Spring is here and before we know it, wild blueberries will be blooming and ready for pollination. Engaging in wild blueberry pollination is a major undertaking for many Atlantic beekeepers and demand for this service is high. In the upcoming blogs, we will discuss some important aspects to consider for successful pollination.
Honey Bee Stocking Density on Wild Blueberries
Honey bees are not the only pollinators of wild blueberries. The presence of wild pollinators impacts the demand on honey bees, in that fewer wild pollinators call for more managed pollinators. The population of wild pollinators can be measured in a field to get an estimate of the pollination force they will provide (Drummond 2002). However, this can only be performed once blooms are out, well after honey bee orders should be organized. Nonetheless, gaining a deeper understanding of the wild pollinators across fields each season can help producers decide where to allocate honey bee hives. Wild pollinator populations are subject to fluctuation between years, so be careful in using one year’s population to predict future demands. Honey bees are useful in reducing the risk associated with relying solely on fluctuating populations of wild pollinators.
Other important considerations are the species of wild blueberries being cultivated as well as other flowering plant species that exist within and around the edge of the field. More than one species of wild blueberry plants may grow together on a field, for example Vaccinium angustifolium and Vaccinium myrtilloides. This is important to recognize as unfortunately, these two species are not compatible in pollination. Simply put, blueberry pollination is successful when an insect collects pollen from one flower and carries it to another flower of a compatible species (Eaton et al. 2004). V. angustifolium and V. myrtilloides are not compatible, so the transfer of pollen between flowers will not result in a harvestable berry. This is sometimes the reason why one field stocked with honey bees can see such a greater improvement in pollination than another. On a field mixed with these two blueberry species, pollination may not improve with higher numbers of pollinators because pollination has not been successful. On the other hand, if there is compatibility between plants, for example on a field with only V. angustifolium, increasing pollinator numbers can significantly increase pollination success.
Other flowering plant species within and around a wild
blueberry field will impact the demand for managed honey bee colonies, as well.
Surrounding flowering species might attract pollinators and draw some of the
pollination force away from the wild blueberries. Nonetheless, these
neighboring floral species can provide important habitat for wild pollinators.
In consideration of all of these variables, there are general recommendations for honey bee hive stocking densities on wild blueberry fields. For example, the University of Maine Cooperative extension recommends small fields with little floral surrounding should be stocked at two hives per acre. Comparatively, small fields with many competing floral species should be stocked at two to three hives per acre. On a large field, the recommendation is to increase to three to five hives per acre. The table below lists a range of recommendations and their sources. Next week, we will compare and elaborate on these recommendations.
|
Stocking Density (Hives/Hectare) |
||
|
Hive
number |
Location |
Reference |
|
10
(range 4.5–12.5) |
Maine |
Asare
et al., 2017 |
|
10 |
NS
& NB |
McCallum
et al., 2020 |
|
5
– 7.5 |
NB |
NB
DAAF (ND) |
|
5
– 12 |
NS |
Eaton, Murray, et al. 2004 |
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