Abstract

The effects of various cane removal treatments on the epidemiology of P. rubi-idaei were studied in 4 experiments in infected raspberry plantations. In 1981, removal of 15 cm high young canes either by cutting or by spraying dinoseb-in-oil reduced infection of a second flush of canes (replacement canes) compared with that of the first flush of canes on untreated plots of cv. Malling Delight in Wales and of cv. Glen Clova in Scotland. In 1982, removal of 20 cm canes reduced infection of cv. Malling Delight in Wales but in Scotland only removal of 60 cm canes by cutting reduced infection of replacement canes. Removal of all fruiting canes and old cane stubs reduced rust on young canes, but removal of successive flushes of replacement canes did not reduce infection of lateral shoots on the fruiting canes. Dinoseb-in-oil applied to the bases of fruiting canes before emergence of young canes had no effect on infection of young canes in either locality. The production of basidiospores was inhibited in vitro by dinoseb-in-oil at concn > 1?g a.i./ml.