Effect of projected climate change on mustard (Brassica juncea)

Mustard is one of the most important rabi season oilseed crops and contribute about 30 per cent of totaloilseed production. It is very sensitive to weather variable. The likely climate change may have varying effect onmustard production. Info Crop a process based crop imulation model was calibrated and validated with experimentalcrop data of 2003-04 to 2006-07 rabi seasons with different dates of sowing at IARI, New Delhi. PRECIS downscaled,baseline weather data for period 1961-1990 and projected A2a scenario data for the period 2071 to 2100 for thegrid covering experimental site were used for computing magnitude of climate change and the same was used forcomputation of weather data for period of 2071 to 2100 using actual observed data of baseline period. Annualmaximum temperature is likely to rise by 5.25°C with maximum of 7.55° for November and minimum 3.21°C for May.Similarly minimum temperature is also likely to rise by 4.83°C with highest increase of 6.34°C during February. Cropsimulation suggests no or little change in mustard production under unlimited soil moisture and nitrogen conditions,but higher coefficients of variation (33%) shows unstable crop performance. Under rainfed condition which ismarked by either one pre-sowing irrigation or sowing on favourable residual moisture mostly practiced in significantpart of mustard growing area, crop yield is likely to reduce by 81% and crop performance is highly unlikely to bestable (116 % CV). Crop duration is also likely to reduce by 25 to 30 days, mainly due to fast accumulation of thermalunit (GDD) required for crop maturity.