Bathurst bur

General description

Erect, spiny annual herb < 1 m tall. Leaves are white and hairy on underside. Flowers are inconspicuous and are borne December – April. Fruits/burs have hooked spines.

What you need to know

To help protect our environment:

• you must not breed, distribute, release or sell Bathurst burr within the Auckland region
• you must not plant Bathurst burr within the Auckland region, unless you are transferring an existing plant on your land to another location within the boundaries of the same property
• you must destroy any Bathurst burr on land that you occupy if it has been planted in breach of the above rules and you are directed to do so by an authorised person
• you must destroy all Bathurst bur plants on the land you are occupying if it is within rural Auckland.

Habitats

Maize crops, poultry farms, moist and disturbed soils.

Dispersal

Seeds dispersed by attachment to animal pelts, gravity and water. Human-mediated dispersal through attachment to clothing, contamination of maize and livestock.

Impact on environment

Burs contaminate and reduce value of sheep wool. Spines prevent stock from grazing and can damage feet or hinder movement. Weedy in summer crops, potentially reducing crop yield. Can displace desirable pasture species.

Control

Site management

Follow up treated areas 3 times per year. Encourage natural regeneration of native plants or replant treated areas where possible after 2-3 treatments to establish dense ground cover and minimise reinvasion.

Recommended approaches

Physical control

Method: Dig out.

Plant parts requiring disposal: Seeds.

Disposal options: Remove to greenwaste or landfill if practical.

Biocontrol

Biocontrol is currently not available for this species.

Community agrichemical control recommendations

No qualifications: Foliar spray with 100ml glyphosate green per 10L of water.

Basic Growsafe certified: Foliar spray with 1g metsulfuron-methyl per 10L of water.