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Para grass (Urochloa mutica)

Para Grass invades native wetlands and can replace native vegetation, alter fire regimes and increase sedimentation. It is also a serious weed in sugarcane fields.

Key facts

Type: Weed, grass.

Native to: Tropical western and northern Africa.

Established in: QLD, NSW, WA, NT.

Other names: Bancroft Grass, Buffalo Grass, California Grass, Dutch Grass.

Best time to act: Treating plants when they develop inflorescences is recommended, with the optimum herbicide treatment time stated as December to April.

Identification

  • A perennial grass growing up to 1 m tall, with creeping stems that can grow longer.
  • Its hollow, robust stems often develop roots at the lower nodes and can float on deep water, forming thick mats.
  • The leaf sheaths and nodes are densely hairy; the dark green leaf blades grow up to 20 cm long and 2 cm wide.
  • The flowering stem is up to 18 cm long, with 10–30 spikelike branches; its hairless spikelets are 3–3.5 mm long.
  • Look-alike: Tanner Grass (Urochloa arrecta) is similar, but has single rather than paired spikelets and is not known to be naturalised in Australia.

Where it grows

In Australia it is naturalised in tropical and subtropical areas, including northern New South Wales, Queensland, the Northern Territory and northern Western Australia, especially in freshwater wetlands, stream and lake margins, and floodplains.

Why it matters

  • It can form pure stands that replace native vegetation in wetlands and along river margins.
  • By changing fuel characteristics in floodplains, it can contribute to more or more severe fires that further displace native grasses and damage or kill trees.
  • It can slow water flow along streams and increase sedimentation.
  • Dense stands can reduce the abundance and diversity of terrestrial invertebrates and have a detrimental effect on wetland bird populations.

How it spreads

  • It can reproduce by seed, but commonly spreads through broken stem pieces that root and grow into new plants.
  • Floodwater can carry stem pieces, and birds occasionally move them.

Control options

  • Prioritise small, isolated stands over large infestations, which can be hard to eradicate.
  • Intensive grazing, hand grubbing or slashing can lead to at least a short-term decline in cover.
  • Use registered herbicides according to their directions; treatment is best when plants develop inflorescences, and herbicides should not be used on plants growing over water.
  • Slashing or burning can be done some time before herbicide application to remove dead material and promote susceptible fresh growth.

Hygiene and washdown

  • Practise weed hygiene at infested sites to avoid spreading Para Grass to other areas.
  • Inspect and clean vehicles, plant and footwear before leaving an infested area, paying attention to tyres, radiators, belly plates, tracks and floor mats.
  • Wash down at a designated bay where runoff is contained and can be monitored for seedlings.
  • Record each washdown so the client has evidence of clean entry and exit.

Classification by state

  • Australia (national): Key threatening process. Listed under the EPBC Act, with a national threat abatement plan for invasion by five invasive grass species.
  • Queensland: Not prohibited or restricted. Not listed as prohibited or restricted matter in Queensland. Everyone must also take all reasonable and practical steps to minimise its risks (the general biosecurity obligation).
  • New South Wales: Not a priority weed. Not a state or regional priority weed in NSW. The general biosecurity duty applies: anyone dealing with it must prevent, eliminate or minimise the risk it poses.
  • Victoria: Not declared. Not declared under the Catchment and Land Protection Act 1994. Other Victorian laws may still apply.
  • South Australia: Not declared. Not declared under the Landscape South Australia Act 2019. Other laws may still apply.
  • Western Australia: Permitted, not declared. Listed as a permitted organism in WA, so it can be brought in, but it is not a declared pest.
  • Tasmania: Not declared. Not a declared weed in Tasmania. Other laws may still apply.
  • Northern Territory: Check NT list. There is no NT weed profile for it. Check the NT declared weeds list for its current status.
  • Australian Capital Territory: Not declared. Not declared under the Biosecurity Act 2023 (ACT). A general biosecurity duty still applies.

Legal obligations

Every state and territory places a duty on landholders and people working on land to prevent the spread of invasive species, such as the general biosecurity obligation in Queensland and the general biosecurity duty in New South Wales. Declarations and control requirements differ between states and local government areas, so check the current official list before work starts.

  • Queensland: Biosecurity Act 2014 (Qld), administered by Biosecurity Queensland (13 25 23)
  • New South Wales: Biosecurity Act 2015 (NSW), administered by NSW Department of Primary Industries and Regional Development
  • Western Australia: Biosecurity and Agriculture Management Act 2007 (WA), administered by the WA Department of Primary Industries and Regional Development
  • Northern Territory: Territory Parks and Wildlife Conservation Act 1976 (NT), administered by NT Department of Lands, Planning and Environment

Sources