A “re-greening” and urban agriculture movement in Detroit, Michigan and the surrounding area has grown in recent years. The cultivation of fresh fruits and vegetables on urban farms and in community gardens could improve nutrition and access to food, especially in impoverished neighborhoods. However, little is known about what factors influence crop yield on urban farms. Our study aimed to investigate factors influencing strawberry production in urban agriculture and to develop strategies to enhance productivity. We selected strawberries as a focal study system not only because of their popularity in urban gardens, but also because they are a nutritious crop that will fruit in the first year planted and several years after. In June 2016, we planted three everbearing strawberry cultivars (Tribute, Seascape, Albion) at five farm sites in the Detroit metropolitan area across a gradient of urbanization. We surveyed flower and fruit phenology as well as fruit production from August to November. Additionally, we used bee bowls and vane traps to capture bees in strawberry plots over a ten-day period in mid-September. We collected bees from traps three times during this period to characterize bee abundance and species richness during peak strawberry flower bloom.
Results/Conclusions
Preliminary results revealed that flower and strawberry production varied across sites. Specifically, productivity at our most northern site appeared to suffer from delayed phenology indicated by late flowering and evidence of frost damage on ripening green fruits. We also found that weekly strawberry production was approximately 40% lower at two urban sites compared with production at two suburban sites. Additionally, strawberry cultivars demonstrated slight differences in the number and weight of fruit produced. Tribute produced the largest number of fruit, while Seascape produced the highest fruit weight. We found no statistical differences in bee abundance and diversity across sites, though bee abundances were low overall and replication was limited (n=3 samples/site). We will continue this study in coming years, increasing the number of sites (n =15) surveyed across a gradient of urbanization. Additionally, we plan to increase the number of insect sampling events, including surveys of potential pollinators and pests of strawberries. Future studies will also involve detailed observations of bee visitors to strawberry flowers. Finally, we will evaluate the influence of local floral abundance and diversity and the degree of urbanization in the landscape on crop productivity, pest pressure, and pollinator services.