Weed of Week – Chilean Needle Grass

We’re into week five of our ‘Weed of the Week’ series, continuing to share important information on our region’s priority weeds. This week we’re focusing on Chilean Needle Grass.

As we head into the warmer months, Snowy Monaro Regional Council is calling on all community members to get to know our region’s priority weeds so we can understand how to play our part to protect our environment, help our farmers and support our community.

The impact of weeds on natural vegetation can be devastating and is estimated to cost the NSW economy about $1.8 billion annually (NSW Department of Industry, 2018).

What is Chilean Needle Grass?

As the name suggests, Chilean Needle Grass (Nassella neesiana) is native to South America. In Australia, it is a Weed of National Significance.

Chilean Needle Grass is a highly invasive, perennial, tussock grass and is considered a Priority Weed in the Snowy Monaro Regional Council area. It is a common invasive weed throughout much of south-eastern NSW where it dominates native and introduced pastures, roadsides and disturbed areas.

The true distribution of Chilean needle grass within the Snowy Monaro region is not well understood due to its insidious nature and ability to blend into grazed pastures; however heavy infestations are known to occur in the northern parts of the Snowy Monaro and in the Bombala district. Sporadic infestations are also known to occur on many roadsides throughout the region where livestock and machinery movements have contributed to its introduction and spread.

Livestock actively graze Chilean needle grass, making it particularly difficult to distinguish from other grasses in a pasture situation.

Why is Chilean Needle Grass a problem?

• It is highly invasive, producing both conventional seed heads as well as stem seeds at nodes under the leaf sheath. Seeds remain viable in the ground for many years. The persistent seed bank makes Chilean Needle Grass extremely difficult to control.

• It out-competes and dominates both native vegetation and improved pasture, reducing carrying capacity and biodiversity

• Adult plants are long-lived and very hardy

• It is very difficult to identify in grazed paddocks and can be confused with native spear grasses, Danthonia and fescue

• It injures animals eyes whilst grazing

• It can affect meat quality

• Seeds penetrate the skin of sheep causing irritation and reducing hide value

• Animals, vehicles, and machinery spread Chilean needle grass seeds. The hairs at the sharp end of the seed anchor in wool or fur

• Seeds can stay attached to animals for months

• Hay baled from paddocks with Chilean needle grass may contain seeds that then spread in the fodder

• Seeds disperse along waterways in floodwater and runoff

What can you do?

• Identification is key – learn how to identify and control Chilean Needle Grass

• Contact Council if you have any questions regarding Chilean Needle Grass or any other weeds on your property

• Long-term control aims to stop Chilean Needle Grass from seeding, and to reduce the soil seed bank

• Control options include crop rotation, pasture management and herbicide application

• Early detection and removal is vital – seed is long-lived in the soil and produced in large quantities, so preventing seeding is critical

• Control any plants found, before they set seed – this will prevent further infestation

• Keep livestock away from seeding plants

• Restrict animal movement from infested areas into clean paddocks

• The best control strategy is to keep Chilean Needle Grass off the property

• Avoid purchasing fodder from areas with known Chilean Needle Grass infestations – ensure purchases of fodder, produce, stock and soils are free of weed matter

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