RISK ANALYSIS OF DISEASE EPIDEMICS ON WHEAT BY SIMULATION STUDIES

Risk analysis on disease epidemics of wheat was studied by simulations , using a weather model (based on the weather generator developed by S hen (1988, Ph.D. thesis, Beijing Agricultural University)) and a multi ple disease epidemic simulation model for wheat (Dong, 1988, Ph. D. th esis, Beijing Agricultural University). Monte-Carlo simulations were u sed to link these two models. Expected yield losses in wheat caused by three diseases under various weather conditions combined with differe nt initial inoculum levels could be estimated The information about th e risk of disease epidemics was primarily obtained from analysis of th e frequency distribution of expected simulated yield losses. Two sets of simulations were performed to study the risk of yield loss on wheat in general. Two additional sets of simulations were run for the Beiji ng and Gangu districts to pro vide examples of risk assessment tables in specific environments. Risk assessment tables could provide decisio n makers with a powerful tool to manage diseases.