Low tunnels, or ”caterpillar tunnels” are a new trend for strawberry crops around the world (Figure 1) . Low tunnels are basically sheets of plastic laid over support hoops. They are constructed over strawberries grown on raised plastic-mulched beds . The plastic is secured over the support hoops with cords or wires, so that the plastic is easily pushed up or down to open or close the tunnels. Unlike high tunnels, which are designed to accommodate humans and equipment, the low tunnels are only about 30 inches tall.
Are low tunnels an option for Ontario growers? There are many potential advantages. They are less costly than other forms of protected culture of strawberries, compared to high tunnels or greenhouse production. Weather- related problems, such as damage from wind, hail and rain splash are prevented. Diseases, especially anthracnose and botrytis grey mould, are reduced in a low tunnel environment. However, input costs are significant, with additional investment needed for hoops and plastic. Labour costs include cost of installation, as well the cost of routine , sometimes daily venting to prevent heat build-up.
At OFVC 2014 Dr. Kim Lewers reported on her research using low tunnels for strawberries in Beltsville, Maryland. She was encouraged by the extended season, disease control, and ease of frost protection provided by this system. She felt the spectrum of light transmitted through the plastic was an important factor affecting disease control and fruit quality.
At OFVC 2015, the berry program Wed Feb 18 features another presentation about low tunnels. This year’s speaker is OBGA member and grower Graham Shaw, of Taylor Berry Farms in Muskoka. What better way is there to learn about low tunnels than from a grower who has taken this system to the farm and made it work.
Are low tunnels for you? Find out at OFVC 2015.