Abstract :
In order to understand the various factors which affect Beet mosaic virus (BtMV) epidemics, different aspects of the relationships between this virus, its vectors and sugar beet were studied. The latency and incubation periods, determined under growth chamber and field conditions, responded inversely to the temperature and leaf growth rate. Field-infected plants could function as virus sources during the whole growing season. The virus was transmitted by Acyrthosiphon pisum, Aphis fabae, Macrosiphum euphorbiae, Metopolophium dirhodum, Myzus persicae and Ropalosiphum padi. Myzus persicae retained the virus for at least 16 h. Alatae and apterae of M. persicae transmitted the virus with the same efficiency, and in at least two consecutive probes. The proportion of infected plants increased as a logarithmic function of the number of alatae of six aphid species used in the arena tests.
