A study was conducted to determine if bumblebee pollination
of small greenhouse tomato
operations would be as effective and economical as hand-held electric vibrators. Results indicated that bumblebee-pollinated plants produced significantly less marketable yield than did vibrator-pollinated plants.
However, yield differences between the two treatments were not significant when bumblebees were allowed to forage on tomato flowers for four days and pruning excess flowers was delayed until all flowers ceased to produce pollen. Yield losses from plants pollinated by bumblebees resulted from excessive visitation by bees
, leading to flower injury and abortion.
Closing the bee hive on Mondays, Wednesdays and Fridays of the week may have helped to reduce flower injury. Pruning excess flowers after they ceased to produce pollen provided additional pollen for the foraging bees. Bumblebee pollination of 640 plants for 18 weeks required a class C hive replaced every 6 weeks at a total cost of $300.
Pollinating the same number of plants for the same period of time with an electric vibrator required 16.27 person hours at $113.88 labor cost plus $40 vibrator depreciation. Smaller grower may need bumblebee pollination during maximum demand on their time to harvest and market the crop.