Does Pollen ‘Neighborhood’ Affect Berry Yield In Lowbush Blueberry (Vaccinium AngustifoliumAit)?

Proximally growing individuals of wild, lowbush blueberry (Vaccinium angustifolium Ait.) vary widely in yield despite being grown under conditions in which environmental heterogeneity is minimized by cultivation practices. We recently established that the relative self-fertility of the bearing plant is a significant predictor of its outcross yield. Further, although the species has historically been characterized as largely self-infertile, we, and others, have documented large variation in this trait among individuals within fields, and, thus, relative self-fertility stands as a partial explanation of yield variation in addition to other genetic factors, such as significant general and specific combining abilities. Here, we extend our scope by experimentally addressing whether pollen neighborhood affects yield. Lowbush blueberry is not sown, rather individuals have colonized fields by natural processes. Commercial fields of lowbush are generally pollinated by rented honey bees, which tend to pollinate nearby flowers. Our hypothesis is that clones may have become situated in differentially suitable pollen environments, at least partly explaining yield differences. We identified two high and two low natural yielders from each of two managed fields and collected pollen mixes from five donors surrounding each (n = 8). Under field conditions, each recipient received four pollination treatments including its' own neighborhood and the other three donor neighborhoods within the same field. Results showed that one of the low producers in each field had significantly higher yields when pollinated by any but their own neighborhood, thus substantiating our hypothesis that pollen neighborhood has an effect on yield.