Tropical soda apple is a fertile pest on the North Coast and adjacent Tablelands and its fate remains at tipping point. But more than stop gap funding is required if it is to be eradicated from our landscape.
If pulling or spraying this invasive species isn’t continued, apace, Australia might lose its grip on yet another expensive introduced weed.
The current approach is three-pronged, with Local Lands Services providing on the ground support while Department of Primary Industries deals with inspections and detailed mapping.
Landholders are responsible for their own patch.
The approach works well, says Jonathan Lawson from Northern Tablelands LLS, who has waged war on this weed in the Upper Macleay Valley since 2013.
“But government needs to support the work of the landholder if we don’t want to see grazing country set back by $20m a year in lost production,” he said. “Until four months ago I didn’t have funding.”
What started as a misconstrued threat in the late 1990s was recognised several years later as the same weed which in Florida went from 10,000 hectares to 500,000 ha in less than a decade.
In 2013, when the Northern Tablelands Local Land Services formed and began a co-ordinated attack on the “weed from hell”, the brazen Brazilian occupied rugged eastern fall country across 7500ha with bushes in some places a storey high.
Today tropical soda apple in that area of the upper Macleay is light and scattered,
“It used to take two weeks and now it takes four to five days, every three months, to patrol that area and we use a fraction of the chemical that we once did,” said Mr Lawson.
But a funding cut in 2017 by the NSW treasury put at risk seven years of hard work as the resilient feral species has a propensity for re-seeding with viable genetics remaining in the soil for up to 10 years.
Work carried out by DPI scientist David Officer at Grafton research station has proven that tenacity in seed propagation.
Not only that, but the sticky mucus which holds the seed within its pod is like glue when exposed to air. Slasher blades and mower shields become key ingredients in seed transport.
Actually, cattle provide the primary vector for moving seed around, while deer do as well and sometimes cockatoos and galahs. But cattle love the seed pods, which appear like miniature watermelons just before turning yellow and ripe.
Their manure provides terrific compost so quarantining stock in a clean, fenced paddock one week before trucking them out for sale is encouraged as part of biosecurity. There is every chance that monetary fines will come into place to encourage this quarantine.
To successfully eliminate the weed involves specific use of expensive Grazon Extra - with Triclopyr, Picloram and Aminopyralid. Plain old Grazon doesn’t cut it and apparently neither do the generic brands.
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When plants are young they can be hand pulled but as they are armed with impressive spikes Mr Lawson suggests wearing leather riggers’ gloves underneath a pair of welder’s gauntlets for protection.
In the war on this weed, hired hands are required to patrol the rugged country in which it resides, like islands of thick vegetation in the middle of the Macleay – places no grazier would wish to spray and chip for weeds.
“The law says landholders must control their own properties but we can’t expect them to wade across rivers and crawl through tea tree to pull Tropical soda apple,” Mr Lawson says. “It just wouldn’t get done.”
For this year the eradication program has been funded for another 12 months with $40,000 from the NSW Government and a further $50,000 from the Australian Government’s 2018 Pest and Weed Drought Funding Program.
“We are extremely grateful for this ongoing investment. It is positive to see this joint partnership between all tiers of government, landholders, Local Land Services and the New England Weeds Authority” said Mr Lawson.
Sticky beginning
Landholders in the upper Macleay first reported the Florida import in the late 1990s but was first mistaken for a native Solanum. The popular story says sticky seed came into the country on haymaking equipment, imported from Florida. During a drought year everybody bought hay and it got away.
For seven years Northern Tablelands weeds officers were funded to keep the species in check – patrolling from Georges Junction above Bellbrook downstream to Comara Station, where the Kempsey council rangers took over and continued their fight for another 30km of river towards Kempsey and beyond, where scattered pockets exist all the way to the tea tree swamps lying just behind coastal sandhills.
The team eradicated the plant from the top of the Tablelands but was still actively controlling it, through quarterly expeditions down the Macleay. Where quarterly controls had once taken a fortnight now patrols are down to four or five days, focussing on GPS targeted locations.
Last year weed funding was cut and the fate of this vigorous import hung in the balance.
“There is still a lot of work to do,” Mr Lawson said, pointing to detailed and careful mapping so spray contractors can return to known infestations. LLS is working on placing a switch on the trigger of a spray unit so every squeeze of the handle records a GPS mark.
In saying that Mr Lawson noted that there had never been an invasive weed success story in the history of Australia, but the eradication of tropical soda apple is still within reach provided everyone steps up to the challenge.