Origin
Digitaria horizontalis Willd. var. porrantha (Steud.) Henrard ex C.E.Hubb. & Vaughan, commonly known as Porcupine Grass, is a perennial grass species native to Africa.
Common Names
Porcupine Grass is also known by several other common names such as Pensacola Bahia, hairy crabgrass, and large crabgrass.
Uses
Porcupine Grass is commonly used as a forage plant for grazing livestock as it has high nutritional value. It is also used in soil stabilization projects and erosion control, as its extensive root system helps to anchor soil in place. Additionally, porcupine grass is used in traditional medicine as it is believed to have various therapeutic properties.
General Appearance
Porcupine Grass grows up to 1 meter tall and spreads by stolons and rhizomes. Its leaves are flat and hairy on both sides, with a prominent midrib. The inflorescence is a branching panicle of spikes that can be up to 30 cm long. The spikelets are arranged in digitate fashion, hence the name Digitaria. The seeds are oval and flattened with a groove on one side.
Light Requirements
Digitaria horizontalis Willd. var. porrantha (Steud.) Henrard ex C.E.Hubb. & Vaughan requires full to partial sun exposure for optimal growth. The plant thrives well in areas with bright sunlight for 6-8 hours each day. In shaded environments, the plant may grow slower and produce fewer flowers.
Temperature Requirements
The plant is a warm-season grass and typically grows in temperatures ranging from 20°C to 35°C. Temperatures below 15°C may cause growth retardation, and frost can be detrimental to the plant. It grows best in tropical to subtropical climates with warm temperatures and high humidity.
Soil Requirements
Digitaria horizontalis Willd. var. porrantha (Steud.) Henrard ex C.E.Hubb. & Vaughan grows well in well-drained sandy or loam soils with a pH ranging from 5.0 to 7.5. The soil should be moist but well-drained to prevent waterlogging. The plant can tolerate moderately saline and drought-prone soils but may require additional watering during extended periods of drought.
Cultivation
Digitaria horizontalis Willd. var. porrantha (Steud.) Henrard ex C.E.Hubb. & Vaughan thrives in well-draining soils. It is tolerant of many soil types, including sandy, loamy, and clay soil. However, it prefers soils enriched with organic matter.
The best time to propagate the plant is during the warm seasons of spring or early summer. Plant the seeds in a well-prepared bed, with a depth of about 0.5 inches, and maintain a spacing of at least 6 inches between seedlings.
Watering Needs
The plant grows best in soils with moderate moisture content. Avoid overwatering as this can cause root rot. Water the plant moderately in summer but reduce watering frequency in winter because of dormancy.
Fertilization
When the plant is about six inches tall, apply nitrogen-rich fertilizer. Fertilizer should be applied only once per year during spring, and in the appropriate amount, so as not to damage the plant or surrounding ecosystem.
Pruning
To keep the plant looking neat, prune regularly, especially when the plants reach a height of about eight inches. Trim the plants to remove any dead or damaged stem or leaf. Use a sharp, sterile pruning tool to avoid bruising the plant. After pruning, it may take some time for the plant to regrow, keeling soil moisture in check during this time is crucial.
Propagation of Digitaria horizontalis Willd. var. porrantha
The most common method of propagating Digitaria horizontalis Willd. var. porrantha is through seed propagation. Seeds should be sown during the early spring months in a well-draining soil mixture. It is important that the soil is kept moist until germination occurs. Germination usually happens within 10 to 14 days.
Another method of propagating Digitaria horizontalis Willd. var. porrantha is through rhizome division. The rhizomes can be carefully divided in the early spring, making sure that each division has several shoots. The divisions can be planted in a well-draining soil mixture and kept moist until they establish themselves.
If the plant is being used for its ornamental value, then vegetative propagation can also be used. This involves taking stem cuttings during the early summer months and planting them in a rooting hormone and a well-draining soil mixture. The cuttings should be kept moist until they establish roots and start to grow.
Disease and Pest Management for Digitaria horizontalis Willd. var. porrantha (Steud.) Henrard ex C.E.Hubb. & Vaughan
Digitaria horizontalis Willd. var. porrantha (Steud.) Henrard ex C.E.Hubb. & Vaughan, also known as tropical crabgrass, is a warm-season annual grass that is commonly used for forage. However, it can be susceptible to a range of diseases and pests that may affect its growth and yield. Here are some common diseases and pests that might affect the plant and ways to manage them.
Diseases
Tropical crabgrass can be affected by various fungal and viral diseases, such as leaf spots, anthracnose, and mosaic virus. These diseases can reduce the plant's vitality and yield. To manage these diseases:
- Plant disease-resistant varieties if available
- Remove and destroy infected plants and debris promptly to prevent the spread of diseases
- Avoid overwatering and provide adequate drainage to prevent waterlogged conditions that can favor disease development
- Practice crop rotation and avoid planting in areas where infected plants grew in the previous year
- Apply appropriate fungicides or bactericides as recommended by agricultural extension services or specialists
Pests
Tropical crabgrass can also be attacked by various insects and pests, such as armyworms, cutworms, chinch bugs, and grasshoppers. These pests can cause severe damage to the plant by feeding on the foliage, stems, and roots. To manage these pests:
- Inspect plants regularly and monitor pest populations
- Apply appropriate insecticides or biological control agents as recommended by agricultural extension services or specialists
- Use sticky traps or pheromone traps to catch and monitor adult pests
- Remove weeds and debris that can harbor pests and their eggs
- Practice crop rotation and avoid planting in areas where pests were prevalent in the previous year
By following these disease and pest management practices, growers can minimize the impact of diseases and pests on their tropical crabgrass crop and maintain healthy plants with optimal yield and quality.
