Defra - Department for Environment, Food and Rural Affairs.

Science Search

Science and Research Projects

Return to Science Search homepage   Return to Project List

Monitoring occurrence of GM oilseed rape volunteers in subsequent oilseed rape crops at FSE sites - CB02033

Genetically-modified herbicide tolerant oilseed rape was grown as spring and winter sown varieties as part of the farm-scale evaluation between 1999-2003. The release consents under which all of these crops were grown specify that non-oilseed rape crops should be grown in the fields in subsequent years for a period of one or two years and that measures should be taken to minimise the occurrence of oilseed rape volunteers.

In mid-2003 we became concerned that once the one or two year period was up, many farmers were likely to want to return to growing conventional oilseed rape in the former FSE fields. The concern was raised that if conventional oilseed rape was grown in the field that the occurrence of GM oilseed rape volunteers would go undetected. The presence of GM material in the harvested crop may present problems concerning the labelling should the crop be marketed.

Aims and objectives

The project will involve collecting data that will allow the validity of published models on the persistence of oilseed rape seed, and occurrence of oilseed rape volunteers in subsequent oilseed rape crops, to be tested.

To enable this to be tested farmers who have previously grown GM oilseed rape as part of the FSEs will be allowed to return to growing conventional oil seed rape in FSE fields.

The work will be conducted in oilseed rape crops planted in spring and autumn 2004.


There are potentially 65 former FSE GM oilseed rape fields in which spring-sown or winter sown oilseed rape may be planted in 2004 and a further 48 additional fields in which winter-sown rape alone may be sown.

We are seeking proposals to quantify the occurrence of GM oilseed rape volunteers in subsequent conventional oilseed rape fields and to use this data to assess published models on oilseed rape seed persistence and emergence.

Access to fields will be negotiated with FSE farmers. Field sampling method should be based on achieving a 0.1% detection limit while being cost-effective. Both in situ and ex situ assessment methods, based on either spraying-off or PCR methods will be considered. Sampling methods that allow assessment of GM presence pre-flowering and/or pre-harvest are preferable, although subsequent analysis of GM presence post-harvest for comparison may also be considered.

Not all fields used in the FSE need to be sampled, however we are looking for clear justification for the number of fields selected based on an analysis of statistical power.

Where possible conclusions should be applied separately to different spring-winter sown oilseed rape combinations. In practice, however the availability of spring sown sites in 2004 will be limited and the bulk of work will be concentrated on sites growing winter-sown oilseed rape sown in autumn 2004.

If the successful contractors were to be currently involved in sampling at FSE sites through other Defra-funded work we would expect to see cost-saving economises incorporated.

Tenders should include provision for compensating the farmers and disposal of the harvested crop should it turn out to have levels of GMHT rape higher than the permitted threshold at the time of harvest.

Timetable and deliverables

The project will commence in March 2004 and be completed by August 2005.

The contractor will provide 6 monthly interim reports

The contractor will provide a final report on completion of the work.

The contractors are encouraged to submit the findings for publication in the peer reviewed scientific press. Published or in press papers may be provided in lieu of the relevant sections of the final report. Arrangements in this case should be agreed in advance with Defra.

The final report may be subject to anonymous peer review.

Time-Scale and Cost
From: 2004

To: 2005

Cost: £500,000
Contractor / Funded Organisations
Scottish Crop Research Institute
Agricultural Land              
Environmental Protection              
GM Non-Food              
GM Risk Assessment              
Fields of Study
Biotechnology and GMOs