North West Weeds 
          Your local guide to local noxious weed control (NSW, Australia)

THIS WEBSITE PROUDLY SPONSORED BY: Suppliers of a huge range of weed control herbicides AND Specialised spray equipment

ADVERTISE HERE... Contact the webmaster

North West Weeds
ABN 16 052 158 879
Postal address:
20 Dinoga Street
BINGARA
NSW 2404

PRINT VERSION1  PRINT VERSION2 (mailout flyer)  Identification │ Effect on animals │ More info? │ Control methods │Using pesticides │Disclaimer   

MIMOSA BUSH FIELD DAY - YETMAN NSW 10 DEC 07- Approximately 150 people attended the field day - a lot of interest in finding viable methods of managing this pest plant.  Full report on the meeting will be posted on this website ASAP - in the meantime the photo (right) shows some of the attendees during the speaker presentation in Yetman Hall.  Please see herbicide trial results sheet issued at the field day - as prepared by Tony Cook, DPI, Tamworth  

Mimosa bush* (Vachellia - previously Acacia - farnesiana) is an invasive and thorny plant spreading onto many grazing properties in north-western New South Wales.  It has taken over large areas around Yetman, Pallamallawa, Moree etc. and is continuing to move eastwards.

[*Mimosa bush - not to be confused with northern Australia's Mimosa pigra.  Also sometimes incorrectly referred to as "prickly acacia" - Acacia nilotica.]

Mimosa bush is NOT a declared noxious weed in Gwydir or Inverell Shires.  It is, in fact, classed as a native plant (despite its origin.) Flora of New South Wales states that Mimosa bush is:

"Native of trop. Amer., probably introduced into Aust. prior to European settlement. Widely cultivated overseas for its decorative qualities and the essential oil obtained from its flowers for use in the perfume industries. It is grown for hedges and windbreaks, however, it may form dense thickets and become weedy."

Mimosa bush has some uses: it is regarded by some as a valuable source of food for sheep. Sheep (and goats) tend to keep the plant under control, but over the past 20 years or more changes in land management, reduced sheep numbers and the move into cattle has seen the plant really "take off".  Cattle also find food value in the plant (especially the seed pods), but the viable seeds pass unscathed through the stomach and are a major contributor to the ever-increasing number of new plants every year.

                        [Click on photos to download a larger picture]

Photo - above left:  close-up of mimosa bush.  Note the thorns, and the bean-like seed pods.  Each seed pod contains about 10 seeds.  The pods are a good food source, rich in protein.  Photo - right:  close-up of the seed pods and the seeds.

Photo - left:  Bingara (NSW) Common during a drought period.  Scattered mimosa bush plants.  Cattle feed on the mimosa bush pods.  The seeds pass through the animals and are subsequently dropped at random anywhere in the paddock.

Return to top of the page

EFFECT ON ANIMALS
Mimosa bush has useful qualities as a food source at different times of the year.  However, it is a very invasive and drought-resistant plant and if left unchecked will severely reduces a property’s stock-carrying capacity. As time progresses, the plants can effectively take over the whole paddock!  The photo, left, shows how Mimosa bush has taken over a travelling stock route in the Pallamallawa NSW area...

IDENTIFICATION
Mimosa bush usually grows to a height of around 1 to 1.5 metres.  Almost every part of the plant contains sharp thorns.  Flowers are fluffy and yellow (see photo).  The seed pods are a prominent feature of the plant.  Stock seek out and eat the pods, spreading the seeds as they move on around the paddock. 

Photo, above left - close-up of mimosa bush leaves and flower - new spring growth - October 2002

MORE INFORMATION:
Plants of Western New South Wales, by Cunningham, Mulham, Milthorpe & Leigh (published by Inkata Press).

CONTROL METHODS - SUBJECT TO COMPLIANCE WITH NATIVE VEGETATION ACT

Mimosa bush is a native plant, and subject to Native Vegetation Act restrictions.  Without Catchment Management Authority approval, control can only apply to new/regrowth plants that have appeared since 1 Jan 1990.  For more information on your legal requirements in this regard check out the CMA website, in particular www.nativevegetation.nsw.gov.au,   Or, talk to your local CMA representative! - in your area this plant may be classed as an Invasive Native Species, meaning less restriction on clearing.

Non-Chemical Options:  Manual control, in the form of pushing plants out of the ground with a tractor blade or the like, is NOT RECOMMENDED unless whole area followed up with careful herbicide treatment or ploughing, cropping etc.   While clearing gives an immediate impression that the problem has been solved, the same area will soon be infested with regrowth from broken root parts.  And, dozens of small seedlings will also emerge because the parent plants have been taken out.   Again, these control options are subject to the requirements of the Native Vegetation Act. 

Return to top of the page

Chemical Options: At this time, there are four (4) herbicides registered for use in New South Wales for treatment of Mimosa bush (see table, below). None of them will do a 100% job every time, because mimosa bush is just so hard to kill - especially when the plants get a bit of size on them!  Timing is another factor - like all plants, they need to be healthy and with plenty of leaf to absorb the herbicide.

Further trials are in progress (including Yetman Common Mimosa Bush Trials) to try to gain more effective use of herbicides.  Gwydir Shire (with assistance from Tony Cook, DPI Tamworth) applied for two (2) APVMA general permits: one to use a mix of Grazon® and Uptake Oil® (or equivalents) and the other to use Graslan® pellets (or equivalent).  The permit for the pellets has been approved (see above table) but we are still waiting for approval for Grazon.  Again, like the other herbicides already registered, there is no guarantee these two new mixtures will do the complete job. It seems we have to accept the fact that most mature plants will require a second treatment.  That is why it is so important for landholders to get in early and stop this plant before it becomes established.

IMPORTANT:  USE OF PESTICIDES – ALWAYS READ THE LABEL
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.

Return to top of the page

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.
LRT - 05/02/07

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