Overview
Digitaria diagonalis (Nees) Stapf var. hirsuta (De Wild. & T.Durand) Troupin is a plant species belonging to the family Poaceae. It is commonly known as hairy crabgrass and it is native to Africa, but is now found in other parts of the world.
General Appearance
Hairy crabgrass is an annual grass that can reach up to 90 cm in height. The plant has a smooth stem that is sometimes hairy at the nodes. The leaves are flat and narrow with a pointed tip, ranging from 5 to 15 cm in length. The flowering stems are much longer than the leaves and can have up to 11 spikes that are 2-9 cm in length. The spikes have a reddish-brown color and each spike can have up to 15 spikelets. The plant is self-pollinating and produces seeds that can remain viable for up to 3 years.
Uses
Hairy crabgrass has been traditionally used as a medicinal plant. In some parts of Africa, it is used in the treatment of urinary tract infections, diarrhea, and other ailments. The plant has also been used as animal fodder due to its high nutritional content. Additionally, hairy crabgrass has been used to stabilize soil and prevent erosion.
In some parts of the world, hairy crabgrass is considered a weed and can be a nuisance to gardeners and farmers. The plant has a high growth rate and can spread quickly, making it difficult to control.
Light Requirements
Digitaria diagonalis var. hirsuta prefers to grow in full sun, with at least six hours of direct sunlight per day. In areas with very high temperatures, some shade in the hottest part of the day can be beneficial.
Temperature Requirements
This variety of Digitaria diagonalis is a warm-season grass that thrives in temperatures between 20°C to 30°C (68°F to 86°F). It is not tolerant of frost and may suffer severe damage or death if exposed to freezing temperatures.
Soil Requirements
Digitaria diagonalis var. hirsuta is adaptable to different soil conditions but prefers well-drained soils with a slightly acidic to neutral pH between 5.5 and 7.0. It can tolerate dry soils but also grows well in soils with moderate moisture. This grass can grow in a range of soil textures, from sandy to clay soils, but performs best in loamy soils.
Cultivation
Digitaria diagonalis (Nees) Stapf var. hirsuta (De Wild. & T.Durand) Troupin, commonly known as hairy crabgrass, thrives in warm climates with full sun exposure. It prefers well-drained soils but can tolerate a wide range of soil types- sandy, loamy, or clay soils.
It can tolerate a pH range of up to 8.5, and soil moisture should be moderate.
Watering
Hairy crabgrass is drought resistant but requires watering once a week if there is no rainfall.
It would be best to water the plant in the morning to allow the leaves and soil to dry out before dusk to prevent fungal diseases.
Fertilization
Applying a balanced fertilizer with an NPK ratio of 4-4-4 or 10-10-10, every four to six weeks will help the plant grow healthily and robustly.
It would be best to avoid overfertilization to prevent excessive stem and leaf growth.
Pruning
Pruning hairy crabgrass involves removing dead or damaged leaves and stems to promote new growth and to remove any eyesores.
If you choose to prune, do it before the growing season to avoid stunting growth during the critical growth stage.
By following these simple guidelines, you will have a thriving hairy crabgrass plant in no time.
Propagation of Digitaria diagonalis var. hirsuta
Digitaria diagonalis var. hirsuta can be propagated through both sexual and asexual means.
Sexual propagation
The plant produces inflorescences that bear the seeds, which can be collected for sowing. The seeds should be sown in a well-draining potting mix and kept moist until germination occurs. Germination can take up to two weeks depending on the conditions.
Asexual propagation
Digitaria diagonalis var. hirsuta can also be propagated through division. This is best done during the spring when the plant is actively growing. The plant should be carefully dug up and the root ball divided into several sections. Each section should have a healthy rhizome and several shoots. Each section can then be planted in a new location and watered regularly until established.
Disease Management
Digitaria diagonalis var. hirsuta is generally a hardy plant and it is not usually affected by many diseases. However, some fungal pathogens such as leaf spot and rusts have been known to attack the plant, especially during periods of high humidity or prolonged periods of rainfall. To manage such diseases, it is important to maintain appropriate cultural practices that promote healthy growth of the plant.
The following are some management practices for controlling diseases in Digitaria diagonalis var. hirsuta:
- Ensure proper drainage and avoid overwatering as this can lead to leaf spot diseases
- Remove and destroy diseased plant parts as soon as they are noticed to prevent the spread of diseases
- Avoid planting the same species or related crops in the same field where the disease has previously occurred
- Use fungicides as a last resort and only after consulting with a professional agronomist
Pest Management
Digitaria diagonalis var. hirsuta is also relatively resistant to most pests. However, some common pests that may attack the plant include armyworms, webworms, and aphids. These pests can cause significant damage to the plant, reducing its productivity. To manage such pests, it is important to undertake regular field monitoring.
The following are some management practices for controlling pests in Digitaria diagonalis var. hirsuta:
- Use certified seeds to reduce the risk of pests and diseases
- Rotate crops to minimize pest impact
- Undertake regular field monitoring to check for the presence of pests and their damage
- Use appropriate insecticides in case of severe pest infestation, but only after consulting with a professional agronomist
