Hudson pear infestation at Cooladdi covering hundreds of hectares

It's a familiar story of a garden plant that escaped and has since gone rampant, potentially reducing the viability of the affected land, and land values, to say nothing of the serious injury it can do to humans, livestock and wildlife.

Southern Queensland Landscapes project officer Lucas Mackie said the invasive cactus species of Mexican origin, a weed of national significance, was dotted over thousands of hectares but a targeted spraying campaign was working on 320ha of the worst affected sites.

Overland flow has been washing the pear into Quilberry Creek and then into the Paroo River, and down into the Darling River system.

"Hudson pear infestations are hard to kill because the spines have a harpoon barb on them and they will get onto anything," Mr Mackie said. "Even if you just graze past the cactus, pieces of it will stick to you and then you will spread it anywhere you go; with each piece able to reproduce new plants very quickly."

The spines are encased in a detachable sheath that remains embedded in a wound even after the body of the spine is removed, which means the spines can kill owing to infection.

Funding through the federal and state governments' Queensland Feral Pest Initiative has allowed a four-year strategic control program to be implemented, working with land managers and the Kooma Aboriginal Corporation on repeated spraying efforts.

Contractors are equipped with GPS trackers to pinpoint where they've sprayed and to allow follow-up control.

A recent inspection showed some plants recovering from their December treatment, thanks to the density of the infestation, difficulty reaching all parts, and the good wet season that the area's been experiencing.

Mr Mackie said its persistence meant they would need all the years allocated to make a difference.

"SQ Landscapes is grateful to local land managers for the opportunity to collaborate because a community approach for control of a weed like this is essential to minimise the spread and risk," he said.

Margaret Vetter of Cooladdi Park said she and her husband Paul devote over 40 days each season to weed management but despite this, Hudson pear has been a threat for over a decade.

"Weed management is part of our yearly program. Every year we try to check any areas, particularly flood areas, that may have unwanted plants," she said.

"Our creek channels are extremely important with the body of feed grown after floods.

"It is our most productive country and controlling Hudson pear is a high priority for our 20,000ha grazing operation."

Kooma Aboriginal Corporation's Senior Ranger Geoff Drury said the infestation in the Cooladdi area was one of the worst he's seen.

"You couldn't ride, walk or lay a picnic blanket down; the infestation was that bad.

"If we all don't play our part in managing these invasive weeds, it will become a big problem. The country has lost productivity, and you just can't enjoy it anymore.

"If your land becomes less productive, it costs more money to run, and it costs you more to produce your product. Before long, you have to throw hundreds of thousands of dollars at it."

He said it was important for indigenous people to be involved in landcare because everyone cares for land in different ways.

"The minute you stop looking after Country, is the minute it won't look after you," he said.

Hudson pear is a category 2,3,4 and 5 restricted invasive plant under Biosecurity Act 2014 requiring all sightings to be reported to Biosecurity Queensland within 24 hours of discovery.

Biosecurity Queensland can be contacted on 13 25 23.

Each local government has a biosecurity plan that covers invasive plants in the area, and land managers should contact their local government for more information.

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