ORGANIC DAY-NEUTRAL STRAWBERRY PRODUCTION IN THE UPPER MIDWEST

Abstract

The use of the traditional perennial June bearing strawberry production system in the Upper Midwest region of the U.S. presents many challenges to organic production, including increased weed, insect, and disease pressure. This study examined the feasibility of producing organic day-neutral strawberries by testing the impact of four mulches (black, metallic, and white-on-black, and biodegradable paper) on pollinator visitation rates, yield, and fruit quality during the 2022 and 2023 growing seasons in Madison, WI, and St. Paul, MN. Mulch type was not found to impact pollinator visitation, which was only studied in Madison, WI. Pollinators were found to consist greatly of small, solitary bees and flies of family Syrphidae. In WI, the metallic mulch led to higher total and marketable yields in comparison to black and white mulches, while in MN mulch treatments had no significant impact on yield. Berry size was generally improved by paper mulch in WI, and mulch type did not affect fruit quality metrics or the storage ability of fruit in either location. Mulch type did not influence the percentage of unmarketable fruit, however this varied significantly over year and location. This study highlights the importance of solitary bees and flies for commercial fruit pollination and found that metallic and paper mulches are viable options for growing organic strawberries which may produce comparable or improved marketable yields compared to the current growers’ standards of black or white-on-black polyethylene mulches.