Origin
Digitaria cognata (J.A. Schultes) Pilger, commonly known as the Caribbean fingergrass or Cognate crabgrass, is a warm-season perennial grass that is native to the tropics and subtropics of South and Central America. It can be found in countries such as Brazil, Peru, Ecuador, Colombia, and Costa Rica.
Common Names
Digitaria cognata is commonly known by several names, including Caribbean fingergrass, Cognate crabgrass, Brazilian fingergrass, and Cognate fingergrass.
Uses
Digitaria cognata is often used as a forage grass for livestock in the tropics due to its high nutritional value. It is also known to have medicinal properties and is used in traditional medicine to treat various ailments such as fever, diarrhea, dysentery, and respiratory infections. In addition, it is a popular ornamental plant and is used in landscaping as a ground cover or as an accent plant in garden beds.
General Appearance
Digitaria cognata is a low-growing grass that can reach a height of 10 to 30 cm. Its leaves are slender, flat, and about 3 to 15 cm long, with a bluish-green color. The inflorescence consists of several spikelets that are arranged in a finger-like manner, hence its common name ‘fingergrass’. The spikelets are about 5 to 9 mm long, with purplish-colored flowers that bloom from summer to fall.
Light requirements
Digitaria cognata typically thrives in areas with bright sunlight or partial shade. It can grow well in open areas or partially shaded areas.
Temperature requirements
Digitaria cognata grows well within a temperature range of 20°C to 28°C. However, it can also tolerate temperatures as low as 10°C and as high as 35°C.
Soil requirements
The plant prefers well-drained and fertile soils that are rich in organic matter. However, it can also grow in soils of varying types including sandy, loamy or clay soils. It can even grow in clay soils that are poorly drained and prone to waterlogging. Nonetheless, the plant is intolerant to strongly alkaline soils with pH levels higher than 8.5.
Cultivation Methods for Digitaria Cognata
Digitaria cognata, also known as the Fall Witchgrass, can be propagated by seeds or divison. Seeds can be sown in the spring at a depth of 1/4 inch or deeper to ensure germination. Division can be done in the spring or fall by digging up the root ball and cutting it into sections.
Watering Needs for Digitaria Cognata
The Fall Witchgrass prefers consistently moist soil but does not tolerate waterlogged conditions. Water the plant deeply once a week, and adjust according to rainfall and humidity levels. To prevent root rot, it is advised to water the plant early in the day so that the foliage can dry before nightfall.
Fertilization of Digitaria Cognata
Digitaria cognata benefits from regular fertilization with a balanced, water-soluble fertilizer every three to four weeks during the growing season. When using a granular fertilizer, incorporate it into the soil surrounding the plant and water it deeply.
Pruning of Digitaria Cognata
Pruning is minimal for Fall Witchgrass, remove any yellow or damaged foliage throughout the growing season. In the fall, cut the foliage back to ground level to remove any unsightly debris from the winter landscape. This will also help the plant to grow back more vigorously in the next growing season.
Propagation of Digitaria cognata
Digitaria cognata can be propagated through both sexual and asexual methods.
Sexual Propagation
The plant can be propagated through seeds, which can be obtained from mature flower spikes. The seeds can be sown directly in the ground during the spring season. The planting depth should not exceed 1 cm as the seeds require light to germinate.
Alternatively, the seeds can be sown in germination trays filled with seed-starting mix. The trays should be kept moist and placed in a warm, well-lit area. Once the seedlings have grown to a suitable size, they can be transplanted into larger containers or directly into the ground.
Asexual Propagation
Digitaria cognata can also be propagated asexually through division.
The plant can be divided during the spring season when new growth is visible. The clump of the plant can be carefully dug up and divided into smaller sections. Each section should have an equal amount of roots and leaves.
The divided sections can be immediately planted in their desired location, making sure to water thoroughly.
Disease and Pest Management for Digitaria Cognata
Digitaria cognata, commonly known as the Hairy Crabgrass, is a summer annual grass that is native to North America. Although it is a hardy plant that can withstand dry conditions, it is still susceptible to various diseases and pests that can reduce its quality and yield. In this article, we will discuss some of the common diseases and pests that can affect Digitaria cognata and suggest some ways to manage them.
Common Diseases
One of the most common diseases that affect Digitaria cognata is the Southern corn leaf blight, caused by the fungus Bipolaris maydis. The disease causes the grass to develop brown, oval-shaped lesions on the leaves and stems, which can result in stunted growth and reduced yield. Another common disease is dollar spot, caused by the fungus Sclerotinia homeocarpa, which manifests as small circular spots on the leaves. The spots can merge into large patches and ultimately lead to the death of the plant.
To manage these diseases, it is crucial to maintain good cultural practices, such as proper irrigation, fertilization, and mowing. Furthermore, the use of resistant varieties can help prevent the spread of these diseases. Fungicides can also be applied to control the spread of the disease, but it is essential to follow the manufacturer's instructions and apply them in a timely manner.
Common Pests
Digitaria cognata can also attract various pests, such as the armyworm, cutworms, and flea beetles. Armyworms are caterpillars that can cause significant damage to the plant by chewing the leaves and stems. Cutworms, on the other hand, are larvae that live in the soil and feed on the roots of the plant. Flea beetles are small insects that can cause severe damage to the leaves by creating small holes and pits.
To manage these pests, it is crucial to maintain good cultural practices, such as proper irrigation, fertilization, and mowing. Furthermore, the use of biological control agents, such as parasitic wasps, can be effective in controlling the population of armyworms and cutworms. Insecticides can also be applied to control the spread of these pests, but it is essential to follow the manufacturer's instructions and apply them in a timely manner.
Conclusion
Digitaria cognata is a hardy plant that can withstand various environmental stressors. However, it is still susceptible to various diseases and pests that can reduce its quality and yield. To manage these diseases and pests, it is crucial to maintain good cultural practices and use resistant varieties whenever possible. If the infestation is severe, fungicides and insecticides can be applied, but it is essential to follow the manufacturer's instructions and apply them in a timely manner.
