Abstract

A single population of container-grown raspberry plants was divided and grown in 2 environments prior to wound inoculating young canes with D. applanata in late July. The plants were then sub-divided and held in 1 of 3 post-inoculation environments. Inoculation of internodes showed that D. applanata produced longer lesions and more pseudothecia on canes grown in spring in an unheated greenhouse than on canes grown outside, but post-inoculation conditions had little effect on these aspects of disease. Petiole inoculations showed that dwarfing of axillary buds in the first season and lateral shoot failure in the year after infection were most serious on canes grown outside in spring but held at relatively high temp. in Aug. and Sep. after inoculation. The results indicate that spur blight may have the potential to cause higher yield losses in areas with warmer spring and autumn conditions than those usually experienced in NE Scotland.