Overview
Digitaria gazensis Rendle, also known as Rhodes grass or rooi gras, is a warm-season perennial grass that is native to Africa. It belongs to the family Poaceae, and is commonly used for grazing, hay production, and as a soil stabilizer.
General Appearance
Rhodes grass typically grows to a height of 1-2 meters, with slender culms that may reach up to 5mm in diameter. The leaves are flat and narrow, measuring up to 60 cm in length and 3-10 mm in width. The plant produces numerous spikelets that vary in color from green to reddish-brown.
Distribution
The species is native to Africa and is widely distributed throughout the tropics and subtropics. It is commonly found in South Africa, Zimbabwe, and Botswana, but has also been introduced to other regions including Australia and the United States.
Uses
Rhodes grass is commonly used for grazing and hay production, as it is highly palatable to livestock. It is also used for soil stabilization, particularly in erosion-prone areas. In addition, the plant is believed to have medicinal properties, and has been used to treat various ailments including fever, headaches, and kidney problems.
Light Requirements
Digitaria gazensis Rendle thrives in areas exposed to full sunlight, making it suitable for cultivation in sunny gardens, lawns, and fields. The grass requires at least 6 hours of sunlight daily to grow to its full potential.
Temperature Needs
The plant can grow in a wide range of temperatures, from 18°C to 32°C, but the optimum growth temperature for Digitaria gazensis Rendle is between 22°C to 25°C. The plant can survive in colder temperatures, but growth may be slower than usual.
Soil Requirements
The grass variety prefers well-draining soils with sandy or loamy texture that remain moist for longer periods. It can also grow in soils with lower fertility levels. However, the soil pH must be between 5.5 to 7.5, preferably neutral. Digitaria gazensis Rendle can tolerate drought conditions but requires regular irrigation in extremely dry climates.
Cultivation Methods
Digitaria gazensis Rendle, also known as Rhodes grass, is commonly cultivated in tropical and subtropical regions of the world. It prefers warm temperatures and can grow in a wide range of soil types, from sandy to clay-based soils.
For optimal growth, plant this grass in full sun, as it requires adequate sunlight to photosynthesize. The recommended planting depth is approximately 1-2cm, and the seed rate should be around 12-15kg per hectare.
Watering Needs
Digitaria gazensis Rendle requires consistent moisture during its growth period. Ensure that the soil is kept damp but not overly saturated as this can adversely affect the growth of the plant. It is advisable to use drip irrigation to ensure that the plant gets enough water to allow for its healthy growth.
Fertilization
Regular fertilization is critical for the growth and productivity of Digitaria gazensis Rendle. Nitrogen is essential to its growth, and applying 60-80kg of nitrogen per hectare is recommended. Avoid excessive phosphorus application, as this can lead to phosphorus toxicity.
It is advisable to test the soil to determine the nutrient composition before applying any fertilizers. This will help you apply the right amount of fertilizer and ensure that your plant has sufficient nutrients for optimal growth.
Pruning
Pruning can help keep Digitaria gazensis Rendle tidy and improve seed production. Prune the grass at the end of its growing season and remove all vegetative materials to ensure a clean field and prevent disease build-up.
It is best to prune with a sharp blade or mower, and to avoid cutting too deeply, as this can damage the plant and impede future growth. Also, remove any seed heads to prevent excessive reseeding and maintain uniform growth of the plant.
Propagation of Digitaria gazensis Rendle
Digitaria gazensis Rendle can be propagated through various methods including:
Seed propagation
Seed propagation is the most common method for propagating Digitaria gazensis Rendle. The seeds can be collected from mature plants during harvesting season. The collected seeds should be cleaned and dried before planting. Sow the seeds in moist soil and keep them at a temperature of 25-30°C, and keep them moist until the germination period.
Division of rhizomes
Digitaria gazensis Rendle can also be propagated through division of rhizomes. Dig out the plants and carefully separate the rhizomes with roots. Divide the rhizomes with a sharp knife, ensuring that each division has enough roots and shoots. Plant the divisions in new pots or a prepared bed, ensuring that the soil is moist and well-drained.
Cutting propagation
Digitaria gazensis Rendle can be propagated by cuttings. Take stem cuttings from the mature plant, ensuring that each cutting has at least two nodes. Place the cuttings in a rooting hormone for enhanced rooting. Plant the cuttings in damp soil, and keep them in a shaded area. Maintain moisture and humidity by covering the cuttings with a plastic cover.
Disease Management
Digitaria gazensis Rendle, also known as Rhodes grass, is susceptible to various diseases, including leaf spot, rust, and smut. Leaf spot appears as brown spots with yellow halos on the leaves, rust as yellowish spots on leaves and stems, and smut as black soot-like spores on the plant's flowers and seeds. To manage these diseases:
- Practice crop rotation to avoid planting Digitaria gazensis Rendle on infected soil.
- Cultivate healthy soil and ensure proper drainage.
- Apply fungicides as prescribed by a professional, taking care to follow instructions to prevent overuse, which can lead to further problems.
Pest Management
Several pests can affect Digitaria gazensis Rendle, such as armyworms, aphids, and spider mites. These pests can cause severe damage to the plant by chewing on leaves and stems or by sucking out sap. Here are some ways to manage pest infestations:
- Regularly monitor for signs of infestation, such as chewed leaves, webbing, or discoloration.
- Use organic pest control methods such as releasing natural predators or spraying with horticultural oil or soap.
- If using chemical pesticides, carefully follow directions and take precautions to avoid harming beneficial insects or the environment.
- Remove infested plants and dispose of them appropriately to prevent spreading to other plants.
