Pest plant concerns
FARMERS in Tairawhiti have been urged to keep an eye out for Chilean Needle Grass in their paddocks, and, if they spot it, contact Gisborne District Council or the Rural Support Trust.
The pastoral pest has flourished not far away from this district, in Hawke's Bay.
“I have been alerted that Chilean Needle Grass is now rampant down there,” said long-time Gisborne farmer Simon Cave.
“It has also infested on the Tukituki Plains, with another outbreak east of the Tukituki.
“My contact down in Hawke's Bay warned the Hawke's Bay Regional Council years ago about it, but, like other issues, the council woke up too late,” Mr Cave said.
“He said Chilean Needle Grass could jeopardise the future of livestock farming as we know it in Hawke's Bay.”
The grass primarily affects sheep.
“If it gets into Gisborne hill country it will be bleak,” Mr Cave said.
“It is semi-controllable in cropable flats, but it is not only unpalatable for stock, it penetrates the hides.”
Chilean needle grass — scientific name Nassella neesiana — is a tufted perennial tussock which can grow up to 1m tall when ungrazed.
Online information indicates it is drought tolerant and very competitive with pasture species.
The seeds are approximately 7cm long, with sharp, needle-like tips that can penetrate skin and flesh. The corkscrew-like awn helps to force the seed through the skin and muscle.
Seeds also have backward-pointing bristles which make them hard to remove once they are embedded.
Leaves are bright green, 1-5mm wide and up to 30cm long. They roll inwards when plants are under drought stress.
Leaves are covered with small, erect hairs giving them a shaggy appearance. The upper leaf surface is strongly ribbed and leaf edges feel rough to the touch.
Chilean needle grass produces many tillers when grazed, forming dense tussocks that exclude other pasture species. Tillers are swollen at the base.
In summer, before flowering, the plant appears lighter green than other grasses.
However, it can be hard to identify and is sometimes confused with danthonia (Rytidosperma spp.).
Seed heads up to 30cm long are present from mid-October to early January. When they first emerge, they are reddish-purple in colour with long, light green awns (bristles).