Scientists from the Central Science Laboratory have published research which they claim suggests current separation distances between GM rape and conventional rape keeps cross-pollination within EU limits.
The researchers carried out their study during the Farm Scale Evaluations and found that oilseed rape from fields grown 50m from GM varieties met the EU threshold for GM content for food of 0.9% GM.
This was except for varietal association oilseed rape, which scientists said was likely to exceed this threshold at 50m.
The researchers found that cross pollination of conventional crops decreased rapidly with distance from the GM plots.
But they said that rare pollination events could occur at up to 200m from the GM crop.
Leader of the research Dr Christine Hendry said: “Our statistical models based on results from this research confirm that when fields of conventional rape are isolated from GM crops by the industry’s recommended separation distances, harvested seed is likely to be acceptable with respect to the EU thresholds for food.
“However, as was expected, to achieve a lower level of GM presence, for example 0.1%, then larger separation distances are required.”
The CSL work will be used to inform on-going discussions within DEFRA about separation distances.
The government has separately commissioned NIAB to produce a report on crop separation distances for maize and oilseed rape.
On the basis of the NIAB results, DEFRA plans to issue a consultation paper on the co-existence of GM and non-GM crops.
But while CSL based their statistical work on a 95% confidence interval, DEFRA has asked NIAB to use a more precautionary 98% interval for their report.
This means that the figures should ensure that cross-pollination is within the specified threshold at least 98 times out of 100.
“It is anticipated that this difference will produce proposed separation distances that are appreciably longer than those indicated by the CSL study,” said DEFRA.