Incidence of three viruses in vegetable brassica plantings and associated wild radish weeds in south-west Australia

Abstract

During the spring and summer of 2001, surveys of 50 plantings of vegetable brassicas (broccoli, cabbage and cauliflower) and associated wild radish (Raphanus raphanistrum) weeds were done to determine the occurrence of three aphid-borne viruses, Beet western yellows virus (BWYV), Cauliflower mosaic virus (CaMV) and Turnip mosaic virus (TuMV). Plantings at 15 widely separated farms were sampled in the Perth metropolitan and Manjimup regions of south-west Australia. None of the three viruses was detected in vegetable brassica plantings at Manjimup and neither were CaMV or TuMV detected in the Perth metropolitan region. BWYV was only detected at a low incidence (2% infection) in one planting of cabbage at Carabooda. In contrast, populations of wild radish from one farm in Perth and five out of six farms at Manjimup were infected with BWYV at incidences up to 65%. One population of wild radish was also infected with TuMV at an incidence of 2%. Additional keywords : Cauliflower mosaic virus, Turnip mosaic virus, Beet western yellows virus, surveys, virus reservoirs, control.