2006 Annual Report 4d.Progress report. This report serves to document research conducted under a non-funded cooperative agreement between ARS and the University of Maine. Additional details of research can be found in the report for the parent CRIS 1931-21000-012-00D, "Small Fruit Production Systems." 'Boysenberry', 'Navaho', and 'Triple Crown' blackberries were established in the field or potted and grown in a plastic house at the Maine Agricultural Research Center in Manmouth, ME in 2005. The purpose of this project (1931-21000-012-01N) is to develop novel blackberry cultural techniques to mitigate low temperature damage. In spring 2006, one-year-old plants in the field were evaluated for winter survival. Due to lack of adequate snow cover, all canes were killed back to the crown. Crowns were not injured and vigorous primocanes emerged in May. The rotatable cross-arm trellis will be installed in 2006 and primocanes will be trained onto it and next winter the plants will be covered with protection material. An effective winter protection system will help farmers to grow blackberries in northern states.