Dear Bugsy,

It has been a few years now since I looked into the issue in any depth. I thought I had saved my links but they appear to have slipped into the ether.

I have managed to find one of the articles that had come to my attention from Scientific American, a magazine I have subscribed to for many years. It details serious concerns about some of the ingredients in Roundup.

http://www.scientificamerican.com/article/weed-whacking-herbicide-p/

I had also gone to the trouble of looking at the herbicide loads on corn and soy crops in the US pre and post Ht strains being introduced. There was certainly no drop in the lb/acre applications of herbicides rather there was a marked increase.

Therefore forgive me if I continue to regard Shadowminister's claim of a
2/3rds reduction as nonsensical.

Steele, yeah I remember that particular storm in a teacup. The POEA that the anti-GM campaign researchers (i.e. Seralini et al) said affected human cells was a surfactant (i.e. detergent) that put straight into cell cultures at concentrations well above what would be considered normal. Dishwashing liquid would have been more toxic to the cell cultures.

It's not the only dodgy science that these particular researchers have been involved in: https://en.wikipedia.org/wiki/S%C3%A9ralini_affair

The overall use of herbicide (read: glyphosate) would increase certainly, because the crops that can use it in that particular way have increased markedly.

If you are concerned about Roundup use in particular, perhaps you could suggest a more environmentally friendly herbicide?

Perhaps you could suggest another method of weed control that is cost effective enough so it won't send farmers broke?

"While there were some initial reductions seen in herbicide use in the corn, cotton and soy crops in the US much of the credit was given to new tillage practices rather than the introduction of HT seeds. Since the start of the century the total herbicide use on each of these staples has markedly risen."

In fact it was the availability of herbicide tolerant crops that allowed new tillage practices to be adopted. The ability to control weeds after planting as opposed to having to incorporate herbicides into the soil prior to planting the crop, facilitated the adoption of no-till practices in canola and soybean. It was the availability of HT crops that drove no-till adoption. In North American canola production, it would have been virtually impossible to adopt no-till without HT canola.

Changes in herbicide use are an interesting thing and the data is not always as you suppose. For example: http://weedcontrolfreaks.com/2015/06/trends-in-corn-herbicide-use-1990-to-2014/

There has been an increase in the number of herbicide applications, but a decrease in the total amount of herbicide used.

"I have managed to find one of the articles that had come to my attention from Scientific American, a magazine I have subscribed to for many years. It details serious concerns about some of the ingredients in Roundup."

Soaking human cell cultures in high concentrations of detergents for 24 h is likely to cause some damage. As Bugsy wrote, dishwashing liquid would do the same. Its relevance to agricultural use of glyphosate is effectively nil.

Dear Bugsy,

As stated I did my research on this topic quite a few years ago. My tendency is to go through the available evidence as thoroughly as I can then form my own opinion. Once that is done it generally takes a compelling piece of evidence to get me to delve into the issue in any great depth.

I note the subsequent issues with Seralini's study you have raised. As this was only one of the many papers I went through I am as yet disinclined to do the work again, but thank you for alerting me to it.

Dear Agronomist;

You offered this link;

http://weedcontrolfreaks.com/2015/06/trends-in-corn-herbicide-use-1990-to-2014/

Then you wrote;

“There has been an increase in the number of herbicide applications, but a decrease in the total amount of herbicide used.”

How on earth have you managed that conclusion?

Here is what I see when I look at the primary graph. From 1990 till 2002 the amount of herbicide per acre had been rapidly decreasing primarily because of the phasing out of Alachlor and Cyanazine but also of EPTC and Butylate. These decreases were not driven by genetically modified crops allowing replacement by Roundup since field releases up until 2002 were quite small in number. It was in that year that the shackles came off and Ht crop field releases shot to over 500. By 2013 this number was 7,800 for corn alone. This is clearly reflected in the graph which shows the use of glyphosate mimicking those releases. Up until 2002 the impact of glyphosphate resistant crops was very minor indeed.

What is also patently clear is that the overall trend of the total amount of herbicides applied per acre stopped decreasing and instead increased as the percentage of GM crops grew.

So why would you claim the opposite? Mind you you are not alone perpetuating this theme as it seems to be fairly ubiquitous among supporters of GM crops.

Or perhaps you saw something in the graph that I missed. If so could you be so kind as the enlighten me?