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Wednesday 30, Oct 2019


ATM’s resident turf and scientific expert Peter McMaugh looks at the recent fallout surrounding the herbicide glyphosate and the need for real understanding of the basic science behind the product to form a balanced assessment.

Recently in the press and visual media there have been reports and programmes highlighting the possible carcinogenic effects of glyphosate herbicide.

These have been brought into focus by the Californian Superior Court award of damages to a school maintenance operator who had used glyphosate (as Roundup) for many years and who had sued Monsanto for culpability and damages for the occurrence of his non-Hodgkin lymphoma. 

As this edition of ATM was going to print a second similar case heard in San Francisco was also ruled in favour of the plaintiff.  There were claims by investigative journalists and lawyers of systemic cover-ups by Monsanto (now Bayer owned) and obfuscation of data and general insinuations of malpractice.

A great deal of the impetus for this came as a result of a report issued by the International Agency for Research in Cancer (IARC), a subsidiary of the World Health Organisation (WHO), placing glyphosate on the list of possible carcinogenic substances.  

This led to some countries placing a ban on the use of glyphosate in their territories.

There was reaction worldwide to the initial IARC listing which covered a wide spectrum from ‘let’s ban it immediately’ to ‘let’s investigate it more thoroughly’.  

The USA court cases upped the ante and put the Bayer/Monsanto machine on the defensive and into overdrive.

They have and will be appealing the court decisions and it will be a fascinating show watching the empanelling of the jury because a great deal hangs on the ability to understand the science and epidemiology that underlie the truth and facts in these cases.


Turf was one of the early uptake users of glyphosate, with the big attractions being its lack of any notable residual activity, its ability to kill most plants at very low concentrations and how safe it was to anything that wasn’t green


It is very easy to cause consternation in using the word ‘carcinogen’ and science has, in general done a very poor job of transferring the knowledge of science and scientific fact into popular mainstream understanding of the facts in ways that allows them to converse sensibly about these issues.

The fact that we have hardly improved on this aspect of our communication ability since the 1950s – when Rachel Carson’s book ‘Silent Spring’ became a wrecking ball for the chemicals industry – means that the lessons of this have not been learned by the scientific community in general.


The ferocity of the charges of cover-up in this Roundup case has not been helped by the well-known cover ups by the giant chemical conglomerates on other products.  

This has created a climate of mistrust, which pervades much of our thinking when approaching new products from ‘big pharma’.

Unfortunately, this propensity of the marketing divisions of these companies to put only positive spin on new products, leaving you to dig out the negatives yourself, still dominates their thinking.  

If you see this through the eyes of the territory sales manager in terms of dollar turnover, it is good.

If you see it through the eyes of the end producer who has seen the expensive chemical fail to perform, it is bad.  And then the further spin sets in – ‘Did you use it properly according to the label?’ If the answer is a resounding ‘yes’ then along with the suggestion that may be you should have used it earlier or at a higher rate, you finally dig out the fact that, well, yes we know it doesn’t work on the third or fourth stage instars comes to light.  Recompense? Not in my experience.



There is some pertinent early history around the development and marketing of glyphosate.  It was first discovered by J.E. Franz.  The dates in the literature are a little confusing and vary between 1970 and 1972.  It was manufactured in 1972 and sold commercially in 1974 as Roundup.

It was hailed as a new miracle herbicide because of its safety and its effectiveness on many plants at very low concentrations.  Monsanto marketed it very aggressively and developed new technologies around it by harnessing genetic resistance technology to widen its agricultural usefulness and market success.

In 1985, a monograph ‘The Herbicide Glyphosate’ was published by Butterworths which contained 29 papers by 39 authors.  It was edited by E. Grossbard and D. Atkinson and while dated is still very useful. 

Interestingly, in the foreword, J.D. Fryer (Agricultural and Food Research Council, Weeds Research Organisation, Yarnton, Oxford, UK) made this statement: ‘Regrettably, much of the research which has been undertaken on glyphosate remains, for commercial reasons, unpublished’.

It is also interesting to note that only eight pages out of 490 are devoted to a paper on toxicology.  Most of the data in this is sourced from EPA registration data.

When we come to consider the current issues around glyphosate, we need to be aware of some facts...

To read the full article which was originally published in Volume 21.2 (March-April 2019) of the Australian Turfgrass Management Journal click here