Histological studies on the axillary region of naturally infected canes revealed that the outer suberized phellem layer of the polyderm and a primary protective layer of suberized and lignified cells across the adaxial cortex of the petiole precluded infection of the axillary buds by hyphae growing from a saprophytic base in the leaf. No protective layer formed through the abaxial cortex at the petiole base; consequently both fungi colonized the epidermis, primary cortex and outermost non-suberized phelloid cells of the polyderm beneath the node.