Botryosphaeria dothidea and other fungi associated with excoriose and dieback of grapevines in Portugal

In a study of fungi associated with symptoms of excoriose in Portugal, the most prevalent ones were found to be Botryosphaeria dothidea and Phomopsis viticola. In artificial inoculations, these two fungi infected grapevines causing dark lesions on the shoots and bud mortality. They were re-isolated from the shoot lesions and necrotic buds. Two further species of Botryosphaeria, namely B. obtusa and B, stevensii, were also isolated and they caused small lesions on wounded shoots but did not infect unwounded shoots. B. dothidea was also isolated from grapevines with a dieback of the trunk. These isolates were more virulent on young shoots and one-year-old canes than the ones from grapevines with excoriose.