Differences in Disease Syndrome with Pathogen Race and with Host and Environment

Abstract

Of the three components involved in the interaction that results in Scleroderris canker, the host is the most stable. Particular provenances can be chosen and used as the basis upon which the effects of diverse forms of the pathogen are manifested. Of the environmental elements germane to the problem, climate is the most difficult to predict even over long intervals. Short-term extreme variation may predispose plants to extraordinary degrees of infection and/or colonization by certain facultative saprophytes such as Brunchorstia. pinea. The arena for elucidating Scleroderris canker in terms of interacting disease components should be international.