Weed of the Quarter - Bellyache Bush

Most infestations are associated with old townships, dumps, roadsides, over-grazed paddocks, and the banks of watercourses. The worst infestations in Queensland exist along the banks of the Burdekin River and its tributaries, where some 40,000 hectares are infested. 

Since bellyache bush is unpalatable to stock it tends to proliferate at the expense of palatable pasture species.  The development of dense infestations can prevent the growth of pasture grasses and reduce the profitability of cattle enterprises. Most parts of the plant, including the seeds, are toxic. 

Bellyache bush reproduces from seeds and vegetatively from broken stems and roots.  Most seeds fall close to the parent plants.  However, if the plant is growing close to waterways, flowing water can disperse the plant’s pods.  Seeds can also be transported as a contaminant of garden soil and within mud adhering to stock and machinery.  Dispersal of seeds by birds has been reported.  Prolific seedling emergence can occur for at least four years following destruction of mature plants.  Fire can kill young plants, provided sufficient fuel exists.  Regular slashing can reduce the plant’s rate of spread and can kill mature plants, although seedlings survive.  Chemical control is effective and two herbicides, metsulfuron methyl and fluroxypyr, are registered for use in Queensland. 

Burdekin Shire Biosecurity Plan 20-25 has identified Bellyache bush as one of the priority pests with the management option to containment and asset protection.

Burdekin Shire:  Dense populations with some pure stands exist along the banks of the Burdekin River.  Most populations are less than one hectare in size, but some are 2-3 km long and 200 m wide.  Scattered infestations exist elsewhere in the Shire.

Considering the plant’s impact in the Burdekin catchment, containment and asset protections will produce substantial long-term savings to the Shire economy. Without continued intervention, bellyache bush will become more abundant. 

Burdekin Shire Pest management team besides undertaking regular roadside spraying has participated in UQ research project with landholders for biocontrol using moths.

Under Biosecurity Act 2014 it is an individual landholder’s responsibility to manage the declared weeds on their land parcel. Burdekin Shire Pest management team assists in identification, advice on management and subsidised herbicide policy to help landholders meet their biosecurity obligations.

• Restricted invasive plant recognised in Australia as a Weed of National Significance.
• Escaped Ornamental in North Queensland.
• Somewhat similar appearance to Castor Oil Plant (Ricinus comminus)
• Belly ache bush is a squat, thick stemmed shrub. 2.5-4m tall.
• Young leaves lobed and purple coloured, older leaves light green colour.
• Flowers are small and red with yellow centres.
• Flowering occurs throughout the year when moisture is suitable.
• Seed pods are smooth and oval, size of a Cherry.
• Seeds germinate Oct-Dec.
• Highly invasive, taking over very quickly.
• Spread by fruit eating birds, water, livestock, and machinery.
• Poisonous to stock, usually accidently eaten amongst grass when weed is young.

• Herbicide control includes Metsulfuron-methyl or Starane Advanced, foliar spraying and thoroughly wet plants.
• Repeated slashing will help reduce density and planting heavy grasses inhibits infestation.
• Some Trial Biocontrol agents released in the Burdekin Area recently.

More information can be obtained on https://www.business.qld.gov.au/industries/farms-fishing-forestry/agriculture/biosecurity/plants/invasive/restricted/bellyache-bush Or by contacting BSC Pest Management on 07 47839800

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