Submitted to: Genetics, Genomics, and Breeding in Stone Fruits
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/30/2010
Publication Date: 4/30/2011
Citation: Takeda, F., Phillips, J.G. 2011. Horizontal cane orientation and rowcover application improve winter survival and yield of trailing 'Siskiyou' blackberry. HortTechnology. 21(2):170-175. Interpretive Summary: Western trailing blackberries are susceptible to low temperature injury and are not grown commercially in the central or eastern United States. Winter injury was determined in vertically-oriented and horizontally-oriented canes that were covered or not in winter with a light weight spun-bound polypropylene frost protection fabric. Our research showed that the combination of having canes close to the ground and covering them with a floating rowcover reduced winter injury and improved plant productivity. Winter injury was high, and plant productivity was low in plants with canes oriented vertically, whether they were covered or not in winter. This study showed that trailing blackberries that lack winter hardiness can be grown satisfactorily in the mid-Atlantic coast region and produce fruit if the adverse effects of low winter temperatures are mitigated.
Technical Abstract: Western trailing blackberries (Genus Rubus subgenus Rubus Watson) are susceptible to low temperature injury and are not grown commercially in the central or eastern United States. Seven-year-old trailing 'Siskiyou' blackberry plants were trained to the rotating cross-arm (RCA) trellis system. In winter, the cross-arms were held vertically or rotated down to horizontal and either covered with a non-woven floating rowcover or left uncovered. Cane injury was least in plants with lateral canes oriented horizontally and covered in the winter. Cane injury was high in plants with lateral canes oriented vertically in the winter, whether covered or not, and among plants with lateral canes laid close to the ground but not covered. 'Siskiyou' blackberry plants that had lateral canes oriented horizontally and covered with a floating rowcover in the winter produced 250 flower clusters and 6.0 kg.plant-1 compared to 72 flower clusters and 1.7 kg of fruit for plants that were not covered in the winter. Fewer flower clusters were producted on plants with lateral canes oriented vertically. The findings suggested that 'Siskiyou' blackberry can be grown in the eastern United States, where winter injury has frequently caused a crop failure, if the lateral canes are positioned close to the ground and covered with a floating rowcover.