WCROC study looks at a new crop in a new time period

December 8, 2015

Kim Ukura, Morris Sun Tribune

Locally produced strawberries in September and October are becoming more likely thanks to work being done at the West Central Research and Outreach Center. Researchers have completed their third year of a study looking at best practices for growing day-neutral strawberries.

Most strawberries are harvested in early June or July. Day-neutral strawberries were developed in California and are designed for production in cooler temperatures, explained Steve Poppe, horticulture scientist at the WCROC – “It’s a whole new crop growing during a whole new time period.”

The first two years of the study looked at how well different varieties of day-neutral strawberries performed in the Midwest. The next two years are focused on how best to fertilize and feed day-neutral strawberries for successful harvests, focusing on one variety, Albion.

The WCROC has also been testing a low-tunnel growing system to see how it impacts growth. There are three videos available about the project and the low-tunnel growing system: 

Poppe said the low-tunnel system can enhance growth by protecting the strawberry plants from spores spread by splashing rainwater. The tunnels can also protect strawberries from early frost, which can extend the growing season.

With the day-neutral strawberries and the low tunnel system, the WCROC can harvest strawberries as many as 24 times between late July and mid-October, Poppe said.

Studies on sugar levels in the strawberries show late-season strawberries are just as sweet as fruit grown in June.

Each year of the trial teaches researchers new techniques for growing day-neutral strawberries.

“I’ve been a strawberry researcher and a grower for a long, long time, and I think I know how to grow those plants, but this system, since it’s so new, is throwing a different curveball at us every other week,” said Poppe.

Low Tunnel construction

The low-tunnel system can enhance growth by protecting the strawberry plants from spores spread by splashing rainwater. Photo: Brooke Kern, Morris Sun Tribune

One new challenge this year was bugs. The low-tunnels create a “mini greenhouse” that can be attractive to insects like spider mites, Poppe said. The WCROC strawberries also suffered from rhizoctonia, black root rot, but the cause is still unknown.

Because some of the trial sites are organic farms, researchers have also looked at effective organic insecticide protocols to protect from insects like the tarnished plant bug.

The long growing season can make it particularly challenging to protect the plants from insects and diseases, Poppe said.

The overall goal of the project is to help grow more growers, making late-season strawberries more accessible to people in the upper Midwest.

Researchers have chronicled their results of the project online at http://fruit.cfans.umn.edu/category/strawberries/low-tunnel-strawberry/.