A Marlborough farmer battling an invasive pest plant has found a way to manage it, but says it will take decades to repair damaged land.
Chilean needle grass Photo: Supplied / Marlborough District Council
Philip Pratt's Seddon farm was among many in the region to be badly infested with Chilean needle grass, but a recently available targeted herbicide has had good results, along with an intensive follow-up land management plan.
Stock do not like to eat the weed and during the flowering season it produces a spear-like seed which attaches itself to animal fleece or hair, and is capable of cutting and injuring animals.
It is spread by soil, machinery, vehicles, hay or baleage, humans and animals.
The new chemical, Taskforce, had longer-term residual properties and targeted Chilean needle grass and another tussock, Mr Pratt said.
"We can say we now have it managed, a lot better than previously when we relied on glyphosates and others but as soon as it wore off, the needle grass was back almost immediately."
A report to the council's environment committee said the weed is still a serious problem for the rural community in Marlborough and is likely to be so for many years.
It estimated close to 3000 hectares of land had been damaged by infestations of the weed.
Twenty-six Marlborough properties are classified as heavily infested, which means they have to clear boundaries back 10 metres and keep them free of the pest weed.
There are 40 fringe properties with moderate infestation and landowners have to destroy all Chilean needle grass each year. A further 110 properties are under surveillance, meaning they have small, light or recently found infestations.
Hawke's Bay and North Canterbury rank second and third for levels of infestation, which are not as severe as in Marlborough.
Marlborough district council's proposed plan to tackle the weed includes an application to the Environmental Protection Authority to introduce a rust fungus as another way to fight the spread of the grass.
Mr Pratt co-chaired the Chilean Needle Grass Action Group, and said as well as spraying, farmers were rotating crops as much as possible to manage the problem.
His property was one of the 26 with a heavy infestation and he was not sure he would ever fully get on top of the problem.
"But as far as I'm concerned I can now manage it, as long as the follow-up after the spray is intensive."
