Hi All

I have had a number of queries on this term that I used in a recent post.
I have replied individually, the exact details may be specific to the UK,
but I will share it with the list

OSR (Oil Seed Rape, canola) has been grown for many years, originally as a
tempering medium
for steels, then cattle feed.

Up until about twenty years ago the varieties grown contained toxins that
made the bees "nasty" after they had been foraging on the crop for about 3
weeks. The crop only flowered for 4 weeks and so there was a 7-10 day period
when the bees were unapproachable.

The seed growers introduced "double low" varieties that contained less
toxins and could be used for human consumption as an emulsion (margerine)
for spreading on bread.

The lower toxins had less effect on the behaviour of the bees, which is a
good thing, because the growing of the crop became more common and different
planting regimes brought about overlapping flowering of neighboring crops.

Triple low varieties are now available with even lower toxins.

This year in UK with the outbreak of "foot & mouth" and alterations in
subsidies the cruder forms of  OSR, known as "Bio Diesel Rape" are being
grown again for use as tractor fuel.

Consequently the bees and beekeepers are exposed to a phenomena that has not
been present for about twenty years. I have no idea whether this will be a
future trend or just a glitch due to "foot & mouth" .


Regards From:- Dave Cushman, G8MZY
Beekeeping and Bee Breeding, http://website.lineone.net/~dave.cushman
IBList Archives, http://website.lineone.net/~d.cushman