Optimizing pear orchard productivity through managed Osmia bicornis L.: A study on pollination efficiency and its role in geitonogamy

Most pear cultivars require cross-pollination to enhance yields in both self-fertile and partially self-fertile cultivars. Due to the deficit of wild bees and the limited pollination efficiency of honey bees, alternative commercial pollinators should be considered. This study examined the pollination efficiency of the managed bee Osmia bicornis in a pear orchard containing three cultivars: ‘Conference’, ‘Deyonne du Comice’, and ‘Alexander Lucas’. The introduction of O. bicornis into the pear orchard proved effective, with this species comprising up to one-fifth of the total pollinator population when nesting sites were located within 60 m of the trees. The management of O. bicornis improved fruit set in self-sterile cultivars but did not affect parthenocarpic cultivars. The higher number of fruits per inflorescence, as well as greater fruit weight and diameter, when flowers were pollinated by red mason bees rather than self-pollination, predict an improvement in the total yield. compared to self-pollination. The pollen bag method employed in the study highlighted the vital role of O. bicornis in geitonogamy in pears. The findings demonstrate that the use of these managed bees can enhance yields in single-cultivar orchards, including self-pollinating and parthenocarpic cultivars.