20 September, 2021
Fireweed blazing through local paddocks
An increasing amount of the invasive plant Madagascan Fireweed (Senecio madagascariensis) has been spotted in the area surrounding Clifton, causing concern for primary producers as it competes with pasture and is toxic to livestock.
Fireweed is a restricted invasive plant under the under the Queensland Government’s Biosecurity Act 2014.
This means landholders have a General Biosecurity Obligation (GBO) to manage the biosecurity risks associated with invasive plants and animals that are under their control and that they know about or should reasonably be expected to know about.
Fireweed generally begins to become visible in the landscape around August.
It has been burnt into the mind of many farmers for a few years now.
It is usually a weed of beef and dairy pasture and even light infestations can produce one million seeds per hectare.
In 2016, the Cambooya Landcare Group held a field walk to educate the public about the weed after the Queensland Herbarium confirmed speciments taken from East Greenmount and Felton were in fact Madagascan Fireweed.
Toowoomba Regional Council’s Environment and Community Committee portfolio lead Cr Tim McMahon said there are 27 native species of Senecio in Queensland, with two varieties commonly found across most parts of the Toowoomba Region.
Nine species have similar flowers with conspicuous yellow rays.
“Only the introduced Madagascan Fireweed (senecio madagascariensis), is a category 3 restricted invasive plant under the Biosecurity Act 2014,” Cr McMahon said.
“Senecio madagascariensis has been identified in a few isolated areas along the eastern boundaries of the escarpment.”
“All species of fireweed can be toxic to livestock (native and introduced), and affected landholders are encouraged to manage those infestations”
To assist with the identification of this invasive plant, Cr McMahon said council has developed
fact sheets, which are available to the community, in addition to material from the Department of Agriculture and Fisheries.
“These fact sheets are distributed to landholders and relevant stakeholders through educational and awareness programs.”
“Information about this plant is also included in a Pest Management Newsletter which goes out to relevant landholders and stakeholders,” he said.
Wild turnip can also be mistaken for Madagascan Fireweed, as it grows as a yellow flowering field.
All senecio plants have a similar ability to set seed and produce pyrrolizidine alkaloids which are toxic to livestock, particularly cattle and horses, causing chronic liver damage.
The damage to the liver is cumulative over the life of the animal, it is irrerversible and no treatment is available.
Fireweed is preferentially avoided by livestock, therefore poisoning is more likely to occur if there is a shortage of other feed on offer.
HOW TO SPOT IT
- Flowers have conspicuous yellow rays (petal-like structures) more than 2mm long.
- Involucral bracts (green part surrounding the flower head) are all more or less the same length and slightly overlapping.
- There are 18 to 22 involucral bracts per flower head.
- Leaves nearly always whole or undivided except for small teeth on the margin (lower leaves sometimes have a few large lobes).
- Achenes (seeds) are 1.5–2mm long (excluding pappus) and 0.3–0.5mm in diameter.
The Department of Agriculture and Fisheries suggests “the best control for fireweed incorporates integrated management strategies, including herbicides and mechanical methods in addition to vigorous permanent pastures that can compete strongly with fireweed seedlings.”
Reports of suspected fireweed infestations can be made to TRC on 131 872.
For more information, visit the Department of Agriculture and Fisheries website.