GolPhyto, forecasting model of potato late blight in Gorgan

Late blight (PLB), caused by Phytophthora infestans, is the most important diseases of potato in the world and Iran that 16 models have been developed for forecasting so far. Gorgan county had the largest potato cultivated area in the province and during recent 17 years, PLB appeared in 11 years with different severities. In order to developing a forecasting model based on “blight favorable day” concept, daily weather data converted to periodic and conditional variables, at last three predictor variables were developed. FTP was the best predictor variable which composed of three temperature variables and two precipitation variables and its daily score was -2 to 4. Accumulated FTR from 21 March to disease appearance was 64 and in no-disease years was 4. Prediction accuracy of the model was 75% and 89% based on logistic regression and discriminant analysis, respectively and sensitivity and specificity of final model was 92 and 100%, respectively.