The EU study states that in oilseed rape production the co-existence of GE and non-GE crops in a same region, even when "technically possible", would be "economically difficult" because of the additional costs and complexity of changes required in farming practices in order to avoid genetic contamination. Both organic and conventional farmers "would probably be forced to stop saving seed and instead buy certified seed", because of the increased risk of GE impurity for seeds that have been exposed to field contamination. The study predicts that smaller farms would face relatively higher costs compared to larger entities, and that cultivation of GE and non-GE crops in the same farm "might be an unrealistic scenario, even for larger farms".

The main specific findings of the report were:

· Commercialisation of GE oilseed rape and maize and to a lesser extent potatoes will increase costs of farming for conventional and organic farmers at a range between 10 and 41 per cent of farm prices for oilseed rape and between one and nine percent for maize and potatoes.

· Coexistence of GE farming and organic farming would be actually impossible in many cases.