What is a buffer zone and why is it needed?
A buffer zone is an area of non-GM crops planted around the GM crop to prevent pollen drifting into nearby fields and pollinating other crops and weeds. It acts as a trap for pollen carried from the GM plants by insects such as bees. Bees are more likely to visit the flowers on the buffer plants than to fly over to visit plants further away. Estimates of the necessary width of buffer zones vary depending on the GM crop. For example, as cotton pollen has a low tendency to drift around, the buffer zone does not need to be so large (20 metres). But for crops like GM canola, where insect and wind dispersal of pollen occurs, buffer zones up to 50 metres are recommended. During field trials of GM canola, pollen is contained by placing plastic bags over flowers prior to maturity. Crop management practices like pruning are also used to minimise flower formation.
