A new study has revealed Chilean needle grass could cost New Zealand more than a billion dollars unless more is done to control its spread.
The grass can ruin pasture and has sharp penetrating seeds that can cause blindness, deafness and abscesses in animals. And it could also increase the price of meat.
This little seed is a big problem. Posing a $1.1 billion threat to the country, Chilean needle grass can cut farm productivity by 25 percent.
The seeds drill their way into animals' eyes, ears and bellies which can cause permanent damage.
"It really is a serious animal health issue," said AgResearch principal scientist Dr Graeme Bourdôt.
The noxious plant was first found here in about 1930 - and has since taken hold in Hawke's Bay, Marlborough and Canterbury.
But new modelling shows under future warmer climates it could spread to nearly 6 million hectares of New Zealand.
"It can spread across all regions of New Zealand except the West Coast," Dr Bourdôt said.
"To determine this potential range we built what we call a climate niche model, based on the distribution of the plant overseas."
The findings are a concern for farmers who've been battling the pest for years.
Marlborough farmer Warwick Lissaman has been leading a Chilean Needle Grass Action Group since 2014.
"Your ability to earn income from your land is really restricted if you have Chilean needle grass and want to run livestock," he warned.
Which can drive meat prices up, due to a lack of supply.
"Ultimately there will be less viable businesses, so therefore less volume of product," Lissaman said.
However, that could be avoided. Researchers and farmers are calling for the Government to treat needle grass as a national threat rather than a localised problem being dealt with by individual councils.
They want the Ministry for Primary Industries to oversee the issue and fund surveillance programmes.
"Aimed at stopping its spread from the current infestations," Dr Bourdôt said.
And stopping the damage to animals and farms.