Crop Loss and Disease Incidence Classified by Climatic Parameters1

A method of analysing survey data, collected to obtain information on various aspects of cereal crop performance, especially disease incidence, plant population, and yield, has been developed to allow estimates of potential yield, and hence total loss, to be made. The method also allows the losses to be partitioned and the components attributed to different stages of the crop's growth - establishment, tillering and grain formation. The farms used in the survey have been classified according to winter, spring and summer temperatures and rainfall. Attempts have been made to associate trends in disease incidence and losses occurring at different times of the year with the climatic parameters.