Oregon State University researchers report that studies conducted at the university have confirmed plastic tunnel systems can significantly extend the growing season and boost the percentage of marketable yields for Oregon strawberries.

Because the tunnels help protect strawberry plants from rain and cold, raise temperatures around the plants, and extend the growing season, OSU researchers believe this could provide growers with new tools to lengthen the strawberry harvest window.

The tunnel research began in fall 2021. The team tested two popular types of day-neutral strawberries, ‘Albion’ and ‘Seascape,’ planted in both fall and spring.

The plants were grown using organic methods and carefully managed to keep pests under control. Researchers compared four growing setups: low tunnels, high tunnels, a combination of both (double tunnel), and open fields.

Results showed that strawberries grown under low tunnels had the highest amount of marketable fruit, followed by high tunnels, open field, and double tunnels.

Among the two strawberry cultivars, ‘Albion’ produced better results overall. The variety yielded more fruit, larger berries, more plant growth and higher sugar levels.

According to the university, low tunnels required more frequent adjustments but are less expensive, ranging from about $42 to $156 per 100-foot row, depending on the materials used. High tunnels offered similar yield benefits with less daily labor but are significantly more costly.

"There is a great potential for fresh market strawberry production in Oregon, where most of the strawberry harvest is processed rather than sold whole," the university said. "Growers want to produce fresh, locally grown fruit for the market, which people say they want."

According to Erica Chernoh, assistant professor of practice in the Department of Horticulture in the College of Agricultural Sciences, there’s an opportunity for Oregon growers to fill that market.

"A lot of fruit is imported from out of state and is harvested at 75% ripeness. We will never compete with the scale of strawberry production in California, but we can produce a great-tasting and fresh Oregon berry that’s available in local markets more than just a few weeks in the summer," she added.