GM Potatoes – Facts and Fictions

In August 2006, German chemicals company BASF applied to start GM potato field trials
in Cambridge and Derbyshire as early as next spring. The GM industry is making many
claims about this product, but are these based on the truth? Andy Rees investigates


Late blight (Phytophthora infestans) costs UK farmers around £50m each year, even with regular application of fungicides. BASF claims that its GM potato would reduce fungicide spraying from around 15 times a year to just two.

This sounds impressive, until you realise that just 1,300 of the 12,000 tonnes of agrochemicals used on UK potatoes are fungicides – meaning that, at most, pesticide usage would be reduced by only 10 per cent.

As far as actually reducing pesticide usage is concerned, Robert Vint of Genetix Food Alert observes that “such claims ... usually [soon] prove to be extreme exaggerations”. The biotech industry has a long track record of first exaggerating a problem, then offering an unproven and oversold GM solution. A classic example of this was Monsanto’s showcase project in Africa, the GM sweet potato. It was claimed
that the GM potato would be virus resistant, that it would increase yields from four to 10 tonnes per hectare, and that it would lift the poor of Africa out of poverty.

However, this crop not only wasn’t virus-resistant, but yielded much less than its non-GM counterpart. Moreover, the virus it targeted was not a major factor affecting yield in Africa. The claims were made without any peer-reviewed data to back them up. And the assertion
that yields would increase from four to 10 tonnes per hectare relied upon a lie – according to FAO statistics, non-GM potatoes typically yield not four but 10 tonnes. Furthermore, a poorly resourced
Ugandan virus-resistant sweet potato, that really was roughly doubling yields, was studiously ignored by the biotech lobby.

Also conveniently overlooked are any non-GM solutions to blight. Many conventional potato varieties are naturally blight-resistant, some of which the organic sector are currently trialling. Another non-GM control, used by organic farmers against late blight in potatoes, is the use of copper sprays in low doses. This is applied to the foliage of the plant and does not contaminate the tuber.


An article in The Guardian, which reads more like a BASF press release (the corporate takeover of the media is a subject covered in my forthcoming book), reports that “Andy Beadle, an expert in fungal resistance at BASF, said the risks of contamination from GM crops are minimal because potatoes reproduce through the production of tubers, unlike other crops such as oil seed rape [canola], which produces pollen that can be carried for miles on the wind.”

Not only is this remark economical with the facts, it seems a little brazen given the biotech industry’s rather prolific history on contamination issues, which has resulted in at least 105 contamination incidents (some of them major), over 10 years, and in as many as 39 countries.

Amongst many other things, Mr Beadle forgot to mention that there is less direct risk of contamination by cross-pollination, not no risk.
Furthermore, cross-pollination is much higher when the GM and non-GM potato varieties are different; one study showed that, even at
plot-scale, 31 per cent of plants had become hybrids as far as 1km from a GM variety. Crosspollination also increases greatly when the chief pollinator is the ‘very common’ pollen beetle, which travels considerably further than another potato pollinator, the bumble bee.

Years later, cross-pollination is still possible through potato
volunteers (plants from a previous year’s dropped tubers or seed); Defra itself has acknowledged this problem. And similarly, ‘relic’ plants can persist in fields or waste ground. What is more, blight-resistant varieties create a far greater risk of GM contamination because the flowering tops are more likely to be left on than with non blight resistant varieties. This is because tops are usually removed from non-blight-resistant varieties to reduce disease incidence. Also, a number
of modern strains can produce considerable numbers of berries, each producing 400 seeds; these can lay dormant for seven years, before
becoming mature tuber-producing plants.

And if all that isn’t enough to suggest that ‘minimal’ contamination is the figment of the corporate imagination, then it is well worth checking out the March 2006 GM Contamination Register, set up by Greenpeace
and GeneWatch UK, and available at

This includes some of the worst contamination incidents to date,
including the following three.

In October 2000, in the US, GM StarLink corn, approved only as animal feed, ended up in taco shells and other food products. It led to a massive recall of more than 300 food brands and cost Aventis an immense $1 billion to clear up. StarLink corn was just one per cent of the total crop, but it tainted 50 per cent of the harvest. In March 2005, Syngenta admitted that it had accidentally produced and isseminated – between 2001 and 2004 – ‘several hundred tonnes’ of an unapproved corn called Bt10 and sold the seed as approved corn, Bt11.

In the US, 150,000 tonnes of Bt10 were harvested and went into the food chain. And in April 2005, unauthorised GM Bt rice was discovered to have been sold and grown unlawfully for the past two years in the Chinese province of Hubei. An estimated 950 to 1200 tons of the rice entered the food chain after the 2004 harvest, with the risk of up to 13,500 tons entering the food chain in 2005. The rice may also have contaminated China’s rice exports. And now, in 2006, BASF’s application comes amidst the latest biotech scandal, that of US rice contamination by an unauthorised, experimental GM strain, Bayer’s LLRice 601.


The GM lobby have proposed a buffer zone of 2-5m of fallow land  round the GM potato crop, together with a 20m separation with non-GM potato crops.

The National Pollen Research Unit (NPRU), on the other hand, has recommended separation distances of 500m. Interestingly, pro-industry
sources have always claimed that only very small separation distances are necessary, with buffer zones for rape set at a derisory 200m in the UK crop trials. Judith Jordan (later Rylott) of AgrEvo (now Bayer) gave evidence under oath that the chances of cross-pollination beyond 50m were as likely as getting pregnant from a lavatory seat.

Well, you have been warned. But oilseed rape pollen has been found to travel 26km, maize pollen 5km, and GM grass pollen 21km.

Meanwhile, good ol’ Defra is once again paving the way for the biotech industry, with its so-called ‘co-existence’ paper of August 2006. This will determine the rules for commercial GM crop growing in England – yet astonishingly, it proposes no separation distances. GM contamination prevention measures will be left in the slippery hands of the GM industry in the form of a voluntary code of practice.


The biotech industry has from the very beginning assured us that their products are entirely safe. This is because, they claim, they are so similar to conventional crops as to be ‘Substantially Equivalent’, a discredited concept that led to GM crop approval in the US (and thence the EU).

The truth is that, as far as human health goes, the biotech industry cannot know that their products are safe, because there has only
been one published human health study – the Newcastle Study, which was published in 2004. And although this research project was very
limited in scope, studying the effects of just one GM meal taken by seven individuals, it nonetheless found GM DNA transferring to gut
bacteria in the human subjects.

As for tests of the effects of GM crops on animals, there are only around 20 published studies that look at the health effects of GM
food (not hundreds, as claimed by the biotech lobby), as well as some unpublished ones. The findings of many of these are quite alarming.
The unpublished study on the FlavrSavr tomato fed to rats, resulted in lesions and gastritis in these animals. Monsanto’s unpublished 90-day
study of rats fed MON863 maize resulted in smaller kidney sizes and a raised white blood cell count.

And when it comes to GM potatoes, Dr Ewen and Dr Pusztai’s 1999 10-day study on male rats fed GM potatoes, published in the highly respected medical journal The Lancet, showed that feeding GM potatoes to rats led to many abnormalities, including: gut lesions; damaged immune systems; less developed brains, livers, and testicles; enlarged tissues, including the pancreas and intestines; a proliferation of cells in the stomach and intestines, which may have signalled an increased potential for cancer; and the partial atrophy of the liver in some animals. And this is in an animal that is virtually indestructible.


The proposed UK trials would follow those being carried out in Germany, Sweden and the Netherlands. Barry Stickings of BASF explains: “We need to conduct these [in the UK] to see how the crop grows in different conditions. I hope that society, including the NGOs, realise
that all we are doing is increasing choice.”

So, how much choice has GM crops given farmers? Well, in Canada, within a few years, the organic canola industry was pretty much
wiped out by GM contamination. And in the US, a 2004 study showed that, after just eight years of commercial growing, at least 50 per cent of conventional maize and soy and 83 per cent of conventional canola were GM-contaminated – again dooming non-GM agriculture.


Regarding BASF’s application to trial GM potatoes, the Financial Times reported that “Barry Stickings of BASF said he did not expect too much
opposition to the application”. What had clearly slipped Stickings’ mind was that BASF had already faced protests with this product in Sweden, where it is in its second year of production.

In Ireland, where one may have expected more enthusiasm for the project, given the history of blight during the 1840s famine, BASF
was given the go-ahead earlier this year for trials of its GM blight-resistant potato, only to face stiff public resistance and rigorous conditions enforced by the Irish Environmental Protection Agency. BASF later discontinued the trials.

In the UK and Europe, as Friends of the Earth points out: "Consumers ... have made it clear that they do not want ... GM food.” In fact, the British Retail Consortium, which represents British supermarkets, has already stated that they ‘won’t be stocking GM potatoes for the conceivable future’ because ‘people remain suspicious of GM.’ My forthcoming book goes into the rejection of GM crops in more depth.

And even more surprisingly, in the US, where 55 per cent of the world’s GM crops are grown, GM potatoes were taken off the market back in
2000 when McDonald’s, Burger King, McCain’s and Pringles all refused to use them, for fear of losing customers.

So, having reviewed the claims made about BASF’s GM potatoes, and having found them, well, somewhat lacking, there is only one course
of action open to the government, and that is, as Friends of the Earth’s GM Campaigner Liz Wright recently said, to “...reject this
application and prevent any GM crops from being grown in the UK until it can guarantee that they won’t contaminate our food, farming
and environment.”

Genetically Modified Food – A Short Guide for the Confused by Andy Rees (Pluto Press, £12.99)

This article first appeared in the Ecologist October 2006