Chilean Needle Grass (RPMP 2018)
How Do I Identify It?
CNG is very difficult to identify when it is not seeding. It can look very similar to other pasture species although generally has a thinner more pointy leaf - more of a tussock look than grass. The root system is bulbous, similar to Nassella Tussock.
The panicle seeds can be identified by the sharp feathery tip, a collar at the base of the seedhead called a corona and a long twisted tail (awn).
YouTube Video - Chilean Needle Grass
Below is a video to help with identification. If you are still unsure if you have the plant, take a picture of the plant and send it to CNG@marlborough.govt.nz or ring the Biosecurity team on Ph: 03 520 7400.
How Is It Spread?
The seed is heavy and will generally fall close to the parent plant, building up a large amount of seed in the soil around the existing plants. The seed is very sharp and spreads by attaching itself to anything that brushes past the plant. Therefore CNG seed is spread predominantly through stock, people, vehicles and machinery. Stock feed such as hay is also how seed can be spread to new areas.
Earthmoving machinery is a high spread risk due to the seed remaining viable in the soil for 12+ years, therefore dirty earthmoving machinery can carry contaminated soil.
How Can It Be Controlled?
- CNG has been in Marlborough since the 1970s. Prior to 2011, CNG was near impossible to control, which is the reason it has been able to spread to the large area it is in now. In 2011, a herbicide called Taskforce was registered in NZ for the control of CNG.
- Taskforce is an effective product that kills the plant through the root system and leaves a residue in the soil for up to 4-5 years. The product is still new to NZ and we are still finding out the best use of the product for our conditions.
- If using Taskforce please read the label carefully as it is a technical herbicide and must be applied correctly, and there are stock withholding periods.
- All broad acre application of Taskforce should be followed up with an improved pasture regime otherwise there is likely to be an increase in broadleaf weeds and thistles on the sprayed site.
- Taskforce is also effective on nassella tussock.
- Currently the Council is running a programme to assist landholders in their CNG control. Please ring the Biosecurity Team for more information - Ph: 03 520 7400.
- Glyphosphate on its own is not an effective control method as the general foliage death in the area treated allows more CNG to germinate and increases the amount of CNG present.
- Glyphosphate can be added with Taskforce to give an immediate knockdown of seeding plants and Taskforce will provide a residue to keep CNG seeds in the ground from germinating.
- Grubbing is not effective as the disturbance of the soil allows more seeds to germinate and grow back quickly.
- Mowing is not an effective control method as with continued mowing the plant will modify its growth to produce stunted panicle seeds below the mowing height. Also the plant is still producing seeds mid-stem and from the base to enable its spread. Mowing should not be used when CNG is seeding as there is an increased risk of spreading the plant further through the mowing activity.
How Can I Stop It Spreading If I Already Have CNG?
- It is a legal offence to knowingly spread CNG therefore if you have CNG on your property you must take all precautions to minimise any spread from your property.
- Fence CNG areas off to stock and vehicles over the seeding period or ensure that CNG areas are not entered into. If stock must enter seeding areas they should not be sold at sales but go straight to slaughter.
- Hay or other stockfeed containing CNG should not move off the property. Agricultural contractors need to be told of the spread risk of CNG so they can initiate appropriate vehicle hygiene protocols.
- No stock and vehicles used in CNG areas should move off the property over the seeding period and in times of muddy conditions.
- If spot spraying you can add Glyphosphate with the Taskforce, Glyphosphate will kill the plant to eliminate seeding for the current season and the Taskforce will leave residue in the soil to stop any further seeds from germinating.
- Even the most experienced eye for the plant can miss individual plants so always keep a clean vehicle or have a specific vehicle that is used on the farm only.
- Check your clothes, dogs and vehicles regularly for the seed and destroy the seed if found.
- Inform people coming on to your property about the risk of CNG spread and make sure they stick to formed roads and tracks and park up in designated areas.
- If you have a washdown facility ensure they use it before leaving the property.
- To minimise the spread risk you can apply Taskforce on the sides of major thoroughfares and park up areas on your property.
How Do I Stop CNG From Coming to My Property?
- Know how the plant can be spread and take precautions to ensure minimal vehicle and stock movement on your property
- Have washdown facilities available to clean vehicles before entering your property.
- Do not buy stock or hay from known CNG properties and do not send your stock to CNG vineyards for grazing that are going to be returned to your property - it is not worth the risk.
- Ensure you know what the plant looks like and search your property for it - found and controlled early is the best chance we have of eliminating it on your property.
- For further advice, see our on-farm biosecurity page. There are on-farm biosecurity signs available for your farm; if you are interested these are available free from the Council.