Influence of Rootstock on Susceptibility of Peach to Peach Canker

Abstract

Perennial canker was first recognized in 1908 by Caesar (1) as a major disease problem in Ontario peach orchards. The principal investigation of the nature and pathogenicity of the disease was conducted by Willison (3, 4, 5) with the result that Valsa cincta Fr. was identified as the major pathogenic fungus. Valsa leucostoma (pers.) Fr. was also isolated consistently from diseased tissues, but pathogenicity tests revealed a low rate of virulence for this species. From detailed observations on the influence of various sources of tree wounds, e.g., pruning cuts, stubs, brown rot cankers, fruit moth and borer injuries, on the incidence of perennial canker, Willison drafted a series of cultural recommendations (3) which emphasized the necessity of precise cultural practices to keep the incidence of canker to a minimum level.