Rainfall Pattern and Wheat Productivity in Uttarakhand, India.

The rainfall pattern aberration during Rabi (winter) season ( December to March) in north India is a cause of concern to administrators and researchers. Field experiment was laid down in Factorial Design during 2013-14 and 2014-15 at IIT Roorkee with treatment combinations including four wheat varieties (PBW-292, HD-2967, PBW-154 and PBW-550) and three sowing dates (20 November, 5 December and 20 December ) with three replication. Soil was sandy loam and moderate in fertility. Crop was grown under best management practice. Weather data was recorded from Automated Weather Station installed at the Farm. Observations were recorded on growth, development, yield and yield attributes of the crop. Field experiment results showed that the total rainfall during the growing season was astonishingly same i.e. 223.7 mm in 2013-14 and 234.1 mm in 2014-15 but the pattern was totally different. During the Rabi season 2013-14, very high rainfall in January ( 98 mm) and February (52 mm) was recorded which coincided with the grand growth phase of wheat resulting into bumper harvest. On the contrary, during Rabi season 2014-2015, very high rainfall in March (115 mm) and April (62 mm) which coincided with flowering and grain setting resulted into reduced productivity due to lodging. The experimental results showed that the average productivity of wheat during 2013-14 was 43.7 q/ha whereas during 2014-15 was 37.8 q/ha. Productivity during 2014-15 was reduced by 13.6% in comparison to 2013-14. Loss in productivity was remarkable (ranging from 11.4% to 42.1 %) in timely sown. The late sown (Dec 20) treatment did not recorded much productivity loss and remained within 5% during 2014-15. Normal sown varieties (PBW-292, HD-2967, PBW-154 ) suffered serious productivity loss as compared to late sown variety (PBW-550). DSSAT model simulated result compared well during 2013-14. However during 2014-15 the heavy rainfall in March & April caused severe lodging and the model perhaps could not detect it.