Khaki Weed (Alternanthera pungens).
Khaki Weed is also known as Creeping Chaff weed. Originally from Southern America, it is a long-lived creeping perennial with a deep taproot and has spiny burrs.
The burrs injure people and animals, and cause hay fever, asthma and skin redness. Khaki Weed is a declared weed in VIC, NT and SA.
After you read this, you will be able to:
- Identify Khaki weed in your lawn or turf area.
- Know what conditions favour its establishment and growth.
- Know how to control this weed.
The distribution map of Khaki Weed in Australia is courtesy of The Atlas of Living Australia.
How to Identify Khaki Weed.
The easiest way to recognise Khaki Weed:
- An annual matt forming weed.
- Its dark green leaves are in opposite pairs of unequal size. They are 1 to 4 cm long, and 1 to 2 cm wide.
- The leaves are egg-shaped, hairless or sparsely hairy leaves.
- It has cream flowers in clusters, that are 6 to 10 mm long and have sharp points.
Photosynthetic Pathway: Khaki Weed is a C4 weed.
Flower: From Spring to Autumn, Khaki Weed produces small clusters of flowers in the leaf forks. As these mature they develop sharp points at the tip and prickles at the base. The flowers are unobtrusive cream-coloured, and have an oval shape. They have hairs with barbs at their base. The fruit is a chaff-coloured prickly burr about 1cm long.
Height: Khaki Weed is prostrate weed.
Leaf length: The hairless leaves of Chaff Weed are 1 to 4 cm long.
Leaf width: The leaf width is 1 to 2 cm, and the leaves do not have stalks.
How Does Khaki Weed Spread.
Khaki weed spreads by seeds that stick to tyres, clothing and animals. It is a prolific seeder, and the seeds are viable for many years. Local spread occurs by spreading stems that root at nodes. These reddish stems are 50 to 60 cm long, with soft silky hairs, and often form extensive mats.
Comments: The roots of Khaki Weed form at the nodes of the stems. The stems are prostrate, have a reddish colour, and can be up to 60 cm long. Under a microscope, the stems of Chaff Weed have fine teeth and soft silky hairs.
The leaves have prominent veins on their underside. Khakiweed produces a deep taproot that it uses to store carbohydrates for emergence and growth in subsequent years.
Habitat: Creeping Chaff weed prefers tropical and subtropical regions. It is widespread in waste areas, caravan parks, and playing fields.
Khaki weed is a strong indicator of light, high moisture soils over the spring and summer, and is included in our weed ID Chart. It tolerates periods of drought due to its deep taproot and waxy leaves.
How to Control Creeping Chaff weed.
Cultural and chemical control will control Khaki Weed in your lawn and turf.
Cultural control of Khaki Weed.
- Practice good hygiene if you are using machinery in infected areas.
- Hand removal works as long as you remove the crown and the taproot. You must make sure that you remove all root material. If you break the tap root of Khaki Weed when you remove it, new plants will grow from any material left in the soil. Aim to dig down 100 mm or more beside the root. Remove and destroy any burrs.
Chemical control of Khaki Weed.
Khaki Weed grows from roots and seeds, so to get the best results treat it before it seeds.
Post Emergent Control of Khaki Weed.
It is best to apply selective post-emergents when Khaki Weed is growing strongly and not under stress. Ideally you should aim to treat seedlings, as these are most susceptible to chemical treatment.
Due to its waxy leaves we recommend you use a non-ionic surfactant to maximize herbicide efficacy. We suggest Optispread 1000.
The aim is to make repeat treatments until you eradicate the Khaki Weed. Several herbicides control Creeping Chaff weed in turf and lawns. Gilba Solutions recommends:
- Casper. Do not use Casper on Buffalo grass.
- Weed Blast MA.
- Duke 100WG.
- ProForce Contra M. Do not use Contra M Buffalo grass.
- Warhead Trio.
- Dicamba. Do not use Dicamba on Buffalo grass.
- or 2,4-D Amine.
In the USA Trifloxysulfuron (Recondo 100WG) is registered for Khaki Weed control.
Non Selective Control of Khaki Weed.
- Renegade.
- Glyphosate (Rapid Fire 800).
- Numchuk Quad and
- Cortex Duo.
If you use Glyphosate and water quality is an issue then we recommend the use of ProForce Manta Ray.
$310.00
ProForce Cortex Duo Industrial Herbicide is a non glyphosate weed killer. It is both a non-selective knockdown & a residual herbicide. You can use this to kill seedling & young
$140.00 – $295.00
ProForce Renegade 800WG is a preemergent soil herbicide for up to 12 months control of grass & broadleaf weeds in industrial areas & public rights-of-way.
$180.00
Rapid Fire 800SG is a non-selective herbicide contains 800g/kg of the active ingredient glyphosate. It controls a wide range of perennial and annual weeds in a range of situations that
$350.00
ProForce Weed Blast MA Herbicide is a post-emergent broadleaf herbicide, for use on a range of established turfgrass species that includes Couch, Qld Blue Couch, Kikuyu, Paspalum, Buffalo, Fescue, Bent
$105.00
Casper Turf Herbicide is a selective post-emergent herbicide. It controls broadleaf weeds in turf and contains the actives Dicamba and Prosulfuron. Do not use on Buffalo Turf.
$150.00
ProForce Warhead Herbicide is a premium selective herbicide and an equivalent to Turf Control, Spearhead and Javelin herbicides. It gives outstanding control of broadleaf weeds in turf.
$220.00
ProForce Contra M Herbicide is a broad-spectrum weedkiller giving quick kill of broadleaf weeds & it controls 38 weeds in turf. Do not use on Buffalo Turf.
$80.00 – $430.00
Numchuk Quad is a non-selective knockdown and residual herbicide. It gives post and pre-emergent weed control for up to 12 months.
$225.00
2,4-D Amine is a selective broadleaf herbicide for weed control in lawns and playing fields.
$270.00
Dicamba 500 Selective Herbicide controls broadleaf weeds in turf, pasture, & Non-crop Areas. Do not use on Buffalo turf.