Glyphosate in Australian agriculture

Glyphosate is one of the most widely used herbicides in the world, and an invaluable tool for farmers, businesses, and property owners across Australia. It is suitable for use in an array of contexts, including agricultural, commercial, and home settings, which is responsible for its popularity over the last 40 years.

In this guide, we’ll explore glyphosate’s many uses, break down the different strengths and formulas on the market, and pass along our top tips for using it to manage weeds in Australia.

What is glyphosate?

Glyphosate is a non-selective herbicide that effectively kills most plants it comes into contact with. It was developed in 1970 by Monsanto, and since 1974, it has been predominantly marketed under the brand name Roundup®. It has been registered for use in Australia for over 40 years.

It’s one of the most well-known herbicides in the world and is used to eradicate a number of different plant species, including annual and perennial weeds, unwanted trees, and noxious woody weeds.

How does glyphosate work?

Glyphosate works by inhibiting the shikimic acid pathway, a crucial metabolic route for plant growth, and occasioning plant death as a result. This swift mode of action is what makes it so effective against weeds like broadleafs and certain grass species.

Is glyphosate safe?

Despite its proven track record as an effective herbicide, there has been lots of commentary around the safety of glyphosate. However, we’re here to reassure you that not only is glyphosate incredibly useful for landowners and home gardeners alike, but it’s also very safe as long as it’s used correctly.

According to the Australian Pesticides and Veterinary Medicines Authority (APVMA), the regulatory body for all herbicides in Australia, products containing glyphosate are entirely safe to use as long as the user follows label instructions. All our bestselling glyphosate products are registered with APVMA, ensuring they have gone through rigorous chemical risk assessments, including exposure risks and any links to cancer.

All glyphosate products offered by Specialist Sales include a product label and safety data sheet, which together outline the directions for correctly using the herbicide. This includes the provision of appropriate protective attire when handling and using glyphosate-based herbicides.

Uses of glyphosate herbicide in agriculture

Glyphosate has become a mainstay in Australian and global agriculture because of its suitability for a number of contexts, including broadacre farming, general farming, commercial use, and at-home use.

Broadacre farming

Glyphosate is a cornerstone of broadacre farming systems throughout Australia. It’s extensively used for pre-planting weed control, wherein farmers apply glyphosate to clear paddocks before planting crops like wheat, barley, and canola.

It’s also a key tool in fallow management. During fallow periods, glyphosate prevents weed growth, conserving soil moisture and nutrients for subsequent crops.

General farming

In mixed farming systems, glyphosate is used to control weeds around irrigation systems, and to maintain clean areas in and around livestock grazing paddocks.

Commercial use

For commercial properties such as orchards, vineyards, industrial sites, and commercial properties, glyphosate is used to manage vegetation along fence lines, pathways, and around buildings. This can help reduce fire risk and maintain accessibility.

Home use

In residential areas, glyphosate is used for eradicating weeds in driveways and pathways, along fencelines, and the edges around garden beds. It’s also an excellent tool for controlling invasive species in landscaping.

Weeds in lawns can be eradicated using glyphosate; however, the non-selective (knockdown) nature of the product means it will also affect any wanted plant life in the area. It’s not recommended for lawn use, as it will kill both the weeds and the lawn itself if using glyphosate to eliminate broadleaf weeds in your lawn, be sure only to spot spray or paint the weeds with glyphosate.

Effectiveness of glyphosate on weeds in Australia

Glyphosate is used to control a range of common Australian weeds, including broadleaf weeds, noxious woody weeds, annuals, and perennials.

It’s particularly effective against more than 200 broadleaf weed species that compete with crops and reduce yields, making it an excellent choice for farmers.

Common weeds controlled by glyphosate include:

Thistles, including variegated, scotch, and saffron thistles
Capeweed
Weed grasses and clovers (e.g., African lovegrass, carpet grass, barnyard grass)
Wild radish
Turnip weed
Silverleaf nightshade
Paterson’s curse
Fleabane
Paddy melon
Marshmallow weed
Cobbler’s pegs (black-jack)
Tradiscantia (wandering Jew)
Pigweed
Bindweed

By attacking the plant’s metabolic pathways, glyphosate ensures comprehensive eradication, making it a top choice for broadleaf weed control in agricultural settings and home gardens alike.

Glyphosate strengths and their applications

Glyphosate products are available in a range of strengths which are generally categorised by the concentration of active ingredients. The most common formulations are:

- 360g/L (low strength): Suitable for home gardens and small-scale applications. 360/L glyphosate concentrations commonly contain a bioactive formulation that makes them safe to use on aquatic weeds, including around frogs.

450g/L to 600g/L (medium-strong strength): Widely used in agricultural, commercial, and industrial settings. These concentrations are ideal for managing weeds in larger areas, as well as tougher-to-kill plant species.

700g/kg (high-strength granules): Used for industrial and broadacre applications. Expressed in g/kg, high-strength concentrations as such are only available as granules. They provide highly targeted and potent weed control for difficult-to-manage species.

Formulations of glyphosate

Glyphosate is available in three forms: liquid, granules, and ready-to-use sprays. They all have their own pros and cons, so the formulation you select will depend on the weeds you’re trying to control, the area you’re treating, and your unique needs.

Liquid glyphosate formulations

Liquid glyphosates are water-soluble, non-volatile, non-selective herbicides. They are particularly effective and practical for broadacre use.

These formulations are:

Easy to mix and apply
Popular in both farming and residential settings
Available in various strengths and formulations to suit different application needs
Available for purchase in bulk for high-volume farming applications

Liquid glyphosate can be applied with a hose sprayer, a knapsack sprayer, or a boom sprayer for higher volumes.

Granular formulations

Granular glyphosate is essentially just the hard version of the liquid, taking the form of small pellets. These formulations are designed for both broadacre farming and general use, and there are aquatic and non-aquatic versions available on the market.

Granular glyphosate formulations are:

Highly concentrated
More rainfast than liquid formulations (one-hour rainfast window)
Pre-loaded with wetting agents
Effective at eradicating tough-to-kill weeds
Easy to handle and store
Packaged in an environmentally friendly way

Granules are best administered to target species as a liquid, so they must be diluted with water and applied using a sprayer just like their liquid counterparts. The granules will completely dissolve in water to form a spray mix that can be used alongside other compatible herbicides.

Ready-to-use sprays

For the ultimate ease of use, glyphosate is also available in pre-mixed spray formulations that are well-suited to smaller applications and at-home use.

Spray formulations of glyphosate are:

Convenient for small-scale and home applications
Pre-mixed with no additional preparation required

They must be sprayed directly on the weeds to be effective. Simply grab a bottle, follow the label instructions, and go – there’s no additional work to be done when using these convenient sprays.

How to apply glyphosate to eradicate weeds in different settings

Your chosen method of glyphosate application will be highly dependent on the context – that is, the size and nature of the area you are dealing with. Here’s how to apply glyphosate to eradicate weeds in different settings.

Broadacre farming

Method: Sprayed using boom sprayers for uniform application in large areas.
Timing: Best applied pre-sowing or during fallow periods.
Benefits: Reduces competition, enhances crop establishment, and conserves soil moisture.

General farming

Method: Spot-spraying or broadcast application using a knapsack sprayer or quad bike-mounted system.

Focus areas: Fence lines, irrigation channels, and paddock edges.

Benefits: Keeps critical farming areas weed-free.

Commercial properties

Method: Applied using hand-held or backpack sprayers for precise control.

Focus areas: Around infrastructure and key access points.

Benefits: Maintains aesthetics and reduces fire and safety hazards.

Home gardens

Method: Administered using ready-to-use sprays or diluted liquid concentrates applied with hand-held sprayers.

Focus areas: Driveways, patios, and garden beds.

Benefits: Easy to use for controlling stubborn weeds.

Mixing and applying glyphosate

Once you’ve selected your chosen concentration, formulation, and application method for glyphosate, you’ll need to prepare your product (unless you’ve opted for a pre-mixed spray).

It’s crucial to mix your glyphosate correctly for a few reasons:

Effectiveness: The listed application rate ensures the right concentration of active ingredient reaches the plant to kill it effectively. Too little, and it might not work; too much, and you’re wasting valuable product.

Plant uptake: Plants absorb herbicides at a certain pace. The mixing rate provided is designed for optimal absorption so as to not overwhelm the plant’s system.
Environmental impact: Correct mixing minimises the amount of herbicide that ends up in the soil or water, consequently reducing harm to other organisms.

Dosage rates for granular glyphosate

When you purchase glyphosate granules, you’ll need to mix them yourself to form a liquid concentrate that can then be applied using a sprayer.

The general purpose mixing rate for granular glyphosate is 5g for every litre of water. A 10kg bag of granular glyphosate will make 2,000L of liquid glyphosate.

Comparison rates for granular versus liquid glyphosate are as follows:

515g of glyphosate 700 granules = 1L glyphosate 360 liquid concentrate
640g of glyphosate 700 granules = 1L glyphosate 450 liquid concentrate
770g of glyphosate 700 granules = 1L glyphosate 540 liquid concentrate

If you are boom spraying at 1L per hectare of liquid glyphosate, then use the above grams in granules to determine the grams per hectare.

Individual boom spraying mixing rates, as well as comprehensive safety instructions, will be listed in your chosen product’s directions of use.

Is using more glyphosate better?

Many first-time users of glyphosate assume the higher the product-to-water ratio, the better – but that’s far from the truth. Increasing the concentration of glyphosate you use can have negative impacts, including:

- Reduced efficacy: Over-concentrated herbicide can ‘burn’ the plant, preventing proper absorption and making it harder to kill.
- Increased resistance: Weeds can develop resistance to herbicides, and the main culprit for this is overuse. Always stick to the provided concentration to avoid resistance, which can actually lead to more weed growth if left uncontrolled.

Wasted money: Simply put, there’s no added benefit to using more glyphosate – which means you’re wasting product and losing money as a result.

Instead of overdoing it with glyphosate, the best way to increase its effectiveness or guarantee the best kill is the addition of a quality wetting agent.

Managing glyphosate resistance

Like any other herbicide, glyphosate doesn’t come without its challenges – and the primary one to consider is resistance. In infrequent cases, over-reliance on glyphosate has led to resistance amongst certain grass weeds in Australia, including annual ryegrass, barnyard grass, and liverseed grass.

To mitigate this, always rotate herbicides with different modes of action, and employ integrated weed management strategies, including mechanical and crop rotation control methods.

Glyphosate safety and environmental considerations

While glyphosate is a highly effective herbicide, it is crucial to use it responsibly. Always ensure you do the following for the most effective, safe application:

Apply as directed: Follow label instructions to adhere to the law, ensure your safety, and increase glyphosate effectiveness.
Stay protected: Use appropriate protective equipment including gloves, goggles, and masks when handling glyphosate.
Mitigate environmental impacts: Avoid runoff to prevent glyphosate from entering waterways and to protect aquatic ecosystems.

Is glyphosate cost effective?

One of glyphosate’s most significant advantages is its cost-effectiveness. Compared to other herbicides, glyphosate provides:

Broad-spectrum control: A single application targets multiple weed species, reducing the need for more than one product.
Low application rates: Even a small quantity of glyphosate can be used to cover large areas.
Long-lasting results: Because glyphosate is so effective, there’s no need for frequent reapplication.

For farmers, this translates into significant savings on input costs. Home gardeners will benefit from glyphosate’s affordability, ease of application, and highly effective results.

The best glyphosate alternatives

Of course, glyphosate may not be the perfect product for everyone. If you don’t want to use glyphosate, there are a few alternatives to consider that still offer highly effective solutions to kill common weeds.

Glufosinate-ammonium

Glufosinate-ammonium is a broad-spectrum weed control product that works by inhibiting enzymes critical for plant growth. It has a high level of crop safety and is extremely effective at controlling over 80 species of broadleaf and grass weeds.

There are a few brands of glufosinate-ammonium available on the market with varying concentrations to suit differing needs. The best options we’ve found are Surefire Gamma Herbicide (200 strength) and Glufosinate 400 Herbicide (400 strength).

While glufosinate-ammonium is a strong alternative herbicide to glyphosate, it’s important to note that it does require 100% coverage to be effective.

Learn more about using glufosinate-ammonium to control weeds.

Slasher Organic Weedkiller

An organic alternative to glyphosate, Slasher Organic Weedkiller is non-selective and fast-acting. It was designed for use in both public and private areas where herbicides may pose a safety risk to the user, the environment, or to the general public. It helps to control the spread of seedlings, young broadleaf weeds, grass weeds, perennial species, moss, and algae.

Note that Slasher Organic Weedkiller will take longer to control weed species than its non-organic alternatives due to its mode of action.

SureFire Slayer Organic Herbicide

Another organic alternative to glyphosate is the liquid organic herbicide SureFire Slayer. This non-selective product is ideal for suppressing established weeds, perennial species, and moss and algae.

SureFire Slayer is only effective when it comes into contact with the plant’s foliage. It’s fast-acting – in a matter of hours after using SureFire Slayer, you should observe browning and wilting. It is suitable for commercial use, residential use, and in certain agricultural settings like orchards, vineyards, and fallow soil.

Glyphosate is an indispensable tool for managing broadleaf and grass weeds in Australia. It provides effective, practical, affordable, and versatile weed control in settings including broadacre farming, general farming, commercial environments, and home gardens.

As one of the most potent and well-researched herbicides on the market, glyphosate offers reliable results when used correctly. Users can maximise the benefits of glyphosate and minimise environmental risks by understanding its strengths, formulations, and applications.

Shop glyphosate across various concentrations and formulations now.

If you need support selecting the right glyphosate formulation, application, or product for your unique circumstances, we’d love to help. Our team at Specialist Sales have over a decade of experience in supporting customers across Australia with their agricultural needs – get in touch to chat.