MEASURING THE IMPORTANCE OF HONEYBEES IN RAPE SEED PRODUCTION
I FRIES AND J STARK
A method of measuring the effect of honeybees on a field of rapeseed (Brassica campestris) was tested. The density of honeybees in the field was significantly related to distance from an apiary. Other gradients in the field were investigated with cages that excluded honeybees, the cages being used to calculate correction factors to compensate for variations in yield due to parameters other than insect density. The results showed that the design was practicable, and indicated that higher densities increased both seed yield and oil content of seed. The method needs to be tested where a more pronounced density gradient can be obtained.