Weed control

Why is Council using chemical sprays to control weeds?

Community members often express concern to us when they hear Shire of Dardanup staff or contractors are about to undertake another round of chemical weed treatments.

The following information is provided in response to those expressed concerns.

Further information is also provided below on these FAQs:

  • What about the environment?
  • What else have you tried?
  • What precautions do you take?
  • I am particularly sensitive to chemical exposure. What can I do to protect myself?

 

Overview

Regular weed treatments play a vital part in maintaining our Shire’s natural reserves, pristine grassed ovals, parks and gardens. And not only that, controlling weeds:

  • Reduces fuel loads to mitigate bushfire threats;
  • Protects our roads and paths which can be severely damaged by invasive weeds;
  • Keeps drains clear of roots;
  • Promotes turf growth;
  • Facilitates natural biodiversity.

Keeping weeds at bay (especially in urban areas) is no easy task but Council works to strike a balance of using minimal amounts of chemicals in an appropriate, cost-effective and safe way to achieve the best possible outcomes for the community.

Here’s a quick overview on why Council uses chemicals and sprays (including Glyphosate) to control weeds in the Shire, in favour of other trialed alternatives:

  • They are the most effective;
  • They offer the best value for money;
  • State and national regulators and researchers have indicated the products do not pose a carcinogenic or genotoxic risk to humans.

 

What is Glyphosate?

Glyphosate is a type of herbicide available at your local hardware store and sold under many different product names such as “Zero’, “Weed out”, Samurai” and “Roundup”.

It can be sprayed on any plant at the required dosage at the right time and it will kill the plant by modifying its ability to photosynthesise.

Some forms of glyphosate are ‘catchment friendly’. This means the surfactant used will not harm aquatic animals. As this “Bioactive” form is almost twice the cost of the terrestrial version, it is only used in the Shire in areas around wetlands, waterways and the river.

Glyphosate is mostly used by the Shire to spot spray on lawns, verges and garden beds, as necessary, and on paths for weeds emerging in pavement cracks.

It breaks down quickly and according to all of the Australian legislation, is not residual.

Council’s decision to use glyphosate for weed control is based on the latest advice received regarding its use from the WA Department of Health.

This aligns with an assessment by the Australian Pesticides and Veterinary Medicines Authority (APVMA), which undertook a comprehensive review of the existing research and the International Agency for Research on Cancer (IARC).

If you would like to research the issue in greater detail these assessments and further relevant scientific literature are attached here; https://apvma.gov.au/node/13891#IARC.

The research results were summarised in a WA Local Government Association Position Statement released in October 2018. A copy of this is available if required.

In light of this assessment, APVMA and the Federal Agriculture Minister have restated that Glyphosate is registered for use in Australia and approved products containing glyphosate can continue to be used safely according to label directions.

APVMA has also stated it will continue to track and consider any new scientific information associated with safety and effectiveness of glyphosate, including the information available from other regulators. This statement is made on its website regarding use.

Council will continue to monitor the latest available scientific data on use of Glyphosate for weed control and ensure practices remain in line with recommendations of advisory groups. You may also find answers to below questions on this issue of interest…

 

What about the environment?

The research in Australia around herbicide use is currently primarily focused on human health, and there are very few studies into the impacts on biodiversity. However, it is well understood for natural area management that Glyphosate use is one of the most effective tools that can be used to reduce the threat of weeds which are scientifically-recognised as having a large impact on natural environments.

The importance of controlling weeds to restore soil health, improve land management and facilitate restoration of natural biodiversity is receiving plenty of attention in emerging environmental science research.

Weed control in areas around wetlands, waterways and the river is undertaken using a form of Glyphosate that is ‘catchment friendly’. This means the surfactant used will not harm aquatic animals. As this “Bioactive” form is almost twice the cost of the terrestrial version, it is only used in the Shire in these areas of environmental significance.

 

What else have you tried?

Peppery Oil – A trial was undertaken a few years ago using the peppery oil from an existing pelargonium plant to manage weeds in parks. This material, in a concentrated form, was thought to be effective as an alternative to traditional man-made chemicals. Unfortunately it did not kill the plants, just burn them back, so the plant would recover.

Staff determined that not only was the product less effective in achieving the main aim of killing weeds, it required twice as many applications to be effective. It was also found to be approximately four times the cost of using an Australian certified herbicide.

Hot water/steam – Trial undertaken in 2016 revealed steam was expensive to apply and although did burn the leaves of plants, it also watered the roots, so they actually came back stronger afterwards.

To work effectively it would require twice as many staff to use on a more frequent basis. Steam also can’t be used on lawns as it burns, and the machine required to apply it was difficult to use off road.

Biological controls – In 2015, weed control in the Shire of Dardanup was assisted using a cutting edge bio-control method saving time and money and drastically reducing the need for general spraying of a broad-based chemical herbicide.

Bridal Creeper is a declared weed of national significance and is prevalent in the Shire of Dardanup.

It’s easily spread and left uncontrolled, it smothers and kills off native vegetation.

So Parks and Environment staff got busy helping with the spread of a targeted rust fungus that stops the creeper in its tracks. Today as a result, the fungus is widespread and most bridal creeper is infected and therefore does not thrive.

 

What precautions do you take?

Contractors responsible for weed treatment are licensed technicians and will continue to be made fully aware of Council’s safety requirements when handling herbicides such as Glyphosate.

Shire of Dardanup staff, while not required by the Department of Health to be licensed technicians, are inducted and continually monitored for best practice when using any herbicide in public open space, including new OSH regulations with wearing appropriate personal protective equipment and following all safety instructions.

Every chemical comes with detailed material safety data sheets (MSDS). These outline what rates and how best the herbicides can be used to minimise costs and maximise outcomes. It also outlines what protective equipment is required to handle and use the herbicide in the field.

Shire staff are trained in using these chemicals appropriately and not wasting them. Overuse of chemicals does not happen as it is ineffective and expensive. It causes the plants to go into shock and actually not die.

All of these herbicides contain the active ingredient, water and a surfactant, like soap, that breaks down plant waxes to penetrate into the plant itself. Staff know correct rates and places to apply the most effective chemical at any time.

Staff now wear full protective equipment when spraying all chemicals. This is merely a precautionary measure based on local government health and safety advice, however is actually not required in the MSDS for the chemicals listed below.

 

I am particularly sensitive to chemical exposure. What can I do to protect myself?

The Shire of Dardanup maintains a register which lists community members that do not want chemical weed treatments undertaken adjacent to their property. Please contact us on 9724 0000 to be added to the register.

If you have any further questions in relation to weed control, please contact our Manager Operations on 9724 0000 or email: records@dardanup.wa.gov.au