Flower reservoirs in organic stone fruit orchards: promoting functional biodiversity with a low input strategy

Summary in the original language of the document

Promotion of biodiversity has great potential to contribute to organic fruit growing by increasing and facilitating natural pest control. To obtain the required fruit quality and limit the use of direct plant protection measures, most organic stone fruit orchards in Switzerland are netted against fruit flies and have an installed rain protection to protect trees against diseases. However, this enclosure changes the microclimate in the orchard and promotes the build-up of aphid colonies.
Additionally, the natural enemies of the aphids (e.g. hoverflies, lacewings or ladybirds) are kept outside the orchard because of the enclosure. Therefore, there is a need to promote biocontrol agent’s diversity and abundance in orchards as well as pollination. Flower strips are a known management strategy used in orchards and vegetable production and used to provide habitat for beneficial insects increasing biocontrol of pests and pollination of crop plants. However, in organic stone fruit production perennial flowers strips are not as widely implemented because of the high efforts needed for maintenance and the logistical challenges, for example additional machinery, such as tractors which can transit between tree rows while preserving the flowers strips. In this project, we will exploit our large experience in Agroecology to promote biodiversity and natural pest control in organic orchards with a low input strategy. The overall goal of this research project is to test whether flower reservoirs implemented in areas adjacent to the tree rows and in anchoring areas where tractors do not transit can provide similar benefits as those provided by flower strips in the orchard alley, while reducing the logistical challenges and maintenance efforts needed from farmers, and therefore, increasing its acceptance and implementation. We will carry out field trials on commercial organic cherry and apricot orchards with and without flower reservoirs. We expect to increase pollinator visitation and biocontrol of aphids in orchards where flower reservoirs have been implemented. In this poster, we will introduce you to our challenges, design, methods and specific research questions of a project that starts in spring 2024.