GM Free Cymru

Sloppy seed-sorting confirmed as main culprit in GM crop contamination

This is an important paper which confirms (yet again) that GM crops cannot be contained, that GM and non-GM coexistence is impossible, and that genetic contamination of related crops will always occur, no matter what "separation distances" may be applied. The key point to come out of the paper by Heuberger and others is that human "error" and slapdash seed-sorting / seed handling / harvesting procedures are very important factors in allowing gene flow and GM contamination to occur on an epidemic scale. The authors sound as if they are surprised by that finding. Not quite sure which planet they have been inhabiting, but GM opponents have been saying this for years, and citing one example after another where GM contamination incidents can be traced back to inadequate biosecurity measures and -- let's spell it out here --


There is one thing that really makes me angry about the article by Heuberger et al -- and that is their frequent use of the terms "adventitious presence" and "adventitious Bt plants" throughout the text. In fact, these terms occur so frequently that I smell a rat -- I'm sure they were inserted quite deliberately as a sop to the GM industry, on the basis that Monsanto and the other GM corporations were going to be angry enough as it was, to see their past protestations about the impossibility of GM gene flow shown up to be a load on nonsense. Best not to upset them too much -- so let's continue to pretend that all of this gene flow is "adventitious" -- down to chance, and accidents, and acts of God.

The authors have made a serious contribution with this paper, but they should be ashamed of themselves for this intellectual cop-out. Let's get this straight. The contamination they are talking about here is not adventitious at all. It is predictable, controllable, and deliberate. It occurs because people cannot be bothered to stop it -- and many people have been saying for years that total contamination of the food supply with GM materials is a key part of the industry strategy. Monsanto and the other GM seed suppliers have no interest whatsoever in "containing" GM crops -- and indeed their key message to farmers is that their GM products will lead to simplified on-farm management, reduced manpower requirements, and lower production costs. Clearly they are going to do nothing whatsoever to encourage tight biosecurity measures like the use of separate machinery and silos for GM materials and more onerous cleaning procedures. Indeed, if GM material escapes onto somebody else's land, that becomes a tidy earner, as Percy Schmeiser and many others have found to their cost.

Jochen Koester and others have been pointing out at least since 2005 that in Europe and elsewhere in the world, the terms "adventitious presence" and "technically unavoidable" have been cynically misinterpreted by the GM industry and its supporters, and even by regulators, in the course of a united campaign to push GM products into the food chain on a larger scale. Adventitious … or just money thrown out the window?By Jochen Koester, IMCOPA (Europe)

The best analysis of what these terms actually mean is contained in the excellent legal opinion obtained by FoE, GM Freeze and Soil Association from Lasok and Haynes in 2006. Here is an extract:

44. The terms “adventitious” and “technically unavoidable” are not defined in the relevant legislation. They are clearly separate concepts, either of which may be satisfied in order to exercise the labelling exemption.

45. “Adventitious” is defined in the Oxford English Dictionary as: “Coming from without, accidental, causal.” Our examination of other language versions of the term do not suggest that that is an unreliable guide to the meaning of the word. It seems to us that adventitious in this context means accidental and arising from outside the process, or non-inherent. Some support for that proposition, if needed, is derived from Commission Regulation (EEC) No 1470/68 on the drawing and reduction of samples and the determination of the oil content, impurities and moisture in oil seeds. Article 2.3 provides: “Special care is necessary to ensure that all sampling apparatus is clean, dry and free from foreign odours. Sampling should be carried out in such a manner as to protect the samples of oilseeds, the sampling apparatus and the containers in which the samples are placed from adventitious contamination such as rain, dust, etc.”

46. It would seem to us to be strongly arguable that GM presence which is “built-in” or inherent by virtue of a generally applicable base- line norm or tolerance does not accord with the definition of adventitious presence.

47. As regards GM presence that is “technically unavoidable”, we consider that term to introduce an absolute requirement (since it is not tempered by any reference to “reasonable” or any further qualification) that the GM presence is a result of the objective impossibility of avoiding GM content by technical methods. In our view, “technically unavoidable” presence would also exclude presence arising systemically where GM content could in fact technically be avoided. It is not a subjective test confined to the circumstances of each case. What is in fact objectively technically unavoidable on the basis of available techniques is a matter for scientific assessment.

---- OPINION For Friends of the Earth, GM Freeze and the Soil Association on the DEFRA Consultation on proposals for managing the coexistence of genetically modified (“GM”), conventional and organic crops commenced in July 2006. .......................................................................

This advice makes it clear that the "adventitious" presence of Bt plants in "unexpected" places to which Heuberger et al refer is NOT adventitious at all, since it has nothing at all to do with truly accidental or random natural or external events that could not reasonably have been predicted. Neither are these GM occurrences technically unavoidable in the sense that there is no technology available which might have prevented them. As Lasok and Haynes point out, there is no test permitted here as to what is "reasonable" or economically justifiable -- this is a straightforward matter of technology. To return to the point made above -- the occurrences of GM gene flow referred to by the authors WERE technically avoidable, and they were NOT adventitious in the legal sense of that word.

Heuberger et al should be ashamed of themselves for muddying the waters on the definition and use of key terms, and for allowing their otherwise important research to be used as a vehicle for the promotion of the GM industry's anti-regulation agenda.


SUMMARY: "The most important finding was that gene flow in an agricultural landscape is complex and influenced by many factors that previous field studies have not measured," said Heuberger. "Our goal was to put a tool in the hands of growers, managers and legislators that allows them to realistically assess the factors that affect gene flow rates and then be able to extrapolate from that and decide how they can manage gene flow."


Heuberger S, Ellers-Kirk C, Tabashnik BE, Carrière Y (2010) "Pollen- and Seed-Mediated Transgene Flow in Commercial Cotton Seed Production Fields". PLoS ONE 5(11): e14128. doi:10.1371/journal.pone.0014128


Bees do it, humans do it - move genes among crop plants, that is. But until now, researchers and growers had a hard time getting a grip on the factors that determine how much of this gene flow happens in an agricultural landscape.

A new data-driven statistical model that incorporates the surrounding landscape in unprecedented detail describes the transfer of an inserted bacterial gene via pollen and seed dispersal in cotton plants more accurately than previously available methods.

Shannon Heuberger, a graduate student at the University of Arizona's College of Agriculture and Life Sciences, and her co-workers published their findings in the open access journal, PLoS ONE.

The transfer of genes from genetically modified crop plants is a hotly debated issue. Many consumers are concerned about the possibility of genetic material from transgenic plants mixing with non-transgenic plants on nearby fields. Producers, on the other side, have a strong interest in knowing whether the varieties they are growing are free from unwanted genetic traits.

Up until now, realistic models were lacking that could help growers and legislators assess and predict gene flow between genetically modified and non-genetically modified crops with satisfactory detail.

This study is the first to analyze gene flow of a genetically modified trait at such a comprehensive level. The new approach is likely to improve assessment of the transfer of genes between plants other than cotton as well.

"The most important finding was that gene flow in an agricultural landscape is complex and influenced by many factors that previous field studies have not measured," said Heuberger. "Our goal was to put a tool in the hands of growers, managers and legislators that allows them to realistically assess the factors that affect gene flow rates and then be able to extrapolate from that and decide how they can manage gene flow."

The researchers measured many factors in the field and developed a geographic information system-based analysis that takes into account the whole landscape surrounding a field to evaluate how it influences the transfer of genes between fields. Genes can be transferred in several ways, for example by pollinators such as bees, or through accidental seed mixing during farming operations.

Surprisingly, the team found that pollinating insects, widely believed to be the key factor in moving transgenic pollen into neighboring crop fields, had a small impact on gene flow compared to human farming activity, with less than one percent of seeds collected around the edges of non-Bt cotton fields resulting from bee pollination between Bt and non-Bt cotton.

Most previous studies focused on the distance between the non- transgenic crop field and the nearest source of transgenic plants.

"Although this approach is simple, it is potentially less useful for understanding gene flow in commercial agriculture where there can be many sources of transgenic plants," Heuberger said.

Heuberger and her co-workers broadened the scope to include flower- pollinating bees, humans moving seeds around and the area of all cotton fields in a three-kilometer (1.9 mile) radius. This approach turned out to be more powerful in understanding the effect of surrounding fields than using the customary model based solely on distance.

For the study, the scientists chose 15 fields across the state of Arizona planted with cotton that did not have the transgenic protein encoded by a gene from the bacterium Bacillus thuringiensis, or Bt. They assessed the number of pollinators visiting cotton flowers through field observations and determined the transfer of genes by collecting samples of cotton bolls and determining their genetic identity.

"We saw a need for a spatially explicit model that would account for the whole surrounding landscape," Heuberger said. "Our model takes into account the distance and area of all relevant neighboring fields, the effect of pollinators like bees and human factors that can result in the mixing of seed types."

Heuberger's findings have implications not just for genetically engineered traits but also more generally for seed production.

"When you grow a crop and want the variety to be pure, just being able to know how far gene flow will occur and how it is affected by pollinators and human farming activity in the area is very valuable."

The research was funded by Western Region Sustainable Agriculture Research and Education and an Environmental Protection Agency STAR Fellowship.