A Raywood ash limb with a reddish brown canker at the base (right) that was killed by drought stress in combination with a weak pathogen, Botryosphaeria stevensii. This disease complex is called Raywood ash canker and decline.

Close-up of Raywood ash dead limb (right) killed by Raywood ash decline, caused by drought stress in combination with a secondary (weak) pathogen (Botryosphaeria stevensii). Modesto CA by JKC Credit: Jack Kelly Clark
Credit: Jack Kelly Clark