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Musk weed (Myagrum perfoliatum)

Musk weed is a significant cropping weed in South Australia and western Victoria, affecting crops including chickpeas, lentils, lupins, field peas, faba beans and canola. It can be difficult and costly to control once established, and its seeds can contaminate grain and hay.

Key facts

Type: Weed, herb.

Native to: Parts of western Asia and Europe.

Established in: NSW, VIC, SA.

Other names: Bird’s-eye cress, Mite cress, Mitre cress, Dog mustard.

Best time to act: In Australia it flowers from late July to mid-October and produces seed from mid-August to early December, so inspect paddocks during flowering and seed production.

Identification

  • An annual herb with erect, branching stems, usually 20 to 80 cm tall but sometimes reaching about 1 m.
  • Basal leaves form a flat rosette up to about 45 cm wide.
  • Yellow flowers with oblong petals appear in summer, with the flower stalks pressed close to the stem.
  • The hard, wedge- or pear-shaped pods are usually about 5 to 7 mm long, reddish-brown or straw-brown, and do not split open.
  • Each pod usually contains one reddish-brown seed, rarely two.
  • Look-alike: The pods are similar in size and shape to grain, including wheat and barley.

Where it grows

In Australia it grows in cropping paddocks and pastures, and is recorded in South Australia, Victoria, Queensland and New South Wales.

Why it matters

  • It is a major weed of several crops in western Victoria and South Australia, including chickpeas, lentils, lupins, field peas, faba beans and canola, and is also a weed of winter cereals and lucerne.
  • In chickpeas and lentils it can cause yield losses of up to 50 percent, and it can smother cereal and canola crops or outcompete crops late in the season.
  • Its bulky, branched growth can clog harvesting equipment and slow harvests.
  • Seed and hay contamination can reduce commodity value and lead to additional cleaning.

How it spreads

  • Seeds or pods can be moved on harvesting equipment and in contaminated grain, crop seed, hay, birdseed and wool.
  • Cut plants can tumble across paddocks while shedding seed pods.
  • Seeds can persist in the soil for several years, so infestations may reappear after initial control.

Control options

  • Use weed-free seed and clean farm machinery to reduce the chance of introducing or moving seed.
  • Control options described for musk weed include suitable herbicides, fallow phases, weed wiping, heavy grazing and soil solarisation.
  • Herbicide options can be limited in some crops, and the plant tolerates some commonly used herbicides; use only products registered for the site and crop, following the label and local advice.
  • Plan for follow-up control over several years because the persistent seed bank can require sustained management.

Hygiene and washdown

  • Clean harvesting equipment and other machinery after working infested paddocks, removing seed pods and contaminated material before moving to clean areas.
  • Avoid moving contaminated grain, hay, wool or soil to uninfested 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): No national listing. Managed under state and territory law.
  • 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: Declared plant. Depending on the declaration, it can be an offence to move it on public roads or sell it, and landowners may be required to control it on their land.
  • 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: Not declared. Not on the NT A to Z weed list, and Weeds Australia does not list it as declared in the NT. Check the NT declared weeds list before moving or planting it.
  • 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.

  • New South Wales: Biosecurity Act 2015 (NSW), administered by NSW Department of Primary Industries and Regional Development
  • Victoria: Catchment and Land Protection Act 1994 (Vic), administered by Agriculture Victoria
  • South Australia: Landscape South Australia Act 2019 (SA), administered by the regional landscape board

Sources