How to get rid of broadleaf weeds

Australia’s diverse agricultural landscape is facing a constant battle – the management and eradication of broadleaf weeds. These persistent plants compete with crops and pastures for water and nutrients, which can consequently impact yields, crop returns, and farm profitability. In fact, weeds are estimated to cost the Australian agricultural industry $4.9 billion annually in lost production and control measures. 

So, if you’re facing this problem yourself, what’s the solution? Ultimately, weed eradication is complex, and must be approached in a strategic, controlled way. This guide will equip you with the knowledge, strategies and recommendations required to effectively deal with broadleaf weeds. 

What are broadleaf weeds? 

Broadleaf weeds are a common type of weed and can easily be identified by their distinctive flat, broad leaves. They are not to be confused with other prevalent weed varieties like noxious weeds and woody weeds. 

Broadleaf weeds are poorly digestible by animals, meaning they often compromise the yield of crops and pastures quickly and aggressively. Their tendency to spread like wildfire makes them incredibly tough to eradicate without a strong strategy in place. 

Some common varieties of broadleaf weeds found in Australian settings include thistles, clovers, pigweed, turnipweed, annual ryegrass, annual phalaris, fleabane, bindweed, Paterson’s curse, and capeweed.

Why should we control broadleaf weeds? 

Broadleaf weeds have historically had major economic, environmental, and health impacts in the Australian agricultural context, causing indiscriminate damage to agricultural lands, natural flora and fauna, waterways, and coastal areas. They pose a huge threat to the agricultural industry, reducing farm productivity by invading crops, smothering pastures, and in some cases, harming livestock. They aggressively compete with crops and pastures for water, soil nutrients, and sunlight, making them a source of stress and devastation for farmers as they try to maintain their crop yield and quality. 

More broadly, with a list of over 3,000 weed species present in Australia – both introduced and native – many types of weeds require dedicated management under federal or state legislation such as the Biosecurity Act. 

Simply put, broadleaf weeds, among other harmful weed species, endanger many aspects of the agricultural industry as we know it, making weed management strategies absolutely crucial. 

How can you prevent the spread of broadleaf weeds on farms?

While broadleaf weeds can be devastating, there are several ways to prevent them from invading or spreading on your property and wreaking havoc on your crops or livestock. From a weed control perspective, the most important piece of the puzzle is undoubtedly herbicides, which can be used to eradicate broadleaf weeds and stop damage at the source. 

To prevent new species of weeds from occurring, and to mitigate the spread of existing weeds, strategies include monitoring all livestock and fodder that enters your property; ensuring seeds, crops, and fodder from suppliers are not contaminated with weeds; and, cleaning harvest machinery and other equipment regularly. Undertaking these checks regularly and consistently will reduce the potential for contamination throughout your property. 

How to control broadleaf weeds with herbicides

While the battle to control broadleaf weeds is persistent and ongoing, you’re not alone – farmers and producers all over the country are also dealing with this issue, and at Specialist Sales, we’re here to help. The good news is there is a wide range of effective herbicides on offer to combat broadleaf weeds. 

Choosing the right broadleaf weedkiller is critical to success and relies on a number of factors, including: 

• Your target weed/s: Each herbicide will have a different list of targets, so you’ll need to ensure the herbicide you select matches the weed/s you are trying to control. 
• Crop type: Some herbicides can harm certain crops and pastures, so ensuring compatibility is crucial to avoid damaging your yields. 
• Application method: Herbicides come in various forms, including foliar sprays and soil applications. Each application method has its advantages and limitations, making some methods more suitable for certain contexts. 

The best herbicides for controlling broadleaf weeds

There are several types of herbicides to consider that have been proven effective at controlling broadleaf weeds. Whichever option you choose, keep in mind that it’s critical to do your own research into the best herbicides to suit your specific circumstances and needs to ensure success and reduce the likelihood of weed recurrence. 

Selective or post-emergent herbicides

Selective herbicides aim to eradicate just the target species without causing any damage to other plants or crops, whereas post-emergent herbicides are applied directly to the weed after it has emerged fully from the soil to avoid potentially affecting the surrounding growths. Examples of selective or post-emergent broadleaf weed control include: 

• Metsulfuron-methyl
• Aminopyralid combined with metsulfuron-methyl
• Picloram
• Triclopyr
• 2,4-D amine
• Fluroxypyr
• Oxyfluorfen
• MCPA (2-methyl-4-chlorophenoxyacetic acid)
• Bromoxynil 
• Dicamba 

Non-selective herbicides

These broad-spectrum products kill all plant life in their path, making them useful for clearing paddocks before planting, or for controlling difficult-to-eradicate mixed weed infestations. Common non-selective herbicides for broadleaf weeds include: 

• Glyphosate
• Glufosinate 
• Oxyfluorfen

Residual herbicides

Residual herbicides, also known as pre-emergents, are applied to the soil prior to weeds developing. The chemical then remains active in the soil, which prevents weed seeds from germinating in the first place. Popular choices of residual herbicide for broadleaf weeds include:

• Atrazine
• Metolachlor
• Pendimethalin 

Remember to follow herbicide label instructions carefully to guarantee safe and effective application.

Why is a weed management approach important to control broadleaf weeds? 

Herbicides are a powerful tool in weed eradication, but they become even more effective when they are part of a comprehensive and integrated weed management plan that combines various strategies for long-term weed control success. In addition to using herbicides, our team of experts at Specialist Sales recommends implementing the following strategies: 

• Crop rotation: Planting different crop types can disrupt weed life cycles and depletes their seed banks in the soil, leading to reduced weed viability over time.
• Competitive crop selection: Choosing crops that naturally outcompete weeds for resources can suppress their growth. 
• Grazing management: Strategic grazing with sheep or cattle can control certain broadleaf weeds whilst also promoting the growth of desirable pasture species.
• Good hygiene practices: Cleaning machinery and equipment regularly and comprehensively can prevent weed seeds from spreading between fields. 

While broadleaf weeds are some of the trickiest to control – making them a significant burden for many landowners across Australia – effective management is possible by implementing the right herbicides and weed control strategies. The success of this multi-pronged approach is heavily reliant on consistent upkeep, so remember, knowledge and quick action are the best tools in your toolkit. Consult regularly with your agronomist and other farmers in the district to stay up-to-date on common weeds in your area, as well as the latest weed control initiatives and herbicides of choice.

At Specialist Sales, we have over a decade of experience supplying the Australian agricultural industry with effective and high-quality products. If you’d like to speak to one of our knowledgeable staff about the right approach for you, get in touch today.