Tension on the Grapevine (IMAGE) American Society for Horticultural Science Caption Trellis Tension Monitoring (TTM) assembly (center) in line with the main trellis wire in a wine grape vineyard. The row in the background also contains a TTM assembly (toward right). The metal post supports the vine at the left edge of the photo and is a normal part of this trellis system. Credit Photo courtesy of Julie Tarara Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.