Prediction of Rice leaf folder Cnaphalocrosis medinalis (Guenee) for future periods under Climate change scenario of 4.5 representative concentration pathway

摘要

Standard meteorological week (SMW) based catches of leaf folder in light traps (Chinsurah type) during kharif (22-44 SMWs) over 2011-15 and corresponding weather were used for development of location specific rule based predictions for three rice growing locations from different agro ecological regions viz., Ludhiana (Punjab), Raipur (Chhattisgarh) and Aduthurai (Tamil Nadu) representing three agro climate zones. The order of importance of leaf folder incidence across locations during 2011-15 was Ludhiana (PB)> Aduthurai (TN)> Raipur (CG). Weather based criteria evolved indicated the importance of maximum temperature (°C), minimum temperature (°C), morning relative humidity (%), rainfall (mm) and sunshine hours (h/day) in determining leaf folder severity as to high, moderate and low on fulfilling more than three, three and less than three weather criteria, respectively. Such weather based predictions revealed an accuracy of 82.6%, 86.9% and 100% for Ludhaina (PB), Raipur (CG) and Aduthurai (TN),respectively for kharif 2016. Future projections on climate change made using representative concentration pathways (RCP) at radiative forcing level of 4.5 W/m2 with stabilization after 2100 used in conjunction with weather based criteria and rules of prediction indicated increase in moderate severity of leaf folder at Raipur (CG)> Ludhiana (PB) > Aduthurai in 2020. Moderate severity of leaf folder was on more occasions during 2050 and 2080 over 2020 and present periods at Ludhiana (PB). Ludhiana (PB) also had more of high severity in 2020 with similarities of 2050 and 2080 to present period (2016). Although moderate severity was the highest in 2020 followed by 2080 and 2050 at Raipur (CG), high severity was absent during 2080 and lower than present status in 2020 and 2050. Absence of high severity at all periods was the scenario of leaf folder at Aduthurai (TN). Future projections imply lesser significance of leaf folder at Aduthurai (TN), its careful monitoring until 2020 at Raipur (CG) and relatively increasing and continued importance at Ludhiana (PB) in the context of changing climate.