jazzie I don't know about the flea beetle... A few years ago a farmer told me that there's even too much oil seed rape produced here, so that only those farmers who do grow it since a long time are still allowed to do so. Not sure if I got him right, though.
tigg We were amazed how much oil seed rape we saw, especially in France. Most farmers no longer grow it here as they are not allowed to spray against flea beetle (?).
In this photo, the green area in the middle - without any flowers - looks like a tunnel sucking the viewer in!