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$1.8 billion cost to ag in absence of paraquat

three men in suits standing

A fact that many in the Australian agriculture industry don’t know is that Syngenta has fought over the past few years for paraquat to stay in the Australian market, and crucially, it is now here to stay.

Paraquat plays a crucial role in modern agriculture by providing growers with an effective weed management tool; a fact reaffirmed by the Deloitte Access Economics report, The Economic Impact of Paraquat.

Syngenta supported the research, with Deloitte Access Economics working independently to consult a range of Australian academics, industry experts, crop advisors and leading grower to explore scenarios that could result if paraquat was deregistered.

The report found that if paraquat was no longer available in Australia, growers would face a $1.8 billion yield loss over 10 years across all industries.

The independent report also explored the broader contribution of paraquat to the Australian economy finding that if all paraquat products were deregistered in Australia, Australia’s GDP would fall by $362 million per year by 2025 and full-time employment would be impacted, with a loss of 594 full-time employees in 2017. The report also found that Australia’s exports would fall by $588 million between 2019 and 2025.

So, how is this issue relevant to our viticulture industry? The Australian Glyphosate Sustainability Working Group (AGSWG) has close to 600 confirmed sites with glyphosate resistant Annual Ryegrass populations (May 2014 report). A staggering 36 per cent of these are in South Australia and 23 per cent in Western Australia. While there are only 25 confirmed cases in Australian vineyards, it’s likely this number is only the tip of the iceberg. The cases of glyphosate resistance in vineyards accounts for 4.4 per cent of known cases, but consider how much of the cropped land area vines represents - far less than this!  

For these sites the importance of paraquat is now elevated to a new level. The danger for these sites is they create an over reliance on paraquat which could lead to new resistance issues. In fact, in 2013 there was a site found in Western Australia where an Annual Ryegrass population was found to be resistant to both glyphosate and paraquat.

Having a sensible rotation strategy for controlling weeds and under-vine spraying can be seen as essential to preserve the effectiveness of both glyphosate and paraquat. Over-reliance on any one of these compounds will then also place the other at an increased risk. A very effective strategy gaining in popularity is the “double knock” strategy where a grower sprays with glyphosate and then a few days later returns to spray with SPRAY.SEED. The use of residual herbicides as well as cultural control methods such as mowing and mulching can also form a key part in the management of your vineyard.

You sometimes hear comments such as “I don’t worry too much about resistance, there’ll be another herbicide that comes along soon”. Unfortunately, the fact is there is no new mode of action non-selective herbicides globally in development for at least 10 years. The take home message therefore is we need to preserve the effectiveness of all our herbicides by adopting a sensible resistance management plan.  


Preston, C. The Australian Glyphosate Sustainability Working Group