ngin - Norfolk Genetic Information Network

GM Crop Trials.
Concerned? You should be.

Introduction - GM farm scale trials

Four GM crops are being looked at in the current UK farm scale trials: fodder maize, spring oilseed rape and winter oilseed rape tolerant to the herbicide glufosinate ammonium (Liberty) and sugar and fodder beet tolerant to glyphosate (Roundup).

The oilseed rape and maize have been developed by the multinational company Aventis who also produce glufosinate ammonium. The sugar and fodder beet has been developed by Monsanto, in partnership with Novartis. Monsanto also manufacture glyphosate. Glufosinate and glyphosate are broad spectrum herbicides which kill all green plants except those protected as a result of the genetic modification. Therefore, farmers will be able to spray the GM crop with the relevant herbicide to remove weeds without harming the crop.

What is the aim of the trials?

Modern industrial farming has already been linked with declines in farmland wildlife and there are fears that the increased use of broad spectrum herbicides with resistant GM crops will result in the highly efficient removal of weeds and a consequent decrease in food supplies for invertebrates and birds. Trial fields will be divided into two, one half growing the GM crop and the other half growing a non-GM variety, and numbers of insects, wild flowers and birds will be compared in each half of the field.


The GM crop will be grown for one year and each trial field will be monitored for another two years. Farmland ecology is poorly understood and the wildlife in these fields will never have been studied before. Soil type is an important factor in determining what lives in the field, yet it may vary from one part of the field to another. Modern fields are often two or three older fields joined together, each of which may have a different history, soil structure and wildlife. Insect numbers vary naturally from one year to the next, so effects will have to be large, otherwise they wonít be detected. Earthworms and soil fungi and bacteria are vital to the health of the soil, yet their numbers arenít being monitored.

The effects of GM crops and their herbicides are likely to be subtle. It took many years for the devastating effects of DDT on birds to be realised and over fifty years for scientists to discover the damage caused to the ozone layer by CFCs, previously thought to be safe and inert. Three years of limited studies is simply not long enough to say that GM crops are "safe". Remember that chemical pollution can be contained but DNA can reproduce itself indefinitely and canít be recalled.

What about cross-pollination?

Maize has no wild relatives in Europe and cannot survive our winters. However, non-GM maize and sweet corn can be cross-pollinated and maize pollen can travel at least 800 metres (1). Sugar (and fodder) beet is a biennial, flowering in its second year. However, a proportion of plants, known as "bolters" flower in their first year and, if not detected, can cross-pollinate with relatives ? other sugar beet, sea beet, spinach beet, Swiss chard and beetroot. In crop trials, all bolters should be removed, but if GM beet is commercialised, some bolters are bound to be missed. Experiments in Italy have shown that gene flow has occurred between sea beet and sugar beet across distances of up to 20 miles (2). Although a large proportion of Oilseed Rape is self-pollinating, pollen can be moved by both bees and wind and cross-pollination occurs at a 5% frequency at a distance of 4km (1). It is the single most important honeybee forage crop (27). Oilseed rape will cross with other oilseed rape and also other members of the cabbage family including cabbage, wild radish and charlock (1). In Norfolk, wild radish is a widely distributed annual or short-lived perennial; charlock is an abundant weed of fields and waste ground (28).

Soil contamination

DNA from GM crops may spread into the wider environment through the transfer of genetic material to soil microbes. DNA from GM sugar beet persists for up to two years in the soil (3). In laboratory experiments DNA from GM plants was taken up by both fungi (Aspergillus) and bacteria (Acinetobacter) (4, 5). Agricultural soils are often very mobile, especially in Norfolk, so it is likely that soil contaminated by GM crops will spread to other fields.

Sugar beet seed can remain in the ground, dormant but fertile, for at least 10 years (30), giving rise to GM sugar beet plants long after monitoring of the fields has stopped. Viable GM oilseed rape seeds can give rise to volunteers for at least three years (29). GM seeds or plant material may also be moved by birds and mammals (6). In Germany, sugar beet trials have to be netted to prevent animals removing the seed ? this isnít a requirement in the UK (7).

Effects on farmers and beekeepers

A 1999 report by Norwichís John Innes Centre described contamination of non-GM crops with GM pollen as "inevitable"(8). GM contamination will affect livelihoods of other farmers, especially organic farmers, who will be unable to sell contaminated crops.  Honey contaminated with GM pollen from last yearís crop trials has already been found (9). Beekeepers provide a vital service to fruit growers but will be forced to move their hives from areas near GM crop trials if they wish to avoid GM contamination.

A Royal Institution of Chartered Surveyors report last year suggested that land values may be affected by growing GM crops (10). TESCO refuses to buy crops from land where GM crops have been grown and NFU Mutual Insurance wonít provide insurance cover against GM cross-pollination or decline in land value due to GM crops.

Conventional plant breeding

In conventional plant breeding, genes are swapped about but no new genes are introduced into the plant. This swapping about is under the precise, well-ordered control of the plant and has evolved over millions of years. Even when radiation or chemicals are used to cause mutations, existing genes may be altered but no new genes are introduced.

Genetic modification

The GM forage maize grown in these crop trials contains four different, introduced DNA sequences and the GM sugar beet contains no less than seven, isolated from other plants, viruses and bacteria (11).

Insertion of the DNA is done using a bacterium that naturally infects plant roots, called Agrobacterium, or by the "gene gun" method, where the DNA is attached to a tiny gold or tungsten pellet and fired at high velocity into the receiving cell.

Keeping the gene switched on

If a single gene is transferred into a plant on its own, the plantís cells will recognise the foreign DNA as surplus to requirements and add chemical groups to inactivate it. Therefore a piece of DNA known as a promoter is also introduced into the plant. This turns the inserted gene(s) on permanently, in all plant cells and tissues. The most commonly used promoter is from cauliflower mosaic virus. In the natural state this promoter is under the control of the virus and is locked away inside a protein coat. In recent years research has shown that both plant and animal cells contain dormant viruses, which would have infected the plant or animalís ancestors thousands or millions of years ago. Normally, including during conventional crossing, these sequences are quite harmless. However, in the genetically modified plant, the viral promoter is potentially able to recombine with other DNA in the cell and either reactivate these viruses or create new viruses (16).

Plant genes are normally switched on and off in particular plant tissues according to the plantís needs and environmental conditions. However, inserted genes in a GM plant are always switched on in every plant cell. In the United States, GM insect resistant crops are starting to become less effective, as the insect pests they were designed to resist rapidly develop tolerance. Similarly, weeds will develop herbicide tolerance as they are exposed to more of the same few herbicides (such as glyphosate and glufosinate ammonium) (21).

The DNA is inserted at random

There is no control over where the introduced DNA will be incorporated in the host plantís DNA. Existing genes may be disrupted or switched on by the inserted promoter, leading to unexpected effects.  Already, various GM plants have unexpectedly had higher levels of toxins, extra fungal resistance, woodier stems or more starch, when none of these were the intended result of the genetic modification (12). Genes cannot be considered in isolation. Genes tend to work in groups in an organised but barely understood way. Introducing new genes and DNA sequences, in combinations never ever known before, will disrupt gene function in ways we simply cannot predict.

Environmentally friendlier?

In the short term, growing GM crops is likely to cause a switch to glyphosate and glufosinate ammonium from other herbicides. Glyphosate in particular is often referred to as an "environmentally friendly" chemical. HoweverÖ

Glufosinate ammonium causes birth defects in experimental animals, causing premature cell death in the immature brain by a process called apoptosis. It also prevents development of glutamate channels in the brain, disrupting cellular communication (13). It is also highly soluble in water and is classified as persistent and mobile by the US Environmental Protection Agency (14). Little is known on general effects on wildlife but glufosinate is toxic to several species of freshwater fish, daphnia and larvae of clams and oysters (14). It inhibits soil fungi and bacteria at realistic field rates of application, completely suppressing the activity of 40% of soil bacteria and 20% of soil fungi (15). Maize is frequently grown year after year on the same site without crop rotation, yet in the crop trials maize is only for one year, so any longer term effects of using glufosinate ammonium wonít be measured.

Glyphosate reduces the growth of earthworms and increases their mortality(17), is toxic to many of the beneficial mycorrhizal fungi which help plants take up nutrients from soils (18), can inhibit anaerobic nitrogen fixation in soil and is the second most toxic out of nine herbicides tested for toxicity to a range of soil bacteria, fungi, actinomycetes and yeasts (19). It has been linked to Non-Hodgkin's Lymphoma (NHL) and has caused gene mutations and chromosomal aberrations in animal experiments (20). (NHL is a group of cancers that arise in the white blood cells.)

Evidence from the United States suggests that GM herbicide resistant crops do not cause herbicide use to fall or cause an increase in yields (21). And of course, the levels of other pesticides used on these crops will not decrease either. In contrast, organic farming and integrated crop management can significantly reduce or even eliminate chemical usage.

What about "extensive tests"?

For GM fodder maize, there is no publicly available evidence giving the effects of feeding to cattle, either in the EU or United States. The nearest appear to be trials where rats were fed on novel protein extracted from GM oilseed rape and other trials, which have not been made public, involving broiler chickens. The Governmentís own Advisory Committee on Animal Feeding stuffs (ACAF) has stated that "feeding trials carried out with monogastrics [animals with one stomach, such as rats and chickens] would not be directly applicable to ruminants [such as cows]" ? i.e. the results of feeding trials on rats cannot be extrapolated to cattle. Yet Aventis have presented evidence that shows that its GM fodder maize differs from conventional maize in fat, carbohydrate, amino acid and fatty acid content. Furthermore, maize makes up 30 ? 50% of the diet of some dairy cattle (22).
The maize is banned in both Austria and Switzerland for environmental reasons.

Alternatives to GM

Biotechnology can be used as a diagnostic tool. Using recently acquired knowledge of gene sequences, desirable genes can be found and followed around during conventional plant breeding (23).

Organic farming looks after the health of the soil and the plants and animals dependant on it, conserving scarce water resources and reducing disease and weed problems through crop rotation. In contrast, GM continues the simplistic thinking of intensive farming, concentrating on a single symptom at a time and a short-term cure rather than long-term prevention.

Maize trials over fifteen years in the United States have shown that there is an initial drop in yield when organic farming is first introduced but after four years the yields increase and go on increasing (24). Whatís more they can stay high in the long term, after "conventional" farming has damaged the soil structure and often polluted water supplies and damaged farmersí health as well. In many developing countries, yields have doubled and trebled since organic and sustainable farming methods were introduced, in crops as diverse as maize and coffee (25). Even when yields are reduced, dry matter content of organic crops, including levels of nutrients, is actually much higher than in "conventional" crops (26).

It is very unfortunate that £52 million of taxpayers money is spent each year on developing GM crops, for which there is almost no demand, while only £1.7 million is spent on research on organic food, where supply outstrips demand by 200%.

Some Quotes

"In no way do we actively encourage farmers to take part in the farm-scale trials of GM crops" - Graham Wynne, Chief Executive, Royal Society for the Protection of  Birds, in response to a letter expressing concerns at RSPBís endorsement of GM crop trials.

GM may be like "BSE in Technicolor". Professor Terje Traavik, University of Tromso, Norway. Parliamentary briefing to UK Government, 10 ? 11 February 2000.  (Prof. Traavik has been a professional genetic engineer for twenty years. He used to be a total "believer" in thinking there were only benefits in GM, but changed his mind as a result of studies in his own laboratory.)

 " If anyone tells you that GM is going to feed the world, tell them that it is not. Equinox was a mistake and went too far. To feed the world takes political and financial will, itís not about production and distribution. It is not the single answer, it is one of many areas that is being investigated. It may produce more for less and create more food but it won't feed the world." Steve Smith, Novartis Seeds, Tittleshall GM Crop Meeting, March 2000.

Some References

1. R. Treu and J. Emberlin (2000), "Pollen dispersal ? Evidence from Publications", a report for the Soil Association from the National Pollen Research Unit. Available at
2. D. Bartsch and M. Schmidt (1997),  J. Vegetation Science, Vol 8, 81 ? 84; Y. Vigoroux (1999). Gene flow between sugar beet and weed beet. BCPC Symposium Proceedings No. 72. British Crop Protection Council, Farnham, Surrey.
3. F. Gebhard and K. Smalla (1999), FEMS Microbiology Ecology Vol 28, 261 ? 272.
4. T. Hoffmann, C. Golz and O. Schneider (1994), Current Genetics, Vol 27, 70 ? 76.
5. K.M. Nielsen, A.M. Bones, K. Smalla and J.D. van Elsas (1998), FEMS Microbiology Reviews, Vol 22, 79 ? 103.
6. Charles Darwin (1859). "The Origin of Species" ? beet seeds germinated after 12 to 21 hours in the gut of birds of prey.
7. D. Bartsch. Affidavit to Irish court case, Clare Watson v The Environmental Protection Agency and Monsanto.
8. C. L. Moyes and P. J. Dale (1999), John Innes Centre, Norwich.
9. Friends of the Earth Press Release, 16 May 2000. Two out of nine batches of honey sampled were contaminated.
10. Reported in Eastern Daily Press, 15 March 1999.
11. UK Crop Trials 2000. Gene Watch fact sheets. Available at
12. For various examples see Luke Anderson (1999), "Genetic Engineering, Food and Our Environment".
13. T. Fujii and T. Ohata (1994), J. Toxicol. Sci. Vol 19, 328; T. Watanabe and T. Iwase (1996), Terat. Carcinog. Mutagen. 287; T. Watanabe (1997), Neurosci. Lett. Vol 222, 17; T. Watanabe (1995), Teratology Vol 4, 258.
14. Glufosinate Ammonium Fact sheet, available at (Pesticides Action Network UK.)
15. I. Ahmed and D. Malloch (1995). Agric. Ecosystems and Environ. Vol 54, 165 ? 174.
16. See, for example, M.W. Ho, A. Ryan and J. Cummins (2000), Microbial Ecology in Health and Disease ? in press.
17. J.A. Springett and R.A.J. Gray, Soil Biol. Biochem. Vol 24(12), pp1739 ? 1744.
18. D. Estok, B. Freedman and D. Boyle (1989), Bull. Environ. Contam. Toxicol. Vol 42, pp835 ? 839;  P. Chakravarty and L. Chatarpaul (1990) Pestic. Sci. Vol 28, pp233 ? 241; P. Chakravarty and S.S. Sidhu (1987), Eur. J. For. Path., Vol.17, pp.204-210; S.S. Sidhu and Chakravarty (1990), Eur J. For. Path., Vol.20, pp.77-94.
19. S.M. Carlisle and J.T. Trevors (1988). Soil, Water and Air Pollution Vol. 39, pp. 409-420.
20. A. Harras et. al. (eds). Cancer Rates and Risks, 4th edition. NIH Publications No. 96-691. Bethesda, Maryland: National Cancer Institute, 996, p17; M. Nordstrom et. al. British Journal of Cancer, Vol. 77, pp2048 - 2052. (1998); L. Hardell and M. Eriksson. Cancer, Vol. 85, No. 6, pp 1353 - 1360.
21. "Do Genetically-Engineered (GE) Crops reduce pesticides? The emerging evidence says Not Likely". WWF Canada, February 2000 (; C. Benbrook (1999), "Evidence of the Magnitude and Consequences of the Roundup Ready Soybean Yield Drag from University-Based Varietal Trials in 1998".
22. "Genetically Modified Maize ĎChardon LLí, Friends of the Earth briefing, April 2000; Minutes of ACAF and ACNFP joint meeting, 1 December 1999.
23. See, for example, "Exquisite Taste", New Scientist, 3 April 1999, p17.
24. Luke Anderson (1999), "Genetic Engineering, Food and Our Environment", p59.
25. See, for example, J. Pretty (1998), Splice, Vol 4, pp4 ?5,
26. N. Lampkin (1990), "Organic Farming", pp557 - 575, Farming Press, Ipswich.
27. G. Ramsey et. al. (1999), in P.J.W. Lutman, "Gene flow and agriculture: Relevance for transgenic crops". BCPC Symposium Proceedings no. 72.
28. G. Beckett and A. Bull (1999). "A Flora of Norfolk".
29. C. E. Norris et. al. (1999), in P.J.W. Lutman (see reference 27).
30. From "Sugar Beet ? A Growers Guide ? Weed Beet" at

GeneWatch UK has produced a very good series of fact sheets on the UK farm scale trials available at