Maple (Acer spp.) - Verticillium Wilt
Cause The disease has never been reported or found in the PNW. The tree is considered an invasive species since it can out compete native vegetation and is a prohibited nuisance plant in Portland and Salem, Oregon. (And is a good host for the invasive spotted lanternfly!) For that reason, we may want this disease since it is being considered as a biocontrol to kill the tree. Verticillium nonalfalfae is a fungal wilt pathogen but is different than the one that attacks other crops. The disease can spread from one inoculated tree in a natural setting to surrounding noninoculated trees. The more common fungus, V. dahliae, can also infect this tree but it is not as aggressive and does not spread naturally to other trees.
Symptoms Wilting and defoliation of leaves from the tree. The vascular cambium shows yellow streaking when the bark is stripped away. Trees eventually die.
Cultural control Not sure any is needed.
Reference Kasson, M.T., Short, D.P.G., O'Neal, E.S., Subbarao, K.V., and Davis, D.D. 2014. Comparative pathogenicity, biocontrol efficacy, and multilocus sequence typing of Verticillium nonalfalfae from the invasive Ailanthus altissima and other hosts. Phytopathology 104:282-292.