• Summary & Conclusion
• part 1
• part 2
• part 3
• part 4
• sitemap

THE STATE OF SCOTLAND'S FARMED ENVIRONMENT 2005

14. GENETICALLY MODIFIED (GM) CROPS

BACKGROUND – REGULATORY FRAMEWORK

The release of Genetically Modified Organisms (GMOs) in the EU is controlled under Directive 2001/18/EC which, in the UK, is implemented via the Environmental Protection Act (1990) and the Genetically Modified Organisms (Deliberate Release) (Scotland) Regulations 2002. This is a devolved responsibility: The Scottish Executive consents to the release of GM crops for research and development purposes in Scotland . DEFRA acts as a clearing house for applications for deliberate release, provides the secretariat for the Advisory Committee on Release to the Environment (ACRE), and co-ordinates the international presentation of UK policy. Ministers also take advice from the Health and Safety Executive, the Food Standards Agency and SNH as appropriate. (Scottish Agricultural Science Agency, 2004)

FARM SCALE TRIALS IN SCOTLAND

The farm scale evaluations (FSEs) were a three-year research programme which lasted until 2002/2003. The FSEs allowed independent researchers to investigate the impact on biodiversity of the management of four types of herbicide tolerant GM crop: spring oil seed rape, winter oil seed rape, fodder maize and beet (the latter two not tested in Scotland ). The FSEs took place on 18 trials sites on five farms in Scotland in Aberdeenshire, Fife , and Ross-shire. The main results for oil seed rape (OSR) were:

Winter OSR: Similar total weed densities were found in both GM and conventional crops. However, there were significant differences in the abundance of different types of weed. Seed numbers from grass weeds were five times greater in the GM crop and this difference persisted in the seedbank in the following year. Broad-leaved weeds produced three times more seeds in the conventional crops. As a consequence, there were more butterflies and bees in conventional winter rape because there were more flowering weeds. The numbers of springtails, however, were higher in the GM crop.

Spring OSR: Although the numbers of surviving broad-leaved weeds were similar in conventional and GM crops, the plants had a 70% lower biomass in the GM crops. Seed rain was also lower, with 80% fewer broad-leaved weed seeds. Overall, the weed seedbank was smaller following GM crops. Butterfly numbers were higher in the fields and field margins of conventional spring rape crops, attracted mainly by the greater number of flowering weeds. Most other insect groups, including bees, were found in similar numbers in the GM and conventional fields, although there were some seasonal differences. (Scottish Executive, 2005)

Overall, conventional fields in the FSEs showed greater numbers of broad-leaved, flowering weeds and consequently more butterflies and bees. Seed numbers from grass weeds were higher in the GM crops. However, there were differences between winter and spring sown OSR, as well as seasonally.

GM NATION – THE PUBLIC DEBATE >>