Rising temperature coupled with reduced rainfall will adversely affect yield of kharif sorghum genotypes

The DSSAT-CERES-Sorghum model was used to test performance of four kharif sorghum genotypes to changes in rainfall and temperature over three sowing windows. Three rainfall scenarios (no change, –10%, –20%) and three temperature scenarios (no change, +1°C, +2°C) were incorporated to past 32 year (1985 to 2016) of recorded weather data, and average simulated outputs showed that, irrespective of cultivar and sowing time, reduction in rainfall had minimal effect on crop duration, but lowered grain yield by 3.34% and 12.85% respectively, at –10% and –20% rainfall scenarios. Rise in temperature from current levels to +1°C and +2°C reduced crop duration by 7 and 12 days, while final yield reduced by 9.4% and 20% respectively. Further, per cent reduction in yield increased with delay in sowing under both scenarios. This effect was more pronounced with combined effect of reduced rainfall and increased temperature. CSH-16 cultivar performed the best across scenarios, while the remaining cultivars followed the order: CSV-17 > CSV-23 > CSH-23. Early sowing (15 June) is suitable to attain higher yield compared to 30 June and 15 July sowing across scenarios