Effectiveness of red mason bees on pollination of floricane raspberry cultivars 'Lagorai Plus' and 'Vajolet'

P. Zucchi, L. Osti, G. Comploi
Red mason bees (Osmia bicornis L.) (RMB) are beneficial insects that have potential as orchard pollinators. The interest in their use is increasing because of the possibility to cold-store them in order to synchronize their time of activity with the flowering. This could be very important in protected crops, especially in scheduled productions. Thus, a trial was set up in order to assess RMB effectiveness on red floricane-fruiting raspberries (Rubus ideaus L.). On April 4, 2018, longcanes of ‘Vajolet’ and ‘Lagorai Plus’ raspberries were transplanted in soilless system in two screenhouses, one with RMB and one without pollinators. RMB increased the rate of normally-shaped raspberry fruits. Furthermore, a significant difference between the two cultivars was recorded: RMB ‘Vajolet’ reached 96.9% of the total fruits showing a regular shape vs. 92.4% of ‘Lagorai Plus’. This difference is completely explained by the significant higher rate of ‘Vajolet’ self-pollination: 6.3 vs. 1.5% of ‘Lagorai Plus’, and thus it is not connected to a greater attractiveness of this cultivar for RMB. Flower position on the plant influenced the incidence of deformed fruits: deformation increased from the apical to the basal part of the canes, while the orientation of the two sides of the row, east or west, had no significant effect. A 90.8% overall RMB pollination effectiveness was estimated on raspberries. Probably because of the good combination of nectar and pollen available on flowers, raspberries were attractive for RMB, which resulted in a very effective drupelet set.
Zucchi, P., Osti, L. and Comploi, G. (2020). Effectiveness of red mason bees on pollination of floricane raspberry cultivars 'Lagorai Plus' and 'Vajolet'. Acta Hortic. 1277, 353-358
DOI: 10.17660/ActaHortic.2020.1277.50
Osmia bicornis L., Rubus ideaus L., deformed fruit, scheduled production, orchard pollinator

Acta Horticulturae