Long-term Meteorological Prediction Model on the Occurrence and Development of Rice Leaf Roller Based on Atmospheric Circulation

To understand the possible influencing mechanism of atmospheric circulation on the occurrence and development of rice leaf roller in China, relationships between atmospheric circulation characteristic indices and ratios of the occurrence area of rice leaf roller in China are fully analyzed from 1980 to 2016. 74 atmospheric circulation characteristic indices and their combinations are analyzed by factor puffing. Results show that 46 indices of these atmospheric circulation characteristic ones have significant influences on the ratio of occurrence area of rice leaf roller, and main influencing periods are from July to September, as well as last July to March. Indices of subtropical high category are most influential, followed by polar vortex category, circulation category, trough category and then others. Among 46 significant atmospheric circulation characteristic factors, 27 subtropical high factors and 10 polar vortex factors, accounting for 59% and 22% of the total, respectively, are the main factors influencing the ratio of the occurrence area of rice leaf roller. 10 key atmospheric circulation characteristic indices that directly influence the ratio of occurrence area of rice leaf roller are determined, and 7 of them have great change at 4 occurrence levels of rice leaf roller as light, partially light, partially severe and severe. 9 prediction models for ratios of the occurrence area of rice leaf roller are established to predict at the beginning of January and March to October. The hindcast of 9 models from 1980 to 2014 are good and accuracies in extending prediction years of 2015-2016 are 86.6%, 90.5%, 91.8%, 93.4%, 93.4%, 94.0%, 94.0%, 94.3% and 95.4%, respectively. Key atmospheric circulation characteristic factors represent climate background for the occurrence area of rice leaf roller very well in China. In the rice-planted area the atmospheric circulation influences the temperature, precipitation, etc., and thus affects the ratio of occurrence area of rice leaf roller. The ratio of the occurrence area of rice leaf roller in dry-warm and wet-warm years is usually larger than that in dry-cold years.