An invasive weed spreading on the New South Wales north coast has been described as one of the biggest biological threats seen in decades
There’s growing concern in the region about recent outbreaks of Tropical Soda Apple.
One of the planet’s most invasive weed species has been identified on four separate properties in recent months.
Jim Willmott, from Far North Coast Weeds, says it has the potential to cause serious damage to grazing land.
He says Tropical Soda Apple represents one of the biggest biological threats seen in decades.
“This has the potential to be the biggest impact on the grazing industry since Giant Parramatta grass was first discovered some 25 years ago,” he said.
“In the (United) States, where they found it in 1987 and it covered 10,000 hectares, it’s now spread to half a million hectares in 10 years covering nine states.”
Mr Willmott says one outbreak already covers about 1000 hectares, and there are fears it will continue to spread.
“These plants have a lot of mature seeds on them which cattle like to eat and we’re very worried that, as has happened in America, that the native animals have started to get a taste for this fruit and once that happens it will be very hard to contain,” he said.
Identification of the weed
Tropical Soda Apple is an upright perennial shrub growing to two metres in height.
It has broad-based, straight, cream-coloured prickles to 12mm long scattered on most plant parts.
Leaves are mostly 10-20cm long and 6-15cm wide.
The upper and lower leaf surfaces are densely covered in short hairs; mid-veins and primary lateral-veins are cream coloured on both sides of the leaves.
Flowers are white, with five petals 2-4mm long. They occur in clusters of three to six, off a short stem.
Mature fruit are yellow and golf-ball size (20-30mm in diameter). When immature they are pale green with dark green veins, like immature water melons.