Methods of Weed Control
Integrated Weed Management
Effective weed control is not only achieved by controlling the reproductive individuals within a population, but also by ensuring that weed seed reserves are depleted and by maintaining a strong, resilient pasture that minimises further weed germination.
Some weeds spread by reproductive means, while others spread by vegetative means. Others have evolved to reproduce by a combination of both, so it’s important to understand the target weed and ensure that individual plants are either controlled before seeding and/or all vegetative plant part are removed, including the roots, stems, branches, stolons, tubers or other plant parts which may allow the plant to propagate vegetatively.
For effective weed control an integrated management program needs to be implemented where a coordinated range of suitable chemical and non-chemical control methods are used. The following methods may be used:
- Herbicide application
- Biological control
- Digging or Grubbing out (for small infestations)
- Use of farm animals such as sheep and goats for grazing management
Some of these methods however may be more effective than others depending on the target weed. It is important to ensure when implementing a weed management program that your chosen methods comply with your weed control obligations under the Biosecurity Act 2015. Ongoing control is required to control new germination's and, in the case of some woody weeds, regrowth. This can be achieved by regularly checking your property for new growth, bearing in mind different weeds germinate and grow at different times of the year. Prior to control, care needs to be taken in correctly identifying weed species.
To achieve long term control it is necessary to maintain a strong, competitive pasture to compete with new weed germination's. If your existing pasture is badly deteriorated you should seek agronomic advice, as your best option may be to establish a new pasture.
If you are using herbicides, caution needs to be exercised. The product label and safety directions must be followed. The herbicide should be applied using correctly calibrated equipment under suitable environmental conditions to avoid damage to non-target plants. Council's Vegetation Management Officers can provide advice on correct selection, mixing and application of herbicides.
The NSW Department of Primary Industries also provide valuable advice on controlling weeds and pasture management. Visit their website at: NSW WeedWise
Or consult their latest publication:
NSW Weed Control Handbook
Biological Control of Weeds
In recent years, the release of biological control agents on weeds has advanced. Bio-control agents have been released in the Snowy Monaro Region in selected areas for the control of St John's Wort, Nodding Thistle, Scotch Thistle, Paterson's Curse/Viper Bugloss, Scotch Broom, Cape Broom and Blackberry. Releases of existing and new agents will continue. These agents will not totally control the priority weeds, so other methods of control will be required in an integrated approach.
For more information refer to the CSIRO Biological Control website.