• Leafy plant producing high quality palatable forage,
  with good production on fertile soils.
• Responds quickly after rain.
• Moderately tolerant of drought.
• Green panic is tolerant of shade.

• Requires soils of moderate to high fertility
• Intolerant of waterlogging
• Sensitive to frost

Plant: Generally erect, tussocky, leafy, perennial grass; clones are shortly rhizomatous, and tussocks can grow up to 50 cm in diameter.

Stems: Slender, branching and from .5 – 1.5 m tall

Leaves: Green, glabrous to hairy, 40 – 100 cm long, up to 1.4 cm wide.

Seeds: Vary from a dull green to straw in colour, 1.5 million seeds/kg.

Seedhead: A large open panicle 18 – 25 cm long and 15 – 18 cm wide.

Summer growing perennial grass that is used widely in cattle grazing systems. Highly palatable plant with good forage quality when green. Green panic is tolerant of shady conditions.

Rainfall
500 – 1500 mm/ann (subtropics); > 425mm/ann (Western Australia).

Soils
Well adapted to a wide range of soils except heavy clays including sands, loams and lighter clay soils of moderate to high fertility. The species is intolerant of waterlogging.

Temperature
Summer growing grass with most production occurring in the warmer months. Plants frosted are in winter but shoot in early spring when moisture is available. Heavy frosting can cause plant mortality after heavy grazing in the late summer and autumn.

Companion species
Grasses: May be sown with Rhodes grass (Chloris gayana), creeping blue grass (Bothriochloa insculpta) digit grass (Digitaria eriantha spp eriantha) tall finger grass (Digitaria milanjiana).

Legumes: Sown frequently with legumes, including the annual winter growing medics (Medicago spp.), sub clover (Trifolium subterraneum) and biserrula (Bisererrula pelecinus); and the summer growing legumes lucerne (Medicago sativa), Carbon Buster™ stylo (Stylosanthes guianensis.) desmanthus (Desmanthus virgatus), butterfly pea (Clitoria ternatea), siratro (Macroptilium atropurpureum), glycine (Neonotonia wightii) and leucaena (Leucaena leucocephala).

Sowing/planting rates as single species
Sown at 2-4 kg/ha; seed quality is usually high; it is advisable to sow seed harvested the previous season as fresh seed is likely to be dormant.

Sowing/planting rates in mixtures
Sow at a pro rata rate depending on the number of species sown in the mixture; sowing rate is unchanged when sown with legumes; if sowing with lucerne, reduce lucerne sowing rate to 0.75 kg/ha to minimise competition.

Sowing time
In summer dominant rainfall regions sow between mid-January and mid-March to coincide with the highest probability of post-sowing rain; however, if there is a profile of subsoil water, sowing may be planned for mid-November or December (perhaps into standing winter crop stubble), or from late August-early September. In winter dominant rainfall regions an early spring sowing is recommended.

Inoculation
Not applicable

Fertiliser
Generally sown on fertile soils; responds to N fertiliser, possibly to P and S on very alkaline soils.

Maintenance fertiliser
Generally sown with legumes that supply N. In grass pastures without legumes, provision of N at 100 kg N/ha/ann may be used selectively, particularly for seed production.

Grazing/cutting
Withstands heavy grazing during good seasons but this is inadvisable during dry periods as recovery will be slow. Similarly, heavy grazing is not advisable in the autumn as plant mortality can occur due to frosting. Graze lightly during the establishment year.

Ability to spread
Does not colonise readily except during wet conditions.

Weed potential
Very low

Major pests
No significant insect pests.

Major diseases
No significant diseases

Herbicide susceptibility
Atrazine can be used for weed control in P. maximum at 4 L/ha. ‘Gatton’ can tolerate over 4.5 kg/ha AI of atrazine. Broadleaf weeds can be controlled using pre-emergent 2,4-D ester. P. maximum is susceptible to glyphosate to selective grass herbicides (young plants), and to diuron I. Mature plants are also susceptible to 2,2-DPA plus paraquat.

Feeding value
Digestibility ranges from 64% (2 week regrowth) to 50% (8 week regrowth), and crude protein from 6-25% depending on age and N supply. In 12 week old regrowth, crude protein values range from 5-10%, P from 0.15-0.18%, Ca from 0.6-0.8% and Na from 0.07-0.12%.

Palatability
Is well eaten by all livestock, with particularly high intakes of young leafy growth.

Production potential
DM yields of 5 – 20 t/ha (commonly 10 t/ha) if high levels of N applied). Live weight gains of up to 0.8 kg/head/day are measured, depending on stocking rate and N fertiliser rate.

Livestock disorders/toxicity
‘Petrie’ may cause ‘big head’ in horses, and hypocalcaemia in ruminants, due to oxalate accumulation. Pastures dominated by panic may cause photosensitisation.

Carbon Buster™ guinea grass mix

‘Petrie’ green panic (suited to fertile soils)
‘Gatton’ panic (superior to green panic on soils of lower fertility)