ICAN consultant Mark Congreve and AHRI director Ken Flower are in slightly different minds

Since then, Western Australia has seen a range of different herbicide resistances, and some researchers are concerned whether farmers are correctly managing herbicide resistance.

ICAN consultant Mark Congreve is concerned that herbicide resistance is getting worse, and there may reach a point in the future where herbicide resistance overlaps affordable herbicides entering the industry.

However, Australian Herbicide Resistance Initiative (AHRI) director Ken Flower is much more optimistic, believing farmers are doing the necessary tasks to effectively manage resistance.

Mr Congreve believes herbicide resistance is continuing to get worse, and is cautious about how reliant farmers are on herbicides.

He said farming was an economic operation, and it was sometimes too optimistic to expect farmers to swap out herbicides for mechanical alternatives.

"Even though they've heard the message, they keep using one herbicide until it breaks and then they hope there's another herbicide they can move on to, but unfortunately, we're starting to run out," Mr Congreve said.

Generally when products are launched, manufacturers distribute small batches around the world and the product is quite expensive.

According to Mr Congreve, for growers looking for an affordable and wide-spread herbicide it can take between five and ten years after the product is launched.

The consolidation of the industry, with a decrease in the amount of companies experimenting with herbicides, also didn't help the problem.

Mr Congreve said it perhaps wasn't always that farmers can't find a herbicide alternative, but rather they can't find an affordable one.

"If you go into the insecticide space, for example, the products that growers are using are mostly less than $10 a hectare," he said.

"There's a lot of other products, which can also do the job, but they might be $30 or $40.

"Sometimes it just comes down to economics, if we're not prepared to spend that amount of money, then we get resistance."

In an ideal world, Mr Congreve said he would like to see farmers using a range of non-chemical control methods with chemicals, instead of solely relying on chemical solutions.

He believed more grower education had to be done, so that growers could consider the best long-term solution for their farm.

"It's just human nature, everybody wants to grab the easy, cheap option and just pray it'll fix our problems, and then we think about resistance down the track," Mr Congreve said.

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Dr Flower believes that Australia certainly hasn't reached the stage where herbicide resistance has overtaken the effectiveness of herbicides, and believes the country is well positioned to counter the risk in the future.

He said new herbicide technology, be it mixes or new products, had increased the effectiveness and longevity of herbicides, and farmers were doing a good job keeping ahead of the curve.

Dr Flower said there was increasing resistance to particular chemicals, such as glyphosate, which posed a potential threat in the future, however Australia was well positioned to counter this with a range of working herbicide options.

"Through research, we can estimate how quickly weeds might develop resistance to a new herbicide, so we can forewarn farmers and also look at ways to slow down the development of resistance," Dr Flower said.

While the future couldn't be predicted, he said the issue was "in check" - with farmers able to use a combination of herbicides and non-herbicide or cultural options to control resistance.

The timeframe to produce herbicides may have increased, with more testing and regulation required by companies when compared to the 1970s, but Dr Flower doesn't believe this is a barrier at the moment, as companies can bring older chemistries or different herbicide mixes that were not previously registered in our cropping to market.

"So, it's not just a case of inventing new molecules," he said.

Dr Flower said the cropping system had also changed over the years, meaning different use patterns for the herbicides.

For example, farmers have converted from tilled systems, where residual herbicides were fully incorporated into the soil, to no-tillage where herbicides may be left on the surface.

Farmers are also seeding much earlier now, so the residual herbicides need last long enough to be activated by rain.

Dr Flower said people were working hard to find products that were suited to these different uses, and he was confident the industry was moving along well.