Honey bees, Apis mellifera, are important pollinators of the highbush blueberry variety Ventura despite the inability to sonicate Honey bees are important pollinators of blueberries despite their inability to sonicate

No abstract

Blueberry plants require large quantities of pollen deposited on stigmas to produce commercialquality fruit. Like many agricultural crops, the interaction between pollen-source variety and pollenrecipient variety can be a major determinant of fruit quality in blueberries. However, little information exists to guide growers in optimising fruit set and quality. Using five commonly grown blueberry varieties, I determined whether crossing between varieties (inter-varietal) increased fruit mass and decreased developmental time relative to crossing within a variety (intra-varietal), and if so, what the best crossing combinations are. While intra-varietal pollination often produced fruit, for certain varieties the fruit set and fruit mass were highly reduced compared to inter-varietal pollination. Furthermore, intra-varietal pollination resulted in longer fruit developmental time in comparison to pollination between varieties. For the same pollen-recipient variety, inter-varietal crosses typically outperformed intra-varietal crosses in fruit mass and developmental time; however, the extent to which inter-varietal crosses outperformed intra-varietal crosses differed between pollen-donor varieties. This result suggests that combinations of varieties are not trivial as some inter-varietal combinations may outperform others. Furthermore, some varieties appear to be more susceptible to the negative effects of intra-varietal crosses than others and that less susceptible varieties may be better suited to conditions where pollinator movement is poor. While our study can guide growers in determining optimal co-planting schemes for the varieties tested, for example in South Africa where these varieties are frequently grown. It also serves as a blueprint for similar compatibility studies that can easily be performed prior to planting to determine the best intervarietal combinations.

Honey bees, Apis mellifera, are important pollinators of the highbush blueberry variety Ventura 2 despite the inability to sonicate 3 Honey bees are important pollinators of blueberries despite their inability to sonicate Abstract 11 Animal-mediated pollination is an essential ecosystem service which over a third of the world's 12 agricultural crops depend on. Blueberry fruit production is highly dependent on pollinators and in 13 their native range they are pollinated mostly by bumble bees (Bombus spp.). Demand for blueberries 14 has increased in recent years due to their perceived health benefits. Consequently, blueberry 15 cultivation has expanded well beyond their native range, including several regions where bumble 16 bees are not present. In many areas, honey bees may be the only commercially available pollinators 17 of blueberries because many countries ban the importation of bumble bees. This study aimed to 18 determine the benefits of honey bee pollination on blueberry fruit quality and quantity for the 19 variety Ventura by comparing yields of honey-bee-pollinated flowers to flowers where pollinators 20 had been excluded. Honey bees significantly increased berry mass and diameter. Our results suggest 21 that the presence of honey bee pollinators potentially increases revenue by approximately $86422 501/ha in areas without bumble bees. We conclude that Ventura is reliably pollinated by honey 23 bees, and that honey bee pollination may be a useful substitute for bumble bees in areas where 24 bumble bees are absent. We also determined the extent to which blueberry yields could still be 25 improved by comparing fruit quality and quantity under honey bee pollination to fruit quality and 26 quantity achieved through ideal hand pollination. We found that blueberry yields may be still be 27 significantly increased relative to ideal hand pollination and we discuss potential ways to improve 28 the efficiency of honeybee pollination in the future. Additional research is required to study how 29 beneficial honey bees are to fruit yield on varieties as the benefits of honey bees are likely to vary 30 across different varieties.2 31