Progress 05/01/08 to 12/31/08
OUTPUTS: The goal of Phase I was to demonstrate the feasibility of a modular trellis system for raspberries and blackberries in a variety of growing conditions with specific requirements in canopy management and winter protection. Phase I was a collaborative exercise with Trellis Growing Systems LLC, Cornell University, and USDA-ARS. The project focused on the following: 1) required capacity of end post tension, 2) design for rotatable tension wire mechanism for end posts, 3) develop prototype components and materials for structural and field testing, 4) analyze material costs, 5) analyze manufacturing costs, 6)analyze comparative costs of assembly and installation, 7) measure and quantify the value of features, 8) evaluate load capacities of prototypes, and 9) evaluate functionality for rotation and management of plant canopy. Dr. Fumiomi Takeda, Research Scientist, USDA-ARS, developed a trellis system for the management of trailing and semi-erect blackberries called the Rotatable Cross-arm (RCA) trellis system. The high cost of trellis posts and hardware has limited the expansion of this system into the commercial sector. In Phase I, TGS, in collaboration with Dr. Takeda, developed an advanced prototype of the RCA trellis system and supplied these components for testing to the USDA-ARS in Kearneysville, WV. Improvements and additions to the system focused on components that consisted of a fiber-reinforced profile used for the post and cross-arm and formed metal brackets with standard hardware for connecting. The objective is to develop a universal trellis post and hardware system for bramble production that will reduce trellis component and installation costs by more than 50%. During Phase I, Cornell University installed prototypes provided by TGS of a trellis design (AV) for primocane-fruiting red raspberries, primocane-fruiting blackberries, black raspberries and summer-fruiting blackberries in a high tunnel. A trellis for thornless blackberries in the field that will be trained to a rotating cross-arm (RCA) trellis was also established. Phase I results confirmed the technical feasibility of substantially lowering total trellising cost with modular components while increasing performance and features. Outreach activities of Phase I findings include several industry related conferences and field days. Richard Barnes participated in a panel presentation "Trellising, Training, and Pruning" at the Great Lakes Fruit & Produce Expo in December, 2008. Dr. Marvin Pritts presented our findings at the NARBGA annual meeting in Grand Rapids, Michigan in December, 2008. Cornell hosts many growers groups throughout the year including "Field Days" which tour the high tunnel installations of TGS prototypes at Cornell's research center. Dr. Takeda, USDA-ARS, has made several presentations to various berry growers associations throughout the year. PARTICIPANTS: Richard Barnes, Owner/Manager of Trellis Growing Systems LLC, PD/PI for Phase I. Developed concept and design of modular components for trellis system. Applied for patent May of 2008. Areas of expertise are product design, manufacturing, and marketing. Dr. Marvin P. Pritts, Cornell University, Department of Horticulture, Professor and Chairman, Co-PD/PI for Phase I. Areas of expertise are small fruit culture and management; plant physiology; pest management; weed management, replant problems, sustainable agriculture. Dr. Fumiomi Takeda, Research Horticulturist and Lead Scientist, Appalachian Fruit Research Station, United States Department of Agriculture, Agricultural Research Service, Co-PD/PI. Areas of expertise are innovative fruit production and protection research. Camille Cupa, Graduate Student. Areas of expertise are plant management, pest management, and data collection. TARGET AUDIENCES: Small to large commercial raspberry and blackberry growers, home gardeners. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
The installation of prototypes at TGS, Cornell, and the USDA provided valuable feedback on performance and value of features such as the canopy rotation, adjustable wire stays, and ground stabilizer brackets. Cornell's Dr. Marvin Pritts participated in the installation of these RCA and AV trellis systems and stated the relatively easy installation, especially when compared to standard methods currently employed. Despite the light weight of the trellises, they supported the heavy fruit load quite well. In addition, little space was required for anchoring - a critical criterion for high tunnels. At the USDA-ARS, blackberry plants with maturing fruit and trained to the USDA RCA trellis system with 4 high tensile wires were transferred to a prototype RCA trellis system developed by TGS in May. The posts were easily installed and required no heavy equipment as needed for USDA RCA post installation. It took one person about 2 minutes to pound a TGS post in the ground about 2 feet deep. Once in the ground, it took 80 lbs of pull to displace the post 1/2 inch at the soil line. When the TGS flange unit is used during post installation, this displacement or rotation should be none to minimal. The TGS RCA trellises with 4 monofilament strings were installed 25 feet apart and there were 5 mature blackberry plants between the posts. The fruit harvested from the five plants from June to July totaled 70 lbs and the canes and leaves that supported the fruit weighed 150 lbs. The post and cross arm showed no visible deflection from their original positions indicating that the TGS post/cross-arm assembly was sturdy enough to hold the weight of 220 lbs distributed across 25 feet. The ends of TGS cross-arm positioned for harvesting or about 60 degrees above horizontal experienced no deflection vertically. No downward deflection occurred when a downward pull of 300 lb was applied. With only about 10 lb pull force, the end of the cross-arm assembled to the post moved 1 inch. This indicated that the base of the cross where the cross-arm is fastened to the post by two plates need some modifications to reduce play. The updated prototype design appears to have corrected the problem. From June to September, primocanes were trained and tied to wires on the cross-arms. In mid December, the entire cross-arm was rotated from its 60 degree above horizontal up to vertical and over until the ends of the cross-arms touched the ground. The entire operation for rotating the cross-arms in a 200 foot long row was performed with two workers in less than 5 minutes. No breakage or snag of TGS trellis components occurred during arm rotation. The reverse rotation to position the cross-arms for harvesting will be performed in late spring 2009. Based on the results obtained in December 2008, no problem is anticipated during spring cross-arm rotation. Our Phase I results have proven the feasibility of a modular trellis system for brambles which can be economically produced and distributed. This knowledge will be used in the design of components and trellis system prototype construction during Phase II.
- No publications reported this period