Prediction models for sorghum shootfly, Atherigona soccata during Rabi season for Dharwad region

Weather based prediction model for shoot fly incidence in sorghum crop was developed for Dharwad region of Karnataka using the weather variables viz., maximum and minimum temperature, relative humidity in morning and evening, rainfall and shoot fly egg and dead heart per cent data during Rabi season. Stepwise regression analysis was carried out to know the important weather parameter in incidence of shoot fly. The backward elimination procedure was followed to retain the important variables and the best model for the prediction of shoot fly egg and dead heart development was selected based on high coefficient of determination and less standard error. The best model for the prediction of egg development found in the year 2000 (R2= 0.933) with less standard error (SE=0.30) for 7 days after emergence of crop and during 14 DAE model in the year 2005(R2= 0.999, SE=0.179), for 21 DAE in the year 2005(R2=0.993 SE=1.442) and 2006 (R2=0.990 SE=0.749) and for 28 DAE model in the year 2003(R2=0.992 SE=0.702) were found best fit. The developed stepwise models in this study could be used to determine the incidence of shoot fly during 7, 14, 21 and 28 days after emergence of the crop and for taking up the timely crop protection measures during the Rabi season.