Oregon State University Extension educator Lynn Long (right) asks partners Steve Agidius (left) and John Morton about the benefits of the Voen rain cover, which is installed over an acre of Agidius’s Rainier cherries in The Dalles, Oregon. The cover’s flaps open and close in the breeze.
Steve Agidius, a cherry grower at The Dalles, Oregon, has the first Voen rain and hail cover in the United States. The cover, with its unique opening and closing flaps, was developed and made in Germany, and is popular in Europe. Agidius is using a steel support structure manufactured by Oak Sun Cherries in Melbourne, Australia.
He installed the cover over an acre of Rainier cherries as a demonstration project. He and neighbor John Morton are partners in a consulting company called Oak Sun USA, which is the exclusive distributor for Oak Sun in North America.
The total retail cost of the cover, including the steel support and about $10,000 in freight and import fees, is about $30,000 per acre, depending on exchange rates. But Agidius believes it’s a good investment. Using software developed by agricultural economist Clark Seavert at Oregon State University, he calculated that with returns on field-run Rainier cherries at $2.50 a pound, the cover would pay for itself if it rained 1.5 times in ten years. In addition, he hopes to reap wind protection benefits.
Reinhard Vöhringer, an apple and cherry grower in southern Germany, invented the Voen cover 11 years ago after buying a Chinese cover that rotted after a couple of seasons, Morton explained during a summer field tour in The Dalles. Vöhringer and his wife sewed their first 50-foot-long cover on a sewing machine. They patented the design and now have a multimillion-dollar business supplying growers of various high-quality crops, such as cherries and berries.
Morton said the Voen system is unique in that it has flaps that open and close to provide ventilation so that there is no increased risk of disease in covered trees. The temperature is actually about 2°F cooler under the cover in the summer but 6 to 8°F warmer during the spring.
The partners recently installed a cover at a Colorado orchard that is being used for frost control as well as to protect the crop from wind, rain, hail, and birds. For bird control, no side enclosure is necessary because the movement of the flaps scares the birds away, Morton said.
Agidius said that most of the time, the cover is kept rolled up over his tree rows. He planned to unfurl it only when rain was predicted. At first, it was difficult for his workers to roll out the cover, but now it takes four people (a tractor driver, two people in elevated buckets, and one on a lower platform) about 45 minutes to cover a row. “I think we can improve on that,” he said. “I think we can easily get one acre done in half a day.”
Morton said the covers are custom made and so the row spacing is not critical. For a 14-foot row spacing, like Agidius’s, a three-meter (10-foot) wide cover would be suitable. For a 16-foot row, the cover should be about 3.5 meters (11.5 feet) wide. A clearance of 1.5 feet is needed between the top of the trees and the cover. Agidius’s trees are on Gisela 6 rootstocks. Morton said larger trees on more vigorous rootstocks can be accommodated, but the cover can be no more than 16.5 feet high.