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Why GM maize should not be grown in the UK


Exposing the flaws in the science behind the one GM product that the government has approved

Bayer CropScience argues that its Chardon LL GM maize is ‘distinctive, uniform and stable’.

1.1 The crop was originally given European consent in 1996, on the recommendation of the French authorities, in accordance with a piece of EU legislation that has now been replaced. The plant’s T25 transgenic insert (its alien genetic material) has since changed from the structure originally reported by Bayer. This indicates that it is unstable and, therefore, illegal under the current European Commission directive on the deliberate release of GMOs. If an application for full commercial consent for the crop were submitted today, it would fail.

1.2 Bayer argues that Chardon LL is distinctive enough to be given its own place on the National Seeds Listing (NSL). But at the same time, it claims that it is ‘substantially equivalent’ to the non-GM variety of maize from which it was engineered, and that, therefore, no health or safety assessments are needed with Chardon LL; Bayer says the GM variety is just as healthy and safe as ‘normal’ fodder maize. However, there is not a single peer-reviewed paper on the effects of feeding GM maize to ruminants, and a feeding study undertaken two years ago at Reading University is still shrouded in mystery. What did the Reading researchers find, and why has there been no reporting of their findings? Did the cattle fed on GM maize die, like the 12 cattle which died after feeding with Syngenta Bt-176 GM maize in Germany between 2001 and 2002?

Studies done on feeding other animals GM maize were not considered relevant by the UK government’s GM advisory body the Advisory Committee on Releases to the Environment (Acre) when it ruled in 1996 that Chardon LL was ‘safe’. Yet the Aventis dossier referred to a ‘feeding trial’ using broiler chickens. This was a very inadequate study, but the mortality rate was twice as high among chickens fed on GM maize as on ones fed on normal maize.

Government spokesmen argue that GM maize does not pollinate readily in the UK, and that because its pollen is heavy it is unlikely to travel far from GM maize fields.

2.1 But maize is a wind-pollinated crop and has been shown to cross-pollinate regularly over many hundreds of metres. A famous study by Chapela and Quist showed that GM out-crossing (cross-pollination with conventional varieties) and hybridisation of maize has occurred on a substantial scale in Mexico. Subsequent studies by the Mexican government have shown that the problem is even more serious than was originally suggested.

2.2 Evidence has recently emerged in a number of countries of conventional blue maize out-crossing with other maize varieties planted as much as five kilometres away. Similar concerns have arisen about purple maize in Iowa. As a result, there is concern that it will be impossible to uphold EU contamination threshold requirements – even if there are legally enforceable ‘separation zones’ between conventional and GM maize crops.

Bayer claims that Chardon LL’s herbicide Liberty is perfectly safe if used according to its instructions.

3.1 Liberty is toxic to butterflies and other insects, larvae and some freshwater fish. It causes gastrointestinal and respiratory problems in humans. It is also a neurotoxin with known links to birth defects in mammals, including humans.

3.2 The EU is sufficiently uncertain about Liberty’s safety to have requested a major study, currently being conducted in Sweden. It would be highly irregular and irresponsible if Britain were to give Liberty full pesticide approval until this new study has been properly assessed across the EU.

3.3 There was no guidance about the efficacy of Liberty in the NSL trials that were conducted for Chardon LL in 1996: the herbicide mixes used in those trials involved the use of ‘conventional’ maize herbicides including atrazine; no Liberty was used. This was allowed because Bayer argued that Chardon LL is no different from ‘normal’ fodder maize (see 1.3, above).

3.4 Evidence from the US shows that using Liberty on its own does not control weeds satisfactorily. After a few years of spraying, herbicide tolerance develops in a wide range of weeds, including rye-grass, goose-grass, horsetail and water-hemp. In order to maintain weed control, Bayer advises GM maize farmers to use atrazine as well. This product has been in use for at least three years in GM maize-growing areas. The UK regulator the Pesticides Safety Directorate (PSD) knows that there are problems surrounding Liberty, but it is apparently unable to investigate them until Bayer submits an application for a specific herbicide use.

Acre advised that the planting of Chardon LL ‘would not result in adverse effects – if [it was] grown and managed as in the farm-scale evaluations (FSEs)’.

The committee also recommended that seed listing should be conditional upon ‘any future commercial cultivation of GM maize being limited to the conditions under which it was grown in the FSEs’. Because of Liberty’s deficiencies, these conditions cannot and will not be replicated in the future. The logic has to be, therefore, that no consents should be issued that would result in GM maize commercialisation.

The objective of the trials was ‘to mimic the expected UK commercial farming practice with GM crops under UK conditions’. Research groups were asked to test the hypothesis that the effect of GM crops ‘on the abundance and diversity of wildlife… does not differ from the effect of the management of the conventional equivalent[s]’.

5.1 NGOs were concerned that the trials were ‘fixed’ in order to maximise the biodiversity of the GM crop plantations. Bayer and the pro-GM lobby Scimac interfered with the spraying regimes on the GM maize plots, and experimented with spray timings and herbicide concentrations. For example, the campaign GM-Free Cymru has been told that farmers were not allowed to ‘follow their instincts’ on spray timings and concentrations as they would have done if they were trying to maximise yields; Bayer told the farmers when to spray and at what concentrations. There were clearly unauthorised experiments going on within the FSEs; the most blatant of these involved the oilseed rape trials, in which consent was given for a substantial increase in seed densities during planting so as to compensate for lousy germination rates.

5.2 The non-GM maize plots were managed in order to maximise yields, while the GM maize plots were managed in order to achieve ‘cost-effective weed control’. This means the hypothesis has not been properly tested.

5.3 Atrazine was used on over 90 per cent of the non-GM maize plots at a time when it was becoming increasingly clear that it would be banned for future use in Europe. Meanwhile, Bayer suggested that only Liberty should be used on the GM plots, and this was agreed to by Scimac and the Scientific Steering Committee, the body overseeing the trials. However, all of those involved in the trials must have been aware of the evidence of Liberty’s failure to control weeds in GM maize plantings in the US (see 3.4, above). Thus, none of the maize plots examined in the trials involved management practices that will be employed in the future: a banned herbicide was used on one side, and an ineffective one on the other.

Dr Brian John is a geographer, and taught geomorphology and environmental management at Durham University. He now lives in Wales, where he is involved in a number of environmental groups. He is one of the founders of the pressure group GM-Free Cymru