Waikato farmers urged to keep sharp biosecurity measures against Chilean needle grass

Chilean needle grass is a particular risk for sheep and beef farming areas.

Waikato Regional Council is asking farmers for vigilance to help keep the region free of a grass with needle-like seeds that can cause irreparable harm to stock and outcompete other pasture species.

Pest plants team leader Darion Embling says while not found in the Waikato, Chilean needle grass seeds can easily hitch a ride from other regions by screwing into clothing and stock pelts, skin and flesh, on equipment and machinery, and even in gravel or fodder.

“This is really nasty stuff and it is found in the North Island in Hawke’s Bay and in the South Island in Marlborough and Canterbury.

“We really need farmers to be vigilant about inadvertently bringing Chilean needle grass into the region, so that means understanding the likely pathways of spread and always ensuring biosecurity starts at any farm gate.”

Chilean needle grass, which does well in drought, will outcompete and displace other pasture grasses and is a particular risk for sheep and beef farming areas.

“If it were to establish in the Waikato, that would put over half a million hectares of sheep and beef farming at risk.”

Left: Identifying Chilean needle grass. Right: Chilean needle grass caught in sheep wool.

Chilean needle grass can cause considerable economic losses by downgrading lamb and sheep meat, wool, skins and hides. The needle-like seeds, which are about 7cm long, can penetrate the skin and the flesh of animals.

A corkscrew-like awn helps force the seed through the skin and muscle. The seeds also have backward-pointing bristles, which make them hard to remove once they are embedded.

“If it gets caught in sheep’s wool it’s next to impossible to remove, in the eye it can cause blindness, and if eaten by stock it can cause mouth abscesses or internal injuries,” says Embling.

“It’s also very hard to eradicate as it seeds prolifically and builds up large seed reserves in the soil.”

What does it look like?

• A tussock-like grass up to 1m high
• Leaves are 1-5mm wide and up to 30cm long, and bright green in spring and summer.
• Leaves are covered with small erect hairs giving them a shaggy appearance — the upper surface is strongly ribbed, and the edges feel rough to the touch
• Leaves roll inwards when plants are under drought stress
• Purple-tinged flowerheads form on long stalks above the foliage in spring and summer.
• Flowering heads have a 60mm-long pale-green awn (tail) at the end of the seed and a wind-blown horizontal appearance

If you think you’ve found Chilean needle grass on your property or machinery or would like to know about source areas and clean-down advice, please call the regional council’s pest plant team on freephone 0800 800 401.

Stay up to date with the Waikato Herald

Get the latest Waikato headlines straight to your inbox Monday to Saturday. Register for free today - click here and choose Local News.