Declared plant in Western Australia

African thistle (Berkheya rigida)
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See also: Control Method | Weed description | Declared plants list
 
(Locality Code: C= City; S=Shire; T=Town)
 
Category: P1, P2
Location: for the whole of the State
 

Control Codes and Landholder Obligations

P1

REQUIREMENTS

Prohibits movement

The movement of plants or their seeds is prohibited within the State.

This prohibits the movement of contaminated machinery and produce including livestock and fodder.

 

P2

REQUIREMENTS

Aim is to eradicate infestation

Treat all plants to destroy and prevent propagation each year until no plants remain. The infested area must be managed in such a way that prevents the spread of seed or plant parts on or in livestock, fodder, grain, vehicles and/or machinery.

Control Method

Recommended herbicides

:
  • Spring - before flowering
    :2,4-D amine
    Clopyralid + MCPA

Herbicide

:

2,4-D amine
(various trade names - AVPMA site)

Active ingredient 

:

a) 500 g/litre 2,4-D amine        ( Group I)

b) 625 g/L 

Amount of product per 10 litres water

:

a) 50 mL

b) 40 mL

Wetting agent dilution

:

1:400

Time of application

:

Seedlings to early flowering stage

Remarks

:

Permit required if spraying within 5 km of a commercial vineyard or tomato garden

Herbicide

:

Clopyralid
(various trade names - AVPMA site) (Group I)
+ MCPA (various trade names - AVPMA site) (Group I)

Active ingredient

:

300 g/L clopyralid + 500 g/L MCPA amine

Amount of product per 10 litres water

:

5 mL clopyralid + 15 mL MCPA

Wetting agent dilution

:

1:400

Time of application

:

Seedlings to early flowering stage

Remarks

:
  • Permit required if spraying within 5 km of a commercial vineyard or tomato garden
  • Avoid spraying other vegetation, especially clovers
  • Could also use clopyralid concentration at 750 g/kg - rates adjusted to 2 g/10L


Weed Description

Family:            Asteraceae

Form :             Herbaceous – Perennial

Status:            Present in WA 

                    (click to view image)

A creeping plant native of South Africa, also known as Berkheya thistle, Hamelin thistle and Augusta thistle.

African thistle is a herbaceous perennial plant 0.3 to 0.6 m high. It has an extensive root system with creeping underground stems (rhizomes).

Leaves:        It has spiny leaves about 5-10 cm long densely covered with white hairs on the lower surface with deeply cut spiny lobes.

Flowers:       Heads of small yellow flowers on short peduncles (flower stalks). The flower head is surrounded by pointed green bracts.

Seeds:         Smooth, 2.5 mm long and without the normal feathery pappus of other thistles. Seeds may remain dormant for several years in the soil.

 

Other relevant information related to this topic:

·       Quarantine WA

·       Permitted and quarantine species list

·       Permit for minor off-label-use of a registered agvet chemical product
(Permit number – per9655)

·       Off-label permit (olp) for use of a registered agvet chemical product
(Permit number - per4590)

·       Off-label permit (olp) for use of a registered agvet chemical product
(Permit number – per4594)