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Although the results of the UK's BRIGHT ('Botanical and Rotational Implications of Genetically Modified Herbicide Tolerance') project are being spun in a pro-GM direction, it is clear from the BBC report below, as it proceeds, that the study raised some important problem issues.

In fact, as early as 2000 the BRIGHT Project confirmed that gene-flow was occurring between different herbicide tolerant (HT) oilseed rape (OSR) crops in its field trials, creating unintended multiple herbicide tolerance: "There was some hybridisation between adjacent plots of different HT rape varieties...", the 2000 report noted.

The report, then as now, tried to play down the significance of the discovery but, as land agent Mark Griffiths pointed out at the time, a number of important points arose, including:

*Multiple herbicide tolerance is being unintentionally created within individual plants.

*Because shed oilseed rape seed can remain dormant in the ground for several years farmers are clearly going to have problems further down the line with this situation. This is likely to happen, for example, when spraying stubbles later in the rotation which have freshly germinated OSR seeds in them.

*How are farmers going to know which herbicides to use in these cases several years later on? Stubbles are often 'cleaned' using the very types of 'total' herbicides that these genes provide tolerance to...

*These findings are unlikely to be a short term 'marginal' issue as similar problems are already cropping up in Canada on a wider scale after several years of commercial canola (oilseed rape) cropping. The problem is sufficiently severe that it has necessitated the introduction of a complex 9 point management plan in order to attempt to deal with the issue...

*The introduction to this latest BRIGHT report acknowledges that in this type of scenario: "Land could become infested with herbicide tolerant weeds and volunteers to the extent that GM crops could no longer be exploited and conventional crop management would need to be modified."

*This may not be a problem just for those farmers who plant genetically modified herbicide tolerant crops, but also for neighbours where pollination or other forms of transmission (e.g via vehicles or animals) spreads genetic material across farm boundaries. In this way one farmer can end up making herbicides on another's farm ineffective. This type of situation is already leading to litigation in Canada (see: http://www.netlink.de/gen/Zeitung/1999/991224.htm ).
http://www.btinternet.com/~nlpwessex/Documents/UKOSRHTGMgene-flow.htm

Four years later the report authors have been unable to avoid acknowledging some of these problems, although the focus is primarily on the problems arising from the recurrent use of the same herbicide. The following are excerpts from the BBC piece (full text given below the excerpts):

"Bright did show some potential problems with cross-breeding between herbicide-tolerant varieties of rape, producing seeds immune to more than one herbicide.

"We did create a stock of oil-seed rape seeds in the soil following the growing of GM crops," said Dr Peter Lutman, from Rothamsted Research, one of the agricultural centres that took part in Bright.

"And that seed bank, although it declines quite rapidly, does stay in the field for a number of years; so there is a question about how soon you could grow a non-GM crop in the same field and not have a problem arising from the GM plants from the previous crop."

Dr Lutman believes there could be further problems if, in the future, GM beet and rape were grown in rotation with cereals which were also genetically modified to be tolerant to the same herbicide.

"My experience of managing weeds over many years is that if you use the same herbicide year on year on year on year, then you will build up problems.

"Indeed there are problems arising in North America where people are growing Roundup-Ready soya and Roundup-Ready corn in the same rotations.

"And I would think one would need to look very hard about how one managed a rotation of GM crops."
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Field management is 'key for GM'
By Richard Black
BBC environment correspondent
http://news.bbc.co.uk/1/hi/sci/tech/4050475.stm

A new UK study of a number of specific GM crops has found no evidence that they are more harmful to the environment than conventional varieties.

The Bright Link project studied sugar beet and winter oil-seed rape which had been engineered to make them tolerant of specific herbicides.

This modification allowed them to be sprayed and still prosper while all the weeds around them died.

The novel crops were grown in rotation with non-GM cereals, and compared with similar rotations involving non-GM beet and rape.

The project concluded that the GM varieties used in this way did not deplete the soil of weed seeds needed by many birds and other wildlife.

Apparent contradiction

The findings of the Botanical and Rotational Implications of Genetically Modified Herbicide Tolerance (Bright) Link project have been released eight months after another major GM investigation, called the Farm-Scale Evaluations or FSEs.

The FSEs found that two GM varieties, a sugar beet and a spring rape, were more damaging to biodiversity than conventional crops. There were fewer insect groups, such as bees and butterflies recorded among the plants.

A GM maize, on the other hand, appeared to do better than its conventional cousin.
There were more weeds in and around the biotech maize crops, more butterflies and bees around at certain times of the year, and more weed seeds.

The FSEs were considerably larger in scale than Bright, involving 60-70 fields across the UK, and follow-up measurements were made in years following the planting.

On the face of it, the Bright conclusions appear to contradict the FSE results. Bright found fewer adverse impacts, whereas the FSEs found more.

"They asked different sets of questions," Chris Pollock, who chaired the FSEs' scientific steering committee but was not involved in Bright, explained to BBC News.

The FSEs were a straight comparison of GM versus non-GM in a single growing season, whereas Bright aimed to reflect normal farming practices in each location, indicating how GM varieties might perform if they were integrated into UK agriculture.

"The FSEs looked at single-management options," said Professor Pollock, "and we suggested there were important questions of how management practices would need to be modified to include herbicide-tolerant varieties - Bright is now giving us some answers."

Professor Pollock, research director of the Institute of Grassland and Environmental Research in Aberystwyth, was speaking in a personal capacity.

Spray timing

Dr Jeremy Sweet, Bright's scientific co-ordinator, believes that in both studies, the impact on seeds - and so on wildlife - is down to the herbicides used, rather than the GM crops themselves.

"There have been studies in the UK now for many years which have shown the detrimental effect of herbicides, and how they've depleted farmland birds, and all the rest of it," he told BBC News.

"The critical thing is how the herbicides are used on these crops; so what we need to do is to ask whether these herbicides have the potential to do more harm than current ones or, if managed properly, they can be less harmful than the current ones."

Dr Sweet concludes that the herbicides used with the GM varieties can be less harmful than those used on the conventional crops.

"One of the interesting things about the herbicide-tolerant systems is that you can apply the herbicides later, when you've got a much better idea of what spectrum of weeds is in the field, and therefore you can target your weed control more effectively.

"This means that you have some scope for manipulating populations of weeds so that if you do want to retain a reasonable weed flora in the field, you can do that.

"You can also control the weeds which are competing with the crop, particularly when the crop is being established."

Potential problems

Professor Pollock added: "The most important element of Bright is the fact that it confirms comments made in the FSEs about the importance of management.

"You can use management to generate rotations that give you the best balance between weed control and preservation of the seed supply."

Bright did show some potential problems with cross-breeding between herbicide-tolerant varieties of rape, producing seeds immune to more than one herbicide.

"We did create a stock of oil-seed rape seeds in the soil following the growing of GM crops," said Dr Peter Lutman, from Rothamsted Research, one of the agricultural centres that took part in Bright.

"And that seed bank, although it declines quite rapidly, does stay in the field for a number of years; so there is a question about how soon you could grow a non-GM crop in the same field and not have a problem arising from the GM plants from the previous crop."

Dr Lutman believes there could be further problems if, in the future, GM beet and rape were grown in rotation with cereals which were also genetically modified to be tolerant to the same herbicide.

"My experience of managing weeds over many years is that if you use the same herbicide year on year on year on year, then you will build up problems.

"Indeed there are problems arising in North America where people are growing Roundup-Ready soya and Roundup-Ready corn in the same rotations.

"And I would think one would need to look very hard about how one managed a rotation of GM crops."