High Tunnels for Organic Raspberry Production in the Midwestern US

Demand for organic foods has increased opportunities for sales of fresh organic raspberries (Rubus idaeus). Organic berry production in the US Midwest is challenging because arthropod pests and diseases are abundant. High tunnels suppress some diseases and insect pests and may increase opportunities for organic control methods. Raspberry fruit quality and yields are also enhanced in tunnels compared with outdoor production. Since high tunnels hold promise for organic raspberry production in the Midwest, we initiated a long-term project to study organic strategies for managing soil health, available nutrients, and arthropod pests. Raspberries have a consistent nitrogen requirement throughout the growing season which can be difficult to supply organically under dry environmental conditions. Initial observations suggest that compost and solid organic fertilizer are effective if tilled into the row prior to planting, but are less effective if broadcast over established rows. In addition, we observed a number of arthropod pests that pose a moderate threat but can likely be controlled with organic materials or beneficial arthropods. Currently, control of spotted wing drosophila (SWD, Drosophila suzukii) is the greatest concern.