Development of a Forewarning Model to Predict Rice Leaf Folder (Cnaphalocrocis medinalis Guenee) Incidence in Punjab, India

A forewarning model for rice leaf folder was developed based on peaks of its light trap catches and values of weather parameters observed during 2007–2012. Each of the maximum temperature (°C), morning relative humidity (%), evening relative humidity (%) and sunshine hours (SSH) exhibited highest significant correlation coefficient with leaf folder light trap peaks during 28th standard meteorological week. Forewarning model was thus developed based on maximum temperature, morning relative humidity, evening relative humidity and SSH, wherein these four weather factors together could explain 99 % variability in leaf folder light trap peaks. Likely causes of the leaf folder outbreak that occurred in Punjab during kharif (rainy season) 2012 were also explored. Weather analysis suggested that besides other factors, hotter and drier conditions during June and July in 2012 as compared to other years might have played a role in the leaf folder outbreak. © 2015, The National Academy of Sciences, India.