known as broomcorn or broom sorghum, is a tall grass species that belongs to the family Poaceae. It is native to Africa but has been introduced and cultivated all over the world. This plant is mainly grown for its fibrous seed heads, which are used to make brooms and brushes. However, it also has some medicinal and cultural uses.
Appearance
Broomcorn is an annual plant that can grow up to 3 meters tall. It has broad leaves that are arranged alternately along the stem. The seed heads are large and dense, consisting of numerous branches with small seeds attached. The branches of the seed head are sturdy and straight, making them ideal for brooms and brushes.
Common Names
Broomcorn is known by different common names in different regions. In some parts of the world, it is called great millet, Guinea corn, or durra. In other places, it is referred to as broom sorghum, broomcorn sorghum, broom-corn, sorgho d'alep, or milho vassoura.
Uses
The primary use of broomcorn is the production of brooms and brushes. The straight and sturdy branches of the seed heads are ideal for making sweeping and cleaning tools. The leaves of the plant are also used in some cultures as fodder for livestock. Additionally, broomcorn has some medicinal properties and is sometimes used to treat conditions such as diarrhea, digestive problems, and respiratory ailments.
Light Requirements
Sorghum bicolor var. drummondii requires full sun exposure for optimal growth and development. It cannot tolerate shade or partial shade conditions. Therefore, it is highly recommended to plant it in an area that receives direct sunlight for at least 6-8 hours per day.
Temperature Requirements
This plant is primarily grown in warm climates and requires a temperature range of 20-35°C (68-95°F) for optimal growth. It can tolerate high temperatures, but extremely low temperatures can slow down its growth and development. It is important to note that Sorghum bicolor var. drummondii is extremely sensitive to frost and cannot survive in colder regions.
Soil Requirements
Sorghum bicolor var. drummondii can grow in a wide range of soil types, but it prefers well-drained soils with moderate fertility. It requires a soil pH range of 6.0-7.5. This plant can tolerate drought conditions to some extent, but it cannot survive in waterlogged soils. It is recommended to add organic matter to the soil before planting and to maintain good soil moisture throughout the growing season.
Cultivation Methods
Sorghum bicolor var. drummondii is a warm-season crop and grows best in areas with temperatures ranging from 25°C to 35°C. The plant prefers well-drained soils and requires full sun exposure to thrive. The cultivation of Sorghum bicolor var. drummondii involves preparing the soil by plowing, harrowing, and levelling.
After soil preparation, the seeds can be planted at a depth of 2 to 5 cm and a spacing of 25 to 30 cm between rows and between 5 to 10 cm between each plant. The best time to plant Sorghum bicolor is during the rainy season, as the plant requires proper moisture to germinate and grow vigorously.
Watering Needs
Sorghum bicolor var. drummondii requires consistent watering, especially during hot and dry periods. The plant should be watered immediately after planting, and subsequent watering should be done every 3 to 4 days. The plant needs an average of 600mm to 800mm of water per hectare to produce a healthy crop.
Over-watering should be avoided, as it may lead to waterlogging, which may cause root rot and the eventual death of the plant. Proper drainage channels should be installed in the field to prevent waterlogging.
Fertilization
Sorghum bicolor var. drummondii requires adequate nutrients to produce a healthy crop. The plant's fertilization needs will depend on the soil type, the amount of rainfall, and the type of planting fertilizer used.
Farmers can use organic manure or inorganic fertilizers during the soil preparation stage to enrich the soil with essential nutrients like nitrogen, phosphorus, and potassium. Nitrogen is particularly important during the vegetative growth stage as it promotes leaf and stem growth. After the flowering stage, farmers can use more potassium-rich fertilizers to promote seed development.
Pruning
Pruning Sorghum bicolor var. drummondii is not necessary, as it has limited branching. Nevertheless, if pruning is necessary, it should be done during the early growth stage and may involve removing weak stems or dead buds from the plant.
Pruning can also be done after harvesting to remove the leftover plant materials, which may decompose, providing nutrients for future crops.
Propagation of Sorghum bicolor var. drummondii
Sorghum bicolor var. drummondii, commonly known as Drummond's or Kafir sorghum, is a drought-tolerant, warm-season grass that is widely cultivated for its grain. Propagation of this plant can be done through various methods which are discussed below:
Seed Propagation
One of the most common methods of propagating Sorghum bicolor var. drummondii is through seeds. The seeds should be collected from healthy parent plants that produce good yields. The seeds must be cleaned, dried, and treated with fungicides before planting. Plant the seeds in well-prepared soil at a depth of about 1 inch and water them regularly. Germination usually occurs within 7 to 14 days. The seedlings should be thinned to allow sufficient space for growth.
Stem Cuttings
Sorghum bicolor var. drummondii can also be propagated through stem cuttings. This method is particularly useful when the parent plant has desirable traits that need to be preserved. Collect stem cuttings from healthy, disease-free parent plants. The cuttings should be about 6 inches long and should have at least two nodes. Remove the leaves from the lower half of the stem and plant the cutting in well-prepared soil. Water the cutting regularly and keep it in a warm, humid place until roots form.
Division
Division is another propagation method that can also be used for Sorghum bicolor var. drummondii. This method is particularly useful for mature plants that have produced multiple shoots. Dig up the parent plant and gently separate the root ball into several sections. Each division should have a shoot and a healthy root system. Transplant the divisions into well-prepared soil and water them regularly until they become established.
Disease Management
Sorghum bicolor var. drummondii is susceptible to a variety of crop diseases. Some common diseases that can affect the plant are anthracnose, head smut, rust, and leaf blight.
Anthracnose is a fungal disease that affects the leaves, stems, and pods of the plant. Symptoms include small, oval-shaped lesions that eventually turn dark brown or black with time. To manage anthracnose, farmers should avoid planting infected seeds, maintain healthy soil, and practice crop rotation.
Head smut is another fungal disease that affects the inflorescence of Sorghum bicolor var. drummondii. Infected plants produce distorted heads that contain black powdery spores. To manage head smut, farmers should avoid planting infected seeds and practice crop rotation. Additionally, fungicides can be applied to affected plants.
Rust is a fungal disease that affects the leaves and stems of the plant. Symptoms include small, yellow or brown lesions on the leaves that turn reddish-brown with time. To manage rust, farmers should maintain a healthy garden by avoiding overcrowding and applying fungicides when needed. Additionally, farmers can remove and destroy infected plants.
Leaf blight is a fungal disease that affects the leaves of the plant. Symptoms include irregularly shaped, tan or brown lesions that have a yellow halo. To manage leaf blight, farmers should avoid planting infected seeds and maintain a clean garden. Additionally, fungicides can be applied to affected plants.
Pest Management
Sorghum bicolor var. drummondii is susceptible to insect pests such as aphids, armyworms, and stem borers.
Aphids are small, soft-bodied insects that suck sap from the plant. They can be managed by introducing natural predators such as ladybugs or lacewings in the garden. Additionally, insecticidal soap or neem oil can be used to control aphids.
Armyworms are caterpillars that feed on the leaves and stems of the plant. To manage armyworms, farmers can handpick the insects off the plant. Additionally, insecticides can be used to control the pest. Crop rotation can also help manage armyworms.
Stem borers are insects that bore into the stem of the plant and cause extensive damage. To manage stem borers, farmers should remove and destroy infected stems. Additionally, insecticides can be applied to control the pests.
Overall, farmers should practice good garden management techniques to manage diseases and pests in Sorghum bicolor var. drummondii. This includes maintaining healthy soil, practicing crop rotation, and using natural pest control methods when possible.
