Federal Laboratory Consortium for Technology Transfer

Concept, Development, and Technology Transfer of Blackberry Trellis System
Domestic fresh blackberry production acreage has expanded rapidly in the last 10 years. However, blackberry production is limited in the Midwest and Northeast because blackberry canes are susceptible to injury from low winter temperatures, and in the Southeast and Central California because fruit exposed to intense sunlight become blemished. To address these problems, a team from the Appalachian Fruit Research Station designed a prototype trellis system called the Rotatable Cross-Arm (RCA) to reshape the blackberry plant. The RCA is a growing system that allows blackberry canes to be manipulated from a vertical to a horizontal orientation to achieve the desired plant architecture that provides protection in the winter and positions the fruit in the shade during times of intense sunlight. The ability to rotate the cross-arms allowed the entire blackberry plant to be moved close to the ground in winter. Also, the new cane training technique allowed the canes to be rotated from vertical to horizontal without breaking canes, and this simplified the application of row cover over the low-lying canes to minimize winter injury. Rotating the cross-arms in spring positioned all the fruit to one side of the row under leaves and away from direct sunlight, and facilitated easy hand harvesting.
The team worked with Trellis Growing System (TGS), Fort Wayne, Ind., to improve the design and reduce the manufacturing cost. As a result, TGS was able to develop an affordable, modular RCA trellis system. The combination of TGS RCA trellis and ARS cane training system offers growers a low-cost system for improving plant productivity by minimizing low temperature injury in winter and sunburn damage to fruit in summer, and increasing hand harvest efficiency. The growers have benefited from this innovation in the RCA trellis and cane training system, and now RCA trellis system is used in eight states.