Basics of Commercial Pollination using honeybees

The premise of this research project was that very little was known about the specifics of commercial pollination using honeybees in the deciduous fruit industry in South Africa. The project sought to provide insight into three basic management practices used during commercial pollination with honeybees, as a beginning towards a more comprehensive understanding of the practice.

The premise was proved to be correct during the project, as all three null hypotheses were shown to be incorrect, indicating that we knew even less about commercial pollination that we thought. The general conclusions reached during the project are as follows:

1. Bee-hives in full sun during pollination provided fewer foragers than did hives in the shade, and not more as was expected. This suggests that hive cooling may be a greater limiting factor than hive warming, and that colonies should be placed in the semi-shade during pollination, except during very cold conditions. The nature of the hive dynamics (heat retention) should also be further investigated.
2. No evidence could be found to suggest that there is merit to the practice of using two waves of colonies for the pollination of “difficult” crops such as Packham’s Triumph pears. It is recommended that the optimum number of colonies be introduced into pear orchards from the beginning for optimal pollination.
3. The practice of clustering colonies of bees during pollination was found to cause disrupted foraging near the colonies, reducing the number of foragers near the colonies. It is recommended that colonies be evenly distributed around the orchards for optimal pollination.

Additional information and insights gained during the course of the projects are as follows:

• Colonies of bees are severely disrupted when moved into orchards, and do not resume normal foraging for 1-2 days. Colonies should be moved into orchards earlier to allow for a settling down period.
• The “naïve forager” strategy which underpins the use of honeybees for the commercial pollination of unattractive crops is found not to be supported by data. Foragers do not pour out of colonies and work on the unattractive forage around them until such time as more attractive forage is sourced. On the contrary, only small numbers of foragers ever work on the unattractive crop. This suggests that colonies need not be introduced into orchards after the onset of blossom, but can be introduced earlier without any reduction in pollination activity.
• There is no evidence that foraging bees “switch off” the unattractive pears onto more attractive crops at any stage. This suggests that alternative forage such as weeds are not as much as a threat as previously thought.
• Honeybees are found to make up 94% of all pollinators in deciduous fruit orchards, and hence a healthy and viable honeybee population is critical to the deciduous fruit industry.
• Good weather conditions are concluded to be the critical factor for successful pollination, with only one day of perfect weather probably sufficient for the complete pollination of a crop.

All these results should be considered as preliminary and needing of substantiation, particularly as a number of generally accepted pollination practices are concluded to be without substance. Fortunately, all aspects brought to light are readily tested, and more comprehensive and focused testing is recommended.