2007 Annual Report 1a.Objectives (from AD-416) The objective of this cooperative research project is to determine whether survival of blackberries in colder regions can be improved by micro-environment modifications through lowering the canopy with the rotatable cross-arm trellis and cane training techniques and the use of insulating cover material. 1b.Approach (from AD-416) Rotatable cross trellis components developed by USDA in Kearneysville, WV will be shipped by truck freight to the cooperator at the University of Maine. These components will be assembled and installed in established blackberry plantings and trellis wires will be installed so that emerging canes can be trained onto the trellis. In late fall, the cross-arms will be rotated to re-position all canes close to the ground and covered with insulating fabric. Temperature probes and data loggers will be installed under the cover to measure air and internal bud temperatures hourly for one week per month from November to March. Bud and cane survival will be assessed visually and with viability staining techniques. Yield, % fruit set, fruit number and weight of individual fruit will be measured each year of the study. Analysis will be performed to evaluate economic sustainability of the new production system. 3.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 project 1931-21000-012-00D, "Small Fruit Production Systems." 'Boysenberry', 'Navaho', and 'Triple Crown' blackberries were potted and grown in a plastic house at the Maine Agricultural Research Center in Manmouth, ME in 2006. In late fall the plants were moved indoors and covered with saw dust. In spring 2007 the plants were moved to a high tunnel. Some cane dieback had occurred during winter but about half of the buds bloomed. The plants that were established in the ground in 2005 were once again killed back to the ground and produced no fruit. The purpose of this project is to develop novel blackberry cultural techniques to mitigate low temperature damage. An effective winter protection system will help farmers to grow blackberries in northern states. The ADODR monitored activities at the University of Maine by telephone calls, e-mails, and face-to-face conversations throughout the reporting period.