Continuous picking may increase bilberry yields

Accumulated knowledge about the health benefits of bilberry (Vaccinium myrtillus L.) has increased the demand and utilization of wild bilberries. Intensive berry picking by metal rakes is believed to cause damage in bilberry stands in areas under continuous picking pressure, and hence expected to hamper the production of berries in forthcoming years. We conducted an experiment to examine the effect of continuous bilberry picking by metal rake on the number of bilberry flowers and fruits, fruit mass, compensation for biomass loss after picking, and plant functional type abundance in the understorey in northern Finland. Bilberry lost less than 0.5% of its biomass annually during the three-year study period due to rake harvesting. The number of flowers was not significantly affected by damage caused by picking, while both fruit production and fruit set increased without any indication of reduced fruit mass, and biomass loss was fully compensated. Moreover, the relative abundance of plant functional types was not affected by picking during the study. We suggest that the low intensity and timing of damage act as a buffer against the adverse effects of picking on bilberry fruit production. On the basis of this study, it is reasonable to anticipate that there are no indications that current intensive berry picking would not be on a sustainable level.