Description
Digitaria debilis (Desf.) Willd. var. reimarioides (Andersson) Henrard, also known as Andersson's crabgrass, is a perennial creeping grass species belonging to the family Poaceae and is native to Africa, including South Africa, Namibia, and Botswana.
Common Names
Common names for this plant include Andersson's crabgrass and frail finger grass.
Uses
Digitaria debilis (Desf.) Willd. var. reimarioides (Andersson) Henrard is often used for erosion control because of its ability to grow rapidly and form dense mats. It also provides food for grazing livestock and wildlife.
General Appearance
The plant grows up to 60 cm in height and has a mat-forming growth habit, with slender stems that are up to 40 cm in length. Its leaves are narrow and pointed, up to 10 cm long, and turn red-brown in color as they mature. Its flowers are small and grow in small clusters, with green spikelets that turn brown as they mature. The seeds are small and brown, with a distinctive hooked shape.
hereLight requirements
Digitaria debilis var. reimarioides thrives in full sun exposure. Thus, it needs at least 6 hours of direct sunlight daily to grow optimally.
Temperature requirements
The plant is well adapted to warm temperatures, but it can also tolerate lower temperatures. The optimal range for growth is between 25 and 30° C (77 and 86° F), but it can grow in temperatures as low as 10° C (50° F).
Soil requirements
The plant prefers well-drained soil with a pH range between 6.5 and 7.5. It is tolerant to a wide range of soil textures, from sandy loam to clay loam. However, the soil must be fertile and rich in nutrients to ensure proper growth and development.
Cultivation
Digitaria debilis (Desf.) Willd. var. reimarioides (Andersson) Henrard is a warm-season grass that thrives in tropical and subtropical regions. It prefers well-drained soils that are rich in nutrients, with a pH range of 5.5 to 7.5. The plant is best grown in full sun, but it can tolerate some shade.
Watering
Digitaria debilis (Desf.) Willd. var. reimarioides (Andersson) Henrard requires moderate watering. The plant needs to be watered regularly, especially during dry spells, to prevent the soil from drying out. However, overwatering can cause root rot, so it's important to keep the soil moist but not waterlogged.
Fertilization
Fertilization is essential for the growth and health of Digitaria debilis (Desf.) Willd. var. reimarioides (Andersson) Henrard. It's recommended to fertilize the plant every three months using a balanced fertilizer with equal parts of nitrogen, phosphorus, and potassium. Fertilizer application should be done during the growing season, preferably in early spring.
Pruning
Pruning is not necessary for Digitaria debilis (Desf.) Willd. var. reimarioides (Andersson) Henrard as it is a low-maintenance plant. However, dead or damaged stems and leaves should be removed regularly to promote healthy growth. Additionally, pruning can be done to control the size and shape of the plant.
Propagation of Digitaria debilis var. reimarioides
Digitaria debilis var. reimarioides can be propagated both sexually and asexually. The species produces seeds and can also be propagated through vegetative methods.
Sexual Propagation
Seeds should be collected when they are mature and fully dry. The seeds can be separated and cleaned, and then stratified for 60-90 days before planting. The optimal temperature for germination is around 25-30°C, with a germination rate of approximately 60-80%.
Asexual Propagation
Digitaria debilis var. reimarioides can also be propagated through vegetative methods such as cuttings or division of rhizomes. Cuttings should be taken from healthy plants and treated with rooting hormone before planting. Rhizomes should be divided during the dormant period in early spring, before the start of vegetative growth.
It is important to note that the success of asexual propagation largely depends on environmental conditions, such as humidity, light, and temperature. For best results, propagate during the appropriate season and provide optimal growing conditions.
Disease Management
Digitaria debilis (Desf.) Willd. var. reimarioides (Andersson) Henrard is generally resistant to various diseases. However, some diseases like brown patch disease (Rhizoctonia solani), dollar spot (Sclerotinia homeocarpa), and rust (Puccinia spp.) may affect the plant if the environmental conditions are favorable.
To manage brown patch disease, proper lawn maintenance practices such as adjusting the soil pH, improving drainage, reducing thatch buildup, and avoiding over-fertilization with nitrogen are necessary. Fungicides like azoxystrobin and propiconazole can be applied.
Dollar spot can be controlled by watering the plant deeply and infrequently, applying nitrogen, and mowing at the correct height. Fungicides like thiophanate-methyl, flutolanil, and propiconazole are effective in treating dollar spot.
For rust management, proper air circulation, regular mowing, avoiding over-watering, and maximizing sunlight exposure are essential. Fungicides like myclobutanil, propiconazole, and triadimefon are useful in controlling rust.
Pest Management
Common pests that can affect Digitaria debilis (Desf.) Willd. var. reimarioides (Andersson) Henrard are armyworms, cutworms, and white grubs.
Armyworms can be controlled by using biological control agents such as parasitic nematodes or by using insecticides like pyrethroids and carbaryl.
Cutworms, on the other hand, can be managed by using cultural methods like proper lawn maintenance, using pheromone traps, and applying insecticides.
White grubs can be controlled by following cultural practices like proper irrigation, mowing, and fertilization. Applying insecticides like neonicotinoids, carbaryl, and chlorantraniliprole can be effective in controlling white grubs.
