Khaki weed

Khaki weed (Alternanthera pungens), a native of South America, is widespread throughout north west New South Wales. The plant is spread readily by its many sharp burrs which attach to animals, motor vehicle tyres etc. The same burrs are a real problem for working dogs and, in urban areas, to humans who like walking around without shoes! Khaki weed has a strong tap root which enables it to survive quite well during dry periods.

Khaki weed grows in dense patches and "flat on the ground". It is easily distinguishable by its many white/yellow prickly burrs. When mature, these burrs stick to bare feet, shoes, motor tyres etc.

Also included in the photo on the right is another plant from the same Amaranthacae family - Gomphrena celosioides Mart. (common names "gomphrena weed, or "soft khaki weed").

Gomphrena weed is invasive, and has become widespread in the north west in recent years. Unlike khaki weed, gomphrena does not have annoying "burrs". The soft flowers (photo left) make the plant easy to identify.

Khaki weed is a problem for dogs. The sharp burrs stick into their feet. According to Noxious Plants of Australia by Parsons and Cuthbertson (Inkata Press):

"khaki weed is believed to be poisonous to animals and to cause a skin ailment in cattle. Fortunately it is not readily eaten, although at times young plants are moderately palatable to sheep and are consumed, apparently without ill effect"... "It is claimed also to cause hay fever, asthma and dermatitis in some people".

On gomphrena weed, "Plants of Western New South Wales" by Cunningham, Mulham, Milthorpe & Leigh (Inkata Press) notes "... horses grazing on areas containing large amounts of this species have developed a form of staggers (Everist 1974)...

MORE INFORMATION: "Noxious Plants of Australia", by Parsons and Cuthbertson [Inkata Press].
"Plants of Western New South Wales" by Cunningham, Mulham, Milthorpe & Leigh (Inkata Press)

(The editor does not have any information at this time on treatments for gomphrena weed). According to NSW DPI’s excellent booklet “Noxious and Environmental Weed Control Handbook 2001/2002”, treatments for khaki weed include:

Non-chemical options: Improve lawns and turf density to create competition, grub at least 50mm of the root;

Chemical options	Rate: Spot/Boom	Comments
2,4-D ester 800 g/L Various trade names	70-100 ml in 100 L of water 700 ml to 1.0 L per hectare	Young seedlings only.
2,4-D amine 800 g/kg Baton®	900 g to 1.8 kg per hectare	Seedlings only.
2,4-D amine 500 g/L Various trade names	140-280 ml in 150 L of water 1.4-2.8 L per hectare	Seedlings only.
Picloram and 2,4-D Tordon 75 D®	650 ml in 100 L of water	Active growth in full leaf.
Dicamba + MCPA Various trade names eg Banvel®	470 ml in 100 L of water 4.7 L per hectare	Seedlings only. A second treatment may be required after four weeks
Amitrole + ammonium thiocyanate (various trade names)	1.1 L in 100 L of water	Actively growing plants.
2,4-D isopropylamine Various trade names	3.0-6.1 L per hectare	Spray seedlings only
2,4-DLV ester 400 g/L Nufarm low volatile ester 400®	1.4-2.0 L per hectare	Young seedlings only.

Pesticides must only be used for the purpose for which they are registered and must not be used in any other situation or in any manner contrary to the directions on the label. Never use a herbicide in any way contrary to the label recommendations.

DISCLAIMER: The information contained in this web site is based on knowledge and understanding at the time of writing. However, because of advances in knowledge, users are reminded of the need to ensure that information upon which they rely is up to date and to check currency of the information with the appropriate officer of North West Weeds or the user’s independent adviser.
LRT23/4/03

Send mail to lestanner@aapt.net.au with questions or comments about this web site. Copyright © 2007-2008 Last modified: 25/11/07 - L R Tanner

Send mail to lestanner@aapt.net.au with questions or comments about this web site.
Copyright © 2007-2008 Last modified: 25/11/07 - L R Tanner