APS Abstracts Submitted for Presentation at the 2007 APS Annual Meeting

Abstract

Summary Th e epidemiological model BLIGHTSPACE is a spatiotemporal integro-diff erence equation model of the potato late blight pathosystem. To test and scrutinize the validity of model predictions, simulations were made and compared to independent data, collected in fi eld trials on the spread of two genotypes of Phytophthora infestans in fi ve potato cultivars in the Netherlands. Cultivar-isolate specifi c interactions were characterized in the model using three quantitative components of resistance: infection effi ciency, lesion growth rate, and sporulation intensity. Th ese were measured on potato leafl ets in the laboratory. System and model were compared visually using disease progress curves, and numerically through a comparison of predicted and observed t 5 and t 50 points (time in days until 5 and 50 % disease severity is reached respectively). For 80 % of the epidemics, performance criteria for both the t 5 and t 50 points were met. Sensitivity analyses with the model revealed a dichotomy in the epidemiological eff ects of fi tness parameters of P. infestans, providing two useful reference curves with which to formulate hypotheses regarding diff erences between observed and predicted epidemics.