Abstract

In the United Kingdom, conspicuous virus-like symptoms have been recorded in raspberries and blackberries for many years and have caused the disappearance from commerce of several cultivars. Progressive degeneration in plant vigour, with less obvious foliar symptoms, has also often been attributed to infection with virus. About 11 viruses are now known to infect raspberry and blackberry plants naturally in the country. These are transmitted from plant to plant either by aphids, soil-inhabiting nematodes or infected pollen. The viruses having a common means of transmission tend also to show some similarities in other properties, including the methods used for their control. This leaflet contains information on the 3 types of viruses and their control. Also, certification schemes and symptoms often confused with virus diseases are discussed. The common aphid-borne viruses are raspberry vein chlorosis virus, raspberry leaf mottle and raspberry leaf spot viruses, black raspberry necrosis virus, and Rubus yellow net virus and raspberry vein banding mosaic disease. The first virus is transmitted by Aphis idaei, which is often found colonizing young shoot tips and inducing curling of young leaves, and the others by Amphorophora idaei. A table is given showing vector species, vector relations, particle shape and size and methods of identification for the different viruses.