One honeybee or bumblebee working on each square metre of white clover or red clover gave adequate pollination. This could be obtained with one hive of honeybees to each three hectares of flowering clover. Lucerne seeding averaged only 10% of the potential maximum in open fields with honey- or bumblebees. In cages where honeybees were forced to gather pollen, this was raised to 30% but it was not possible to increase seed set significantly in the fields.
