US: Penn State researchers seek to extend berry season
For berry lovers and local farmers, the season is much too short — usually about one month of strawberry harvest and another for fresh, local raspberries — a span of time researchers at Penn State's College of Agricultural Sciences are working to extend.
"National demand for fresh strawberries and raspberries is strong and growing, but most domestic production occurs in select regions of the United States with the most suited climate," said Kathleen Demchak, senior extension associate in the Department of Plant Science.
"Growers in the Northeast are in a great position geographically to supply more berries to consumers. But our growing season is short, temperatures are variable and rainy weather during harvest can be a big problem."
Demchak and colleague Bill Lamont, professor of vegetable crops, are among a group of researchers examining how the use of high and low tunnels and plastic coverings extend the growing season for strawberries and raspberries, and as a result, increase yields while also reducing pesticide use and improving berry quality and shelf-life.
Their goal is to help local farmers improve productivity, profitability and product while increasing the quantity and quality for consumers.
At the Horticulture Research Farm at Penn State, Demchak, Lamont and colleague Mike Orzolek have grown a wide variety of crops in 32 high tunnels (6 feet or higher), launching a widespread adoption of season-extension technologies by growers.
Now, 18 of those tunnels are devoted solely to growing strawberries and raspberries, while over an acre of low tunnels (3 feet or lower) are being used for growing strawberries. Researchers keep daily detailed records of tunnel conditions, plant health, and the quantity and quality of fruit.
Over the years, Demchak and her colleagues found that with a combination of the right cultivars and season-extension technologies, they could extend the strawberry production season from four weeks to at least five months, and the raspberry harvest season from three-to-four weeks to four months, albeit with a few peaks and dips in production.
Yield of strawberries doubled, and yields of raspberries doubled, tripled or quadrupled compared to the field, depending on production methods. In addition, the group eliminated the use of pesticides, relying totally on natural enemies for pest control, while improving the quality and shelf-life of both berries.
Encouraged by the tunnel data, the researchers now are improving their strategies by studying the effects of various tunnel coverings infused with ultraviolet (UV) light blockers and stabilizers and infrared (IR) light blockers.
Read more at Penn State News