|Demchak, K. - PENN STATE UNIV|
|Handley, David - UNIV OF MAINE|
|Grube, R. - UNIV OF NEW HAMPSHIRE|
|Warmund, Michele - UNIV OF MISSOURI|
Submitted to: HortTechnology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: May 14, 2008
Publication Date: October 1, 2008
Citation: Takeda, F., Demchak, K., Handley, D., Grube, R., Feldhake, C.M., Warmund, M. 2008. Rowcovers improves winter survival and production of western trailing 'Siskiyou' blackberry in the eastern United States. HortTechnology. 18(4):549-745. Interpretive Summary: Little commercial blackberry production exists in areas with severe winters (minimum winter temperatures below 0 degrees F) and short growing seasons. In this study, we evaluated the combination of simple cultural practices, a modified rotatable cross-arm (RCA) trellis system, and covering plants with insulation material in winter to overcome the lack of cold hardiness in trailing ('Siskiyou' and 'Boysenberry') blackberries that have been established at Kearneysville, WV (39 degrees Latitude N). Our findings suggest that trailing blackberries that lack winter hardiness may grow satisfactorily and produce fruit by mitigating the adverse effect of low temperatures and winds with our RCA trellis system and winter protection system. Trailing blackberries could be commercially grown in the eastern United States with practical techniques for improving their winter survival resulting in early-season high-quality blackberry production.
Technical Abstract: Little commercial blackberry production exists in areas with severe winters (minimum winter temperatures below 18 degrees C and short growing seasons. In this study, we evaluated the combination of simple cultural practices, a modified rotatable cross-arm (RCA) trellis system, and covering plants with insulation material in winter to overcome the lack of cold hardiness in trailing 'Siskiyou' and 'Boysenberry' blackberries that have been established at Kearneysville, WV (39 degrees Latitude N). RCA trellis assembly has an upright post and a long cross-arm with a mechanism at the top of the post that permits the cross-arm to be pivoted and rotated as much as 220 degrees. A unique cane training practice spatially separates primocanes and floricanes. After tying canes to trellis wires and rotating the cross-arms to below horizontal, tied canes are close to the ground, allowing them to be covered with protective materials such as floating row cover (FRC) and polyethylene plastic (PE) during the winter months. Covers were removed in early spring and canes remain in the horizontal orientation until bloom, encouraging flowering laterals grow upright. After bloom, the cross-arm is rotated to slightly beyond vertical. This positions the fruit on one side of the row and improves harvest efficiency. In January and February 2005, the daily minimum temperatures under the FRC+PE cover treatment were about 3 degrees C higher than in the open. The FRC+PE cover also provided protection against the wind. Water vapor pressure of the air around the canes was higher when they were under the cover. Tissue damage in trailing blackberries protected with a FRC+PE cover was significantly less than for unprotected plants. 'Siskiyou' plants in FRC+PE covered plots produced 3 to 5 times more fruit than plants that were not protected. Harvesting of 'Siskiyou' fruit occurred during the red raspberry harvest season or two to three weeks earlier than that for 'Chester Thornless' eastern thornless blackberry. Our findings suggest that trailing blackberries that lack winter hardiness can be grown satisfactorily in the mid-Atlantic coast region and produce fruit if adverse effect of low temperatures and winds are mitigated with our unique trellis system and winter protection system. RCA trellis system is amenable to cane manipulation and placement of winter protection material. The trailing blackberries could be included for fruit production in the eastern United States by using cultural techniques or improving their winter survival. With addition of cultivars such as 'Siskiyou', there is a potential for early-season high-quality blackberry production in this region.