Commercial production of northern highbush blueberry (Vaccinium corymbosum) is dependent upon rented colonies of honey bees (Apis mellifera) for meeting pollination requirements. Despite the prevalent use of honey bees, growers in Washington State and the greater Pacific Northwest (PNW), particularly those located in the western regions, claim pollination is limited and yield potential is subsequently reduced due to pollination deficits. However, there have been no studies or surveys that document this occurrence for this economically important region of blueberry production. The objective of this study was to survey honey bee activity in commercial plantings of ‘Duke’ highbush blueberry in western and eastern Washington and to assess the relationship between honey bee activity, growing region, and select yield components. Honey bee colony strength was also assessed to evaluate this variable’s relationship to honey bee activity and measured yield components. Sixteen and 18 commercial ‘Duke’ blueberry fields across Washington State were surveyed in 2014 and 2015, respectively. Average number of honey bee visitations per plant and honey bee colony strength were determined to evaluate overall honey bee activity. Estimated yield, berry number per plant, berry size (mass), and seed number per berry were also determined and analyzed to determine their relationship to honey bee activity through regression analysis. Honey bee visitation rates differed between western and eastern Washington, with western Washington sites consistently below recommended honey bee densities. Colony strength was also below recommended levels, but was lower for western Washington relative to eastern Washington. Estimated yield and berry number differed across sites and years, but were not related to honey bee visitation rates. Regression analysis revealed few significant relationships, although honey bee visitation rates were positively related to seed number per berry and seed number was positively related to berry size (R2 = 0.25 and 0.16, respectively). Berry size was also positively related to colony strength (R2 = 0.63). This study demonstrates that honey bee activity is limited in Washington blueberry production, particularly in western Washington, when compared with recommendations for optimal honey bee activity in blueberry. However, yields were unaffected between the compared regions. The lack of a relationship between honey bee visitation rates and yields suggests that pollination is sufficient for ‘Duke’ blueberry in Washington State and pollination deficits do not limit yield for this cultivar under the conditions of the study.
This work was funded by the Washington Highbush Blueberry Commission.
We acknowledge the assistance of our grower cooperators and Rachel Weber, as well as Doug Walsh, Tora Brooks, Marina Mireles, and Yajun Li for project assistance in eastern Washington. We also acknowledge Elizabeth Elle for assistance with project design.
Assistant Professor and Apiculturist.
County Director of Island County and Apiculturist.
DogteromM.H.WinstonM.L.MukaiA.2000Effect of pollen load size and source (self, outcross) on seed and fruit production in highbush blueberry cv. ‘Bluecrop’ (Vaccinium corymbosum; Ericaceae)Amer. J. Bot.8715841591
Dogterom,M.H.Winston,M.L.Mukai,A.2000Effect of pollen load size and source (self, outcross) on seed and fruit production in highbush blueberry cv. ‘Bluecrop’ (Vaccinium corymbosum; Ericaceae)8715841591)| false
IsaacsR.GibbsJ.HansenE.HancockJ.2014Invest in pollination for success with highbush blueberries. MSU Extension. 8 Apr. 2016. <http://msue.anr.msu.edu/news/invest_in_pollination_for_success_with_highbush_blueberries>
MacKenzieK.E.1997Pollination requirements of three highbush blueberry (Vaccinium corymbosum L.) cultivarsJ. Amer. Soc. Hort. Sci.122891896
MacKenzie,K.E.1997Pollination requirements of three highbush blueberry (Vaccinium corymbosum L.) cultivars122891896)| false
Rodriguez-SaonaC.ParraL.QuirozA.IsaacsR.2011Variation in highbush blueberry floral volatile profiles as a function of pollination status, cultivar, time of day and flower part: Implications for flower visitation by beesAnn. Bot.107813771390
Rodriguez-Saona,C.Parra,L.Quiroz,A.Isaacs,R.2011Variation in highbush blueberry floral volatile profiles as a function of pollination status, cultivar, time of day and flower part: Implications for flower visitation by bees107813771390)| false
StrikB.FisherG.HartJ.InghamR.KaufmanD.PenhallegonR.PscheidtJ.BrunC.AhmedullahM.AntonelliA.AskhamL.WilliamP.BristowP.HavensD.ScheerB.ShanksC.BarneyD.2006Pacific blueberry pollination. In: Highbush Blueberry Production. Department of Extension & Experiment Station Communications Oregon State University. PNW 215
TuellJ.K.IsaacsR.2010Weather during bloom affects pollination and yield of highbush blueberryJ. Econ. Entomol.1033557562
Tuell,J.K.Isaacs,R.2010Weather during bloom affects pollination and yield of highbush blueberry1033557562)| false