Over 2,500 weed species currently impact the Australian environment costing Australian agriculture in excess of $4b annually.
Early prevention of weed problems is key to cost-effective, long-term improvement of land condition and hence enterprise productivity and profitability.
Aims of weed control
Effective and lasting weed control is only be achieved through the development of a well planned approach using a combination of management options, integrated with other pasture and livestock management activities.
These work to:
- Prevent weeds coming onto the property through bought-in feed or machinery.
- Reduce weed seed set.
- Reduce weed germination.
- Encourage competition from desirable species.
Prevention is much better than dealing with an established weed.
Weeds are colonisers, meaning they exploit any opportunity to establish. This may arise from bare ground being available or livestock preferentially grazing desirable pasture species rather than weeds. This grazing can severely reduce a desirable pasture plant's ability to compete with a weed and is why grazing management is critical to weed control.
Principles of weed management
The six principles of weed management provide a basis for the effective control of weeds and include:
- Control and monitoring
Producers should be aware of these principles and be mindful of them when devising their weed management plan.
Implementing weed control
The key questions producers need to address when planning and implementing an effective weed control and pasture improvement program are based on the '3Ds' of weed management:
- Where am I?
- Where do I want to be?
- What tools do I need?
- How do I get there?
- How do I stay here?
Implementing the '3Ds' of weed management can increase the competition from desirable pasture species while minimising the proportion of weed species present within the pasture.
Weeds are often categorised into broad groups depending on their characteristics and impacts. The main groups of weeds are:
- Noxious weeds
- Weeds of National Significance
- Weeds of production systems or agricultural weeds
- Environmental weeds
- National Environmental Alert weeds
Some weeds are notifiable weeds meaning that particular management actions are required by law. Take particular note of priority weeds.
Seed contamination of carcasses
Seed contamination causes significant financial losses for the sheep industry. Awareness of seeds and how to manage issues involving them are essential to profitability.