Setaria sphacelata is a tufted perennial grass that can reach 2m tall. It is native to the tropical and subtropical regions of Africa and is commonly grown as a pasture and fodder grass.
It is easily identified by its blue-green stems, soft bluish-green leaves, and a spike-like, narrow panicle with golden-yellow bristles.
Zakat Grass Classification
- Domain: Eukaryota
- Kingdom: Plantae
- Phylum: Tracheophyta
- Subphylum: Angiospermae
- Class: Monocotyledonae
- Order: Poales
- Family: Poaceae
- Genus: Setaria
- Species: Setaria sphacelata
- Varieties: Setaria sphacelata var. Sphacelata, Setaria sphacelata var. Sericea, and Setaria sphacelata var. torta
- Common Names: Common Setaria, African Pigeon Grass, South African Pigeon Grass, Canary Seed Grass, Rhodesian Grass, Golden Bristlegrass, and Golden Setaria
Nativity and Distribution
Golden Millet is native to tropical and subtropical regions in Africa. These countries include Angola, Senegal, Botswana, Kenya, Tanzania, Namibia, and South Africa.
The grass has since been naturalized in other regions globally, including Australia, the Americas, New Zealand, Hawaii, and Southeast Asia.
Physical Characteristics
- Leaves: Glabrous, soft, bluish-green leaves
- Stems: Flattened blue-green stems
- Flowers: A spike-like, narrow panicle with golden-yellow bristles
- Roots: Fibrous root system
African Bristlegrass is a perennial, stout, densely tufted grass that can reach 2m tall. You can easily identify it by its blue-green stems, soft bluish-green leaves, and a spike-like, narrow panicle with golden-yellow bristles.
The leaves are glabrous, soft, bluish-green, 10-50 cm long and 3-7mm wide, with entire margins and long pointed tips. The leaf sheath is also smooth and glabrous, but a line of hairs occurs where the blade meets the sheath.
Stems are upright, flattened, hairless, and green, reaching 1.8-2 m in height.
Zakat Grass produces an inflorescence consisting of a seedhead that appears spike-like, but it is actually a spiciform panicle, where several short branches are held towards the stem.
The heads (7-50 cm long) bear clustered spikelets, typically in groups of one to four, subtended by golden-yellow bristles, each about 4-12 mm long. Spikelets are elliptic in shape, 1.5-3.5 mm long, and consist of a pair of glumes and two florets.
Reproduction, Dispersal, and Life Cycle
- Life Cycle: Perennial
- Seeds: It is a moderate seed-producing grass
- Climate: Tropical and subtropical climates
- Dispersal: Wind, water, birds, and contaminated produce
S. sphacelata is a perennial grass that thrives in tropical and subtropical climates. It can propagate by seeds but also produces short rhizomes.
The seeds are dispersed by wind, water, granivorous birds, and also as a contaminant of produce. Due to its high demand as a pasture and forage grass, it is also heavily propagated by seed and vegetative means. Zakat grass begins to grow in spring and continues to persist well into late autumn.
It thrives in a variety of soils, including sandy, stony, and loam soils. However, it prefers fertile, well-drained, and moist soil and can therefore tolerate flooding and waterlogging.
It is not well adapted for alkaline, saline, or acidic soils and has low drought tolerance. Several cultivars have been developed that can withstand diverse soil conditions and weather phenomena like cold or frost. The well-known Setaria sphacelata cultivars are Nandi, Narok, and Kazungula.
Apart from desired pastures, Golden Millet is also found in riparian areas, parks, grasslands, roadsides, disturbed sites, and waste areas.
Similar Plants
- Setaria pumila
- Setaria incrassata
- Pennisetum purpureum
Uses
- It is an important fodder, hay, silage, and pasture grass in Africa.
- It is a popular grass for cut-and-carry systems.
- The grass is used for soil stabilization and conservation along waterways.
- It is used in crop rotation in mixed farming systems.
- Grains are a famine food for humans and an important food source for birds.
Impact on Farms and Environment
Setaria sphacelata is a vital pasture grass in many regions globally. However, when introduced without careful management, it can become aggressively weedy.
In cropping systems, for instance, it can spread in unwanted areas, competing for important nutrients and interfering with harvesting.
Where it is grown as pasture grass, it can outcompete native grasses and other desirable pasture grasses. This can affect livestock nutrition, especially in the later growth stages where its crude protein steadily declines.
Some cultivars also tend to have high levels of oxalates that can affect the palatability and digestibility for grazing animals.
In non-agricultural areas, Zakat Grass can colonise disturbed areas such as roadsides and other disturbed sites, forming dense cover that can impede movement and potentially displace native plant species.
While it has not been declared a noxious weed, it is considered to be a significant weed in three Australian states, namely, Western Australia, Queensland, and New South Wales.
Control
- Cultural control: Revegetation and Competition
- Chemical control: Herbicides like haloxyfop and glyphosate
Removing African Bristlegrass using common methods like hand-pulling, mowing, intensive grazing, or prescribed burning may only provide temporary control or encourage further growth.
However, deep cutting the grass and restoring native or more competitive grass species can offer effective and long-term control.
For even better results, consider applying herbicides indicated for perennial grass control, like haloxyfop and glyphosate. For any herbicide you decide to use, ensure to follow all the application directions.
Lead Editor for Insight Weeds.