Seasonal growth pattern
In WA, setaria grows actively in autumn after the rains. In areas with mild temperatures, winter growth is better than the other sub-tropical grasses, but in cold areas the plants are dormant over winter. Setaria resumes active growth in early spring and will grow opportunistically in summer depending on soil moisture. In northern NSW, setaria has a similar growth pattern to kikuyu.
| Rainfall (estimated minimum) | >550mm (>475mm south coast) |
|---|---|
| Drought tolerance | Moderate |
| Frost tolerance | Sensitive to moderate – Nandi and Kazungula are frost sensitive, while Narok and Solander will survive frosts of -2.0°C to -3.3°C, but heavier frosts will kill the leaves |
| Soil type | Adapted to a range of soils, especially those with a good water-holding capacity |
| Soil fertility requirements | Medium to high for good production. Highly responsive to N fertiliser and has a high P and K requirement. It will persist on low fertility soils |
| Soil pHCa | >5 (estimated) |
| Aluminium tolerance | Unknown |
| Waterlogging tolerance | Good |
| Salt tolerance | Nil |
| Ability to spread naturally | Low |
| Nutritive value: dry matter digestibility | 57–65% (monthly cuts), 47–53% (when cut after 72 days) |
| Nutritive value: crude protein | Average 9.8% (range 5.5–13.2%) |
Establishment
The suggested seeding rate is 1.5–2.5kg/ha of good quality seed when sown alone. Sow less than 15mm deep into a firm seed bed. Seedling growth is slow in the first year, but once established the plants grow vigorously. Plants are sensitive to moisture stress over the first summer and dry conditions can result in a high mortality.
Livestock disorders
Setaria contains moderate to high levels of oxalate, so is unsuitable for horses and can occasionally cause nephrosis or hypocalcaemia in ruminants. Pastures containing a high content of setaria (>95%) have resulted in cattle poisoning in Queensland.
The oxalate content depends on the variety, the growing conditions, stage of growth and increases with fertiliser nitrogen and potassium. The oxalate tends to be higher in the leaf blades than the stems while there is no oxalate present in the seed heads.