|Botanical Name||Nassella neesiana|
IdentificationIt is an erect, tufted, perennial tussock-forming grass which is harsh to the touch. In the absence of grazing it can reach 1 metre tall and is some what like tall fescue in general appearance. Under grazing it forms dense clumps by producing many shoots from its base. The leaves are 1 to 5mm wide, flat and strongly ribbed on the upper surface, with rough margins caused by short marginal hairs. The upper surface is bright green with the underside a duller or paler grey-green colour. This grass produces distinctive seeds in large, open, drooping flowerheads (panicles) and also hidden seeds at the nodes inside the leaf sheaths. The seed has a long (60 to 80 mm) hair (awn) joined to the hardened seed head, which is 8 to 10mm long. The seed head has a hard, hairy and pointed callus which provides it with an extremely sharp penetrating base.
HabitatsChilean needle grass grows in dry, low fertility open habitats but does not establish in fertile and productive pastures where competition form other plants is too great. The present restricted distribution of the plant is probably due to lack of wind dispersal of seed and lack of stock movement from infested farms to other regions suitable for establishment. Localised spread occurs through seed being transported by stock, in hay, on clothing, by machinery and also in water.
Impact to Biota and EcosystemsChilean Needle Grass is basically unpalatable to stock and forms dense stands in pasture reducing productivity quite drastically. The sharp seeds damage pelts, blind livestock and become a serious wool contaminant. They have the ability to move through the animals skin into the body muscles, causing abscesses and the downgrading of carcasses.
On small infestations all plants should be grubbed out before they flower and set seed (in November and December).
Plants grubbed out should be destroyed by burning.
|Chemical Control||Larger infestations should be treated annually with an
appropriate herbicide before plants flower and set seed. Where
necessary, treated areas should be revegetated with desirable
The most suitable herbicide is: Glyphosate Gunspray 1 litre/100 litres water plus Penetrant
Knapsack 150mls/10 litres water with plus Penetrant
Report any sighting of Chilian needle grass to your local Pest Plant Officer.
This native of Argentina and Chile was first recorded in Auckland, New Zealand in the 1930s. Sites at Western Springs and the Waitakere Ranges are small, however much more extensive infestations occur in Hawke's Bay and Marlborough.