Comparing growth models for inter annual progress of yellow rust (Pucinia striiformis) in wheat (Triticum aestivum) in relation to weather

Weather disease interaction study was carried out at Hisar (75046’E 29010’N and 215.2a.m.s.l). Nineteen years (1996-2014) yellow rust data was recorded during the peak period of yellow rust incidence (20thDecember to 20th February) on six varieties of wheat (WH 147,PBW 343,WH 711,PBW 175, KH 65 and C 306). Weather data of corresponding period (1996 to 2014) was taken from Agrometeorological observatory located at Research farm.Yellow rust incidence values were transformed using Logistic and Gompertz models for development of weather based prediction models.Transformed values of disease incidence were correlated with weather parameters and correlation coefficient indicates that rainy day was the most important/significant weather parameters in disease progression. Rainy day, minimum temperature and morning relative humidity collectively explained maximum variability in disease progression. The Gompertz model was found to be the best fit over the years for describing zonate leaf spot disease incidence in a natural inoculum population of Pucinia striiformis on wheat.