GENETICALLY modified and conventional crops can safely coexist in the European countryside, although they might sometimes need to be kept further apart than normal to prevent unwanted cross-pollination, says a scientific review issued last week by the European Environment Agency.
Plants that need extra isolation from GM crops include those grown solely to supply high-quality seeds. Also at risk are the high-yielding 鈥渕ale-sterile鈥� varieties of oilseed rape, which are pollinated almost exclusively by other plants. But for most crops, existing isolation barriers of up to 100 metres should be enough to keep the level of contamination below the accepted limit of 1 per cent. 鈥淚t just needs careful farm management,鈥� says Jeremy Sweet of the National Institute of Agricultural Botany in Cambridge, who wrote the review with his colleague Katie Eastham.
They rank each of Europe鈥檚 major GM trial crops according to their 鈥減romiscuity鈥濃�攖he likelihood that they will cross-pollinate with other crops or with wild relatives. Oilseed rape topped the league because it spreads its pollen far and wide, both in the air and via insects. Sugar beet and maize pose 鈥渕edium to high鈥� risks.
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Peter Melchett, the Soil Association鈥檚 policy director, points out that these three crops are the ones grown in the British government鈥檚 field trials to discover whether GM crops are a greater risk to farmland wildlife than their conventional counterparts. Sweet says the risk to organic farming is exaggerated. But there are circumstances in which the 100-metre barrier could justifiably be extended to around 400 metres, he says. 鈥淔or seed production crops, there may have to be some zoning if you want very high levels of non-GM purity,鈥� says Sweet.