Understanding pollinator foraging behaviour and transition rates between flowers is important to maximize seed set in hybrid crops

Abstract

Hybrid cauliflower production predominately relies on pollen transfer from hermaphrodite to female lines by honeybees. However, the presence of other pollinators may impact pollination success. Here, we investigate how honeybee visitation frequency and behaviour vary with plant sex and presence of blowflies and affect seed and pod set. We found substantial pollen limitation when honeybees were alone. This was likely due to their higher visitation to hermaphrodite flowers, infrequent transition from hermaphrodite to female flowers and high nectar theft in female flowers. Pollen foragers fed on nectar on hermaphrodite, but not female flowers. Moreover, when blowflies were present, the seed set was lower than that with honeybees alone. Our study highlights the importance of understanding the plant mating system and pollinator foraging behaviour with and without other species present in order to maximize seed set in hybrid crops.