Further Evidence that Eutypa armeniacae—not Phomopsis viticola—Incites Dead Arm Symptoms on Grape. W. J. Moller, Plant Pathologist, Cooperative Extension Service, University of California, Davis, 95616. A. N. Kasimatis, Viticulturist, Cooperative Extension Service, University of California, Davis, 95616. Plant Dis. 65:429-431. . This article is in the public domain and not copyrightable. It may be freely reprinted with customary crediting of the source. The American Phytopathological Society, 1981. DOI: 10.1094/PD-65-429.

Pruning stubs on grapevine cordons, inoculated in 1975 with mycelial cultures of Eutypa armeniacae, Phomopsis viticola, or plain agar, were harvested in 1980. Symptom expression and reisolation of the pathogens confirm that only E. armeniacae is capable of inducing the pruning wound cankers and chlorotic, stunted spring foliage that have historically been associated with “dead arm” disease of grape, previously attributed to P. viticola in North America.