Dieback Disease of Pines with Special Reference to Corsican Pine Pinus nigra var. Calabrica Schn

Abstract

The fungus Brunchorstia pinea Karst. v. H. is found to be consistently associated with early stages of dieback disease in a number of pine species. Inoculation of buds with conidial suspensions of the fungus causes typical disease symptoms to develop. The proportion of successful inoculations depends on the time of year, the location of the tree, and its physiological condition. Vigorous trees are able to avoid infection, while weaker trees are very susceptible to attack. It is suggested that though infection depends on low host resistance, Brunchorstia must be considered a primary pathogen since in all probability trees would survive and produce a crop were it not for the activities of the fungus.