Flowering and Nectar Secretion as they Relate to Honeybee Foraging Activity in Birdsfoot Trefoil ( Lotus Corniculatus )

SummarySix cultivars of commercial birdsfoot trefoil differed in their flowering patterns and attractiveness to honeybees, but not in nectar secretion characteristics. Florets contained from 0·16 to 0·28 μl of nectar, with sugar concentrations ranging between 13·1% and 19·5% (0–03-0·07 mg sugar/floret). All cultivars began to flower within a week of one another and bloomed over a 13-week period, producing 2 floral peaks, except for one cultivar which produced 3. Honeybee activity was closely associated with the progression of flowering throughout the season, and cultivar foraging levels were related to the magnitude of the floral display. The cultivars that produced the most florets had the largest number of foragers. Activity was heaviest during the fifth and sixth weeks of bloom when flowering was at its peak. Introduction of honeybee colonies into fields should be delayed until cultivars are approaching peak floret production.