Our current project continues to build on our last three years of research with organic production systems for day neutral strawberries to extend the season using plasticulture with and without low tunnels. Comparative field trials were established in 2015 on organic-certified land at the University of Minnesota West Central Research and Outreach Center (WCROC), Morris and the University of Minnesota St. Paul Campus.
We examined nutrient requirements and pest management strategies for this system at these two sites. Low tunnel systems were also installed and planted at three grower cooperator sites in 2015. Our project will develop recommendations for organic strawberry plasticulture with and without low tunnels to extend the harvest season and increase yield.
A continuing objective from previous research was to determine if the use of a low tunnel system with day- neutral strawberries could provide adequate yields. Traditional June bearing strawberry varieties in Minnesota have a baseline yield of 5,500 pounds/A. Average yield of the variety Albion grown at the WCROC in the low tunnel (17,000 pounds/A) and non-low tunnel (16,900 pounds/A) far surpassed this baseline.
This higher yield was achieved regardless of fertility practice or low tunnel use. Since the day neutrals in this production system are treated as annuals, growers can enjoy the added economic benefit of yield in the first year, rather than the typical no yield ‘establishment year’ common to June bearing systems. Similarly, labor and other management costs are saved by eliminating the need to overwinter the plants. Day neutrals managed this way can be incorporated into annual crop rotations, reducing the potential buildup of soil pathogens.
For two years we have tracked our time and supplies with this research project. Variable costs include fertilizer, plants, irrigation mulch, clear film, steel hoops and supplies, and straw. Based on these costs, we calculate an investment of $213.54 to install a 100′ row of low tunnel day-neutral strawberries in a low tunnel system. To see an exact breakdown of our costs, visit wcroc.cfans.umn.edu/producing-strawberries.
If you’re interested in learning more about this system, I encourage you to attend Horticulture Night at the WCROC on July 28 from 5 to 9 p.m., where we’ll demonstrate how to build a low tunnel from the beginning to the very end, including how to plant dormant strawberry plants. Low tunnel demonstration times are planned for 5:15 and 7:15 p.m.