Large-scale pollination experiment demonstrates the importance of insect pollination in winter XXXX .

@entity5157 @entity4335
UNASSIGNED: Insect pollination, despite its potential to contribute substantially to crop production, is not an integrated part of agronomic planning. A major reason for this are knowledge gaps in the contribution of pollinators to yield, which partly result from difficulties in determining area-based estimates of yield effects from insect pollination under field conditions. We have experimentally manipulated @entity5157 @entity5157 densities at 43 @entity4335 @entity4335 fields over 2 years in Scandinavia. @entity5157 hives were placed in 22 fields; an additional 21 fields without large apiaries in the surrounding landscape were selected as controls. Depending on the pollination system in the parental generation, the @entity4335 cultivars in the crop fields are classified as either open-pollinated or first-generation hybrids, with both types being open-pollinated in the generation of plants cultivated in the fields. Three cultivars of each type were grown. We measured the activity of flower-visiting insects during flowering and estimated yields by harvesting with small combine harvesters. The addition of @entity5157 hives to the fields dramatically increased abundance of flower-visiting @entity5157 in those fields. @entity5157 affected yield, but the effect depended on cultivar type (p  =  0.04). Post-hoc analysis revealed that open-pollinated cultivars, but not hybrid cultivars, had 11% higher yields in fields with added @entity5157 than those grown in the control fields (p  =  0.07). To our knowledge, this is the first whole-field study in replicated landscapes to assess the benefit of insect pollination in @entity4335 . Our results demonstrate that @entity5157 have the potential to increase @entity4335 yields, thereby emphasizing the importance of pollinator management for optimal cultivation of @entity4335 .
