Flowering banker plants for the delivery of multiple agroecosystem services

Ecosystem services provided by agricultural ecosystems include natural pest control and pollination, and these are important to ensure crop productivity. This study investigates the use of the banker plant Calendula officinalis L. to provide multiple ecosystem services by increasing the abundance of natural enemies for biological control of tomato pests, providing forage resources to wild bees, and improving crop yield. C. officinalis was selected for this experiment as it is used as a banker plant for Dicyphini (Hemiptera: Miridae) predators. Strips of flowering C. officinalis were established in the field edges of tomato fields and arthropod visitation to C. officinalis strips and tomato was measured. Crop damage from multiple pests of tomato was assessed in fields with C. officinalis strips and control sites. The contribution of pollination to crop yield was assessed through a pollinator exclusion experiment. The inclusion of C. officinalis in tomato fields was associated with increased abundance of Dicyphini, parasitoids, bees and other arthropod groups within these strips. A reduction in the total leaf crop damage from Lepidoptera pests was recorded in fields with C. officinalis strips. Increased fruit set and biomass were recorded in open-pollinated tomato but this was not significantly different between control and C. officinalis fields. Results presented here demonstrate that the inclusion of a companion plant can improve the conservation of beneficial arthropods and the delivery of agroecosystem services but efficacy is likely to be improved with the addition of plants, with different functional traits, and with improved attractiveness to crop pollinators.