A SPATIO-TEMPORAL MODEL AND DECISION SUPPORT SYSTEM FOR BARLEY YELLOW DWARF VIRUS
D MORGAN, I BARKER and KFA WALTERS
Central Science Laboratory, Sand Hutton, York, YO4 1LZ, UK
Background and objectives
Traditionally management of the virus has depended upon the application of pesticides to control aphid vector populations. However pesticides tend to be applied routinely and irrespective of the risk of virus infection. Although an empirical infectivity index has been devised in the UK, based on a combination of alate cereal aphids caught in suction traps and the proportion carrying virus, it has proven unreliable for effective management of the disease as it does not take into account secondary spread of virus.
A reliable forecasting system is needed based upon thorough understanding of the biological processes involved. However, until recently little was known about the factors which determine the introduction and spread of BYDV  and no consideration had been given to modelling the spatial dynamics of vector dispersal and subsequent transmission of virus. Thus the aim of the project was to develop a computer model which predicted the spread of BYDV and which would underpin a rational Decision Support System (DSS) for both vectors and virus alike.
Results and conclusions
The predicted spatial dynamics and temporal incidence of both aphids and virus are similar to those observed in cereal fields. Furthermore the model has provided useful insights into understanding the complex interactions between biological processes involved in BYDV epidemiolgy.