Modeling and simulating growth and yield of wheat under varying environments in mid hill conditions in Himachal Pradesh

Abstract

newline A field experiment was conducted during rabi 2015-16 and 2016-17 at Palampur with five dates of sowing (20th October, 5th November, 20th November, 5th December and 20th December) and four varieties (HS-490, VL-829, VL-892 and VL-907) in split plot design with three replications in silty clay loam, acidic soil, medium in available nitrogen, phosphorus, organic carbon and high in potassium. The growth and yield attributes viz., plant height, number of tillers m-2, number of grains tiller-1 and 1000-grain weight were significantly higher in 20th November sown crop during both the years. There was reduction in grain yield with delay in sowing after 20th November. The decrease averaged over two years was 15 percent in 20th October, 6.2 percent in 5th November, 19.5 percent in 5th December and 21.6 percent in 20th December crop. The early sown crop took more days for tillering, flag leaf, earing and maturity. Amongst varieties, VL-907 and VL-829 gave significantly higher values of growth and yield attributes during both the years. The DSSAT CERES- Wheat model performed well [high correlation coefficient (r), low root mean square error (RMSE) and low mean absolute percentage error (MAPE)] in simulating the days to anthesis (r=0.99 and 1.00; RMSE=3.4 and 3.5 days; MAPE=-0.9 and -1.7 %), physiological maturity (r=0.99 and 0.99; RMSE=3.2 and 3.6 days; MAPE=-1.3 and -1.3 %), leaf area index (r=0.91 and 0.83; RMSE=0.4 and 0.4; MAPE=-4.3 and -3.1 %), grain yield (r=0.76 and 0.82; RMSE=381 and 281 kg ha-1; MAPE=0.06 and 3.5 %), biological yield (r=0.89 and 0.98, RMSE=735 and 591 kg ha-1; MAPE=3.2 and -5.9 %) during 2015-16 and 2016-17, respectively. The simulated days to anthesis and physiology maturity, LAI, grain and biological yield matched closely with observed values for all sowing environments. All crop characters in terms of days to attain anthesis and physiological maturity, grain and biological yield increased with all levels of projected CO2 concentration (i.e., 414, 522 and 682ppm in 2020s, 2050s and