Problematic pimelea plant
Queensland’s fight against a toxic weed
I’M A diehard weeds person and, after spending my entire career delving into the vast spectrum of weed management issues, I know the story of pimelea is a unique one.
There are very few weed issues that have inspired such co-investment, cross-industry support, and even graziers donning lab coats all to reduce the impact of pimelea in the paddock.
Pimelea is a native, toxic weed that occurs across inland Australia, predominantly on red clay and sandy soils, including western Queensland.
From Winton, down to Dirranbandi, and as far east as Miles, growing in amongst pasture grass after winter rain, these scrawny little plants – indistinguishable to cattle – average a cost to producers of $40,000 or a loss of 40 head of cattle per year.
A cumulative toxin – even eating one small plant or two grams of dry matter per day for a month – will bring on the symptoms of cattle toxicity, which include diarrhoea, swelling and lethargy, and eventually death, unless early detection occurs.
There has been intermittent research conducted over the years but, being a native plant, pimelea falls out of Biosecurity Queensland’s sights.
Dry summers followed by wet winters provide the perfect conditions for an abundance of plants, and after two very bad years of cattle losses from 2015–2017, producers were desperate for progress.
AgForce committed to finding a solution on behalf of the industry and agreed to act as an intermediary between the Department of Agriculture and Fisheries, the University of Queensland and producers.
Pledging cash and in-kind donations to get the project going, producers’ donations were matched by Meat and Livestock Australia Donor Company funds.
The response was overwhelming, with 43 affected producers and organisations pledging $420,000 over three years.
The first year’s cash pledges of $75,000 were matched by MLA, allowing researchers to begin collecting pimelea plants and rumen fluid samples.
Community feedback, along with the financial cost to industry, was recognised as a major national agricultural issue and resulted in MLA committing a further $1.5 million to a three-year project addressing plant toxins, including pimelea.
Testing of rumen samples from affected and unaffected animals to determine which bacteria survive being trickle fed pimelea in an artificial laboratory rumen could lead to a rumen inoculum which can overcome plant toxins.
While we hold out major hope for a rumen inoculum, AgForce has also commenced seeking resources and collaborators to help reduce the impact and abundance of pimelea in pasture.
These include investigating the role of soil nutrition, herd composition, herd nutrition and herbicide management of pimelea.
We are hopeful all this research will lead to one or more management actions that producers can take during identified high-risk times and protect their herds from suffering due to pimelea toxicity.
I am proud of the part AgForce has played in helping the collaboration of producers, livestock agents, scientists, and industry groups – all to reduce the impact and abundance of this native toxic plant and the devastating effect it can have on cattle and cattle graziers.