MAFF consults on modified herbicide-resistant crops

A discussion paper on the possible advantages and disadvantages of genetically modified herbicide-resistant crops ahead of their commercial availability in the UK next year has been issued by the Ministry of Agriculture, Fisheries and Food (MAFF).1

To date, eight genetically modified organisms (GMOs) have been given the go-ahead to be sold in the EC. These include Novartis' maize, which is resistant to the herbicide glufosinate, and two modified plants - Bejo Zaden's chicory and Plant Genetic Systems' oilseed rape - with herbicide resistance for seed production only. Monsanto's soya beans, which are resistant to the company's Roundup herbicide, have marketing consent for import and storage for processing only.

MAFF first highlighted the potential advantages and disadvantages of resistant crops in 1993 (ENDS Report 239, pp 15-18 ). These are summarised in the discussion paper, which notes that the Government has not yet taken a view on the various options, nor is it preparing any formal proposals. Among the potential advantages are:

  • Economic benefits, with US farmers reporting yields up by 5% since the introduction of modified soya. UK farmers could be "seriously disadvantaged if competitors had better access to this new technology."

  • Build-up of weeds can be dealt with more effectively during rotations, with "potential environmental advantages in reduction of total herbicide use."

  • The environmental risks posed by herbicides most likely to be used in the UK on resistant crops is "in some respects lower than that posed by some of the selective herbicides they may replace." US farmers, notes MAFF, have reported a 33% drop in herbicide use since the introduction of resistant soya.

    Potential disadvantages include:

  • "Volunteer" plants, which appear as weeds in subsequent grown crops, could become hard to control.

  • Growing of resistant crops could lead to the spread of herbicide tolerance to other crops and related wild species. Gene transfer between plants with tolerance to different herbicides may lead to hybrids with multiple tolerance which would be very difficult to control.

  • Uncertainty over whether the introduction of resistant crops will lead to a drop in the use of herbicides in the UK. If the crop has to be treated only once with a broad spectrum herbicide, then the range of herbicides used, and the total dose, may fall. But "more herbicide may be used than strictly necessary."

    The paper outlines several options to address the potential drawbacks:

  • In line with deregulation, to "encourage" farmers, plant breeders and chemical companies to "find commercial solutions to any problems that arose."

  • Draw up a code to encourage practices such as avoidance of planting different crops tolerant to the same herbicide or a crop which is tolerant to different herbicides, and maintenance of separation distances between resistant and conventional crops.

  • UK regulatory controls "for purely agricultural reasons" could be introduced, but "would need a clear justification."

  • A ban on cultivation of resistant crops might be possible, but would almost certainly need the agreement of the European Commission. Austria and Luxembourg have banned the import of Novartis' modified maize, but the Commission is expected to challenge their action soon as creating an unjustifiable barrier to trade. The UK could press for new controls to be included in the proposals for revising the 1990 Directive on deliberate release of GMOs which are expected this autumn.

  • Please sign in or register to continue.

    Sign in to continue reading

    Having trouble signing in?

    Contact Customer Support at
    or call 020 8267 8120

    Subscribe for full access

    or Register for limited access

    Already subscribe but don't have a password?
    Activate your web account here