In Washington State, aging vines and winter injury can be a recipe for grapevine trunk diseases. While eutypa cankers are the most common of trunk diseases, there are other causes of dead arm in vineyards, says a Washington State University pathologist. Canker diseases are reported in both vinifera and labrusca cultivars of grapes, with eutypa (Eutypa lata) and Botryosphaeria spp. common causes of dead arm, said Dr. Gary Grove, WSU pathologist and AgWeatherNet director. Ten years ago, eutypa was the common cause of trunk cankers in Washington, he said. “But now, bot cankers (Botryosphaeria) are also involved with trunk diseases […]